Refactor common steps. by stellaraccident · Pull Request #5 · ROCm/TheRock

stellaraccident · 2024-03-13T01:59:34Z

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# This is the 1st commit message: release_portable_linux_pytorch_wheels: set run-name (ROCm#2342) ## Motivation The actions page doesn't make it obvious which job was running which target. To quickly find the last run of a given target, extend the run name with that. <img width="740" height="874" alt="image" src="https://github.com/user-attachments/assets/7733154d-9d77-49dd-a280-849fdeec76ec" /> ## Technical Details Include important job inputs in the name shown on the Actions/workflow page. This makes it easier to find the last job for a certain target. ## Test Plan I have used the same trick on other repos; beyond that, github actions are hard to test. ## Test Result - ## Submission Checklist - [x] Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests. # This is the commit message ROCm#2: Bump rocm-libraries 20251203 (ROCm#2402) Bump rocm-libraries 20251203 # This is the commit message ROCm#3: Fix upto clang Add modificaton for e_smi.c Add .gitattributes for line ending normalization Normalize line endings across the repository Modification for ppc64le Force-revert windows_patch_fat_wheel.py to match main branch line endings Cleanup: Revert accidental file changes and stop tracking build artifacts Cleanup: Revert accidental file changes and stop tracking build artifacts # This is the commit message ROCm#4: Point rocm-systems submodule to my fork with ppc64le build fixes # This is the commit message ROCm#5: Update amd-llvm submodule pointer to include ppc64le fixes # This is the commit message ROCm#6: Update rocm-systems to changes-for-ppc64le

In some cases GDB will fail when attempting to complete a command that involves a rust symbol, the failure can manifest as a crash. The problem is caused by the completion_match_for_lcd object being left containing invalid data during calls to cp_symbol_name_matches_1. The first question to address is why we are calling a C++ support function when handling a rust symbol. That's due to GDB's auto language detection for msymbols, in some cases GDB can't tell if a symbol is a rust symbol, or a C++ symbol. The test application contains symbols for functions which are statically linked in from various rust support libraries. There's no DWARF for these symbols, so all GDB has is the msymbols built from the ELF symbol table. Here's the problematic symbol that leads to our crash: mangled: _ZN4core3str21_$LT$impl$u20$str$GT$5parse17h5111d2d6a50d22bdE demangled: core::str::<impl str>::parse As an msymbol this is initially created with language auto, then GDB eventually calls symbol_find_demangled_name, which loops over all languages calling language_defn::sniff_from_mangled_name, the first language that can demangle the symbol gets assigned as the language for that symbol. Unfortunately, there's overlap in the mangled symbol names, some (legacy) rust symbols can be demangled as both rust and C++, see cplus_demangle in libiberty/cplus-dem.c where this is mentioned. And so, because we check the C++ language before we check for rust, then the msymbol is (incorrectly) given the C++ language. Now it's true that is some cases we might be able to figure out that a demangled symbol is not actually a valid C++ symbol, for example, in our case, the construct '::<impl str>::' is not, I believe, valid in a C++ symbol, we could look for ':<' and '>:' and refuse to accept this as a C++ symbol. However, I'm not sure it is always possible to tell that a demangled symbol is rust or C++, so, I think, we have to accept that some times we will get this language detection wrong. If we accept that we can't fix the symbol language detection 100% of the time, then we should make sure that GDB doesn't crash when it gets the language wrong, that is what this commit addresses. In our test case the user tries to complete a symbol name like this: (gdb) complete break pars This results in GDB trying to find all symbols that match 'pars', eventually we consider our problematic symbol, and we end up with a call stack that looks like this: #0 0x0000000000f3c6bd in strncmp_iw_with_mode #1 0x0000000000706d8d in cp_symbol_name_matches_1 #2 0x0000000000706fa4 in cp_symbol_name_matches #3 0x0000000000df3c45 in compare_symbol_name #4 0x0000000000df3c91 in completion_list_add_name #5 0x0000000000df3f1d in completion_list_add_msymbol #6 0x0000000000df4c94 in default_collect_symbol_completion_matches_break_on #7 0x0000000000658c08 in language_defn::collect_symbol_completion_matches #8 0x0000000000df54c9 in collect_symbol_completion_matches #9 0x00000000009d98fb in linespec_complete_function #10 0x00000000009d99f0 in complete_linespec_component #11 0x00000000009da200 in linespec_complete #12 0x00000000006e4132 in complete_address_and_linespec_locations #13 0x00000000006e4ac3 in location_completer In cp_symbol_name_matches_1 we enter a loop, this loop repeatedly tries to match the demangled problematic symbol name against the user supplied text ('pars'). Each time around the loop another component of the symbol name is stripped off, thus, we check 'pars' against these options: core::str::<impl str>::parse str::<impl str>::parse <impl str>::parse parse As soon as we get a match the cp_symbol_name_matches_1 exits its loop and returns. In our case, when we're looking for 'pars', the match occurs on the last iteration of the loop, when we are comparing to 'parse'. Now the problem here is that cp_symbol_name_matches_1 uses the strncmp_iw_with_mode, and inside strncmp_iw_with_mode we allow for skipping over template parameters. This allows GDB to match the symbol name 'foo<int>(int,int)' if the user supplies 'foo(int,'. Inside strncmp_iw_with_mode GDB will record any template arguments that it has skipped over inside the completion_match_for_lcd object that is passed in as an argument. And so, when GDB tries to match against '<impl str>::parse', the first thing it sees is '<impl str>', GDB assumes this is a template argument and records this as a skipped region within the completion_match_for_lcd object. After '<impl str>' GDB sees a ':' character, which doesn't match with the 'pars' the user supplied, so strncmp_iw_with_mode returns a value indicating a non-match. GDB then removes the '<impl str>' component from the symbol name and tries again, this time comparing to 'parse', which does match. Having found a match, then in cp_symbol_name_matches_1 we record the match string, and the full symbol name within the completion_match_result object, and return. The problem here is that the skipped region, the '<impl str>' that we recorded in the penultimate loop iteration was never discarded, its still there in our returned result. If we look at what the pointers held in the completion_match_result that cp_symbol_name_matches_1 returns, this is what we see: core::str::<impl str>::parse | \________/ | | | '--- completion match string | '---skip range '--- full symbol name When GDB calls completion_match_for_lcd::finish, GDB tries to create a string using the completion match string (parse), but excluding the skip range, as the stored skip range is before the start of the completion match string, then GDB tries to do some weird string creation, which will cause GDB to crash. The reason we don't often see this problem in C++ is that for C++ symbols there is always some non-template text before the template argument. This non-template text means GDB is likely to either match the symbol, or reject the symbol without storing a skip range. However, notice, I did say, we don't often see this problem. Once I understood the issue, I was able to reproduce the crash using a pure C++ example: template<typename S> struct foo { template<typename T> foo (int p1, T a) { s = 0; } S s; }; int main () { foo<int> obj (2.3, 0); return 0; } Then in GDB: (gdb) complete break foo(int The problem here is that the C++ symbol for the constructor looks like this: foo<int>::foo<double>(int, double) When GDB enters cp_symbol_name_matches_1 the symbols it examines are: foo<int>::foo<double>(int, double) foo<double>(int, double) The first iteration of the loop will match the 'foo', then add the '<int>' template argument will be added as a skip range. When GDB find the ':' after the '<int>' the first iteration of the loop fails to match, GDB removes the 'foo<int>::' component, and starts the second iteration of the loop. Again, GDB matches the 'foo', and now adds '<double>' as a skip region. After that the '(int' successfully matches, and so the second iteration of the loop succeeds, but, once again we left the '<int>' in place as a skip region, even though this occurs before the start of our match string, and this will cause GDB to crash. This problem was reported to the mailing list, and a solution discussed in this thread: https://sourceware.org/pipermail/gdb-patches/2023-January/195166.html The solution proposed here is similar to one proposed by the original bug reported, but implemented in a different location within GDB. Instead of placing the fix in strncmp_iw_with_mode, I place the fix in cp_symbol_name_matches_1. I believe this is a better location as it is this function that implements the loop, and it is this loop, which repeatedly calls strncmp_iw_with_mode, that should be resetting the result object state (I believe). What I have done is add an assert to strncmp_iw_with_mode that the incoming result object is empty. I've also added some other asserts in related code, in completion_match_for_lcd::mark_ignored_range, I make some basic assertions about the incoming range pointers, and in completion_match_for_lcd::finish I also make some assertions about how the skip ranges relate to the match pointer. There's two new tests. The original rust example that was used in the initial bug report, and a C++ test. The rust example depends on which symbols are pulled in from the rust libraries, so it is possible that, at some future date, the problematic symbol will disappear from this test program. The C++ test should be more reliable, as this only depends on symbols from within the C++ source code. Since I originally posted this patch to the mailing list, the following patch has been merged: commit 6e7eef7 Date: Sun Mar 19 09:13:10 2023 -0600 Use rust_demangle to fix a crash This solves the problem of a rust symbol ending up in the C++ specific code by changing the order languages are sorted. However, this new commit doesn't address the issue in the C++ code which was fixed with this commit. Given that the C++ issue is real, and has a reproducer, I'm still going to merge this fix. I've left the discussion of rust in this commit message as I originally wrote it, but it should be read within the context of GDB prior to commit 6e7eef7. Co-Authored-By: Zheng Zhan <zzlossdev@163.com>

Commit 7a8de0c ("Remove ALL_BREAKPOINTS_SAFE") introduced a use-after-free in the breakpoints iterations (see below for full ASan report). This makes gdb.base/stale-infcall.exp fail when GDB is build with ASan. check_longjmp_breakpoint_for_call_dummy iterates on all breakpoints, possibly deleting the current breakpoint as well as related breakpoints. The problem arises when a breakpoint in the B->related_breakpoint chain is also B->next. In that case, deleting that related breakpoint frees the breakpoint that all_breakpoints_safe has saved. The old code worked around that by manually changing B_TMP, which was the next breakpoint saved by the "safe iterator": while (b->related_breakpoint != b) { if (b_tmp == b->related_breakpoint) b_tmp = b->related_breakpoint->next; delete_breakpoint (b->related_breakpoint); } (Note that this seemed to assume that b->related_breakpoint->next was the same as b->next->next, not sure this is guaranteed.) The new code kept the B_TMP variable, but it's not useful in that context. We can't go change the next breakpoint as saved by the safe iterator, like we did before. I suggest fixing that by saving the breakpoints to delete in a map and deleting them all at the end. Here's the full ASan report: (gdb) PASS: gdb.base/stale-infcall.exp: continue to breakpoint: break-run1 print infcall () ================================================================= ==47472==ERROR: AddressSanitizer: heap-use-after-free on address 0x611000034980 at pc 0x563f7012c7bc bp 0x7ffdf3804d70 sp 0x7ffdf3804d60 READ of size 8 at 0x611000034980 thread T0 #0 0x563f7012c7bb in next_iterator<breakpoint>::operator++() /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/next-iterator.h:66 #1 0x563f702ce8c0 in basic_safe_iterator<next_iterator<breakpoint> >::operator++() /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/safe-iterator.h:84 #2 0x563f7021522a in check_longjmp_breakpoint_for_call_dummy(thread_info*) /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:7611 #3 0x563f714567b1 in process_event_stop_test /home/smarchi/src/binutils-gdb/gdb/infrun.c:6881 #4 0x563f71454e07 in handle_signal_stop /home/smarchi/src/binutils-gdb/gdb/infrun.c:6769 #5 0x563f7144b680 in handle_inferior_event /home/smarchi/src/binutils-gdb/gdb/infrun.c:6023 #6 0x563f71436165 in fetch_inferior_event() /home/smarchi/src/binutils-gdb/gdb/infrun.c:4387 #7 0x563f7136ff51 in inferior_event_handler(inferior_event_type) /home/smarchi/src/binutils-gdb/gdb/inf-loop.c:42 #8 0x563f7168038d in handle_target_event /home/smarchi/src/binutils-gdb/gdb/linux-nat.c:4219 #9 0x563f72fccb6d in handle_file_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:573 #10 0x563f72fcd503 in gdb_wait_for_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:694 #11 0x563f72fcaf2b in gdb_do_one_event(int) /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:217 #12 0x563f7262b9bb in wait_sync_command_done() /home/smarchi/src/binutils-gdb/gdb/top.c:426 #13 0x563f7137a7c3 in run_inferior_call /home/smarchi/src/binutils-gdb/gdb/infcall.c:650 #14 0x563f71381295 in call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*) /home/smarchi/src/binutils-gdb/gdb/infcall.c:1332 #15 0x563f7137c0e2 in call_function_by_hand(value*, type*, gdb::array_view<value*>) /home/smarchi/src/binutils-gdb/gdb/infcall.c:780 #16 0x563f70fe5960 in evaluate_subexp_do_call(expression*, noside, value*, gdb::array_view<value*>, char const*, type*) /home/smarchi/src/binutils-gdb/gdb/eval.c:649 #17 0x563f70fe6617 in expr::operation::evaluate_funcall(type*, expression*, noside, char const*, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:677 #18 0x563f6fd19668 in expr::operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/expression.h:136 #19 0x563f70fe6bba in expr::var_value_operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:689 #20 0x563f704b71dc in expr::funcall_operation::evaluate(type*, expression*, noside) /home/smarchi/src/binutils-gdb/gdb/expop.h:2219 #21 0x563f70fe0f02 in expression::evaluate(type*, noside) /home/smarchi/src/binutils-gdb/gdb/eval.c:110 #22 0x563f71b1373e in process_print_command_args /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1319 #23 0x563f71b1391b in print_command_1 /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1332 #24 0x563f71b147ec in print_command /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1465 #25 0x563f706029b8 in do_simple_func /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:95 #26 0x563f7061972a in cmd_func(cmd_list_element*, char const*, int) /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #27 0x563f7262d0ef in execute_command(char const*, int) /home/smarchi/src/binutils-gdb/gdb/top.c:572 #28 0x563f7100ed9c in command_handler(char const*) /home/smarchi/src/binutils-gdb/gdb/event-top.c:543 #29 0x563f7101014b in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /home/smarchi/src/binutils-gdb/gdb/event-top.c:779 #30 0x563f72777942 in tui_command_line_handler /home/smarchi/src/binutils-gdb/gdb/tui/tui-interp.c:104 #31 0x563f7100d059 in gdb_rl_callback_handler /home/smarchi/src/binutils-gdb/gdb/event-top.c:250 #32 0x7f5a80418246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) #33 0x563f7100ca06 in gdb_rl_callback_read_char_wrapper_noexcept /home/smarchi/src/binutils-gdb/gdb/event-top.c:192 #34 0x563f7100cc5e in gdb_rl_callback_read_char_wrapper /home/smarchi/src/binutils-gdb/gdb/event-top.c:225 #35 0x563f728c70db in stdin_event_handler /home/smarchi/src/binutils-gdb/gdb/ui.c:155 #36 0x563f72fccb6d in handle_file_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:573 #37 0x563f72fcd503 in gdb_wait_for_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:694 #38 0x563f72fcb15c in gdb_do_one_event(int) /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:264 #39 0x563f7177ec1c in start_event_loop /home/smarchi/src/binutils-gdb/gdb/main.c:412 #40 0x563f7177f12e in captured_command_loop /home/smarchi/src/binutils-gdb/gdb/main.c:476 #41 0x563f717846e4 in captured_main /home/smarchi/src/binutils-gdb/gdb/main.c:1320 #42 0x563f71784821 in gdb_main(captured_main_args*) /home/smarchi/src/binutils-gdb/gdb/main.c:1339 #43 0x563f6fcedfbd in main /home/smarchi/src/binutils-gdb/gdb/gdb.c:32 #44 0x7f5a7e43984f (/usr/lib/libc.so.6+0x2384f) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #45 0x7f5a7e439909 in __libc_start_main (/usr/lib/libc.so.6+0x23909) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #46 0x563f6fcedd84 in _start (/home/smarchi/build/binutils-gdb/gdb/gdb+0xafb0d84) (BuildId: 50bd32e6e9d5e84543e9897b8faca34858ca3995) 0x611000034980 is located 0 bytes inside of 208-byte region [0x611000034980,0x611000034a50) freed by thread T0 here: #0 0x7f5a7fce312a in operator delete(void*, unsigned long) /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_new_delete.cpp:164 #1 0x563f702bd1fa in momentary_breakpoint::~momentary_breakpoint() /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:304 #2 0x563f702771c5 in delete_breakpoint(breakpoint*) /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:12404 #3 0x563f702150a7 in check_longjmp_breakpoint_for_call_dummy(thread_info*) /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:7673 #4 0x563f714567b1 in process_event_stop_test /home/smarchi/src/binutils-gdb/gdb/infrun.c:6881 #5 0x563f71454e07 in handle_signal_stop /home/smarchi/src/binutils-gdb/gdb/infrun.c:6769 #6 0x563f7144b680 in handle_inferior_event /home/smarchi/src/binutils-gdb/gdb/infrun.c:6023 #7 0x563f71436165 in fetch_inferior_event() /home/smarchi/src/binutils-gdb/gdb/infrun.c:4387 #8 0x563f7136ff51 in inferior_event_handler(inferior_event_type) /home/smarchi/src/binutils-gdb/gdb/inf-loop.c:42 #9 0x563f7168038d in handle_target_event /home/smarchi/src/binutils-gdb/gdb/linux-nat.c:4219 #10 0x563f72fccb6d in handle_file_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:573 #11 0x563f72fcd503 in gdb_wait_for_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:694 #12 0x563f72fcaf2b in gdb_do_one_event(int) /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:217 #13 0x563f7262b9bb in wait_sync_command_done() /home/smarchi/src/binutils-gdb/gdb/top.c:426 #14 0x563f7137a7c3 in run_inferior_call /home/smarchi/src/binutils-gdb/gdb/infcall.c:650 #15 0x563f71381295 in call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*) /home/smarchi/src/binutils-gdb/gdb/infcall.c:1332 #16 0x563f7137c0e2 in call_function_by_hand(value*, type*, gdb::array_view<value*>) /home/smarchi/src/binutils-gdb/gdb/infcall.c:780 #17 0x563f70fe5960 in evaluate_subexp_do_call(expression*, noside, value*, gdb::array_view<value*>, char const*, type*) /home/smarchi/src/binutils-gdb/gdb/eval.c:649 #18 0x563f70fe6617 in expr::operation::evaluate_funcall(type*, expression*, noside, char const*, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:677 #19 0x563f6fd19668 in expr::operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/expression.h:136 #20 0x563f70fe6bba in expr::var_value_operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:689 #21 0x563f704b71dc in expr::funcall_operation::evaluate(type*, expression*, noside) /home/smarchi/src/binutils-gdb/gdb/expop.h:2219 #22 0x563f70fe0f02 in expression::evaluate(type*, noside) /home/smarchi/src/binutils-gdb/gdb/eval.c:110 #23 0x563f71b1373e in process_print_command_args /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1319 #24 0x563f71b1391b in print_command_1 /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1332 #25 0x563f71b147ec in print_command /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1465 #26 0x563f706029b8 in do_simple_func /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:95 #27 0x563f7061972a in cmd_func(cmd_list_element*, char const*, int) /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #28 0x563f7262d0ef in execute_command(char const*, int) /home/smarchi/src/binutils-gdb/gdb/top.c:572 #29 0x563f7100ed9c in command_handler(char const*) /home/smarchi/src/binutils-gdb/gdb/event-top.c:543 previously allocated by thread T0 here: #0 0x7f5a7fce2012 in operator new(unsigned long) /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_new_delete.cpp:95 #1 0x563f7029a9a3 in new_momentary_breakpoint<program_space*&, frame_id&, int&> /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:8129 #2 0x563f702212f6 in momentary_breakpoint_from_master /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:8169 #3 0x563f70212db1 in set_longjmp_breakpoint_for_call_dummy() /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:7582 #4 0x563f713804db in call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*) /home/smarchi/src/binutils-gdb/gdb/infcall.c:1260 #5 0x563f7137c0e2 in call_function_by_hand(value*, type*, gdb::array_view<value*>) /home/smarchi/src/binutils-gdb/gdb/infcall.c:780 #6 0x563f70fe5960 in evaluate_subexp_do_call(expression*, noside, value*, gdb::array_view<value*>, char const*, type*) /home/smarchi/src/binutils-gdb/gdb/eval.c:649 #7 0x563f70fe6617 in expr::operation::evaluate_funcall(type*, expression*, noside, char const*, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:677 #8 0x563f6fd19668 in expr::operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/expression.h:136 #9 0x563f70fe6bba in expr::var_value_operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:689 #10 0x563f704b71dc in expr::funcall_operation::evaluate(type*, expression*, noside) /home/smarchi/src/binutils-gdb/gdb/expop.h:2219 #11 0x563f70fe0f02 in expression::evaluate(type*, noside) /home/smarchi/src/binutils-gdb/gdb/eval.c:110 #12 0x563f71b1373e in process_print_command_args /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1319 #13 0x563f71b1391b in print_command_1 /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1332 #14 0x563f71b147ec in print_command /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1465 #15 0x563f706029b8 in do_simple_func /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:95 #16 0x563f7061972a in cmd_func(cmd_list_element*, char const*, int) /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #17 0x563f7262d0ef in execute_command(char const*, int) /home/smarchi/src/binutils-gdb/gdb/top.c:572 #18 0x563f7100ed9c in command_handler(char const*) /home/smarchi/src/binutils-gdb/gdb/event-top.c:543 #19 0x563f7101014b in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /home/smarchi/src/binutils-gdb/gdb/event-top.c:779 #20 0x563f72777942 in tui_command_line_handler /home/smarchi/src/binutils-gdb/gdb/tui/tui-interp.c:104 #21 0x563f7100d059 in gdb_rl_callback_handler /home/smarchi/src/binutils-gdb/gdb/event-top.c:250 #22 0x7f5a80418246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) Change-Id: Id00c17ab677f847fbf4efdf0f4038373668d3d88 Approved-By: Tom Tromey <tom@tromey.com>

