singlefilehost doesn't link to system libunwind #42661

omajid · 2020-09-24T00:25:41Z

Trying to build runtime (commit 20710bb) with -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND is currently broken:

$ ./build.sh -cmakeargs -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND=TRUE 
...
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `UnwindContextToWinContext(unw_cursor*, _CONTEXT*)':                                                      
  /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:176: undefined reference to `_ULx86_64_get_reg'                                                                                                          
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:177: undefined reference to `_ULx86_64_get_reg'                                                                                             
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:178: undefined reference to `_ULx86_64_get_reg'                                                                                             
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:179: undefined reference to `_ULx86_64_get_reg'                                                                                             
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:180: undefined reference to `_ULx86_64_get_reg'                                                                                             
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o):/home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:181: more undefined references to `_ULx86_64_get_reg' follow                                                                                                                                                                                                                      
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `GetContextPointer(unw_cursor*, ucontext_t*, int, unsigned long**)':                                      
  /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:227: undefined reference to `_ULx86_64_get_save_loc'                                                                                                     
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `PAL_VirtualUnwind':                                                                                      
  /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:340: undefined reference to `_ULx86_64_init_local'                                                                                                       
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:351: undefined reference to `_ULx86_64_step'                                                                                                
  /usr/bin/ld: /home/omajid/devel/dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:360: undefined reference to `_ULx86_64_is_signal_frame'                                                                                     
  clang-10: error: linker command failed with exit code 1 (use -v to see invocation)                                                                                                                                                          
  gmake[2]: *** [cli/apphost/static/CMakeFiles/singlefilehost.dir/build.make:282: cli/apphost/static/singlefilehost] Error 1                                                                                                                  
  gmake[1]: *** [CMakeFiles/Makefile2:510: cli/apphost/static/CMakeFiles/singlefilehost.dir/all] Error 2

Configuration

Which version of .NET is the code running on?

dotnet/runtime commit 20710bbcae006e32f8a133c372c8d78722890982 as well as release/5.0-preview8 tag.

What OS and version, and what distro if applicable?

Fedora 32.

What is the architecture (x64, x86, ARM, ARM64)?

x64, but probably affects everything.

Do you know whether it is specific to that configuration?

Yes: building without -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND works

Regression?

Yes. This build configuration was supported in .NET Core 3.1 and we were using it in source-build to build on Fedora/RHEL. See dotnet/coreclr#17164 and dotnet/source-build#391

Other information

The fix is probably the along the lines of #42094: the singlefilehost needs to link to the system libunwind library.

The text was updated successfully, but these errors were encountered:

ghost · 2020-09-24T00:25:50Z

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omajid · 2020-09-24T00:26:17Z

I am working on a fix for this; will open a PR shortly

ghost · 2020-09-24T00:41:26Z

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See info in area-owners.md if you want to be subscribed.

janvorli · 2020-09-24T09:35:52Z

@omajid I've set the milestone to 6.0, but now I feel we might need this for 5.0, am I right?

omajid · 2020-09-24T14:20:16Z

Ideally we would add it to 5.0 GA (or post GA if GA is absolutely frozen for now).

If this doesn't get added to 5.0, we still have some options: we can carry this as a patch in source-build or in our RPM packages. But that gets reviewed less thoroughly and becomes harder to maintain as runtime gets additional fixes.

I think we should decide to handle this issue consistently with #42094 and #42415: either all go to 5.0 or none of them go to 5.0.

janvorli · 2020-09-24T14:27:10Z

There is still a window to get this in for 5.0 GA, let me update the milestone.

We can now build runtime against the system libunwind using: ./build.sh -cmakeargs -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND This allows Linux distributions that already ship a compatible version of libunwind library to use that instead of carrying a duplicate in .NET. This provides some benefits to them, including smaller build sizes, slightly faster builds and fewer places to fix any vulnerabilities This functionality was already supported in .NET Core 3.1 and has regressed since. CoreCLR already handles `-DCLR_CMAKE_USE_SYSTEM_LIBUNWIND`, so no changes are needed there. The libraries build doesn't care about this cmake varibale, but cmake itself fails if the variable is not used: EXEC : CMake error : [runtime/src/libraries/Native/build-native.proj] Manually-specified variables were not used by the project: CLR_CMAKE_USE_SYSTEM_LIBUNWIND So libraries just needs to check and ignore this variable. The singlefilehost needs to link against libunwind too. Otherwise the linker fails to resolve symbols, making the build fail: /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `UnwindContextToWinContext(unw_cursor*, _CONTEXT*)': dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:176: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:177: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:178: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:179: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:180: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:181: more undefined references to `_ULx86_64_get_reg' follow /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `GetContextPointer(unw_cursor*, ucontext_t*, int, unsigned long**)': runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:227: undefined reference to `_ULx86_64_get_save_loc' /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `PAL_VirtualUnwind': runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:340: undefined reference to `_ULx86_64_init_local' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:351: undefined reference to `_ULx86_64_step' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:360: undefined reference to `_ULx86_64_is_signal_frame' clang-10: error: linker command failed with exit code 1 (use -v to see invocation) Fixes: dotnet#42661