Commit b5661ff ("gdb: fix possible use-after-free when executing commands") attempted to fix possible use-after-free in case command redefines itself. Commit 37e5833 ("gdb: fix command lookup in execute_command ()") updated the previous fix to handle subcommands as well by using the original command string to lookup the command again after its execution. This fixed the test in gdb.base/define.exp but it turned out that it does not work (at least) for "target remote" and "target extended-remote". The problem is that the command buffer P passed to execute_command () gets overwritten in dont_repeat () while executing "target remote" command itself: #0 dont_repeat () at top.c:822 #1 0x000055555730982a in target_preopen (from_tty=1) at target.c:2483 #2 0x000055555711e911 in remote_target::open_1 (name=0x55555881c7fe ":1234", from_tty=1, extended_p=0) at remote.c:5946 #3 0x000055555711d577 in remote_target::open (name=0x55555881c7fe ":1234", from_tty=1) at remote.c:5272 #4 0x00005555573062f2 in open_target (args=0x55555881c7fe ":1234", from_tty=1, command=0x5555589d0490) at target.c:853 #5 0x0000555556ad22fa in cmd_func (cmd=0x5555589d0490, args=0x55555881c7fe ":1234", from_tty=1) at cli/cli-decode.c:2737 #6 0x00005555573487fd in execute_command (p=0x55555881c802 "4", from_tty=1) at top.c:688 Therefore the second call to lookup_cmd () at line 697 fails to find command because the original command string is gone. This commit addresses this particular problem by creating a *copy* of original command string for the sole purpose of using it after command execution to lookup the command again. It may not be the most efficient way but it's safer given that command buffer is shared and overwritten in hard-to-foresee situations. Tested on x86_64-linux. PR 30249 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30249 Approved-By: Tom Tromey <tom@tromey.com>

After this commit: commit baab375 Date: Tue Jul 13 14:44:27 2021 -0400 gdb: building inferior strings from within GDB It was pointed out that a new ASan failure had been introduced which was triggered by gdb.base/internal-string-values.exp: (gdb) PASS: gdb.base/internal-string-values.exp: test_setting: all langs: lang=ada: ptype "foo" print $_gdb_maint_setting("test-settings string") ================================================================= ==80377==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000068034 at pc 0x564785cba682 bp 0x7ffd20644620 sp 0x7ffd20644610 READ of size 1 at 0x603000068034 thread T0 #0 0x564785cba681 in find_command_name_length(char const*) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2129 #1 0x564785cbacb2 in lookup_cmd_1(char const**, cmd_list_element*, cmd_list_element**, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, int, bool) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2186 #2 0x564785cbb539 in lookup_cmd_1(char const**, cmd_list_element*, cmd_list_element**, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, int, bool) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2248 #3 0x564785cbbcf3 in lookup_cmd(char const**, cmd_list_element*, char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, int, int) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2339 #4 0x564785c82df2 in setting_cmd /tmp/src/binutils-gdb/gdb/cli/cli-cmds.c:2219 #5 0x564785c84274 in gdb_maint_setting_internal_fn /tmp/src/binutils-gdb/gdb/cli/cli-cmds.c:2348 #6 0x564788167b3b in call_internal_function(gdbarch*, language_defn const*, value*, int, value**) /tmp/src/binutils-gdb/gdb/value.c:2321 #7 0x5647854b6ebd in expr::ada_funcall_operation::evaluate(type*, expression*, noside) /tmp/src/binutils-gdb/gdb/ada-lang.c:11254 #8 0x564786658266 in expression::evaluate(type*, noside) /tmp/src/binutils-gdb/gdb/eval.c:111 #9 0x5647871242d6 in process_print_command_args /tmp/src/binutils-gdb/gdb/printcmd.c:1322 #10 0x5647871244b3 in print_command_1 /tmp/src/binutils-gdb/gdb/printcmd.c:1335 #11 0x564787125384 in print_command /tmp/src/binutils-gdb/gdb/printcmd.c:1468 #12 0x564785caac44 in do_simple_func /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:95 #13 0x564785cc18f0 in cmd_func(cmd_list_element*, char const*, int) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #14 0x564787c70c68 in execute_command(char const*, int) /tmp/src/binutils-gdb/gdb/top.c:574 #15 0x564786686180 in command_handler(char const*) /tmp/src/binutils-gdb/gdb/event-top.c:543 #16 0x56478668752f in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /tmp/src/binutils-gdb/gdb/event-top.c:779 #17 0x564787dcb29a in tui_command_line_handler /tmp/src/binutils-gdb/gdb/tui/tui-interp.c:104 #18 0x56478668443d in gdb_rl_callback_handler /tmp/src/binutils-gdb/gdb/event-top.c:250 #19 0x7f4efd506246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) #20 0x564786683dea in gdb_rl_callback_read_char_wrapper_noexcept /tmp/src/binutils-gdb/gdb/event-top.c:192 #21 0x564786684042 in gdb_rl_callback_read_char_wrapper /tmp/src/binutils-gdb/gdb/event-top.c:225 #22 0x564787f1b119 in stdin_event_handler /tmp/src/binutils-gdb/gdb/ui.c:155 #23 0x56478862438d in handle_file_event /tmp/src/binutils-gdb/gdbsupport/event-loop.cc:573 #24 0x564788624d23 in gdb_wait_for_event /tmp/src/binutils-gdb/gdbsupport/event-loop.cc:694 #25 0x56478862297c in gdb_do_one_event(int) /tmp/src/binutils-gdb/gdbsupport/event-loop.cc:264 #26 0x564786df99f0 in start_event_loop /tmp/src/binutils-gdb/gdb/main.c:412 #27 0x564786dfa069 in captured_command_loop /tmp/src/binutils-gdb/gdb/main.c:476 #28 0x564786dff61f in captured_main /tmp/src/binutils-gdb/gdb/main.c:1320 #29 0x564786dff75c in gdb_main(captured_main_args*) /tmp/src/binutils-gdb/gdb/main.c:1339 #30 0x564785381b6d in main /tmp/src/binutils-gdb/gdb/gdb.c:32 #31 0x7f4efbc3984f (/usr/lib/libc.so.6+0x2384f) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #32 0x7f4efbc39909 in __libc_start_main (/usr/lib/libc.so.6+0x23909) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #33 0x564785381934 in _start (/tmp/build/binutils-gdb/gdb/gdb+0xabc5934) (BuildId: 90de353ac158646e7dab501b76a18a76628fca33) 0x603000068034 is located 0 bytes after 20-byte region [0x603000068020,0x603000068034) allocated by thread T0 here: #0 0x7f4efcee0cd1 in __interceptor_calloc /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77 #1 0x5647856265d8 in xcalloc /tmp/src/binutils-gdb/gdb/alloc.c:97 #2 0x564788610c6b in xzalloc(unsigned long) /tmp/src/binutils-gdb/gdbsupport/common-utils.cc:29 #3 0x56478815721a in value::allocate_contents(bool) /tmp/src/binutils-gdb/gdb/value.c:929 #4 0x564788157285 in value::allocate(type*, bool) /tmp/src/binutils-gdb/gdb/value.c:941 #5 0x56478815733a in value::allocate(type*) /tmp/src/binutils-gdb/gdb/value.c:951 #6 0x5647854ae81c in expr::ada_string_operation::evaluate(type*, expression*, noside) /tmp/src/binutils-gdb/gdb/ada-lang.c:10675 #7 0x5647854b63b8 in expr::ada_funcall_operation::evaluate(type*, expression*, noside) /tmp/src/binutils-gdb/gdb/ada-lang.c:11184 #8 0x564786658266 in expression::evaluate(type*, noside) /tmp/src/binutils-gdb/gdb/eval.c:111 #9 0x5647871242d6 in process_print_command_args /tmp/src/binutils-gdb/gdb/printcmd.c:1322 #10 0x5647871244b3 in print_command_1 /tmp/src/binutils-gdb/gdb/printcmd.c:1335 #11 0x564787125384 in print_command /tmp/src/binutils-gdb/gdb/printcmd.c:1468 #12 0x564785caac44 in do_simple_func /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:95 #13 0x564785cc18f0 in cmd_func(cmd_list_element*, char const*, int) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #14 0x564787c70c68 in execute_command(char const*, int) /tmp/src/binutils-gdb/gdb/top.c:574 #15 0x564786686180 in command_handler(char const*) /tmp/src/binutils-gdb/gdb/event-top.c:543 #16 0x56478668752f in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /tmp/src/binutils-gdb/gdb/event-top.c:779 #17 0x564787dcb29a in tui_command_line_handler /tmp/src/binutils-gdb/gdb/tui/tui-interp.c:104 #18 0x56478668443d in gdb_rl_callback_handler /tmp/src/binutils-gdb/gdb/event-top.c:250 #19 0x7f4efd506246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) The problem is in cli/cli-cmds.c, in the function setting_cmd, where we do this: const char *a0 = (const char *) argv[0]->contents ().data (); Here argv[0] is a value* which we know is either a TYPE_CODE_ARRAY or a TYPE_CODE_STRING. The problem is that the above line is casting the value contents directly to a C-string, i.e. one that is assumed to have a null-terminator at the end. After the above commit this can no longer be assumed to be true. A string value will be represented just as it would be in the current language, so for Ada and Fortran the string will be an array of characters with no null-terminator at the end. My proposed solution is to copy the string contents into a std::string object, and then use the std::string::c_str() value, this will ensure that a null-terminator has been added. I had a check through GDB at places TYPE_CODE_STRING was used and couldn't see any other obvious places where this type of assumption was being made, so hopefully this is the only offender. Running the above test with ASan compiled in no longer gives an error. Reviewed-By: Tom Tromey <tom@tromey.com>

Expect a `.MIPS.options' section alternatively to `.reginfo' and ignore contents of either as irrelevant for all the affected compact EH tests, removing these regressions: mips64-openbsd -FAIL: Compact EH EB #1 with personality ID and FDE data mips64-openbsd -FAIL: Compact EH EB #2 with personality routine and FDE data mips64-openbsd -FAIL: Compact EH EB #3 with personality id and large FDE data mips64-openbsd -FAIL: Compact EH EB #4 with personality id, FDE data and LSDA mips64-openbsd -FAIL: Compact EH EB #5 with personality routine, FDE data and LSDA mips64-openbsd -FAIL: Compact EH EB #6 with personality id, LSDA and large FDE data mips64-openbsd -FAIL: Compact EH EL #1 with personality ID and FDE data mips64-openbsd -FAIL: Compact EH EL #2 with personality routine and FDE data mips64-openbsd -FAIL: Compact EH EL #3 with personality id and large FDE data mips64-openbsd -FAIL: Compact EH EL #4 with personality id, FDE data and LSDA mips64-openbsd -FAIL: Compact EH EL #5 with personality routine, FDE data and LSDA mips64-openbsd -FAIL: Compact EH EL #6 with personality id, LSDA and large FDE data mips64el-openbsd -FAIL: Compact EH EB #1 with personality ID and FDE data mips64el-openbsd -FAIL: Compact EH EB #2 with personality routine and FDE data mips64el-openbsd -FAIL: Compact EH EB #3 with personality id and large FDE data mips64el-openbsd -FAIL: Compact EH EB #4 with personality id, FDE data and LSDA mips64el-openbsd -FAIL: Compact EH EB #5 with personality routine, FDE data and LSDA mips64el-openbsd -FAIL: Compact EH EB #6 with personality id, LSDA and large FDE data mips64el-openbsd -FAIL: Compact EH EL #1 with personality ID and FDE data mips64el-openbsd -FAIL: Compact EH EL #2 with personality routine and FDE data mips64el-openbsd -FAIL: Compact EH EL #3 with personality id and large FDE data mips64el-openbsd -FAIL: Compact EH EL #4 with personality id, FDE data and LSDA mips64el-openbsd -FAIL: Compact EH EL #5 with personality routine, FDE data and LSDA mips64el-openbsd -FAIL: Compact EH EL #6 with personality id, LSDA and large FDE data Co-Authored-By: Maciej W. Rozycki <macro@orcam.me.uk> gas/ * testsuite/gas/mips/compact-eh-eb-1.d: Accept `.MIPS.options' section as an alternative to `.reginfo' and ignore contents of either. * testsuite/gas/mips/compact-eh-eb-2.d: Likewise. * testsuite/gas/mips/compact-eh-eb-3.d: Likewise. * testsuite/gas/mips/compact-eh-eb-4.d: Likewise. * testsuite/gas/mips/compact-eh-eb-5.d: Likewise. * testsuite/gas/mips/compact-eh-eb-6.d: Likewise. * testsuite/gas/mips/compact-eh-el-1.d: Likewise. * testsuite/gas/mips/compact-eh-el-2.d: Likewise. * testsuite/gas/mips/compact-eh-el-3.d: Likewise. * testsuite/gas/mips/compact-eh-el-4.d: Likewise. * testsuite/gas/mips/compact-eh-el-5.d: Likewise. * testsuite/gas/mips/compact-eh-el-6.d: Likewise.

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I run into: ... (gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache... (gdb) show index-cache enabled The index cache is off. (gdb) PASS: gdb.base/index-cache.exp: test_basic_stuff: index-cache is disabled by default set index-cache enabled on ================== WARNING: ThreadSanitizer: data race (pid=32248) Write of size 1 at 0x00000321f540 by main thread: #0 index_cache::enable() gdb/dwarf2/index-cache.c:76 (gdb+0x82cfdd) #1 set_index_cache_enabled_command gdb/dwarf2/index-cache.c:270 (gdb+0x82d9af) #2 bool setting::set<bool>(bool const&) gdb/command.h:353 (gdb+0x6fe5f2) #3 do_set_command(char const*, int, cmd_list_element*) gdb/cli/cli-setshow.c:414 (gdb+0x6fcd21) #4 execute_command(char const*, int) gdb/top.c:567 (gdb+0xff2e64) #5 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94acc0) #6 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b37d) #7 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x103467e) #8 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a265) #9 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bdd3f) #10 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a064) #11 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a125) #12 stdin_event_handler gdb/ui.c:155 (gdb+0x1074922) #13 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d94de4) #14 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d9551c) #15 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93908) #16 start_event_loop gdb/main.c:412 (gdb+0xb5a256) #17 captured_command_loop gdb/main.c:476 (gdb+0xb5a445) #18 captured_main gdb/main.c:1320 (gdb+0xb5c5c5) #19 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c674) #20 main gdb/gdb.c:32 (gdb+0x416776) Previous read of size 1 at 0x00000321f540 by thread T12: #0 index_cache::enabled() const gdb/dwarf2/index-cache.h:48 (gdb+0x82e1a6) #1 index_cache::store(dwarf2_per_bfd*) gdb/dwarf2/index-cache.c:94 (gdb+0x82d0bc) #2 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:638 (gdb+0x7f1b97) #3 operator() gdb/dwarf2/cooked-index.c:468 (gdb+0x7f0f24) #4 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f285b) #5 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952) #6 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0) #7 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91) #8 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59) #9 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660) #10 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c) #11 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623) #12 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf) #13 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f) #14 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5) #15 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d) #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2) #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2) #18 pthread_once <null> (libtsan.so.0+0x4457c) #19 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd) #20 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224) #21 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852) #22 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef) #23 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac492) #24 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabdb4) #25 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dace63) #26 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac294) #27 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf5c6) #28 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf551) #29 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf506) #30 <null> <null> (libstdc++.so.6+0xdcac2) Location is global 'global_index_cache' of size 48 at 0x00000321f520 (gdb+0x00000321f540) ... SUMMARY: ThreadSanitizer: data race gdb/dwarf2/index-cache.c:76 in index_cache::enable() ... The race happens when issuing a "file $exec" command followed by a "set index-cache enabled on" command. The race is between: - a worker thread reading index_cache::m_enabled to determine whether an index-cache entry for $exec needs to be written (due to command "file $exec"), and - the main thread setting index_cache::m_enabled (due to command "set index-cache enabled on"). Fix this by capturing the value of index_cache::m_enabled in the main thread, and using the captured value in the worker thread. Tested on x86_64-linux. PR symtab/30392 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I run into: ... (gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache... ================== WARNING: ThreadSanitizer: data race (pid=12261) Write of size 4 at 0x7b4400097d08 by main thread: #0 bfd_open_file bfd/cache.c:584 (gdb+0x148bb92) #1 bfd_cache_lookup_worker bfd/cache.c:261 (gdb+0x148b12a) #2 cache_bseek bfd/cache.c:289 (gdb+0x148b324) #3 bfd_seek bfd/bfdio.c:459 (gdb+0x1489c31) #4 _bfd_generic_get_section_contents bfd/libbfd.c:1069 (gdb+0x14977a4) #5 bfd_get_section_contents bfd/section.c:1606 (gdb+0x149cc7c) #6 gdb_bfd_scan_elf_dyntag(int, bfd*, unsigned long*, unsigned long*) gdb/solib.c:1601 (gdb+0xed8eca) #7 elf_locate_base gdb/solib-svr4.c:705 (gdb+0xec28ac) #8 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3430 (gdb+0xeca55d) #9 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad) #10 find_main_name gdb/symtab.c:6270 (gdb+0xf743a5) #11 main_language() gdb/symtab.c:6313 (gdb+0xf74499) #12 set_initial_language() gdb/symfile.c:1700 (gdb+0xf4285c) #13 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf40e2a) #14 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf427d1) #15 file_command gdb/exec.c:554 (gdb+0x94f74b) #16 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528) #17 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69) #18 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff303c) #19 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94adde) #20 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b49b) #21 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x103479c) #22 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a383) #23 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bde5d) #24 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a182) #25 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a243) #26 stdin_event_handler gdb/ui.c:155 (gdb+0x1074a40) #27 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d94f02) #28 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d9563a) #29 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93a26) #30 start_event_loop gdb/main.c:412 (gdb+0xb5a374) #31 captured_command_loop gdb/main.c:476 (gdb+0xb5a563) #32 captured_main gdb/main.c:1320 (gdb+0xb5c6e3) #33 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c792) #34 main gdb/gdb.c:32 (gdb+0x416776) Previous read of size 1 at 0x7b4400097d08 by thread T12: #0 bfd_check_format_matches bfd/format.c:323 (gdb+0x1492db4) #1 bfd_check_format bfd/format.c:94 (gdb+0x1492104) #2 build_id_bfd_get(bfd*) gdb/build-id.c:42 (gdb+0x6648f7) #3 index_cache::store(dwarf2_per_bfd*, index_cache_store_context*) gdb/dwarf2/index-cache.c:110 (gdb+0x82d205) #4 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:640 (gdb+0x7f1bf1) #5 operator() gdb/dwarf2/cooked-index.c:470 (gdb+0x7f0f40) #6 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f28f7) #7 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952) #8 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0) #9 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91) #10 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59) #11 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660) #12 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c) #13 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623) #14 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf) #15 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f) #16 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5) #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d) #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2) #19 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2) #20 pthread_once <null> (libtsan.so.0+0x4457c) #21 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd) #22 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224) #23 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852) #24 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef) #25 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac5b0) #26 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabed2) #27 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dacf81) #28 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac3b2) #29 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf6e4) #30 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf66f) #31 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf624) #32 <null> <null> (libstdc++.so.6+0xdcac2) ... SUMMARY: ThreadSanitizer: data race bfd/cache.c:584 in bfd_open_file ... The race happens when issuing the "file $exec" command. The race is between: - a worker thread getting the build id while writing the index cache, and in the process reading bfd::format, and - the main thread calling find_main_name, and in the process setting bfd::cacheable. The two bitfields bfd::cacheable and bfd::format share the same bitfield container. Fix this by capturing the build id in the main thread, and using the captured value in the worker thread. Likewise for the dwz build id, which likely suffers from the same issue. While we're at it, also move the creation of the cache directory to the index_cache_store_context constructor, to: - make sure there's no race between subsequent file commands, and - issue any related warning or error messages during the file command. Tested on x86_64-linux. Approved-By: Tom Tromey <tom@tromey.com> PR symtab/30392 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I run into: ... (gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache... ================== WARNING: ThreadSanitizer: data race (pid=24296) Write of size 1 at 0x7b200000420d by main thread: #0 queue_comp_unit gdb/dwarf2/read.c:5564 (gdb+0x8939ce) #1 dw2_do_instantiate_symtab gdb/dwarf2/read.c:1754 (gdb+0x885b96) #2 dw2_instantiate_symtab gdb/dwarf2/read.c:1792 (gdb+0x885d86) #3 dw2_expand_symtabs_matching_one(dwarf2_per_cu_data*, dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>, gdb::function_view<bool (compunit_symtab*)>) gdb/dwarf2/read.c:3042 (gdb+0x88ac77) #4 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16915 (gdb+0x8c1c8a) #5 objfile::lookup_symbol(block_enum, char const*, domain_enum) gdb/symfile-debug.c:288 (gdb+0xf389a1) #6 lookup_symbol_via_quick_fns gdb/symtab.c:2385 (gdb+0xf66403) #7 lookup_symbol_in_objfile gdb/symtab.c:2516 (gdb+0xf66a67) #8 operator() gdb/symtab.c:2562 (gdb+0xf66bbe) #9 operator() gdb/../gdbsupport/function-view.h:305 (gdb+0xf76ffd) #10 _FUN gdb/../gdbsupport/function-view.h:299 (gdb+0xf77054) #11 gdb::function_view<bool (objfile*)>::operator()(objfile*) const gdb/../gdbsupport/function-view.h:289 (gdb+0xc3f5e3) #12 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3455 (gdb+0xeca793) #13 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad) #14 lookup_global_or_static_symbol gdb/symtab.c:2559 (gdb+0xf66e47) #15 lookup_global_symbol(char const*, block const*, domain_enum) gdb/symtab.c:2615 (gdb+0xf670cc) #16 language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const gdb/symtab.c:2447 (gdb+0xf666ba) #17 lookup_symbol_aux gdb/symtab.c:2123 (gdb+0xf655ff) #18 lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) gdb/symtab.c:1931 (gdb+0xf646f7) #19 set_initial_language() gdb/symfile.c:1708 (gdb+0xf429c0) #20 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf40f54) #21 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf428fb) #22 file_command gdb/exec.c:554 (gdb+0x94f875) #23 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528) #24 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69) #25 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff3166) #26 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94af08) #27 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b5c5) #28 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x10348c6) #29 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a4ad) #30 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bdf87) #31 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a2ac) #32 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a36d) #33 stdin_event_handler gdb/ui.c:155 (gdb+0x1074b6a) #34 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d9502c) #35 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d95764) #36 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93b50) #37 start_event_loop gdb/main.c:412 (gdb+0xb5a49e) #38 captured_command_loop gdb/main.c:476 (gdb+0xb5a68d) #39 captured_main gdb/main.c:1320 (gdb+0xb5c80d) #40 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c8bc) #41 main gdb/gdb.c:32 (gdb+0x416776) Previous read of size 1 at 0x7b200000420d by thread T12: #0 write_gdbindex gdb/dwarf2/index-write.c:1229 (gdb+0x8310c8) #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1484 (gdb+0x83232f) #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context*) gdb/dwarf2/index-cache.c:177 (gdb+0x82d62b) #3 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:640 (gdb+0x7f1bf7) #4 operator() gdb/dwarf2/cooked-index.c:470 (gdb+0x7f0f40) #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f2909) #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952) #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0) #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91) #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59) #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660) #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c) #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623) #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf) #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f) #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5) #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d) #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2) #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2) #19 pthread_once <null> (libtsan.so.0+0x4457c) #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd) #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224) #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852) #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef) #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac6da) #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabffc) #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dad0ab) #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac4dc) #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf80e) #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf799) #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf74e) #31 <null> <null> (libstdc++.so.6+0xdcac2) ... SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:5564 in queue_comp_unit ... The race happens when issuing the "file $exec" command. The race is between: - a worker thread writing the index cache, and in the process reading dwarf2_per_cu_data::is_debug_type, and - the main thread expanding the CU containing main, and in the process setting dwarf2_per_cu_data::queued. The two bitfields dwarf2_per_cu_data::queue and dwarf2_per_cu_data::is_debug_type share the same bitfield container. Fix this by making dwarf2_per_cu_data::queued a packed<bool, 1>. Tested on x86_64-linux. Approved-By: Tom Tromey <tom@tromey.com> PR symtab/30392 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

…s_debug_type} With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp and target board debug-types, I run into: ... (gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache... ================== WARNING: ThreadSanitizer: data race (pid=9654) Write of size 1 at 0x7b200000420d by main thread: #0 dwarf2_per_cu_data::get_header() const gdb/dwarf2/read.c:21513 (gdb+0x8d1eee) #1 dwarf2_per_cu_data::addr_size() const gdb/dwarf2/read.c:21524 (gdb+0x8d1f4e) #2 dwarf2_cu::addr_type() const gdb/dwarf2/cu.c:112 (gdb+0x806327) #3 set_die_type gdb/dwarf2/read.c:21932 (gdb+0x8d3870) #4 read_base_type gdb/dwarf2/read.c:15448 (gdb+0x8bcacb) #5 read_type_die_1 gdb/dwarf2/read.c:19832 (gdb+0x8cc0a5) #6 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d) #7 lookup_die_type gdb/dwarf2/read.c:19739 (gdb+0x8cbdc7) #8 die_type gdb/dwarf2/read.c:19593 (gdb+0x8cb68a) #9 read_subroutine_type gdb/dwarf2/read.c:14648 (gdb+0x8b998e) #10 read_type_die_1 gdb/dwarf2/read.c:19792 (gdb+0x8cbf2f) #11 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d) #12 read_func_scope gdb/dwarf2/read.c:10154 (gdb+0x8a4f36) #13 process_die gdb/dwarf2/read.c:6667 (gdb+0x898daa) #14 read_file_scope gdb/dwarf2/read.c:7682 (gdb+0x89bad8) #15 process_die gdb/dwarf2/read.c:6654 (gdb+0x898ced) #16 process_full_comp_unit gdb/dwarf2/read.c:6418 (gdb+0x8981de) #17 process_queue gdb/dwarf2/read.c:5690 (gdb+0x894433) #18 dw2_do_instantiate_symtab gdb/dwarf2/read.c:1770 (gdb+0x88623a) #19 dw2_instantiate_symtab gdb/dwarf2/read.c:1792 (gdb+0x886300) #20 dw2_expand_symtabs_matching_one(dwarf2_per_cu_data*, dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>, gdb::function_view<bool (compunit_symtab*)>) gdb/dwarf2/read.c:3042 (gdb+0x88b1f1) #21 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16917 (gdb+0x8c228e) #22 objfile::lookup_symbol(block_enum, char const*, domain_enum) gdb/symfile-debug.c:288 (gdb+0xf39055) #23 lookup_symbol_via_quick_fns gdb/symtab.c:2385 (gdb+0xf66ab7) #24 lookup_symbol_in_objfile gdb/symtab.c:2516 (gdb+0xf6711b) #25 operator() gdb/symtab.c:2562 (gdb+0xf67272) #26 operator() gdb/../gdbsupport/function-view.h:305 (gdb+0xf776b1) #27 _FUN gdb/../gdbsupport/function-view.h:299 (gdb+0xf77708) #28 gdb::function_view<bool (objfile*)>::operator()(objfile*) const gdb/../gdbsupport/function-view.h:289 (gdb+0xc3fc97) #29 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3455 (gdb+0xecae47) #30 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad) #31 lookup_global_or_static_symbol gdb/symtab.c:2559 (gdb+0xf674fb) #32 lookup_global_symbol(char const*, block const*, domain_enum) gdb/symtab.c:2615 (gdb+0xf67780) #33 language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const gdb/symtab.c:2447 (gdb+0xf66d6e) #34 lookup_symbol_aux gdb/symtab.c:2123 (gdb+0xf65cb3) #35 lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) gdb/symtab.c:1931 (gdb+0xf64dab) #36 set_initial_language() gdb/symfile.c:1708 (gdb+0xf43074) #37 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf41608) #38 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf42faf) #39 file_command gdb/exec.c:554 (gdb+0x94ff29) #40 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528) #41 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69) #42 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff379c) #43 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94b5bc) #44 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94bc79) #45 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x1034efc) #46 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94ab61) #47 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11be4ef) #48 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a960) #49 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94aa21) #50 stdin_event_handler gdb/ui.c:155 (gdb+0x10751a0) #51 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d95bac) #52 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d962e4) #53 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d946d0) #54 start_event_loop gdb/main.c:412 (gdb+0xb5ab52) #55 captured_command_loop gdb/main.c:476 (gdb+0xb5ad41) #56 captured_main gdb/main.c:1320 (gdb+0xb5cec1) #57 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5cf70) #58 main gdb/gdb.c:32 (gdb+0x416776) Previous read of size 1 at 0x7b200000420d by thread T11: #0 write_gdbindex gdb/dwarf2/index-write.c:1229 (gdb+0x831630) #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1484 (gdb+0x832897) #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x82db8d) #3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:645 (gdb+0x7f1d49) #4 operator() gdb/dwarf2/cooked-index.c:474 (gdb+0x7f0f31) #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f2a13) #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952) #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0) #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91) #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59) #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660) #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c) #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623) #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf) #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f) #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5) #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d) #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2) #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2) #19 pthread_once <null> (libtsan.so.0+0x4457c) #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd) #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224) #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852) #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef) #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dad25a) #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dacb7c) #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dadc2b) #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dad05c) #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1db038e) #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1db0319) #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1db02ce) #31 <null> <null> (libstdc++.so.6+0xdcac2) ... SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:21513 in dwarf2_per_cu_data::get_header() const ... The race happens when issuing the "file $exec" command. The race is between: - a worker thread writing the index cache, and in the process reading dwarf2_per_cu_data::is_debug_type, and - the main thread writing to dwarf2_per_cu_data::m_header_read_in. The two bitfields dwarf2_per_cu_data::m_header_read_in and dwarf2_per_cu_data::is_debug_type share the same bitfield container. Fix this by making dwarf2_per_cu_data::m_header_read_in a packed<bool, 1>. Tested on x86_64-linux. Approved-By: Tom Tromey <tom@tromey.com> PR symtab/30392 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392

With gdb build with -fsanitize=thread, and the exec from test-case gdb.base/index-cache.exp, I run into: ... $ rm -f ~/.cache/gdb/*; \ gdb -q -batch -iex "set index-cache enabled on" index-cache \ -ex "print foobar" ... WARNING: ThreadSanitizer: data race (pid=23970) Write of size 1 at 0x7b200000410d by main thread: #0 dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>) gdb/dwarf2/read.c:3077 (gdb+0x7ac54e) #1 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16812 (gdb+0x7d039f) #2 objfile::map_symtabs_matching_filename(char const*, char const*, gdb::function_view<bool (symtab*)>) gdb/symfile-debug.c:219 (gdb+0xda5aee) #3 iterate_over_symtabs(char const*, gdb::function_view<bool (symtab*)>) gdb/symtab.c:648 (gdb+0xdc439d) #4 lookup_symtab(char const*) gdb/symtab.c:662 (gdb+0xdc44a2) #5 classify_name gdb/c-exp.y:3083 (gdb+0x61afec) #6 c_yylex gdb/c-exp.y:3251 (gdb+0x61dd13) #7 c_yyparse() build/gdb/c-exp.c.tmp:1988 (gdb+0x61f07e) #8 c_parse(parser_state*) gdb/c-exp.y:3417 (gdb+0x62d864) #9 language_defn::parser(parser_state*) const gdb/language.c:598 (gdb+0x9771c5) #10 parse_exp_in_context gdb/parse.c:414 (gdb+0xb10a9b) #11 parse_expression(char const*, innermost_block_tracker*, enum_flags<parser_flag>) gdb/parse.c:462 (gdb+0xb110ae) #12 process_print_command_args gdb/printcmd.c:1321 (gdb+0xb4bf0c) #13 print_command_1 gdb/printcmd.c:1335 (gdb+0xb4ca2a) #14 print_command gdb/printcmd.c:1468 (gdb+0xb4cd5a) #15 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x65b078) #16 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x65ed53) #17 execute_command(char const*, int) gdb/top.c:575 (gdb+0xe3a76a) #18 catch_command_errors gdb/main.c:518 (gdb+0xa1837d) #19 execute_cmdargs gdb/main.c:617 (gdb+0xa1853f) #20 captured_main_1 gdb/main.c:1289 (gdb+0xa1aa58) #21 captured_main gdb/main.c:1310 (gdb+0xa1b95a) #22 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xa1b95a) #23 main gdb/gdb.c:39 (gdb+0x42506a) Previous read of size 1 at 0x7b200000410d by thread T1: #0 write_gdbindex gdb/dwarf2/index-write.c:1214 (gdb+0x75bb30) #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1469 (gdb+0x75f803) #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x755a36) #3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:642 (gdb+0x71c96d) #4 operator() gdb/dwarf2/cooked-index.c:471 (gdb+0x71c96d) #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x71c96d) #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x72a57c) #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x72a5db) #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72a5db) #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x72a5db) #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x72a5db) #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x72a5db) #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x724954) #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x724954) #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x72434a) #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72434a) #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x72434a) #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x72434a) #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x72434a) #19 pthread_once <null> (libtsan.so.0+0x4457c) #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72532b) #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x72532b) #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x174568d) #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x174568d) #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x174568d) #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x174568d) #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1748040) #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1748040) #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1748040) #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1748040) #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1748040) #31 <null> <null> (libstdc++.so.6+0xdcac2) ... SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:3077 in dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>) ... The race happens when issuing the "file $exec" command. The race is between: - a worker thread writing the index cache, and in the process reading dwarf2_per_cu_data::is_debug_type, and - the main thread writing to dwarf2_per_cu_data::mark. The two bitfields dwarf2_per_cu_data::mark and dwarf2_per_cu_data::is_debug_type share the same bitfield container. Fix this by making dwarf2_per_cu_data::mark a packed<unsigned int, 1>. Tested on x86_64-linux. PR symtab/30718 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30718

…g_types} With gdb build with -fsanitize=thread, and the exec from test-case gdb.base/index-cache.exp, I run into: ... $ rm -f ~/.cache/gdb/*; \ gdb -q -batch -iex "set index-cache enabled on" index-cache \ -ex "print foobar" ... WARNING: ThreadSanitizer: data race (pid=25018) Write of size 1 at 0x7b200000410d by main thread: #0 dw2_get_file_names_reader gdb/dwarf2/read.c:2033 (gdb+0x7ab023) #1 dw2_get_file_names gdb/dwarf2/read.c:2130 (gdb+0x7ab023) #2 dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>) gdb/dwarf2/read.c:3105 (gdb+0x7ac6e9) #3 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16812 (gdb+0x7d040f) #4 objfile::map_symtabs_matching_filename(char const*, char const*, gdb::function_view<bool (symtab*)>) gdb/symfile-debug.c:219 (gdb+0xda5b6e) #5 iterate_over_symtabs(char const*, gdb::function_view<bool (symtab*)>) gdb/symtab.c:648 (gdb+0xdc441d) #6 lookup_symtab(char const*) gdb/symtab.c:662 (gdb+0xdc4522) #7 classify_name gdb/c-exp.y:3083 (gdb+0x61afec) #8 c_yylex gdb/c-exp.y:3251 (gdb+0x61dd13) #9 c_yyparse() build/gdb/c-exp.c.tmp:1988 (gdb+0x61f07e) #10 c_parse(parser_state*) gdb/c-exp.y:3417 (gdb+0x62d864) #11 language_defn::parser(parser_state*) const gdb/language.c:598 (gdb+0x977245) #12 parse_exp_in_context gdb/parse.c:414 (gdb+0xb10b1b) #13 parse_expression(char const*, innermost_block_tracker*, enum_flags<parser_flag>) gdb/parse.c:462 (gdb+0xb1112e) #14 process_print_command_args gdb/printcmd.c:1321 (gdb+0xb4bf8c) #15 print_command_1 gdb/printcmd.c:1335 (gdb+0xb4caaa) #16 print_command gdb/printcmd.c:1468 (gdb+0xb4cdda) #17 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x65b078) #18 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x65ed53) #19 execute_command(char const*, int) gdb/top.c:575 (gdb+0xe3a7ea) #20 catch_command_errors gdb/main.c:518 (gdb+0xa183fd) #21 execute_cmdargs gdb/main.c:617 (gdb+0xa185bf) #22 captured_main_1 gdb/main.c:1289 (gdb+0xa1aad8) #23 captured_main gdb/main.c:1310 (gdb+0xa1b9da) #24 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xa1b9da) #25 main gdb/gdb.c:39 (gdb+0x42506a) Previous read of size 1 at 0x7b200000410d by thread T2: #0 write_gdbindex gdb/dwarf2/index-write.c:1214 (gdb+0x75bb30) #1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1469 (gdb+0x75f803) #2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x755a36) #3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:642 (gdb+0x71c96d) #4 operator() gdb/dwarf2/cooked-index.c:471 (gdb+0x71c96d) #5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x71c96d) #6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x72a57c) #7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x72a5db) #8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72a5db) #9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x72a5db) #10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x72a5db) #11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x72a5db) #12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x724954) #13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x724954) #14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x72434a) #15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72434a) #16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x72434a) #17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x72434a) #18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x72434a) #19 pthread_once <null> (libtsan.so.0+0x4457c) #20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72532b) #21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x72532b) #22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x174570d) #23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x174570d) #24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x174570d) #25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x174570d) #26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x17480c0) #27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x17480c0) #28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x17480c0) #29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x17480c0) #30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x17480c0) #31 <null> <null> (libstdc++.so.6+0xdcac2) ... SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:2033 in dw2_get_file_names_reader ... The race happens when issuing the "file $exec" command. The race is between: - a worker thread writing the index cache, and in the process reading dwarf2_per_cu_data::is_debug_type, and - the main thread writing to dwarf2_per_cu_data::files_read. The two bitfields dwarf2_per_cu_data::files_read and dwarf2_per_cu_data::is_debug_type share the same bitfield container. Fix this by making dwarf2_per_cu_data::files_read a packed<bool, 1>. Tested on x86_64-linux. PR symtab/30718 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30718

After running a number of programs under Windows gdb and detaching them, I typed run in gdb, and got a hang, here: (top-gdb) bt #0 sharing_input_terminal (pid=4672) at /home/pedro/gdb/src/gdb/mingw-hdep.c:388 #1 0x00007ff71a2d8678 in sharing_input_terminal (inf=0x23bf23dafb0) at /home/pedro/gdb/src/gdb/inflow.c:269 #2 0x00007ff71a2d887b in child_terminal_save_inferior (self=0x23bf23de060) at /home/pedro/gdb/src/gdb/inflow.c:423 #3 0x00007ff71a2c80c0 in inf_child_target::terminal_save_inferior (this=0x23bf23de060) at /home/pedro/gdb/src/gdb/inf-child.c:111 #4 0x00007ff71a429c0f in target_terminal_is_ours_kind (desired_state=target_terminal_state::is_ours_for_output) at /home/pedro/gdb/src/gdb/target.c:1037 #5 0x00007ff71a429e02 in target_terminal::ours_for_output () at /home/pedro/gdb/src/gdb/target.c:1094 #6 0x00007ff71a2ccc8e in post_create_inferior (from_tty=0) at /home/pedro/gdb/src/gdb/infcmd.c:245 #7 0x00007ff71a2cd431 in run_command_1 (args=0x0, from_tty=0, run_how=RUN_NORMAL) at /home/pedro/gdb/src/gdb/infcmd.c:502 #8 0x00007ff71a2cd58b in run_command (args=0x0, from_tty=0) at /home/pedro/gdb/src/gdb/infcmd.c:527 The problem is that the loop around GetConsoleProcessList looped forever, because there were exactly 10 processes to return. GetConsoleProcessList's documentation says: If the buffer is too small to hold all the valid process identifiers, the return value is the required number of array elements. The function will have stored no identifiers in the buffer. In this situation, use the return value to allocate a buffer that is large enough to store the entire list and call the function again. In this case, the buffer wasn't too small, it was exactly the right size, so we should have broken out of the loop. We didn't due to a "<" check that should have been "<=". That is fixed by this patch. Approved-By: Tom Tromey <tom@tromey.com> Reviewed-By: Eli Zaretskii <eliz@gnu.org> Change-Id: I14e4909f2ac2fa83d0d9b6e64418b5831ac4e4e3

This commit fixes an issue that was discovered while writing the tests for the previous commit. I noticed that, when GDB restarts an inferior, the executable_changed event would trigger twice. The first notification would originate from: #0 exec_file_attach (filename=0x4046680 "/tmp/hello.x", from_tty=0) at ../../src/gdb/exec.c:513 #1 0x00000000006f3adb in reopen_exec_file () at ../../src/gdb/corefile.c:122 #2 0x0000000000e6a3f2 in generic_mourn_inferior () at ../../src/gdb/target.c:3682 #3 0x0000000000995121 in inf_child_target::mourn_inferior (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/inf-child.c:192 #4 0x0000000000995cff in inf_ptrace_target::mourn_inferior (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/inf-ptrace.c:125 #5 0x0000000000a32472 in linux_nat_target::mourn_inferior (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/linux-nat.c:3609 #6 0x0000000000e68a40 in target_mourn_inferior (ptid=...) at ../../src/gdb/target.c:2761 #7 0x0000000000a323ec in linux_nat_target::kill (this=0x2fe95c0 <the_amd64_linux_nat_target>) at ../../src/gdb/linux-nat.c:3593 #8 0x0000000000e64d1c in target_kill () at ../../src/gdb/target.c:924 #9 0x00000000009a19bc in kill_if_already_running (from_tty=1) at ../../src/gdb/infcmd.c:328 #10 0x00000000009a1a6f in run_command_1 (args=0x0, from_tty=1, run_how=RUN_STOP_AT_MAIN) at ../../src/gdb/infcmd.c:381 #11 0x00000000009a20a5 in start_command (args=0x0, from_tty=1) at ../../src/gdb/infcmd.c:527 #12 0x000000000068dc5d in do_simple_func (args=0x0, from_tty=1, c=0x35c7200) at ../../src/gdb/cli/cli-decode.c:95 While the second originates from: #0 exec_file_attach (filename=0x3d7a1d0 "/tmp/hello.x", from_tty=0) at ../../src/gdb/exec.c:513 #1 0x0000000000dfe525 in reread_symbols (from_tty=1) at ../../src/gdb/symfile.c:2517 #2 0x00000000009a1a98 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_STOP_AT_MAIN) at ../../src/gdb/infcmd.c:398 #3 0x00000000009a20a5 in start_command (args=0x0, from_tty=1) at ../../src/gdb/infcmd.c:527 #4 0x000000000068dc5d in do_simple_func (args=0x0, from_tty=1, c=0x35c7200) at ../../src/gdb/cli/cli-decode.c:95 In the first case the call to exec_file_attach first passes through reopen_exec_file. The reopen_exec_file performs a modification time check on the executable file, and only calls exec_file_attach if the executable has changed on disk since it was last loaded. However, in the second case things work a little differently. In this case GDB is really trying to reread the debug symbol. As such, we iterate over the objfiles list, and for each of those we check the modification time, if the file on disk has changed then we reload the debug symbols from that file. However, there is an additional check, if the objfile has the same name as the executable then we will call exec_file_attach, but we do so without checking the cached modification time that indicates when the executable was last reloaded, as a result, we reload the executable twice. In this commit I propose that reread_symbols be changed to unconditionally call reopen_exec_file before performing the objfile iteration. This will ensure that, if the executable has changed, then the executable will be reloaded, however, if the executable has already been recently reloaded, we will not reload it for a second time. After handling the executable, GDB can then iterate over the objfiles list and reload them in the normal way. With this done I now see the executable reloaded only once when GDB restarts an inferior, which means I can remove the kfail that I added to the gdb.python/py-exec-file.exp test in the previous commit. Approved-By: Tom Tromey <tom@tromey.com>

It was pointed out on the mailing list that a recently added test (gdb.python/py-progspace-events.exp) was failing when run with the native-extended-gdbserver board. This test was added with this commit: commit 59912fb Date: Tue Sep 19 11:45:36 2023 +0100 gdb: add Python events for program space addition and removal It turns out though that the test is failing due to a existing bug in GDB, the new test just exposes the problem. Additionally, the failure really doesn't even rely on the new functionality added in the above commit. I reduced the test to a simple set of steps that reproduced the failure and tested against GDB 13, and the test passes; so the bug was introduced since then. In fact, the bug was introduced with this commit: commit a282736 Date: Fri Sep 8 15:48:16 2023 +0100 gdb: remove final user of the executable_changed observer This commit changed how the per-inferior auxv data cache is managed, specifically, when the cache is cleared, and it is this that leads to the failure. This bug is interesting because it exposes a number of issues with GDB, I'll explain all of the problems I see, though ultimately, I only propose fixing one problem in this commit, which is enough to resolve the crash we are currently seeing. The crash that we are seeing manifests like this: ... [Inferior 2 (process 3970384) exited normally] +inferior 1 [Switching to inferior 1 [process 3970383] (/tmp/build/gdb/testsuite/outputs/gdb.python/py-progspace-events/py-progspace-events)] [Switching to thread 1.1 (Thread 3970383.3970383)] #0 breakpt () at /tmp/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.python/py-progspace-events.c:28 28 { /* Nothing. */ } (gdb) step +step terminate called after throwing an instance of 'gdb_exception_error' Fatal signal: Aborted ... etc ... What's happening is that GDB attempts to refill the auxv cache as a result of the gdbarch_has_shared_address_space call in program_space::~program_space, the backtrace looks like this: #0 0x00007fb4f419a9a5 in raise () from /lib64/libpthread.so.0 #1 0x00000000008b635d in handle_fatal_signal (sig=6) at ../../src/gdb/event-top.c:912 #2 <signal handler called> #3 0x00007fb4f38e3625 in raise () from /lib64/libc.so.6 #4 0x00007fb4f38cc8d9 in abort () from /lib64/libc.so.6 #5 0x00007fb4f3c70756 in __gnu_cxx::__verbose_terminate_handler() [clone .cold] () from /lib64/libstdc++.so.6 #6 0x00007fb4f3c7c6dc in __cxxabiv1::__terminate(void (*)()) () from /lib64/libstdc++.so.6 #7 0x00007fb4f3c7b6e9 in __cxa_call_terminate () from /lib64/libstdc++.so.6 #8 0x00007fb4f3c7c094 in __gxx_personality_v0 () from /lib64/libstdc++.so.6 #9 0x00007fb4f3a80c63 in _Unwind_RaiseException_Phase2 () from /lib64/libgcc_s.so.1 #10 0x00007fb4f3a8154e in _Unwind_Resume () from /lib64/libgcc_s.so.1 #11 0x0000000000e8832d in target_read_alloc_1<unsigned char> (ops=0x408a3a0, object=TARGET_OBJECT_AUXV, annex=0x0) at ../../src/gdb/target.c:2266 #12 0x0000000000e73dea in target_read_alloc (ops=0x408a3a0, object=TARGET_OBJECT_AUXV, annex=0x0) at ../../src/gdb/target.c:2315 #13 0x000000000058248c in target_read_auxv_raw (ops=0x408a3a0) at ../../src/gdb/auxv.c:379 #14 0x000000000058243d in target_read_auxv () at ../../src/gdb/auxv.c:368 #15 0x000000000058255c in target_auxv_search (match=0x0, valp=0x7ffdee17c598) at ../../src/gdb/auxv.c:415 #16 0x0000000000a464bb in linux_is_uclinux () at ../../src/gdb/linux-tdep.c:433 #17 0x0000000000a464f6 in linux_has_shared_address_space (gdbarch=0x409a2d0) at ../../src/gdb/linux-tdep.c:440 #18 0x0000000000510eae in gdbarch_has_shared_address_space (gdbarch=0x409a2d0) at ../../src/gdb/gdbarch.c:4889 #19 0x0000000000bc7558 in program_space::~program_space (this=0x4544aa0, __in_chrg=<optimized out>) at ../../src/gdb/progspace.c:124 #20 0x00000000009b245d in delete_inferior (inf=0x47b3de0) at ../../src/gdb/inferior.c:290 #21 0x00000000009b2c10 in prune_inferiors () at ../../src/gdb/inferior.c:480 #22 0x00000000009c5e3e in fetch_inferior_event () at ../../src/gdb/infrun.c:4558 #23 0x000000000099b4dc in inferior_event_handler (event_type=INF_REG_EVENT) at ../../src/gdb/inf-loop.c:42 #24 0x0000000000cbc64f in remote_async_serial_handler (scb=0x4090a30, context=0x408a6b0) at ../../src/gdb/remote.c:14859 #25 0x0000000000d83d3a in run_async_handler_and_reschedule (scb=0x4090a30) at ../../src/gdb/ser-base.c:138 #26 0x0000000000d83e1f in fd_event (error=0, context=0x4090a30) at ../../src/gdb/ser-base.c:189 So this is problem #1, if we throw an exception while deleting a program_space then this is not caught, and is going to crash GDB. Problem #2 becomes evident when we ask why GDB is throwing an error in this case; the error is thrown because the remote target, operating in non-async mode, can't read the auxv data while an inferior is running and GDB is waiting for a stop reply. The problem here then, is why does GDB get into a position where it tries to interact with the remote target in this way, at this time? The problem is caused by the prune_inferiors call which can be seen in the above backtrace. In prune_inferiors we check if the inferior is deletable, and if it is, we delete it. The problem is, I think, we should also check if the target is currently in a state that would allow us to delete the inferior. We don't currently have such a check available, we'd need to add one, but for the remote target, this would return false if the remote is in async mode and the remote is currently waiting for a stop reply. With this change in place GDB would defer deleting the inferior until the remote target has stopped, at which point GDB would be able to refill the auxv cache successfully. And then, problem #3 becomes evident when we ask why GDB is needing to refill the auxv cache now when it didn't need to for GDB 13. This is where the second commit mentioned above (a282736) comes in. Prior to this commit, the auxv cache was cleared by the executable_changed observer, while after that commit the auxv cache was cleared by the new_objfile observer -- but only when the new_objfile observer is used in the special mode that actually means that all objfiles have been unloaded (I know, the overloading of the new_objfile observer is horrible, and unnecessary, but it's not really important for this bug). The difference arises because the new_objfile observer is triggered from clear_symtab_users, which in turn is called from program_space::~program_space. The new_objfile observer for auxv does this: static void auxv_new_objfile_observer (struct objfile *objfile) { if (objfile == nullptr) invalidate_auxv_cache_inf (current_inferior ()); } That is, when all the objfiles are unloaded, we clear the auxv cache for the current inferior. The problem is, then when we look at the prune_inferiors -> delete_inferior -> ~program_space path, we see that the current inferior is not going to be an inferior that exists within the program_space being deleted; delete_inferior removes the deleted inferior from the global inferior list, and then only deletes the program_space if program_space::empty() returns true, which is only the case if the current inferior isn't within the program_space to delete, and no other inferior exists within that program_space either. What this means is that when the new_objfile observer is called we can't rely on the current inferior having any relationship with the program space in which the objfiles were removed. This was an error in the commit a282736, the only thing we can rely on is the current program space. As a result of this mistake, after commit a282736, GDB was sometimes clearing the auxv cache for a random inferior. In the native target case this was harmless as we can always refill the cache when needed, but in the remote target case, if we need to refill the cache when the remote target is executing, then we get the crash we observed. And additionally, if we think about this a little more, we see that commit a282736 made another mistake. When all the objfiles are removed, they are removed from a program_space, a program_space might contain multiple inferiors, so surely, we should clear the auxv cache for all of the matching inferiors? Given these two insights, that the current_inferior is not relevant, only the current_program_space, and that we should be clearing the cache for all inferiors in the current_program_space, we can update auxv_new_objfile_observer to: if (objfile == nullptr) { for (inferior *inf : all_inferiors ()) { if (inf->pspace == current_program_space) invalidate_auxv_cache_inf (inf); } } With this change we now correctly clear the auxv cache for the correct inferiors, and GDB no longer needs to refill the cache at an inconvenient time, this avoids the crash we were seeing. And finally, we reach problem #4. Inspired by the observation that using the current_inferior from within the ~program_space function was not correct, I added some debug to see if current_inferior() was called anywhere else (below ~program_space), and the answer is yes, it's called a often. Mostly the culprit is GDB doing: current_inferior ()->top_target ()-> .... But I think all of these calls are most likely doing the wrong thing, and only work because the top target in all these cases is shared between all inferiors, e.g. it's the native target, or the remote target for all inferiors. But if we had a truly multi-connection setup, then we might start to see odd behaviour. Problem #1 I'm just ignoring for now, I guess at some point we might run into this again, and then we'd need to solve this. But in this case I wasn't sure what a "good" solution would look like. We need the auxv data in order to implement the linux_is_uclinux() function. If we can't get the auxv data then what should we do, assume yes, or assume no? The right answer would probably be to propagate the error back up the stack, but then we reach ~program_space, and throwing exceptions from a destructor is problematic, so we'd need to catch and deal at this point. The linux_is_uclinux() call is made from within gdbarch_has_shared_address_space(), which is used like: if (!gdbarch_has_shared_address_space (target_gdbarch ())) delete this->aspace; So, we would have to choose; delete the address space or not. If we delete it on error, then we might delete an address space that is shared within another program space. If we don't delete the address space, then we might leak it. Neither choice is great. A better solution might be to have the address spaces be reference counted, then we could remove the gdbarch_has_shared_address_space call completely, and just rely on the reference count to auto-delete the address space when appropriate. The solution for problem #2 I already hinted at above, we should have a new target_can_delete_inferiors() call, which should be called from prune_inferiors, this would prevent GDB from trying to delete inferiors when a (remote) target is in a state where we know it can't delete the inferior. Deleting an inferior often (always?) requires sending packets to the remote, and if the remote is waiting for a stop reply then this will never work, so the pruning should be deferred in this case. The solution for problem #3 is included in this commit. And, for problem #4, I'm not sure what the right solution is. Maybe delete_inferior should ensure the inferior to be deleted is in place when ~program_space is called? But that seems a little weird, as the current inferior would, in theory, still be using the current program_space... Anyway, after this commit, the gdb.python/py-progspace-events.exp test now passes when run with the native-extended-remote board. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30935 Approved-By: Simon Marchi <simon.marchi@efficios.com> Change-Id: I41f0e6e2d7ecc1e5e55ec170f37acd4052f46eaf

I noticed that on an Ubuntu 20.04 system, after a following patch ("Step over clone syscall w/ breakpoint, TARGET_WAITKIND_THREAD_CLONED"), the gdb.threads/step-over-exec.exp was passing cleanly, but still, we'd end up with four new unexpected GDB core dumps: === gdb Summary === # of unexpected core files 4 # of expected passes 48 That said patch is making the pre-existing gdb.threads/step-over-exec.exp testcase (almost silently) expose a latent problem in gdb/linux-nat.c, resulting in a GDB crash when: #1 - a non-leader thread execs #2 - the post-exec program stops somewhere #3 - you kill the inferior Instead of #3 directly, the testcase just returns, which ends up in gdb_exit, tearing down GDB, which kills the inferior, and is thus equivalent to #3 above. Vis (after said patch is applied): $ gdb --args ./gdb /home/pedro/gdb/build/gdb/testsuite/outputs/gdb.threads/step-over-exec/step-over-exec-execr-thread-other-diff-text-segs-true ... (top-gdb) r ... (gdb) b main ... (gdb) r ... Breakpoint 1, main (argc=1, argv=0x7fffffffdb88) at /home/pedro/gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.threads/step-over-exec.c:69 69 argv0 = argv[0]; (gdb) c Continuing. [New Thread 0x7ffff7d89700 (LWP 2506975)] Other going in exec. Exec-ing /home/pedro/gdb/build/gdb/testsuite/outputs/gdb.threads/step-over-exec/step-over-exec-execr-thread-other-diff-text-segs-true-execd process 2506769 is executing new program: /home/pedro/gdb/build/gdb/testsuite/outputs/gdb.threads/step-over-exec/step-over-exec-execr-thread-other-diff-text-segs-true-execd Thread 1 "step-over-exec-" hit Breakpoint 1, main () at /home/pedro/gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.threads/step-over-exec-execd.c:28 28 foo (); (gdb) k ... Thread 1 "gdb" received signal SIGSEGV, Segmentation fault. 0x000055555574444c in thread_info::has_pending_waitstatus (this=0x0) at ../../src/gdb/gdbthread.h:393 393 return m_suspend.waitstatus_pending_p; (top-gdb) bt #0 0x000055555574444c in thread_info::has_pending_waitstatus (this=0x0) at ../../src/gdb/gdbthread.h:393 #1 0x0000555555a884d1 in get_pending_child_status (lp=0x5555579b8230, ws=0x7fffffffd130) at ../../src/gdb/linux-nat.c:1345 #2 0x0000555555a8e5e6 in kill_unfollowed_child_callback (lp=0x5555579b8230) at ../../src/gdb/linux-nat.c:3564 #3 0x0000555555a92a26 in gdb::function_view<int (lwp_info*)>::bind<int, lwp_info*>(int (*)(lwp_info*))::{lambda(gdb::fv_detail::erased_callable, lwp_info*)#1}::operator()(gdb::fv_detail::erased_callable, lwp_info*) const (this=0x0, ecall=..., args#0=0x5555579b8230) at ../../src/gdb/../gdbsupport/function-view.h:284 #4 0x0000555555a92a51 in gdb::function_view<int (lwp_info*)>::bind<int, lwp_info*>(int (*)(lwp_info*))::{lambda(gdb::fv_detail::erased_callable, lwp_info*)#1}::_FUN(gdb::fv_detail::erased_callable, lwp_info*) () at ../../src/gdb/../gdbsupport/function-view.h:278 #5 0x0000555555a91f84 in gdb::function_view<int (lwp_info*)>::operator()(lwp_info*) const (this=0x7fffffffd210, args#0=0x5555579b8230) at ../../src/gdb/../gdbsupport/function-view.h:247 #6 0x0000555555a87072 in iterate_over_lwps(ptid_t, gdb::function_view<int (lwp_info*)>) (filter=..., callback=...) at ../../src/gdb/linux-nat.c:864 #7 0x0000555555a8e732 in linux_nat_target::kill (this=0x55555653af40 <the_amd64_linux_nat_target>) at ../../src/gdb/linux-nat.c:3590 #8 0x0000555555cfdc11 in target_kill () at ../../src/gdb/target.c:911 ... The root of the problem is that when a non-leader LWP execs, it just changes its tid to the tgid, replacing the pre-exec leader thread, becoming the new leader. There's no thread exit event for the execing thread. It's as if the old pre-exec LWP vanishes without trace. The ptrace man page says: "PTRACE_O_TRACEEXEC (since Linux 2.5.46) Stop the tracee at the next execve(2). A waitpid(2) by the tracer will return a status value such that status>>8 == (SIGTRAP | (PTRACE_EVENT_EXEC<<8)) If the execing thread is not a thread group leader, the thread ID is reset to thread group leader's ID before this stop. Since Linux 3.0, the former thread ID can be retrieved with PTRACE_GETEVENTMSG." When the core of GDB processes an exec events, it deletes all the threads of the inferior. But, that is too late -- deleting the thread does not delete the corresponding LWP, so we end leaving the pre-exec non-leader LWP stale in the LWP list. That's what leads to the crash above -- linux_nat_target::kill iterates over all LWPs, and after the patch in question, that code will look for the corresponding thread_info for each LWP. For the pre-exec non-leader LWP still listed, won't find one. This patch fixes it, by deleting the pre-exec non-leader LWP (and thread) from the LWP/thread lists as soon as we get an exec event out of ptrace. GDBserver does not need an equivalent fix, because it is already doing this, as side effect of mourning the pre-exec process, in gdbserver/linux-low.cc: else if (event == PTRACE_EVENT_EXEC && cs.report_exec_events) { ... /* Delete the execing process and all its threads. */ mourn (proc); switch_to_thread (nullptr); The crash with gdb.threads/step-over-exec.exp is not observable on newer systems, which postdate the glibc change to move "libpthread.so" internals to "libc.so.6", because right after the exec, GDB traps a load event for "libc.so.6", which leads to GDB trying to open libthread_db for the post-exec inferior, and, on such systems that succeeds. When we load libthread_db, we call linux_stop_and_wait_all_lwps, which, as the name suggests, stops all lwps, and then waits to see their stops. While doing this, GDB detects that the pre-exec stale LWP is gone, and deletes it. If we use "catch exec" to stop right at the exec before the "libc.so.6" load event ever happens, and issue "kill" right there, then GDB crashes on newer systems as well. So instead of tweaking gdb.threads/step-over-exec.exp to cover the fix, add a new gdb.threads/threads-after-exec.exp testcase that uses "catch exec". The test also uses the new "maint info linux-lwps" command if testing on Linux native, which also exposes the stale LWP problem with an unfixed GDB. Also tweak a comment in infrun.c:follow_exec referring to how linux-nat.c used to behave, as it would become stale otherwise. Reviewed-By: Andrew Burgess <aburgess@redhat.com> Change-Id: I21ec18072c7750f3a972160ae6b9e46590376643

Running the gdb.threads/step-over-thread-exit-while-stop-all-threads.exp testcase added later in the series against gdbserver, after the TARGET_WAITKIND_NO_RESUMED fix from the following patch, would run into an infinite loop in stop_all_threads, leading to a timeout: FAIL: gdb.threads/step-over-thread-exit-while-stop-all-threads.exp: displaced-stepping=off: target-non-stop=on: iter 0: continue (timeout) The is really a latent bug, and it is about the fact that stop_all_threads stops listening to events from a target as soon as it sees a TARGET_WAITKIND_NO_RESUMED, ignoring that TARGET_WAITKIND_NO_RESUMED may be delayed. handle_no_resumed knows how to handle delayed no-resumed events, but stop_all_threads was never taught to. In more detail, here's what happens with that testcase: #1 - Multiple threads report breakpoint hits to gdb. #2 - gdb picks one events, and it's for thread 1. All other stops are left pending. thread 1 needs to move past a breakpoint, so gdb stops all threads to start an inline step over for thread 1. While stopping threads, some of the threads that were still running report events that are also left pending. #2 - gdb steps thread 1 #3 - Thread 1 exits while stepping (it steps over an exit syscall), gdbserver reports thread exit for thread 1 #4 - Thread 1 was the last resumed thread, so gdbserver also reports no-resumed: [remote] Notification received: Stop:w0;p3445d0.3445d3 [remote] Sending packet: $vStopped#55 [remote] Packet received: N [remote] Sending packet: $vStopped#55 [remote] Packet received: OK #5 - gdb processes the thread exit for thread 1, finishes the step over and restarts threads. #6 - gdb picks the next event to process out of one of the resumed threads with pending events: [infrun] random_resumed_with_pending_wait_status: Found 32 events, selecting #11 #7 - This is again a breakpoint hit and the breakpoint needs to be stepped over too, so gdb starts a step-over dance again. #8 - We reach stop_all_threads, which finds that some threads need to be stopped. #9 - wait_one finally consumes the no-resumed event queue by #4. Seeing this, wait_one disable target async, to stop listening for events out of the remote target. #10 - We still haven't seen all the stops expected, so stop_all_threads tries another iteration. #11 - Because the remote target is no longer async, and there are no other targets, wait_one return no-resumed immediately without polling the remote target. #12 - We still haven't seen all the stops expected, so stop_all_threads tries another iteration. goto #11, looping forever. Fix this by explicitly enabling/re-enabling target async on targets that can async, before waiting for stops. Reviewed-By: Andrew Burgess <aburgess@redhat.com> Change-Id: Ie3ffb0df89635585a6631aa842689cecc989e33f

On aarch64-linux, with gcc 13.2.1, I run into: ... (gdb) backtrace^M #0 break_here () at solib-search.c:30^M #1 0x0000fffff7f20194 in lib2_func4 () at solib-search-lib2.c:50^M #2 0x0000fffff7f70194 in lib1_func3 () at solib-search-lib1.c:50^M #3 0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M #4 0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M #5 0x00000000004101b4 in main () at solib-search.c:23^M (gdb) PASS: gdb.base/solib-search.exp: \ backtrace (with wrong libs) (data collection) FAIL: gdb.base/solib-search.exp: backtrace (with wrong libs) ... The FAIL is generated by this code in the test-case: ... if { $expect_fail } { # If the backtrace output is correct the test isn't sufficiently # testing what it should. if { $count == $total_expected } { set fail 1 } ... The test-case: - builds two versions of two shared libs, a "right" and "wrong" version, the difference being an additional dummy function (called spacer function), - uses the "right" version to generate a core file, - uses the "wrong" version to interpret the core file, and - generates a backtrace. The intent is that the backtrace is incorrect due to using the "wrong" version, but actually it's correct. This is because the spacer functions aren't large enough. Fix this by increasing the size of the spacer functions by adding a dummy loop, after which we have, as expected, an incorrect backtrace: ... (gdb) backtrace^M #0 break_here () at solib-search.c:30^M #1 0x0000fffff7f201c0 in ?? ()^M #2 0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M #3 0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M #4 0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M #5 0x00000000004101b4 in main () at solib-search.c:23^M (gdb) PASS: gdb.base/solib-search.exp: \ backtrace (with wrong libs) (data collection) PASS: gdb.base/solib-search.exp: backtrace (with wrong libs) ... Tested on aarch64-linux.

When running test-case gdb.dap/eof.exp, it occasionally coredumps. The thread triggering the coredump is: ... #0 0x0000ffff42bb2280 in __pthread_kill_implementation () from /lib64/libc.so.6 #1 0x0000ffff42b65800 [PAC] in raise () from /lib64/libc.so.6 #2 0x00000000007b03e8 [PAC] in handle_fatal_signal (sig=11) at gdb/event-top.c:926 #3 0x00000000007b0470 in handle_sigsegv (sig=11) at gdb/event-top.c:976 #4 <signal handler called> #5 0x0000000000606080 in cli_ui_out::do_message (this=0xffff2f7ed728, style=..., format=0xffff0c002af1 "%s", args=...) at gdb/cli-out.c:232 #6 0x0000000000ce6358 in ui_out::call_do_message (this=0xffff2f7ed728, style=..., format=0xffff0c002af1 "%s") at gdb/ui-out.c:584 #7 0x0000000000ce6610 in ui_out::vmessage (this=0xffff2f7ed728, in_style=..., format=0x16f93ea "", args=...) at gdb/ui-out.c:621 #8 0x0000000000ce3a9c in ui_file::vprintf (this=0xfffffbea1b18, ...) at gdb/ui-file.c:74 #9 0x0000000000d2b148 in gdb_vprintf (stream=0xfffffbea1b18, format=0x16f93e8 "%s", args=...) at gdb/utils.c:1898 #10 0x0000000000d2b23c in gdb_printf (stream=0xfffffbea1b18, format=0x16f93e8 "%s") at gdb/utils.c:1913 #11 0x0000000000ab5208 in gdbpy_write (self=0x33fe35d0, args=0x342ec280, kw=0x345c08b0) at gdb/python/python.c:1464 #12 0x0000ffff434acedc in cfunction_call () from /lib64/libpython3.12.so.1.0 #13 0x0000ffff4347c500 [PAC] in _PyObject_MakeTpCall () from /lib64/libpython3.12.so.1.0 #14 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 #15 0x0000ffff434d8cd0 [PAC] in method_vectorcall () from /lib64/libpython3.12.so.1.0 #16 0x0000ffff434b9824 [PAC] in PyObject_CallOneArg () from /lib64/libpython3.12.so.1.0 #17 0x0000ffff43557674 [PAC] in PyFile_WriteObject () from /lib64/libpython3.12.so.1.0 #18 0x0000ffff435577a0 [PAC] in PyFile_WriteString () from /lib64/libpython3.12.so.1.0 #19 0x0000ffff43465354 [PAC] in thread_excepthook () from /lib64/libpython3.12.so.1.0 #20 0x0000ffff434ac6e0 [PAC] in cfunction_vectorcall_O () from /lib64/libpython3.12.so.1.0 #21 0x0000ffff434a32d8 [PAC] in PyObject_Vectorcall () from /lib64/libpython3.12.so.1.0 #22 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 #23 0x0000ffff434d8d88 [PAC] in method_vectorcall () from /lib64/libpython3.12.so.1.0 #24 0x0000ffff435e0ef4 [PAC] in thread_run () from /lib64/libpython3.12.so.1.0 #25 0x0000ffff43591ec0 [PAC] in pythread_wrapper () from /lib64/libpython3.12.so.1.0 #26 0x0000ffff42bb0584 [PAC] in start_thread () from /lib64/libc.so.6 #27 0x0000ffff42c1fd4c [PAC] in thread_start () from /lib64/libc.so.6 ... The direct cause for the coredump seems to be that cli_ui_out::do_message is trying to write to a stream variable which does not look sound: ... (gdb) p *stream $8 = {_vptr.ui_file = 0x0, m_applied_style = {m_foreground = {m_simple = true, { m_value = 0, {m_red = 0 '\000', m_green = 0 '\000', m_blue = 0 '\000'}}}, m_background = {m_simple = 32, {m_value = 65535, {m_red = 255 '\377', m_green = 255 '\377', m_blue = 0 '\000'}}}, m_intensity = (unknown: 0x438fe710), m_reverse = 255}} ... The string that is being printed is: ... (gdb) p str $9 = "Exception in thread " ... so AFAICT this is a DAP thread running into an exception and trying to print it. If we look at the state of gdb's main thread, we have: ... #0 0x0000ffff42bac914 in __futex_abstimed_wait_cancelable64 () from /lib64/libc.so.6 #1 0x0000ffff42bafb44 [PAC] in pthread_cond_timedwait@@GLIBC_2.17 () from /lib64/libc.so.6 #2 0x0000ffff43466e9c [PAC] in take_gil () from /lib64/libpython3.12.so.1.0 #3 0x0000ffff43484fe0 [PAC] in PyEval_RestoreThread () from /lib64/libpython3.12.so.1.0 #4 0x0000000000ab8698 [PAC] in gdbpy_allow_threads::~gdbpy_allow_threads ( this=0xfffffbea1cf8, __in_chrg=<optimized out>) at gdb/python/python-internal.h:769 #5 0x0000000000ab2fec in execute_gdb_command (self=0x33fe35d0, args=0x34297b60, kw=0x34553d20) at gdb/python/python.c:681 #6 0x0000ffff434acedc in cfunction_call () from /lib64/libpython3.12.so.1.0 #7 0x0000ffff4347c500 [PAC] in _PyObject_MakeTpCall () from /lib64/libpython3.12.so.1.0 #8 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 #9 0x0000ffff4353bce8 [PAC] in _PyObject_VectorcallTstate.lto_priv.3 () from /lib64/libpython3.12.so.1.0 #10 0x0000000000ab87fc [PAC] in gdbpy_event::operator() (this=0xffff14005900) at gdb/python/python.c:1061 #11 0x0000000000ab93e8 in std::__invoke_impl<void, gdbpy_event&> (__f=...) at /usr/include/c++/13/bits/invoke.h:61 #12 0x0000000000ab9204 in std::__invoke_r<void, gdbpy_event&> (__fn=...) at /usr/include/c++/13/bits/invoke.h:111 #13 0x0000000000ab8e90 in std::_Function_handler<..>::_M_invoke(...) (...) at /usr/include/c++/13/bits/std_function.h:290 #14 0x000000000062e0d0 in std::function<void ()>::operator()() const ( this=0xffff14005830) at /usr/include/c++/13/bits/std_function.h:591 #15 0x0000000000b67f14 in run_events (error=0, client_data=0x0) at gdb/run-on-main-thread.c:76 #16 0x000000000157e290 in handle_file_event (file_ptr=0x33dae3a0, ready_mask=1) at gdbsupport/event-loop.cc:573 #17 0x000000000157e760 in gdb_wait_for_event (block=1) at gdbsupport/event-loop.cc:694 #18 0x000000000157d464 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:264 #19 0x0000000000943a84 in start_event_loop () at gdb/main.c:401 #20 0x0000000000943bfc in captured_command_loop () at gdb/main.c:465 #21 0x000000000094567c in captured_main (data=0xfffffbea23e8) at gdb/main.c:1335 #22 0x0000000000945700 in gdb_main (args=0xfffffbea23e8) at gdb/main.c:1354 #23 0x0000000000423ab4 in main (argc=14, argv=0xfffffbea2578) at gdb/gdb.c:39 ... AFAIU, there's a race between the two threads on gdb_stderr: - the DAP thread samples the gdb_stderr value, and uses it a bit later to print to - the gdb main thread changes the gdb_stderr value forth and back, using a temporary value for string capture purposes The non-sound stream value is caused by gdb_stderr being sampled while pointing to a str_file object, and used once the str_file object is already destroyed. The error here is that the DAP thread attempts to print to gdb_stderr. Fix this by adding a thread_wrapper that: - catches all exceptions and logs them to dap.log, and - while we're at it, logs when exiting and using the thread_wrapper for each DAP thread. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>

When running test-case gdb.dap/eof.exp, we're likely to get a coredump due to a segfault in new_threadstate. At the point of the core dump, the gdb main thread looks like: ... (gdb) bt #0 0x0000fffee30d2280 in __pthread_kill_implementation () from /lib64/libc.so.6 #1 0x0000fffee3085800 [PAC] in raise () from /lib64/libc.so.6 #2 0x00000000007b03e8 [PAC] in handle_fatal_signal (sig=11) at gdb/event-top.c:926 #3 0x00000000007b0470 in handle_sigsegv (sig=11) at gdb/event-top.c:976 #4 <signal handler called> #5 0x0000fffee3a4db14 in new_threadstate () from /lib64/libpython3.12.so.1.0 #6 0x0000fffee3ab0548 [PAC] in PyGILState_Ensure () from /lib64/libpython3.12.so.1.0 #7 0x0000000000a6d034 [PAC] in gdbpy_gil::gdbpy_gil (this=0xffffcb279738) at gdb/python/python-internal.h:787 #8 0x0000000000ab87ac in gdbpy_event::~gdbpy_event (this=0xfffea8001ee0, __in_chrg=<optimized out>) at gdb/python/python.c:1051 #9 0x0000000000ab9460 in std::_Function_base::_Base_manager<...>::_M_destroy (__victim=...) at /usr/include/c++/13/bits/std_function.h:175 #10 0x0000000000ab92dc in std::_Function_base::_Base_manager<...>::_M_manager (__dest=..., __source=..., __op=std::__destroy_functor) at /usr/include/c++/13/bits/std_function.h:203 #11 0x0000000000ab8f14 in std::_Function_handler<...>::_M_manager(...) (...) at /usr/include/c++/13/bits/std_function.h:282 #12 0x000000000042dd9c in std::_Function_base::~_Function_base (this=0xfffea8001c10, __in_chrg=<optimized out>) at /usr/include/c++/13/bits/std_function.h:244 #13 0x000000000042e654 in std::function<void ()>::~function() (this=0xfffea8001c10, __in_chrg=<optimized out>) at /usr/include/c++/13/bits/std_function.h:334 #14 0x0000000000b68e60 in std::_Destroy<std::function<void ()> >(...) (...) at /usr/include/c++/13/bits/stl_construct.h:151 #15 0x0000000000b68cd0 in std::_Destroy_aux<false>::__destroy<...>(...) (...) at /usr/include/c++/13/bits/stl_construct.h:163 #16 0x0000000000b689d8 in std::_Destroy<...>(...) (...) at /usr/include/c++/13/bits/stl_construct.h:196 #17 0x0000000000b68414 in std::_Destroy<...>(...) (...) at /usr/include/c++/13/bits/alloc_traits.h:948 #18 std::vector<...>::~vector() (this=0x2a183c8 <runnables>) at /usr/include/c++/13/bits/stl_vector.h:732 #19 0x0000fffee3088370 in __run_exit_handlers () from /lib64/libc.so.6 #20 0x0000fffee3088450 [PAC] in exit () from /lib64/libc.so.6 #21 0x0000000000c95600 [PAC] in quit_force (exit_arg=0x0, from_tty=0) at gdb/top.c:1822 #22 0x0000000000609140 in quit_command (args=0x0, from_tty=0) at gdb/cli/cli-cmds.c:508 #23 0x0000000000c926a4 in quit_cover () at gdb/top.c:300 #24 0x00000000007b09d4 in async_disconnect (arg=0x0) at gdb/event-top.c:1230 #25 0x0000000000548acc in invoke_async_signal_handlers () at gdb/async-event.c:234 #26 0x000000000157d2d4 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:199 #27 0x0000000000943a84 in start_event_loop () at gdb/main.c:401 #28 0x0000000000943bfc in captured_command_loop () at gdb/main.c:465 #29 0x000000000094567c in captured_main (data=0xffffcb279d08) at gdb/main.c:1335 #30 0x0000000000945700 in gdb_main (args=0xffffcb279d08) at gdb/main.c:1354 #31 0x0000000000423ab4 in main (argc=14, argv=0xffffcb279e98) at gdb/gdb.c:39 ... The direct cause of the segfault is calling PyGILState_Ensure after calling Py_Finalize. AFAICT the problem is a race between the gdb main thread and DAP's JSON writer thread. On one side, we have the following events: - DAP's JSON reader thread reads an EOF, and lets DAP's main thread known by writing None into read_queue - DAP's main thread lets DAP's JSON writer thread known by writing None into write_queue - DAP's JSON writer thread sees the None in its queue, and calls send_gdb("quit") - a corresponding gdbpy_event is deposited in the runnables vector, to be run by the gdb main thread On the other side, we have the following events: - the gdb main thread receives a SIGHUP - the corresponding handler calls quit_force, which calls do_final_cleanups - one of the final cleanups is finalize_python, which calls Py_Finalize - quit_force calls exit, which triggers the exit handlers - one of the exit handlers is the destructor of the runnables vector - destruction of the vector triggers destruction of the remaining element - the remaining element is a gdbpy_event, and the destructor (indirectly) calls PyGILState_Ensure It's good to note that both events (EOF and SIGHUP) are caused by this line in the test-case: ... catch "close -i $gdb_spawn_id" ... where "expect close" closes the stdin and stdout file descriptors, which causes the SIGHUP to be send. So, for the system I'm running this on, the send_gdb("quit") is actually not needed. I'm not sure if we support any systems where it's actually needed. Fix this by removing the send_gdb("quit"). Tested on aarch64-linux. PR dap/31306 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31306

When building gdb with -O0 -fsanitize=address, and running test-case gdb.ada/uninitialized_vars.exp, I run into: ... (gdb) info locals a = 0 z = (a => 1, b => false, c => 2.0) ================================================================= ==66372==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000097f58 at pc 0xffff52c0da1c bp 0xffffc90a1d40 sp 0xffffc90a1d80 READ of size 4 at 0x602000097f58 thread T0 #0 0xffff52c0da18 in memmove (/lib64/libasan.so.8+0x6da18) #1 0xbcab24 in unsigned char* std::__copy_move_backward<false, true, std::random_access_iterator_tag>::__copy_move_b<unsigned char const, unsigned char>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:748 #2 0xbc9bf4 in unsigned char* std::__copy_move_backward_a2<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:769 #3 0xbc898c in unsigned char* std::__copy_move_backward_a1<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:778 #4 0xbc715c in unsigned char* std::__copy_move_backward_a<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:807 #5 0xbc4e6c in unsigned char* std::copy_backward<unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:867 #6 0xbc2934 in void gdb::copy<unsigned char const, unsigned char>(gdb::array_view<unsigned char const>, gdb::array_view<unsigned char>) gdb/../gdbsupport/array-view.h:223 #7 0x20e0100 in value::contents_copy_raw(value*, long, long, long) gdb/value.c:1239 #8 0x20e9830 in value::primitive_field(long, int, type*) gdb/value.c:3078 #9 0x20e98f8 in value_field(value*, int) gdb/value.c:3095 #10 0xcafd64 in print_field_values gdb/ada-valprint.c:658 #11 0xcb0fa0 in ada_val_print_struct_union gdb/ada-valprint.c:857 #12 0xcb1bb4 in ada_value_print_inner(value*, ui_file*, int, value_print_options const*) gdb/ada-valprint.c:1042 #13 0xc66e04 in ada_language::value_print_inner(value*, ui_file*, int, value_print_options const*) const (/home/vries/gdb/build/gdb/gdb+0xc66e04) #14 0x20ca1e8 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1092 #15 0x20caabc in common_val_print_checked(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1184 #16 0x196c524 in print_variable_and_value(char const*, symbol*, frame_info_ptr, ui_file*, int) gdb/printcmd.c:2355 #17 0x1d99ca0 in print_variable_and_value_data::operator()(char const*, symbol*) gdb/stack.c:2308 #18 0x1dabca0 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::operator()(gdb::fv_detail::erased_callable, char const*, symbol*) const gdb/../gdbsupport/function-view.h:305 #19 0x1dabd14 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::_FUN(gdb::fv_detail::erased_callable, char const*, symbol*) gdb/../gdbsupport/function-view.h:299 #20 0x1dab34c in gdb::function_view<void (char const*, symbol*)>::operator()(char const*, symbol*) const gdb/../gdbsupport/function-view.h:289 #21 0x1d9963c in iterate_over_block_locals gdb/stack.c:2240 #22 0x1d99790 in iterate_over_block_local_vars(block const*, gdb::function_view<void (char const*, symbol*)>) gdb/stack.c:2259 #23 0x1d9a598 in print_frame_local_vars gdb/stack.c:2380 #24 0x1d9afac in info_locals_command(char const*, int) gdb/stack.c:2458 #25 0xfd7b30 in do_simple_func gdb/cli/cli-decode.c:95 #26 0xfe5a2c in cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 #27 0x1f03790 in execute_command(char const*, int) gdb/top.c:575 #28 0x1384080 in command_handler(char const*) gdb/event-top.c:566 #29 0x1384e2c in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:802 #30 0x1f731e4 in tui_command_line_handler gdb/tui/tui-interp.c:104 #31 0x1382a58 in gdb_rl_callback_handler gdb/event-top.c:259 #32 0x21dbb80 in rl_callback_read_char readline/readline/callback.c:290 #33 0x1382510 in gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 #34 0x138277c in gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 #35 0x1fe9b40 in stdin_event_handler gdb/ui.c:155 #36 0x35ff1bc in handle_file_event gdbsupport/event-loop.cc:573 #37 0x35ff9d8 in gdb_wait_for_event gdbsupport/event-loop.cc:694 #38 0x35fd284 in gdb_do_one_event(int) gdbsupport/event-loop.cc:264 #39 0x1768080 in start_event_loop gdb/main.c:408 #40 0x17684c4 in captured_command_loop gdb/main.c:472 #41 0x176cfc8 in captured_main gdb/main.c:1342 #42 0x176d088 in gdb_main(captured_main_args*) gdb/main.c:1361 #43 0xb73edc in main gdb/gdb.c:39 #44 0xffff519b09d8 in __libc_start_call_main (/lib64/libc.so.6+0x309d8) #45 0xffff519b0aac in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x30aac) #46 0xb73c2c in _start (/home/vries/gdb/build/gdb/gdb+0xb73c2c) 0x602000097f58 is located 0 bytes after 8-byte region [0x602000097f50,0x602000097f58) allocated by thread T0 here: #0 0xffff52c65218 in calloc (/lib64/libasan.so.8+0xc5218) #1 0xcbc278 in xcalloc gdb/alloc.c:97 #2 0x35f21e8 in xzalloc(unsigned long) gdbsupport/common-utils.cc:29 #3 0x20de270 in value::allocate_contents(bool) gdb/value.c:937 #4 0x20edc08 in value::fetch_lazy() gdb/value.c:4033 #5 0x20dadc0 in value::entirely_covered_by_range_vector(std::vector<range, std::allocator<range> > const&) gdb/value.c:229 #6 0xcb2298 in value::entirely_optimized_out() gdb/value.h:560 #7 0x20ca6fc in value_check_printable gdb/valprint.c:1133 #8 0x20caa8c in common_val_print_checked(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1182 #9 0x196c524 in print_variable_and_value(char const*, symbol*, frame_info_ptr, ui_file*, int) gdb/printcmd.c:2355 #10 0x1d99ca0 in print_variable_and_value_data::operator()(char const*, symbol*) gdb/stack.c:2308 #11 0x1dabca0 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::operator()(gdb::fv_detail::erased_callable, char const*, symbol*) const gdb/../gdbsupport/function-view.h:305 #12 0x1dabd14 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)#1}::_FUN(gdb::fv_detail::erased_callable, char const*, symbol*) gdb/../gdbsupport/function-view.h:299 #13 0x1dab34c in gdb::function_view<void (char const*, symbol*)>::operator()(char const*, symbol*) const gdb/../gdbsupport/function-view.h:289 #14 0x1d9963c in iterate_over_block_locals gdb/stack.c:2240 #15 0x1d99790 in iterate_over_block_local_vars(block const*, gdb::function_view<void (char const*, symbol*)>) gdb/stack.c:2259 #16 0x1d9a598 in print_frame_local_vars gdb/stack.c:2380 #17 0x1d9afac in info_locals_command(char const*, int) gdb/stack.c:2458 #18 0xfd7b30 in do_simple_func gdb/cli/cli-decode.c:95 #19 0xfe5a2c in cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 #20 0x1f03790 in execute_command(char const*, int) gdb/top.c:575 #21 0x1384080 in command_handler(char const*) gdb/event-top.c:566 #22 0x1384e2c in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:802 #23 0x1f731e4 in tui_command_line_handler gdb/tui/tui-interp.c:104 #24 0x1382a58 in gdb_rl_callback_handler gdb/event-top.c:259 #25 0x21dbb80 in rl_callback_read_char readline/readline/callback.c:290 #26 0x1382510 in gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 #27 0x138277c in gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 #28 0x1fe9b40 in stdin_event_handler gdb/ui.c:155 #29 0x35ff1bc in handle_file_event gdbsupport/event-loop.cc:573 SUMMARY: AddressSanitizer: heap-buffer-overflow (/lib64/libasan.so.8+0x6da18) in memmove ... The error happens when trying to print either variable y or y2: ... type Variable_Record (A : Boolean := True) is record case A is when True => B : Integer; when False => C : Float; D : Integer; end case; end record; Y : Variable_Record := (A => True, B => 1); Y2 : Variable_Record := (A => False, C => 1.0, D => 2); ... when the variables are uninitialized. The error happens only when printing the entire variable: ... (gdb) p y.a $2 = 216 (gdb) p y.b There is no member named b. (gdb) p y.c $3 = 9.18340949e-41 (gdb) p y.d $4 = 1 (gdb) p y <AddressSanitizer: heap-buffer-overflow> ... The error happens as follows: - field a functions as discriminant, choosing either the b, or c+d variant. - when y.a happens to be set to 216, as above, gdb interprets this as the variable having the c+d variant (which is why trying to print y.b fails). - when printing y, gdb allocates a value, copies the bytes into it from the target, and then prints the value. - gdb allocates the value using the type size, which is 8. It's 8 because that's what the DW_AT_byte_size indicates. Note that for valid values of a, it gives correct results: if a is 0 (c+d variant), size is 12, if a is 1 (b variant), size is 8. - gdb tries to print field d, which is at an 8 byte offset, and that results in a out-of-bounds access for the allocated 8-byte value. Fix this by handling this case in value::contents_copy_raw, such that we have: ... (gdb) p y $1 = (a => 24, c => 9.18340949e-41, d => <error reading variable: access outside bounds of object>) ... An alternative (additional) fix could be this: in compute_variant_fields_inner gdb reads the discriminant y.a to decide which variant is active. It would be nice to detect that the value (y.a == 24) is not a valid Boolean, and give up on choosing a variant altoghether. However, the situation regarding the internal type CODE_TYPE_BOOL is currently ambiguous (see PR31282) and it's not possible to reliably decide what valid values are. The test-case source file gdb.ada/uninitialized-variable-record/parse.adb is a reduced version of gdb.ada/uninitialized_vars/parse.adb, so it copies the copyright years. Note that the test-case needs gcc-12 or newer, it's unsupported for older gcc versions. [ So, it would be nice to rewrite it into a dwarf assembly test-case. ] The test-case loops over all languages. This is inherited from an earlier attempt to fix this, which had language-specific fixes (in print_field_values, cp_print_value_fields, pascal_object_print_value_fields and f_language::value_print_inner). I've left this in, but I suppose it's not strictly necessary anymore. Tested on x86_64-linux. PR exp/31258 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31258

From the Python API, we can execute GDB commands via gdb.execute. If the command gives an exception, however, we need to recover the GDB prompt and enable stdin, because the exception does not reach top-level GDB or normal_stop. This was done in commit commit 1ba1ac8 Author: Andrew Burgess <andrew.burgess@embecosm.com> Date: Tue Nov 19 11:17:20 2019 +0000 gdb: Enable stdin on exception in execute_gdb_command with the following code: catch (const gdb_exception &except) { /* If an exception occurred then we won't hit normal_stop (), or have an exception reach the top level of the event loop, which are the two usual places in which stdin would be re-enabled. So, before we convert the exception and continue back in Python, we should re-enable stdin here. */ async_enable_stdin (); GDB_PY_HANDLE_EXCEPTION (except); } In this patch, we explain what happens when we run a GDB command in the context of a synchronous command, e.g. via Python observer notifications. As an example, suppose we have the following objfile event listener, specified in a file named file.py: ~~~ import gdb class MyListener: def __init__(self): gdb.events.new_objfile.connect(self.handle_new_objfile_event) self.processed_objfile = False def handle_new_objfile_event(self, event): if self.processed_objfile: return print("loading " + event.new_objfile.filename) self.processed_objfile = True gdb.execute('add-inferior -no-connection') gdb.execute('inferior 2') gdb.execute('target remote | gdbserver - /tmp/a.out') gdb.execute('inferior 1') the_listener = MyListener() ~~~ Using this Python file, we see the behavior below: $ gdb -q -ex "source file.py" -ex "run" --args a.out Reading symbols from a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 [New inferior 2] Added inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] stdin/stdout redirected Process /tmp/a.out created; pid = 3075406 Remote debugging using stdio Reading /tmp/a.out from remote target... ... [Switching to inferior 1 [process 3075400] (/tmp/a.out)] [Switching to thread 1.1 (process 3075400)] #0 0x00007ffff7fe3290 in ?? () from /lib64/ld-linux-x86-64.so.2 (gdb) [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Inferior 1 (process 3075400) exited normally] Note how the GDB prompt comes in-between the debugger output. We have this obscure behavior, because the executed command, "target remote", triggers an invocation of `normal_stop` that enables stdin. After that, however, the Python notification context completes and GDB continues with its normal flow of executing the 'run' command. This can be seen in the call stack below: (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 #1 0x00005555561c3acd in normal_stop () at src/gdb/infrun.c:9432 #2 0x00005555561b328e in start_remote (from_tty=0) at src/gdb/infrun.c:3801 #3 0x0000555556441224 in remote_target::start_remote_1 (this=0x5555587882e0, from_tty=0, extended_p=0) at src/gdb/remote.c:5225 #4 0x000055555644166c in remote_target::start_remote (this=0x5555587882e0, from_tty=0, extended_p=0) at src/gdb/remote.c:5316 #5 0x00005555564430cf in remote_target::open_1 (name=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0, extended_p=0) at src/gdb/remote.c:6175 #6 0x0000555556441707 in remote_target::open (name=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0) at src/gdb/remote.c:5338 #7 0x00005555565ea63f in open_target (args=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0, command=0x555558589280) at src/gdb/target.c:824 #8 0x0000555555f0d89a in cmd_func (cmd=0x555558589280, args=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0) at src/gdb/cli/cli-decode.c:2735 #9 0x000055555661fb42 in execute_command (p=0x55555878529e "t", from_tty=0) at src/gdb/top.c:575 #10 0x0000555555f1a506 in execute_control_command_1 (cmd=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:529 #11 0x0000555555f1abea in execute_control_command (cmd=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:701 #12 0x0000555555f19fc7 in execute_control_commands (cmdlines=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:411 #13 0x0000555556400d91 in execute_gdb_command (self=0x7ffff43b5d00, args=0x7ffff440ab60, kw=0x0) at src/gdb/python/python.c:700 #14 0x00007ffff7a96023 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #15 0x00007ffff7a4dadc in _PyObject_MakeTpCall () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #16 0x00007ffff79e9a1c in _PyEval_EvalFrameDefault () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #17 0x00007ffff7b303af in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #18 0x00007ffff7a50358 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #19 0x00007ffff7a4f3f4 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #20 0x00007ffff7a4f883 in PyObject_CallFunctionObjArgs () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #21 0x00005555563a9758 in evpy_emit_event (event=0x7ffff42b5430, registry=0x7ffff42b4690) at src/gdb/python/py-event.c:104 #22 0x00005555563cb874 in emit_new_objfile_event (objfile=0x555558761700) at src/gdb/python/py-newobjfileevent.c:52 #23 0x00005555563b53bc in python_new_objfile (objfile=0x555558761700) at src/gdb/python/py-inferior.c:195 #24 0x0000555555d6dff0 in std::__invoke_impl<void, void (*&)(objfile*), objfile*> (__f=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:61 #25 0x0000555555d6be18 in std::__invoke_r<void, void (*&)(objfile*), objfile*> (__fn=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:111 #26 0x0000555555d69661 in std::_Function_handler<void (objfile*), void (*)(objfile*)>::_M_invoke(std::_Any_data const&, objfile*&&) (__functor=..., __args#0=@0x7fffffffd080: 0x555558761700) at /usr/include/c++/11/bits/std_function.h:290 #27 0x0000555556314caf in std::function<void (objfile*)>::operator()(objfile*) const (this=0x5555585b5860, __args#0=0x555558761700) at /usr/include/c++/11/bits/std_function.h:590 #28 0x000055555631444e in gdb::observers::observable<objfile*>::notify (this=0x55555836eea0 <gdb::observers::new_objfile>, args#0=0x555558761700) at src/gdb/../gdbsupport/observable.h:166 #29 0x0000555556599b3f in symbol_file_add_with_addrs (abfd=..., name=0x55555875d310 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1125 #30 0x0000555556599ca4 in symbol_file_add_from_bfd (abfd=..., name=0x55555875d310 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1160 #31 0x0000555556546371 in solib_read_symbols (so=..., flags=...) at src/gdb/solib.c:692 #32 0x0000555556546f0f in solib_add (pattern=0x0, from_tty=0, readsyms=1) at src/gdb/solib.c:1015 #33 0x0000555556539891 in enable_break (info=0x55555874e180, from_tty=0) at src/gdb/solib-svr4.c:2416 #34 0x000055555653b305 in svr4_solib_create_inferior_hook (from_tty=0) at src/gdb/solib-svr4.c:3058 #35 0x0000555556547cee in solib_create_inferior_hook (from_tty=0) at src/gdb/solib.c:1217 #36 0x0000555556196f6a in post_create_inferior (from_tty=0) at src/gdb/infcmd.c:275 #37 0x0000555556197670 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at src/gdb/infcmd.c:486 #38 0x000055555619783f in run_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:512 #39 0x0000555555f0798d in do_simple_func (args=0x0, from_tty=1, c=0x555558567510) at src/gdb/cli/cli-decode.c:95 #40 0x0000555555f0d89a in cmd_func (cmd=0x555558567510, args=0x0, from_tty=1) at src/gdb/cli/cli-decode.c:2735 #41 0x000055555661fb42 in execute_command (p=0x7fffffffe2c4 "", from_tty=1) at src/gdb/top.c:575 #42 0x000055555626303b in catch_command_errors (command=0x55555661f4ab <execute_command(char const*, int)>, arg=0x7fffffffe2c1 "run", from_tty=1, do_bp_actions=true) at src/gdb/main.c:513 #43 0x000055555626328a in execute_cmdargs (cmdarg_vec=0x7fffffffdaf0, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND, ret=0x7fffffffda3c) at src/gdb/main.c:612 #44 0x0000555556264849 in captured_main_1 (context=0x7fffffffdd40) at src/gdb/main.c:1293 #45 0x0000555556264a7f in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1314 #46 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 #47 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) The use of the "target remote" command here is just an example. In principle, we would reproduce the problem with any command that triggers an invocation of `normal_stop`. To omit enabling the stdin in `normal_stop`, we would have to check the context we are in. Since we cannot do that, we add a new field to `struct ui` to track whether the prompt was already blocked, and set the tracker flag in the Python context before executing a GDB command. After applying this patch, the output becomes ... Reading symbols from a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 [New inferior 2] Added inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] stdin/stdout redirected Process /tmp/a.out created; pid = 3032261 Remote debugging using stdio Reading /tmp/a.out from remote target... ... [Switching to inferior 1 [process 3032255] (/tmp/a.out)] [Switching to thread 1.1 (process 3032255)] #0 0x00007ffff7fe3290 in ?? () from /lib64/ld-linux-x86-64.so.2 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Inferior 1 (process 3032255) exited normally] (gdb) Let's now consider a secondary scenario, where the command executed from the Python raises an error. As an example, suppose we have the Python file below: def handle_new_objfile_event(self, event): ... print("loading " + event.new_objfile.filename) self.processed_objfile = True gdb.execute('print a') The executed command, "print a", gives an error because "a" is not defined. Without this patch, we see the behavior below, where the prompt is again placed incorrectly: ... Reading symbols from /tmp/a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 Python Exception <class 'gdb.error'>: No symbol "a" in current context. (gdb) [Inferior 1 (process 3980401) exited normally] This time, `async_enable_stdin` is called from the 'catch' block in `execute_gdb_command`: (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 #1 0x0000555556400f0a in execute_gdb_command (self=0x7ffff43b5d00, args=0x7ffff440ab60, kw=0x0) at src/gdb/python/python.c:713 #2 0x00007ffff7a96023 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #3 0x00007ffff7a4dadc in _PyObject_MakeTpCall () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #4 0x00007ffff79e9a1c in _PyEval_EvalFrameDefault () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #5 0x00007ffff7b303af in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #6 0x00007ffff7a50358 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #7 0x00007ffff7a4f3f4 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #8 0x00007ffff7a4f883 in PyObject_CallFunctionObjArgs () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 #9 0x00005555563a9758 in evpy_emit_event (event=0x7ffff42b5430, registry=0x7ffff42b4690) at src/gdb/python/py-event.c:104 #10 0x00005555563cb874 in emit_new_objfile_event (objfile=0x555558761410) at src/gdb/python/py-newobjfileevent.c:52 #11 0x00005555563b53bc in python_new_objfile (objfile=0x555558761410) at src/gdb/python/py-inferior.c:195 #12 0x0000555555d6dff0 in std::__invoke_impl<void, void (*&)(objfile*), objfile*> (__f=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:61 #13 0x0000555555d6be18 in std::__invoke_r<void, void (*&)(objfile*), objfile*> (__fn=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:111 #14 0x0000555555d69661 in std::_Function_handler<void (objfile*), void (*)(objfile*)>::_M_invoke(std::_Any_data const&, objfile*&&) (__functor=..., __args#0=@0x7fffffffd080: 0x555558761410) at /usr/include/c++/11/bits/std_function.h:290 #15 0x0000555556314caf in std::function<void (objfile*)>::operator()(objfile*) const (this=0x5555585b5860, __args#0=0x555558761410) at /usr/include/c++/11/bits/std_function.h:590 #16 0x000055555631444e in gdb::observers::observable<objfile*>::notify (this=0x55555836eea0 <gdb::observers::new_objfile>, args#0=0x555558761410) at src/gdb/../gdbsupport/observable.h:166 #17 0x0000555556599b3f in symbol_file_add_with_addrs (abfd=..., name=0x55555875d020 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1125 #18 0x0000555556599ca4 in symbol_file_add_from_bfd (abfd=..., name=0x55555875d020 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1160 #19 0x0000555556546371 in solib_read_symbols (so=..., flags=...) at src/gdb/solib.c:692 #20 0x0000555556546f0f in solib_add (pattern=0x0, from_tty=0, readsyms=1) at src/gdb/solib.c:1015 #21 0x0000555556539891 in enable_break (info=0x55555874a670, from_tty=0) at src/gdb/solib-svr4.c:2416 #22 0x000055555653b305 in svr4_solib_create_inferior_hook (from_tty=0) at src/gdb/solib-svr4.c:3058 #23 0x0000555556547cee in solib_create_inferior_hook (from_tty=0) at src/gdb/solib.c:1217 #24 0x0000555556196f6a in post_create_inferior (from_tty=0) at src/gdb/infcmd.c:275 #25 0x0000555556197670 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at src/gdb/infcmd.c:486 #26 0x000055555619783f in run_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:512 #27 0x0000555555f0798d in do_simple_func (args=0x0, from_tty=1, c=0x555558567510) at src/gdb/cli/cli-decode.c:95 #28 0x0000555555f0d89a in cmd_func (cmd=0x555558567510, args=0x0, from_tty=1) at src/gdb/cli/cli-decode.c:2735 #29 0x000055555661fb42 in execute_command (p=0x7fffffffe2c4 "", from_tty=1) at src/gdb/top.c:575 #30 0x000055555626303b in catch_command_errors (command=0x55555661f4ab <execute_command(char const*, int)>, arg=0x7fffffffe2c1 "run", from_tty=1, do_bp_actions=true) at src/gdb/main.c:513 #31 0x000055555626328a in execute_cmdargs (cmdarg_vec=0x7fffffffdaf0, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND, ret=0x7fffffffda3c) at src/gdb/main.c:612 #32 0x0000555556264849 in captured_main_1 (context=0x7fffffffdd40) at src/gdb/main.c:1293 #33 0x0000555556264a7f in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1314 #34 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 #35 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) Again, after we enable stdin, GDB continues with its normal flow of the 'run' command and receives the inferior's exit event, where it would have enabled stdin, if we had not done it prematurely. (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 #1 0x00005555561c3acd in normal_stop () at src/gdb/infrun.c:9432 #2 0x00005555561b5bf1 in fetch_inferior_event () at src/gdb/infrun.c:4700 #3 0x000055555618d6a7 in inferior_event_handler (event_type=INF_REG_EVENT) at src/gdb/inf-loop.c:42 #4 0x000055555620ecdb in handle_target_event (error=0, client_data=0x0) at src/gdb/linux-nat.c:4316 #5 0x0000555556f33035 in handle_file_event (file_ptr=0x5555587024e0, ready_mask=1) at src/gdbsupport/event-loop.cc:573 #6 0x0000555556f3362f in gdb_wait_for_event (block=0) at src/gdbsupport/event-loop.cc:694 #7 0x0000555556f322cd in gdb_do_one_event (mstimeout=-1) at src/gdbsupport/event-loop.cc:217 #8 0x0000555556262df8 in start_event_loop () at src/gdb/main.c:407 #9 0x0000555556262f85 in captured_command_loop () at src/gdb/main.c:471 #10 0x0000555556264a84 in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1324 #11 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 #12 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) The solution implemented by this patch addresses the problem. After applying the patch, the output becomes $ gdb -q -ex "source file.py" -ex "run" --args a.out Reading symbols from /tmp/a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 Python Exception <class 'gdb.error'>: No symbol "a" in current context. [Inferior 1 (process 3984511) exited normally] (gdb) Regression-tested on X86_64 Linux using the default board file (i.e. unix). Co-Authored-By: Oguzhan Karakaya <oguzhan.karakaya@intel.com> Reviewed-By: Guinevere Larsen <blarsen@redhat.com> Approved-By: Tom Tromey <tom@tromey.com>

…ro linux When running test-case gdb.threads/attach-stopped.exp on aarch64-linux, using the manjaro linux distro, I get: ... (gdb) thread apply all bt^M ^M Thread 2 (Thread 0xffff8d8af120 (LWP 278116) "attach-stopped"):^M #0 0x0000ffff8d964864 in clock_nanosleep () from /usr/lib/libc.so.6^M #1 0x0000ffff8d969cac in nanosleep () from /usr/lib/libc.so.6^M #2 0x0000ffff8d969b68 in sleep () from /usr/lib/libc.so.6^M #3 0x0000aaaade370828 in func (arg=0x0) at attach-stopped.c:29^M #4 0x0000ffff8d930aec in ?? () from /usr/lib/libc.so.6^M #5 0x0000ffff8d99a5dc in ?? () from /usr/lib/libc.so.6^M ^M Thread 1 (Thread 0xffff8db62020 (LWP 278111) "attach-stopped"):^M #0 0x0000ffff8d92d2d8 in ?? () from /usr/lib/libc.so.6^M #1 0x0000ffff8d9324b8 in ?? () from /usr/lib/libc.so.6^M #2 0x0000aaaade37086c in main () at attach-stopped.c:45^M (gdb) FAIL: gdb.threads/attach-stopped.exp: threaded: attach2 to stopped bt ... The problem is that the test-case expects to see start_thread: ... gdb_test "thread apply all bt" ".*sleep.*start_thread.*" \ "$threadtype: attach2 to stopped bt" ... but lack of symbols makes that impossible. Fix this by allowing " in ?? () from " as well. Tested on aarch64-linux. PR testsuite/31451 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31451

When running test-case gdb.server/connect-with-no-symbol-file.exp on aarch64-linux (specifically, an opensuse leap 15.5 container on a fedora asahi 39 system), I run into: ... (gdb) detach^M Detaching from program: target:connect-with-no-symbol-file, process 185104^M Ending remote debugging.^M terminate called after throwing an instance of 'gdb_exception_error'^M ... The detailed backtrace of the corefile is: ... (gdb) bt #0 0x0000ffff75504f54 in raise () from /lib64/libpthread.so.0 #1 0x00000000007a86b4 in handle_fatal_signal (sig=6) at gdb/event-top.c:926 #2 <signal handler called> #3 0x0000ffff74b977b4 in raise () from /lib64/libc.so.6 #4 0x0000ffff74b98c18 in abort () from /lib64/libc.so.6 #5 0x0000ffff74ea26f4 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib64/libstdc++.so.6 #6 0x0000ffff74ea011c in ?? () from /usr/lib64/libstdc++.so.6 #7 0x0000ffff74ea0180 in std::terminate() () from /usr/lib64/libstdc++.so.6 #8 0x0000ffff74ea0464 in __cxa_throw () from /usr/lib64/libstdc++.so.6 #9 0x0000000001548870 in throw_it (reason=RETURN_ERROR, error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:203 #10 0x0000000001548920 in throw_verror (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:211 #11 0x0000000001548a00 in throw_error (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed") at gdbsupport/common-exceptions.cc:226 #12 0x0000000000ac8f2c in remote_target::readchar (this=0x233d3d90, timeout=2) at gdb/remote.c:9856 #13 0x0000000000ac9f04 in remote_target::getpkt (this=0x233d3d90, buf=0x233d40a8, forever=false, is_notif=0x0) at gdb/remote.c:10326 #14 0x0000000000acf3d0 in remote_target::remote_hostio_send_command (this=0x233d3d90, command_bytes=13, which_packet=17, remote_errno=0xfffff1a3cf38, attachment=0xfffff1a3ce88, attachment_len=0xfffff1a3ce90) at gdb/remote.c:12567 #15 0x0000000000ad03bc in remote_target::fileio_fstat (this=0x233d3d90, fd=3, st=0xfffff1a3d020, remote_errno=0xfffff1a3cf38) at gdb/remote.c:12979 #16 0x0000000000c39878 in target_fileio_fstat (fd=0, sb=0xfffff1a3d020, target_errno=0xfffff1a3cf38) at gdb/target.c:3315 #17 0x00000000007eee5c in target_fileio_stream::stat (this=0x233d4400, abfd=0x2323fc40, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:467 #18 0x00000000007f012c in <lambda(bfd*, void*, stat*)>::operator()(bfd *, void *, stat *) const (__closure=0x0, abfd=0x2323fc40, stream=0x233d4400, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:955 #19 0x00000000007f015c in <lambda(bfd*, void*, stat*)>::_FUN(bfd *, void *, stat *) () at gdb/gdb_bfd.c:956 #20 0x0000000000f9b838 in opncls_bstat (abfd=0x2323fc40, sb=0xfffff1a3d020) at bfd/opncls.c:665 #21 0x0000000000f90adc in bfd_stat (abfd=0x2323fc40, statbuf=0xfffff1a3d020) at bfd/bfdio.c:431 #22 0x000000000065fe20 in reopen_exec_file () at gdb/corefile.c:52 #23 0x0000000000c3a3e8 in generic_mourn_inferior () at gdb/target.c:3642 #24 0x0000000000abf3f0 in remote_unpush_target (target=0x233d3d90) at gdb/remote.c:6067 #25 0x0000000000aca8b0 in remote_target::mourn_inferior (this=0x233d3d90) at gdb/remote.c:10587 #26 0x0000000000c387cc in target_mourn_inferior ( ptid=<error reading variable: Cannot access memory at address 0x2d310>) at gdb/target.c:2738 #27 0x0000000000abfff0 in remote_target::remote_detach_1 (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6421 #28 0x0000000000ac0094 in remote_target::detach (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6436 #29 0x0000000000c37c3c in target_detach (inf=0x22fce540, from_tty=1) at gdb/target.c:2526 #30 0x0000000000860424 in detach_command (args=0x0, from_tty=1) at gdb/infcmd.c:2817 #31 0x000000000060b594 in do_simple_func (args=0x0, from_tty=1, c=0x231431a0) at gdb/cli/cli-decode.c:94 #32 0x00000000006108c8 in cmd_func (cmd=0x231431a0, args=0x0, from_tty=1) at gdb/cli/cli-decode.c:2741 #33 0x0000000000c65a94 in execute_command (p=0x232e52f6 "", from_tty=1) at gdb/top.c:570 #34 0x00000000007a7d2c in command_handler (command=0x232e52f0 "") at gdb/event-top.c:566 #35 0x00000000007a8290 in command_line_handler (rl=...) at gdb/event-top.c:802 #36 0x0000000000c9092c in tui_command_line_handler (rl=...) at gdb/tui/tui-interp.c:103 #37 0x00000000007a750c in gdb_rl_callback_handler (rl=0x23385330 "detach") at gdb/event-top.c:258 #38 0x0000000000d910f4 in rl_callback_read_char () at readline/readline/callback.c:290 #39 0x00000000007a7338 in gdb_rl_callback_read_char_wrapper_noexcept () at gdb/event-top.c:194 #40 0x00000000007a73f0 in gdb_rl_callback_read_char_wrapper (client_data=0x22fbf640) at gdb/event-top.c:233 #41 0x0000000000cbee1c in stdin_event_handler (error=0, client_data=0x22fbf640) at gdb/ui.c:154 #42 0x000000000154ed60 in handle_file_event (file_ptr=0x232be730, ready_mask=1) at gdbsupport/event-loop.cc:572 #43 0x000000000154f21c in gdb_wait_for_event (block=1) at gdbsupport/event-loop.cc:693 #44 0x000000000154dec4 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:263 #45 0x0000000000910f98 in start_event_loop () at gdb/main.c:400 #46 0x0000000000911130 in captured_command_loop () at gdb/main.c:464 #47 0x0000000000912b5c in captured_main (data=0xfffff1a3db58) at gdb/main.c:1338 #48 0x0000000000912bf4 in gdb_main (args=0xfffff1a3db58) at gdb/main.c:1357 #49 0x00000000004170f4 in main (argc=10, argv=0xfffff1a3dcc8) at gdb/gdb.c:38 (gdb) ... The abort happens because a c++ exception escapes to c code, specifically opncls_bstat in bfd/opncls.c. Compiling with -fexceptions works around this. Fix this by catching the exception just before it escapes, in stat_trampoline and likewise in few similar spot. Add a new template catch_exceptions to do so in a consistent way. Tested on aarch64-linux. Approved-by: Pedro Alves <pedro@palves.net> PR remote/31577 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31577

Similar to the x86_64 testcases, some .s files contain the corresponding CFI directives. This helps in validating the synthesized CFI by running those tests with and without the --scfi=experimental command line option. GAS issues some diagnostics, enabled by default, with --scfi=experimental. The diagnostics have been added with an intent to help user correct inadvertent errors in their hand-written asm. An error is issued when GAS finds that input asm is not amenable to accurate CFI synthesis. The existing scfi-diag-*.s tests in the gas/testsuite/gas/scfi/x86_64 directory test some SCFI diagnostics already: - (#1) "Warning: SCFI: Asymetrical register restore" - (#2) "Error: SCFI: usage of REG_FP as scratch not supported" - (#3) "Error: SCFI: unsupported stack manipulation pattern" - (#4) "Error: untraceable control flow for func 'XXX'" In the newly added aarch64 testsuite, further tests for additional diagnostics have been added: - scfi-diag-1.s in this patch highlights an aarch64-specific diagnostic: (#5) "Warning: SCFI: ignored probable save/restore op with reg offset" Additionally, some testcases are added to showcase the (currently) unsupported patterns, e.g., scfi-unsupported-1.s mov x16, 4384 sub sp, sp, x16 gas/testsuite/: * gas/scfi/README: Update comment to include aarch64. * gas/scfi/aarch64/scfi-aarch64.exp: New file. * gas/scfi/aarch64/ginsn-arith-1.l: New test. * gas/scfi/aarch64/ginsn-arith-1.s: New test. * gas/scfi/aarch64/ginsn-cofi-1.l: New test. * gas/scfi/aarch64/ginsn-cofi-1.s: New test. * gas/scfi/aarch64/ginsn-ldst-1.l: New test. * gas/scfi/aarch64/ginsn-ldst-1.s: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-1.d: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-1.l: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-1.s: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-2.d: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-2.l: New test. * gas/scfi/aarch64/scfi-callee-saved-fp-2.s: New test. * gas/scfi/aarch64/scfi-cb-1.d: New test. * gas/scfi/aarch64/scfi-cb-1.l: New test. * gas/scfi/aarch64/scfi-cb-1.s: New test. * gas/scfi/aarch64/scfi-cfg-1.d: New test. * gas/scfi/aarch64/scfi-cfg-1.l: New test. * gas/scfi/aarch64/scfi-cfg-1.s: New test. * gas/scfi/aarch64/scfi-cfg-2.d: New test. * gas/scfi/aarch64/scfi-cfg-2.l: New test. * gas/scfi/aarch64/scfi-cfg-2.s: New test. * gas/scfi/aarch64/scfi-cfg-3.d: New test. * gas/scfi/aarch64/scfi-cfg-3.l: New test. * gas/scfi/aarch64/scfi-cfg-3.s: New test. * gas/scfi/aarch64/scfi-cfg-4.l: New test. * gas/scfi/aarch64/scfi-cfg-4.s: New test. * gas/scfi/aarch64/scfi-cond-br-1.d: New test. * gas/scfi/aarch64/scfi-cond-br-1.l: New test. * gas/scfi/aarch64/scfi-cond-br-1.s: New test. * gas/scfi/aarch64/scfi-diag-1.l: New test. * gas/scfi/aarch64/scfi-diag-1.s: New test. * gas/scfi/aarch64/scfi-diag-2.l: New test. * gas/scfi/aarch64/scfi-diag-2.s: New test. * gas/scfi/aarch64/scfi-diag-3.l: New test. * gas/scfi/aarch64/scfi-diag-3.s: New test. * gas/scfi/aarch64/scfi-ldrp-1.d: New test. * gas/scfi/aarch64/scfi-ldrp-1.l: New test. * gas/scfi/aarch64/scfi-ldrp-1.s: New test. * gas/scfi/aarch64/scfi-ldrp-2.d: New test. * gas/scfi/aarch64/scfi-ldrp-2.l: New test. * gas/scfi/aarch64/scfi-ldrp-2.s: New test. * gas/scfi/aarch64/scfi-ldstnap-1.d: New test. * gas/scfi/aarch64/scfi-ldstnap-1.l: New test. * gas/scfi/aarch64/scfi-ldstnap-1.s: New test. * gas/scfi/aarch64/scfi-strp-1.d: New test. * gas/scfi/aarch64/scfi-strp-1.l: New test. * gas/scfi/aarch64/scfi-strp-1.s: New test. * gas/scfi/aarch64/scfi-strp-2.d: New test. * gas/scfi/aarch64/scfi-strp-2.l: New test. * gas/scfi/aarch64/scfi-strp-2.s: New test. * gas/scfi/aarch64/scfi-unsupported-1.l: New test. * gas/scfi/aarch64/scfi-unsupported-1.s: New test. * gas/scfi/aarch64/scfi-unsupported-2.l: New test. * gas/scfi/aarch64/scfi-unsupported-2.s: New test.

Since commit b1da98a ("gdb: remove use of alloca in new_macro_definition"), if cached_argv is empty, we call macro_bcache with a nullptr data. This ends up caught by UBSan deep down in the bcache code: $ ./gdb -nx -q --data-directory=data-directory /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/macscp/macscp -readnow Reading symbols from /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/macscp/macscp... Expanding full symbols from /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/macscp/macscp... /home/smarchi/src/binutils-gdb/gdb/bcache.c:195:12: runtime error: null pointer passed as argument 2, which is declared to never be null The backtrace: #1 0x00007ffff619a05d in __ubsan::__ubsan_handle_nonnull_arg_abort (Data=<optimized out>) at ../../../../src/libsanitizer/ubsan/ubsan_handlers.cpp:750 #2 0x000055556337fba2 in gdb::bcache::insert (this=0x62d0000c8458, addr=0x0, length=0, added=0x0) at /home/smarchi/src/binutils-gdb/gdb/bcache.c:195 #3 0x0000555564b49222 in gdb::bcache::insert<char const*, void> (this=0x62d0000c8458, addr=0x0, length=0, added=0x0) at /home/smarchi/src/binutils-gdb/gdb/bcache.h:158 #4 0x0000555564b481fa in macro_bcache<char const*> (t=0x62100007ae70, addr=0x0, len=0) at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:117 #5 0x0000555564b42b4a in new_macro_definition (t=0x62100007ae70, kind=macro_function_like, special_kind=macro_ordinary, argv=std::__debug::vector of length 0, capacity 0, replacement=0x62a00003af3a "__builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:573 #6 0x0000555564b44674 in macro_define_internal (source=0x6210000ab9e0, line=469, name=0x7fffffffa710 "__va_arg_pack", kind=macro_function_like, special_kind=macro_ordinary, argv=std::__debug::vector of length 0, capacity 0, replacement=0x62a00003af3a "__builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:777 #7 0x0000555564b44ae2 in macro_define_function (source=0x6210000ab9e0, line=469, name=0x7fffffffa710 "__va_arg_pack", argv=std::__debug::vector of length 0, capacity 0, replacement=0x62a00003af3a "__builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/macrotab.c:816 #8 0x0000555563f62fc8 in parse_macro_definition (file=0x6210000ab9e0, line=469, body=0x62a00003af2a "__va_arg_pack() __builtin_va_arg_pack ()") at /home/smarchi/src/binutils-gdb/gdb/dwarf2/macro.c:203 This can be reproduced by running gdb.base/macscp.exp. Avoid calling macro_bcache if the macro doesn't have any arguments. Change-Id: I33b5a7c3b3a93d5adba98983fcaae9c8522c383d

The commit: commit c6b4867 Date: Thu Mar 30 19:21:22 2023 +0100 gdb: parse pending breakpoint thread/task immediately Introduce a use bug where the value of a temporary variable was being used after it had gone out of scope. This was picked up by the address sanitizer and would result in this error: (gdb) maintenance selftest create_breakpoint_parse_arg_string Running selftest create_breakpoint_parse_arg_string. ================================================================= ==2265825==ERROR: AddressSanitizer: stack-use-after-scope on address 0x7fbb08046511 at pc 0x000001632230 bp 0x7fff7c2fb770 sp 0x7fff7c2fb768 READ of size 1 at 0x7fbb08046511 thread T0 #0 0x163222f in create_breakpoint_parse_arg_string(char const*, std::unique_ptr<char, gdb::xfree_deleter<char> >*, int*, int*, int*, std::unique_ptr<char, gdb::xfree_deleter<char> >*, bool*) ../../src/gdb/break-cond-parse.c:496 #1 0x1633026 in test ../../src/gdb/break-cond-parse.c:582 #2 0x163391b in create_breakpoint_parse_arg_string_tests ../../src/gdb/break-cond-parse.c:649 #3 0x12cfebc in void std::__invoke_impl<void, void (*&)()>(std::__invoke_other, void (*&)()) /usr/include/c++/13/bits/invoke.h:61 #4 0x12cc8ee in std::enable_if<is_invocable_r_v<void, void (*&)()>, void>::type std::__invoke_r<void, void (*&)()>(void (*&)()) /usr/include/c++/13/bits/invoke.h:111 #5 0x12c81e5 in std::_Function_handler<void (), void (*)()>::_M_invoke(std::_Any_data const&) /usr/include/c++/13/bits/std_function.h:290 #6 0x18bb51d in std::function<void ()>::operator()() const /usr/include/c++/13/bits/std_function.h:591 #7 0x4193ef9 in selftests::run_tests(gdb::array_view<char const* const>, bool) ../../src/gdbsupport/selftest.cc:100 #8 0x21c2206 in maintenance_selftest ../../src/gdb/maint.c:1172 ... etc ... The problem was caused by three lines like this one: thread_info *thr = parse_thread_id (std::string (t.get_value ()).c_str (), &tmptok); After parsing the thread-id TMPTOK would be left pointing into the temporary string which had been created on this line. When on the next line we did this: gdb_assert (*tmptok == '\0'); The value of *TMPTOK is undefined. Fix this by creating the std::string earlier in the scope. Now the contents of the string will remain valid when we check *TMPTOK. The address sanitizer issue is now resolved.

The binary provided with bug 32165 [1] has 36139 ELF sections. GDB crashes on it with (note that my GDB is build with -D_GLIBCXX_DEBUG=1: $ ./gdb -nx -q --data-directory=data-directory ./vmlinux Reading symbols from ./vmlinux... (No debugging symbols found in ./vmlinux) (gdb) info func /usr/include/c++/14.2.1/debug/vector:508: In function: std::debug::vector<_Tp, _Allocator>::reference std::debug::vector<_Tp, _Allocator>::operator[](size_type) [with _Tp = long unsigned int; _Allocator = std::allocator<long unsigned int>; reference = long unsigned int&; size_type = long unsigned int] Error: attempt to subscript container with out-of-bounds index -29445, but container only holds 36110 elements. Objects involved in the operation: sequence "this" @ 0x514000007340 { type = std::debug::vector<unsigned long, std::allocator<unsigned long> >; } The crash occurs here: #3 0x00007ffff5e334c3 in __GI_abort () at abort.c:79 #4 0x00007ffff689afc4 in __gnu_debug::_Error_formatter::_M_error (this=<optimized out>) at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/debug.cc:1320 #5 0x0000555561119a16 in std::__debug::vector<unsigned long, std::allocator<unsigned long> >::operator[] (this=0x514000007340, __n=18446744073709522171) at /usr/include/c++/14.2.1/debug/vector:508 #6 0x0000555562e288e8 in minimal_symbol::value_address (this=0x5190000bb698, objfile=0x514000007240) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:517 #7 0x0000555562e5a131 in global_symbol_searcher::expand_symtabs (this=0x7ffff0f5c340, objfile=0x514000007240, preg=std::optional [no contained value]) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:4983 #8 0x0000555562e5d2ed in global_symbol_searcher::search (this=0x7ffff0f5c340) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:5189 #9 0x0000555562e5ffa4 in symtab_symbol_info (quiet=false, exclude_minsyms=false, regexp=0x0, kind=FUNCTION_DOMAIN, t_regexp=0x0, from_tty=1) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:5361 #10 0x0000555562e6131b in info_functions_command (args=0x0, from_tty=1) at /home/smarchi/src/binutils-gdb/gdb/symtab.c:5525 That is, at this line of `minimal_symbol::value_address`, where `objfile->section_offsets` is an `std::vector`: return (CORE_ADDR (this->unrelocated_address ()) + objfile->section_offsets[this->section_index ()]); A section index of -29445 is suspicious. The minimal_symbol at play here is: (top-gdb) p m_name $1 = 0x521001de10af "_sinittext" So I restarted debugging, breaking on: (top-gdb) b general_symbol_info::set_section_index if $_streq("_sinittext", m_name) And I see that weird -29445 value: (top-gdb) frame #0 general_symbol_info::set_section_index (this=0x525000082390, idx=-29445) at /home/smarchi/src/binutils-gdb/gdb/symtab.h:611 611 { m_section = idx; } But going up one frame, the section index is 36091: (top-gdb) frame #1 0x0000555562426526 in minimal_symbol_reader::record_full (this=0x7ffff0ead560, name="_sinittext", copy_name=false, address=-2111475712, ms_type=mst_text, section=36091) at /home/smarchi/src/binutils-gdb/gdb/minsyms.c:1228 1228 msymbol->set_section_index (section); It seems like the problem is just that the type used for the section index (short) is not big enough. Change from short to int. If somebody insists, we could even go long long / int64_t, but I doubt it's necessary. With that fixed, I get: (gdb) info func All defined functions: Non-debugging symbols: 0xffffffff81000000 _stext 0xffffffff82257000 _sinittext 0xffffffff822b4ebb _einittext [1] https://sourceware.org/bugzilla/show_bug.cgi?id=32165 Change-Id: Icb1c3de9474ff5adef7e0bbbf5e0b67b279dee04 Reviewed-By: Tom de Vries <tdevries@suse.de> Reviewed-by: Keith Seitz <keiths@redhat.com>

When building gdb with gcc 12 and -fsanitize=threads while renabling background dwarf reading by setting dwarf_synchronous to false, I run into: ... (gdb) file amd64-watchpoint-downgrade Reading symbols from amd64-watchpoint-downgrade... (gdb) watch global_var ================== WARNING: ThreadSanitizer: data race (pid=20124) Read of size 8 at 0x7b80000500d8 by main thread: #0 cooked_index_entry::full_name(obstack*, bool) const cooked-index.c:220 #1 cooked_index::get_main_name(obstack*, language*) const cooked-index.c:735 #2 cooked_index_worker::wait(cooked_state, bool) cooked-index.c:559 #3 cooked_index::wait(cooked_state, bool) cooked-index.c:631 #4 cooked_index_functions::wait(objfile*, bool) cooked-index.h:729 #5 cooked_index_functions::compute_main_name(objfile*) cooked-index.h:806 #6 objfile::compute_main_name() symfile-debug.c:461 #7 find_main_name symtab.c:6503 #8 main_language() symtab.c:6608 #9 set_initial_language_callback symfile.c:1634 #10 get_current_language() language.c:96 ... Previous write of size 8 at 0x7b80000500d8 by thread T1: #0 cooked_index_shard::finalize(parent_map_map const*) \ dwarf2/cooked-index.c:409 #1 operator() cooked-index.c:663 ... ... SUMMARY: ThreadSanitizer: data race cooked-index.c:220 in \ cooked_index_entry::full_name(obstack*, bool) const ================== Hardware watchpoint 1: global_var (gdb) PASS: gdb.arch/amd64-watchpoint-downgrade.exp: watch global_var ... This was also reported in PR31715. This is due do gcc PR110799 [1], generating wrong code with -fhoist-adjacent-loads, and causing a false positive for -fsanitize=threads. Work around the gcc PR by forcing -fno-hoist-adjacent-loads for gcc <= 13 and -fsanitize=threads. Tested in that same configuration on x86_64-linux. Remaining ThreadSanitizer problems are the ones reported in PR31626 (gdb.rust/dwindex.exp) and PR32247 (gdb.trace/basic-libipa.exp). PR gdb/31715 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31715 Tested-By: Bernd Edlinger <bernd.edlinger@hotmail.de> Approved-By: Tom Tromey <tom@tromey.com> [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110799

When calling a function with double arguments, I get this asan error: ==7920==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x0053131ece38 at pc 0x7ff79697a68f bp 0x0053131ec790 sp 0x0053131ebf40 READ of size 16 at 0x0053131ece38 thread T0 #0 0x7ff79697a68e in MemcmpInterceptorCommon(void*, int (*)(void const*, void const*, unsigned long long), void const*, void const*, unsigned long long) C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:814 #1 0x7ff79697aebd in memcmp C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:845 #2 0x7ff79697aebd in memcmp C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:840 #3 0x7ff7927e237f in regcache::raw_write(int, gdb::array_view<unsigned char const>) C:/gdb/src/gdb.git/gdb/regcache.c:874 #4 0x7ff7927e3c85 in regcache::cooked_write(int, gdb::array_view<unsigned char const>) C:/gdb/src/gdb.git/gdb/regcache.c:914 #5 0x7ff7927e5d89 in regcache::cooked_write(int, unsigned char const*) C:/gdb/src/gdb.git/gdb/regcache.c:933 #6 0x7ff7911d5965 in amd64_windows_store_arg_in_reg C:/gdb/src/gdb.git/gdb/amd64-windows-tdep.c:216 Address 0x0053131ece38 is located in stack of thread T0 at offset 40 in frame #0 0x7ff7911d565f in amd64_windows_store_arg_in_reg C:/gdb/src/gdb.git/gdb/amd64-windows-tdep.c:208 This frame has 4 object(s): [32, 40) 'buf' (line 211) <== Memory access at offset 40 overflows this variable It's because the first 4 double arguments are passed via XMM registers, and they need a buffer of 16 bytes, even if we only use 8 bytes of them. Approved-By: Tom Tromey <tom@tromey.com>

On Windows gcore is not implemented, and if you try it, you get an heap-use-after-free error: (gdb) gcore C:/gdb/build64/gdb-git-python3/gdb/testsuite/outputs/gdb.base/gcore-buffer-overflow/gcore-buffer-overflow.test warning: cannot close "================================================================= ==10108==ERROR: AddressSanitizer: heap-use-after-free on address 0x1259ea503110 at pc 0x7ff6806e3936 bp 0x0062e01ed990 sp 0x0062e01ed140 READ of size 111 at 0x1259ea503110 thread T0 #0 0x7ff6806e3935 in strlen C:/gcc/src/gcc-14.2.0/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:391 #1 0x7ff6807169c4 in __pformat_puts C:/gcc/src/mingw-w64-v12.0.0/mingw-w64-crt/stdio/mingw_pformat.c:558 #2 0x7ff6807186c1 in __mingw_pformat C:/gcc/src/mingw-w64-v12.0.0/mingw-w64-crt/stdio/mingw_pformat.c:2514 #3 0x7ff680713614 in __mingw_vsnprintf C:/gcc/src/mingw-w64-v12.0.0/mingw-w64-crt/stdio/mingw_vsnprintf.c:41 #4 0x7ff67f34419f in vsnprintf(char*, unsigned long long, char const*, char*) C:/msys64/mingw64/x86_64-w64-mingw32/include/stdio.h:484 #5 0x7ff67f34419f in string_vprintf[abi:cxx11](char const*, char*) C:/gdb/src/gdb.git/gdbsupport/common-utils.cc:106 #6 0x7ff67b37b739 in cli_ui_out::do_message(ui_file_style const&, char const*, char*) C:/gdb/src/gdb.git/gdb/cli-out.c:227 #7 0x7ff67ce3d030 in ui_out::call_do_message(ui_file_style const&, char const*, ...) C:/gdb/src/gdb.git/gdb/ui-out.c:571 #8 0x7ff67ce4255a in ui_out::vmessage(ui_file_style const&, char const*, char*) C:/gdb/src/gdb.git/gdb/ui-out.c:740 #9 0x7ff67ce2c873 in ui_file::vprintf(char const*, char*) C:/gdb/src/gdb.git/gdb/ui-file.c:73 #10 0x7ff67ce7f83d in gdb_vprintf(ui_file*, char const*, char*) C:/gdb/src/gdb.git/gdb/utils.c:1881 #11 0x7ff67ce7f83d in vwarning(char const*, char*) C:/gdb/src/gdb.git/gdb/utils.c:181 #12 0x7ff67f3530eb in warning(char const*, ...) C:/gdb/src/gdb.git/gdbsupport/errors.cc:33 #13 0x7ff67baed27f in gdb_bfd_close_warning C:/gdb/src/gdb.git/gdb/gdb_bfd.c:437 #14 0x7ff67baed27f in gdb_bfd_close_or_warn C:/gdb/src/gdb.git/gdb/gdb_bfd.c:646 #15 0x7ff67baed27f in gdb_bfd_unref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.c:739 #16 0x7ff68094b6f2 in gdb_bfd_ref_policy::decref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.h:82 #17 0x7ff68094b6f2 in gdb::ref_ptr<bfd, gdb_bfd_ref_policy>::~ref_ptr() C:/gdb/src/gdb.git/gdbsupport/gdb_ref_ptr.h:91 #18 0x7ff67badf4d2 in gcore_command C:/gdb/src/gdb.git/gdb/gcore.c:176 0x1259ea503110 is located 16 bytes inside of 4064-byte region [0x1259ea503100,0x1259ea5040e0) freed by thread T0 here: #0 0x7ff6806b1687 in free C:/gcc/src/gcc-14.2.0/libsanitizer/asan/asan_malloc_win.cpp:90 #1 0x7ff67f2ae807 in objalloc_free C:/gdb/src/gdb.git/libiberty/objalloc.c:187 #2 0x7ff67d7f56e3 in _bfd_free_cached_info C:/gdb/src/gdb.git/bfd/opncls.c:247 #3 0x7ff67d7f2782 in _bfd_delete_bfd C:/gdb/src/gdb.git/bfd/opncls.c:180 #4 0x7ff67d7f5df9 in bfd_close_all_done C:/gdb/src/gdb.git/bfd/opncls.c:960 #5 0x7ff67d7f62ec in bfd_close C:/gdb/src/gdb.git/bfd/opncls.c:925 #6 0x7ff67baecd27 in gdb_bfd_close_or_warn C:/gdb/src/gdb.git/gdb/gdb_bfd.c:643 #7 0x7ff67baecd27 in gdb_bfd_unref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.c:739 #8 0x7ff68094b6f2 in gdb_bfd_ref_policy::decref(bfd*) C:/gdb/src/gdb.git/gdb/gdb_bfd.h:82 #9 0x7ff68094b6f2 in gdb::ref_ptr<bfd, gdb_bfd_ref_policy>::~ref_ptr() C:/gdb/src/gdb.git/gdbsupport/gdb_ref_ptr.h:91 #10 0x7ff67badf4d2 in gcore_command C:/gdb/src/gdb.git/gdb/gcore.c:176 It happens because gdb_bfd_close_or_warn uses a bfd-internal name for the failing-close warning, after the close is finished, and the name already freed: static int gdb_bfd_close_or_warn (struct bfd *abfd) { int ret; const char *name = bfd_get_filename (abfd); for (asection *sect : gdb_bfd_sections (abfd)) free_one_bfd_section (sect); ret = bfd_close (abfd); if (!ret) gdb_bfd_close_warning (name, bfd_errmsg (bfd_get_error ())); return ret; } Fixed by making a copy of the name for the warning. Approved-By: Andrew Burgess <aburgess@redhat.com>

This commit adds support for a `gstack' command which Fedora has been carrying for many years. gstack is a natural counterpart to the gcore command. Whereas gcore dumps a core file, gstack prints stack traces of a running process. There are many improvements over Fedora's version of this script. The dependency on procfs is gone; gstack will run anywhere gdb runs. The only runtime dependencies are bash and awk. The script includes suggestions from gdb/32325 to include versioning and help. [If this approach to gdb/32325 is acceptable, I could propagate the solution to gcore/gdb-add-index.] I've rewritten the documentation, integrating it into the User Manual. The manpage is now output using this one source. Example run (on x86_64 Fedora 40) $ gstack --help Usage: gstack [-h|--help] [-v|--version] PID Print a stack trace of a running program -h, --help Print this message then exit. -v, --version Print version information then exit. $ gstack -v GNU gstack (GDB) 16.0.50.20241119-git $ gstack 12345678 Process 12345678 not found. $ gstack $(pidof emacs) Thread 6 (Thread 0x7fd5ec1c06c0 (LWP 2491423) "pool-spawner"): #0 0x00007fd6015ca3dd in syscall () at /lib64/libc.so.6 #1 0x00007fd60b31eccd in g_cond_wait () at /lib64/libglib-2.0.so.0 #2 0x00007fd60b28a61b in g_async_queue_pop_intern_unlocked () at /lib64/libglib-2.0.so.0 #3 0x00007fd60b2f1a03 in g_thread_pool_spawn_thread () at /lib64/libglib-2.0.so.0 #4 0x00007fd60b2f0813 in g_thread_proxy () at /lib64/libglib-2.0.so.0 #5 0x00007fd6015486d7 in start_thread () at /lib64/libc.so.6 #6 0x00007fd6015cc60c in clone3 () at /lib64/libc.so.6 #7 0x0000000000000000 in ??? () Thread 5 (Thread 0x7fd5eb9bf6c0 (LWP 2491424) "gmain"): #0 0x00007fd6015be87d in poll () at /lib64/libc.so.6 #1 0x0000000000000001 in ??? () #2 0xffffffff00000001 in ??? () #3 0x0000000000000001 in ??? () #4 0x000000002104cfd0 in ??? () #5 0x00007fd5eb9be320 in ??? () #6 0x00007fd60b321c34 in g_main_context_iterate_unlocked.isra () at /lib64/libglib-2.0.so.0 Thread 4 (Thread 0x7fd5eb1be6c0 (LWP 2491425) "gdbus"): #0 0x00007fd6015be87d in poll () at /lib64/libc.so.6 #1 0x0000000020f9b558 in ??? () #2 0xffffffff00000003 in ??? () #3 0x0000000000000003 in ??? () #4 0x00007fd5d8000b90 in ??? () #5 0x00007fd5eb1bd320 in ??? () #6 0x00007fd60b321c34 in g_main_context_iterate_unlocked.isra () at /lib64/libglib-2.0.so.0 Thread 3 (Thread 0x7fd5ea9bd6c0 (LWP 2491426) "emacs"): #0 0x00007fd6015ca3dd in syscall () at /lib64/libc.so.6 #1 0x00007fd60b31eccd in g_cond_wait () at /lib64/libglib-2.0.so.0 #2 0x00007fd60b28a61b in g_async_queue_pop_intern_unlocked () at /lib64/libglib-2.0.so.0 #3 0x00007fd60b28a67c in g_async_queue_pop () at /lib64/libglib-2.0.so.0 #4 0x00007fd603f4d0d9 in fc_thread_func () at /lib64/libpangoft2-1.0.so.0 #5 0x00007fd60b2f0813 in g_thread_proxy () at /lib64/libglib-2.0.so.0 #6 0x00007fd6015486d7 in start_thread () at /lib64/libc.so.6 #7 0x00007fd6015cc60c in clone3 () at /lib64/libc.so.6 #8 0x0000000000000000 in ??? () Thread 2 (Thread 0x7fd5e9e6d6c0 (LWP 2491427) "dconf worker"): #0 0x00007fd6015be87d in poll () at /lib64/libc.so.6 #1 0x0000000000000001 in ??? () #2 0xffffffff00000001 in ??? () #3 0x0000000000000001 in ??? () #4 0x00007fd5cc000b90 in ??? () #5 0x00007fd5e9e6c320 in ??? () #6 0x00007fd60b321c34 in g_main_context_iterate_unlocked.isra () at /lib64/libglib-2.0.so.0 Thread 1 (Thread 0x7fd5fcc45280 (LWP 2491417) "emacs"): #0 0x00007fd6015c9197 in pselect () at /lib64/libc.so.6 #1 0x0000000000000000 in ??? () Since this is essentially a complete rewrite of the original script and documentation, I've chosen to only keep a 2024 copyright date. Reviewed-By: Eli Zaretskii <eliz@gnu.org> Approved-By: Tom Tromey <tom@tromey.com>

Recent work in the TUI has improved GDB's use of the curses wnoutrefresh and doupdate mechanism, which improves performance by batching together updates and then doing a single set of writes to the screen when doupdate is finally called. The tui_batch_rendering type is a RAII class which, in its destructor, calls doupdate to send the batched updates to the screen. However, if there is no tui_batch_rendering active on the call stack then any wnoutrefresh calls will remain batched but undisplayed until the next time doupdate happens to be called. This problem can be seen in PR gdb/32623. When an inferior is started the 'Starting program' message is not immediately displayed to the user. The 'Starting program' message originates from run_command_1 in infcmd.c, the message is sent to the current_uiout, which will be the TUI ui_out. After the message is sent, ui_out::flush() is called, here's the backtrace when that happens: #0 tui_file::flush (this=0x36e4ab0) at ../../src/gdb/tui/tui-file.c:42 #1 0x0000000001004f4b in pager_file::flush (this=0x36d35f0) at ../../src/gdb/utils.c:1531 #2 0x0000000001004f71 in gdb_flush (stream=0x36d35f0) at ../../src/gdb/utils.c:1539 #3 0x00000000006975ab in cli_ui_out::do_flush (this=0x35a50b0) at ../../src/gdb/cli-out.c:250 #4 0x00000000009fd1f9 in ui_out::flush (this=0x35a50b0) at ../../src/gdb/ui-out.h:263 #5 0x00000000009f56ad in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at ../../src/gdb/infcmd.c:449 #6 0x00000000009f599a in run_command (args=0x0, from_tty=1) at ../../src/gdb/infcmd.c:511 And if we check out tui_file::flush (tui-file.c) we can see that this just calls tui_win_info::refresh_window(), which in turn, just uses wnoutrefresh to batch any pending output. The problem is that, in the above backtrace, there is no tui_batch_rendering active, and so there will be no doupdate call to flush the output to the screen. We could add a tui_batch_rendering into tui_file::flush. And tui_file::write. And tui_file::puts ..... ... but that all seems a bit unnecessary. Instead, I propose that tui_win_info::refresh_window() should be changed. If suppress_output is true (i.e. a tui_batch_rendering is active) then we should continue to call wnoutrefresh(). But if suppress_output is false, meaning that no tui_batch_rendering is in place, then we should call wrefresh(), which immediately writes the output to the screen. Testing but PR gdb/32623 was a little involved. We need to 'run' the inferior and check for the 'Starting program' message. But DejaGNUU can only check for the message once it knows the message should have appeared. But, as the bug is that output is not displayed, we don't have any output hints that the inferior is started yet... In the end, I have the inferior create a file in the test's output directory. Now DejaGNU can send the 'run' command, and wait for the file to appear. Once that happens, we know that the 'Starting program' message should have appeared. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32623 Approved-By: Tom Tromey <tom@tromey.com>

When building with gcc, with flags -gdwarf-5, -gsplit-dwarf and -fdebug-types-section, the resulting .dwo files contain multiple .debug_info.dwo sections. One for each type unit and one for the compile unit. This is correct, as per DWARF 5, section F.2.3 ("Contents of the Split DWARF Object Files"): The split DWARF object files each contain the following sections: ... .debug_info.dwo (for the compilation unit) .debug_info.dwo (one COMDAT section for each type unit) ... GDB currently assumes that there is a single .debug_info.dwo section, causing unpredictable behavior. For example, sometimes this crash: ==81781==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x508000007a71 at pc 0x58704d32a59c bp 0x7ffc0acc0bb0 sp 0x7ffc0acc0ba0 READ of size 1 at 0x508000007a71 thread T0 #0 0x58704d32a59b in bfd_getl32 /home/smarchi/src/binutils-gdb/bfd/libbfd.c:846 #1 0x58704ae62dce in read_initial_length(bfd*, unsigned char const*, unsigned int*, bool) /home/smarchi/src/binutils-gdb/gdb/dwarf2/leb.c:92 #2 0x58704aaf76bf in read_comp_unit_head(comp_unit_head*, unsigned char const*, dwarf2_section_info*, rcuh_kind) /home/smarchi/src/binutils-gdb/gdb/dwarf2/comp-unit-head.c:47 #3 0x58704aaf8f97 in read_and_check_comp_unit_head(dwarf2_per_objfile*, comp_unit_head*, dwarf2_section_info*, dwarf2_section_info*, unsigned char const*, rcuh_kind) /home/smarchi/src/binutils-gdb/gdb/dwarf2/comp-unit-head.c:193 #4 0x58704b022908 in create_dwo_unit_hash_tables /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:6233 #5 0x58704b0334a5 in open_and_init_dwo_file /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:7588 #6 0x58704b03965a in lookup_dwo_cutu /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:7935 #7 0x58704b03a5b1 in lookup_dwo_comp_unit /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:8009 #8 0x58704aff5b70 in lookup_dwo_unit /home/smarchi/src/binutils-gdb/gdb/dwarf2/read.c:2802 The first time that locate_dwo_sections gets called for a .debug_info.dwo section, dwo_sections::info gets initialized properly. The second time it gets called for a .debug_info.dwo section, the size field in dwo_sections::info gets overwritten with the size of the second section. But the buffer remains pointing to the contents of the first section, because the section is already "read in". So the size does not match the buffer. And even if it did, we would only keep the information about one .debug_info.dwo, out of the many. First, add an assert in locate_dwo_sections to make sure we don't try to fill in a dwo section info twice. Add the assert to other functions with the same pattern, while at it. Then, change dwo_sections::info to be a vector of sections (just like we do for type sections). Update locate_dwo_sections to append to that vector when seeing a new .debug_info.dwo section. Update open_and_init_dwo_file to read the units from each section. The problem can be observed by running some tests with the dwarf5-fission-debug-types target board. For example, gdb.base/condbreak.exp crashes (with the ASan failure shown above) before the patch and passes after). [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119766 (cherry-picked from commit 28f15782adab4e8f984c065e0c793c716dd942f2) Change-Id: Iedf275768b6057dee4b1542396714f3d89903cf3 Reviewed-By: Tom de Vries <tdevries@suse.de>

It is possible for a memory:// code object to be corrupted by some rogue pointers or some such, since it is all in memory. One likely reason for corruption is that the program reuses the memory where the code object's image is stored. GDB creates a snapshot of code objects when it first sees them, to try to work around such programs, but that doesn't help the attach case. Usually, when you attach to an already-running process that has code object images with corrupted ELF headers, you see something like: Error while mapping shared library sections: `memory://118381#offset=0x7d7613311f70&size=29000': not in executable format: file format not recognized We observed a case of such corruption crashing GDB, though. When it happened, the ELF's header was broken such that the e_shoff field pointed outside the bounds of the ELF file (among other broken fields). E.g.: (top-gdb) p pathname $1 = 0x55ec11cff0a0 "memory://44039#offset=0x7da2e363b720&size=16600" And in elfcode.h:elf_object_p: (top-gdb) p /x *i_ehdrp $2 = {e_ident = {0x7f, 0x45, 0x4c, 0x46, 0x2, 0x1, 0x1, 0x40, 0xa5, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, e_entry = 0x7da26c862090, e_phoff = 0x5, e_shoff = 0x7da2e3351fe0, e_version = 0x7f82, e_flags = 0xe3335f80, e_type = 0xe620, e_machine = 0x6b8, e_ehsize = 0x7da2, e_phentsize = 0x0, e_phnum = 0xd, e_shentsize = 0x0, e_shnum = 0x0, e_shs trndx = 0x0} (top-gdb) Here's the crashing backtrace: Thread 1 "rocgdb" received signal SIGSEGV, Segmentation fault. __memmove_avx512_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:317 317 ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: No such file or directory. (top-gdb) bt #0 __memmove_avx512_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:317 #1 0x000055ebbb1151cd in memcpy (__len=64, __src=<optimized out>, __dest=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/string_fortified.h:29 #2 (anonymous namespace)::rocm_code_object_stream_memory::read (this=<optimized out>, buf=<optimized out>, size=64, offset=<optimized out>) at src/ROCgdb/gdb/solib-rocm.c:443 #3 0x000055ebbaf61f34 in operator() (__closure=<optimized out>) at src/ROCgdb/gdb/gdb_bfd.c:963 #4 catch_exceptions<long int, -1, gdb_bfd_openr_iovec(char const*, char const*, gdb_iovec_opener_ftype)::<lambda(bfd*, void*, void*, file_ptr, file_ptr)>::<lambda()> > (f=...) at src/ROCgdb/gdb/event-top.h:96 #5 operator() (__closure=0x0, offset=<optimized out>, nbytes=<optimized out>, buf=<optimized out>, stream=<optimized out>, nbfd=<optimized out>) at src/ROCgdb/gdb/gdb_bfd.c:961 #6 _FUN () at src/ROCgdb/gdb/gdb_bfd.c:971 #7 0x000055ebbb2793f9 in opncls_bread (abfd=<optimized out>, buf=<optimized out>, nbytes=<optimized out>) at src/ROCgdb/bfd/opncls.c:644 #8 0x000055ebbb2727ef in bfd_read (ptr=ptr@entry=0x7ffe98d43d50, size=size@entry=64, abfd=<optimized out>, abfd@entry=0x55ec11d04fb0) at src/ROCgdb/bfd/bfdio.c:369 #9 0x000055ebbb2934e7 in bfd_elf64_object_p (abfd=0x55ec11d04fb0) at src/ROCgdb/bfd/elfcode.h:645 #10 0x000055ebbb276d34 in bfd_check_format_matches (abfd=0x55ec11d04fb0, format=<optimized out>, matching=<optimized out>) at src/ROCgdb/bfd/format.c:510 #11 0x000055ebbb115252 in rocm_solib_bfd_open (pathname=0x55ec11cff0a0 "memory://44039#offset=0x7da2e363b720&size=16600") at src/ROCgdb/gdb/solib-rocm.c:617 #12 0x000055ebbb122a36 in solib_map_sections (so=...) at src/ROCgdb/gdb/solib.c:548 ... Dumping that particularly broken memory ELF to a file and then loading that file back into GDB (with add-symbol-file to trigger the same code paths), GDB rejects it without crashing. That is because there's a bfd_seek call to e_shoff (to 0x7da2e3351fe0 in that example) that turns into an lseek call on a real file, which fails. Here, in bfd/elfcode.h:elf_object_p: /* Seek to the section header table in the file. */ if (bfd_seek (abfd, where, SEEK_SET) != 0) goto got_no_match; <<<<<<<<<<<<<< we hit this When the ELF is in memory, that bfd_seek call always succeeds, as it just manipulates the BFD's 'where' offset. We then reach the bfd_read call just after: /* Read the first section header at index 0, and convert to internal form. */ if (bfd_read (&x_shdr, sizeof x_shdr, abfd) != sizeof (x_shdr)) goto got_no_match; which takes us to rocm_code_object_stream_memory::read [*]. This function assumes the 'offset' argument is within bounds of the m_objfile_image buffer, which it isn't, and thus we crash in the memcpy call. [*] - This method is slighly misnamed IMHO. The BFD side calls the callback 'pread', which is more accurate, as this has an explicit offset argument. Fix it by making rocm_code_object_stream_memory::read bounds check its 'offset' argument. The 'size' parameter is also signed, but if we look up the call stack before we get to rocm_code_object_stream_memory::read, it is unsigned there: bfd_size_type bfd_read (void *ptr, bfd_size_type size, bfd *abfd); IMHO, the abfd->iovec->bread interface should take an unsigned size too, modelling 'pread', but I'm not changing bfd in this patch. So for now, also error out if we see a negative size request, as we'd behave incorrectly if we saw one. Tweak the existing gdb.rocm/snapshot-objfile-on-load.exp testcase to exercise this scenario too, by: - Adding a new command line option to tell the test program how to scramble module image memory. - Adding a new "shoff" mode, that scrambles section offsets instead of zeroing the whole module image buffer. - Forcing GDB to reload shared libraries after the module image buffer has been corrupted, thus discarding the pristine local copy GDB used to have, and forcing GDB to parse the broken ELF. Change-Id: Ie72ef895802057591d6e06cd48f85edf1c177993 (cherry picked from commit b028b782cb2070c50e50a3423e7c4227318ec4d6)

A recent change in the ROCm compiler started to show some timeout in the gdb.rocm/deep-stack.exp testcase. In that test, we have a 12 frames deep stack, and we print a stack trace. With the new compiler output, building this stacktrace would take about 190 seconds... Yes, about 3 minutes to unwind 12 frames. Looking at the unwind information, we now see this new pattern for unwinding vector registers: VGPR40=[ DW_OP_regx VGPR40 DW_OP_swap DW_OP_LLVM_user DW_OP_LLVM_offset_uconst 0x0 DW_OP_LLVM_user DW_OP_LLVM_call_frame_entry_reg EXEC DW_OP_deref_size 0x8 DW_OP_LLVM_user DW_OP_LLVM_select_bit_piece 0x20 0x40 ] This new construct uses DW_OP_LLVM_select_bit_piece, which allows us to build a composite which has one piece per lane of the vector register, each piece referencing either - the register itself (not touched because the lane was not active, so no need to spill), or - a saved copy of the register to memory (at CFA). The issue turned out to be that when building the composite, we ended up creating up to 64 pieces (one per lane), each can be a dwarf_register instance. And even if all of those reference the same register, they do not share anything more than the regnum. When we evaluate something like dwarf_composite::is_optimized_out, we end-up calling dwarf_register::is_optimized_out for each piece in sequence. Each one of those calls will call dwarf_register::read and eventually frame_register_wind, i.e. we fully unwind the register once for each lane. If the next frame, and the next, and the next use the same pattern, we end-up with an impossible complexity of O(lanes ** depth), which explains how we can end-up with 3 minutes to do a 12 frames unwinding. This pattern does not only happen when calling value::optimized_out, this also happens when calling value->entirely_available for example, making things very inefficient.. To solve this, this patch makes two things: - Make it so when we use DW_OP_LLVM_select_bit_piece, all the dwarf_register in the resulting composite share a storage, - Make that storage cache the result of calling frame_register_unwind, so we do not have to repeat this for every piece. The cache is cleared any time we call dwarf_register::write, or if we detect that it might be outdated (target_changed or memory_changed got called since we cached the data). With this, doing the backtrace from the test now takes slightly more than .5 seconds, which is back to acceptable territory. (gdb) bt 2026-04-02 17:40:05.195 - command started #0 base_case () at /home/.../gdb.rocm/deep-stack.cpp:40 #1 0x00007ffff637649c in deep<0u> () at /home/.../gdb.rocm/deep-stack.cpp:54 #2 0x00007ffff637655c in deep<1u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #3 0x00007ffff637661c in deep<2u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #4 0x00007ffff63766e4 in deep<3u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #5 0x00007ffff63767a4 in deep<4u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #6 0x00007ffff6376864 in deep<5u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #7 0x00007ffff6376924 in deep<6u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #8 0x00007ffff63769e4 in deep<7u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #9 0x00007ffff6376aa4 in deep<8u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #10 0x00007ffff6376b64 in deep<9u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #11 0x00007ffff6376c24 in deep<10u> () at /home/.../gdb.rocm/deep-stack.cpp:47 #12 0x00007ffff6376d40 in hip_deep () at /home/.../gdb.rocm/deep-stack.cpp:60 2026-04-02 17:40:05.753 - command finished Command execution time: 0.558060 (cpu), 0.558099 (wall) Change-Id: I976af7fc7d6a946967d3aa986bce5b990891da20 (cherry picked from commit f204e6a13acc73c30ebe029dfa81d0e95932bbd8)

stellaraccident added 4 commits March 12, 2024 18:59

Refactor common steps.

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Add python.

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Update version

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Add to nightly.

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stellaraccident merged commit f51da82 into main Mar 13, 2024

stellaraccident deleted the enably_py_build branch March 13, 2024 02:16

umarinkovic mentioned this pull request Sep 10, 2025

[Issue]: gfx1036 Windows build fails #1443

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erman-gurses mentioned this pull request Oct 10, 2025

[Windows] Enable rocThrust tests by packaging .hip.exe #1753

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erman-gurses mentioned this pull request Oct 22, 2025

[Issue]: One of the rocthrust tests failed #1865

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fuutott mentioned this pull request Nov 29, 2025

gfx906 segmentation fault - llama.cpp - qwen next - HIP version: 7.1.25424-4179531dcd #2347

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puzhengwu mentioned this pull request Dec 19, 2025

[Issue]: llama.cpp segmentation fault during Qwen3-Next-80B-A3B-Instruct-Q4_K_M.gguf model load on gfx1151 with TheRock dev tarball #2595

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rwfsmith mentioned this pull request Jan 21, 2026

[Issue]: [gfx1151] pytorch is allocating vram but then loads in shared GPU memory instead, causing OOM #3032

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jayhawk-commits added a commit that referenced this pull request Feb 2, 2026

Merge PR #5: Add external repository support to fetch_sources.py

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Refactor common steps.#5

Refactor common steps.#5
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stellaraccident commented Mar 13, 2024

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