We can now build runtime against the system libunwind using: ./build.sh -cmakeargs -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND This allows Linux distributions that already ship a compatible version of libunwind library to use that instead of carrying a duplicate in .NET. This provides some benefits to them, including smaller build sizes, slightly faster builds and fewer places to fix any vulnerabilities This functionality was already supported in .NET Core 3.1 and has regressed since. CoreCLR already handles `-DCLR_CMAKE_USE_SYSTEM_LIBUNWIND`, so no changes are needed there. The libraries build doesn't care about this cmake varibale, but cmake itself fails if the variable is not used: EXEC : CMake error : [runtime/src/libraries/Native/build-native.proj] Manually-specified variables were not used by the project: CLR_CMAKE_USE_SYSTEM_LIBUNWIND So libraries just needs to check and ignore this variable. The singlefilehost needs to link against libunwind too. Otherwise the linker fails to resolve symbols, making the build fail: /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `UnwindContextToWinContext(unw_cursor*, _CONTEXT*)': dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:176: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:177: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:178: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:179: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:180: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:181: more undefined references to `_ULx86_64_get_reg' follow /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `GetContextPointer(unw_cursor*, ucontext_t*, int, unsigned long**)': runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:227: undefined reference to `_ULx86_64_get_save_loc' /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `PAL_VirtualUnwind': runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:340: undefined reference to `_ULx86_64_init_local' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:351: undefined reference to `_ULx86_64_step' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:360: undefined reference to `_ULx86_64_is_signal_frame' clang-10: error: linker command failed with exit code 1 (use -v to see invocation) Fixes: #42661

We can now build runtime against the system libunwind using: ./build.sh -cmakeargs -DCLR_CMAKE_USE_SYSTEM_LIBUNWIND This allows Linux distributions that already ship a compatible version of libunwind library to use that instead of carrying a duplicate in .NET. This provides some benefits to them, including smaller build sizes, slightly faster builds and fewer places to fix any vulnerabilities This functionality was already supported in .NET Core 3.1 and has regressed since. CoreCLR already handles `-DCLR_CMAKE_USE_SYSTEM_LIBUNWIND`, so no changes are needed there. The libraries build doesn't care about this cmake varibale, but cmake itself fails if the variable is not used: EXEC : CMake error : [runtime/src/libraries/Native/build-native.proj] Manually-specified variables were not used by the project: CLR_CMAKE_USE_SYSTEM_LIBUNWIND So libraries just needs to check and ignore this variable. The singlefilehost needs to link against libunwind too. Otherwise the linker fails to resolve symbols, making the build fail: /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `UnwindContextToWinContext(unw_cursor*, _CONTEXT*)': dotnet/runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:176: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:177: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:178: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:179: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:180: undefined reference to `_ULx86_64_get_reg' /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:181: more undefined references to `_ULx86_64_get_reg' follow /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `GetContextPointer(unw_cursor*, ucontext_t*, int, unsigned long**)': runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:227: undefined reference to `_ULx86_64_get_save_loc' /usr/bin/ld: runtime/artifacts/bin/coreclr/Linux.x64.Debug//lib/libcoreclrpal.a(seh.cpp.o): in function `PAL_VirtualUnwind': runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:340: undefined reference to `_ULx86_64_init_local' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:351: undefined reference to `_ULx86_64_step' /usr/bin/ld: runtime/src/coreclr/src/pal/src/exception/seh-unwind.cpp:360: undefined reference to `_ULx86_64_is_signal_frame' clang-10: error: linker command failed with exit code 1 (use -v to see invocation) Fixes: #42661 Co-authored-by: Omair Majid <[email protected]>

Dotnet-GitSync-Bot added area-System.Net untriaged New issue has not been triaged by the area owner labels Sep 24, 2020

omajid changed the title ~~singlefilehost doesn't link to system libunwind correctly~~ singlefilehost doesn't link to system libunwind Sep 24, 2020

jkotas added the area-Single-File label Sep 24, 2020

jkotas removed the area-System.Net label Sep 24, 2020

janvorli removed the untriaged New issue has not been triaged by the area owner label Sep 24, 2020

janvorli added this to the 6.0.0 milestone Sep 24, 2020

janvorli modified the milestones: 6.0.0, 5.0.0 Sep 24, 2020

jeffschwMSFT added the blocking-release label Sep 24, 2020

This was referenced Sep 24, 2020

Re-enable support for using the system libunwind #42689

Merged

Re-enable system libunwind support dotnet/source-build#1761

Merged

ghost closed this as completed in #42689 Sep 25, 2020

ghost locked as resolved and limited conversation to collaborators Dec 7, 2020

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singlefilehost doesn't link to system libunwind #42661

singlefilehost doesn't link to system libunwind #42661

omajid commented Sep 24, 2020

ghost commented Sep 24, 2020

omajid commented Sep 24, 2020

ghost commented Sep 24, 2020

janvorli commented Sep 24, 2020

omajid commented Sep 24, 2020

janvorli commented Sep 24, 2020

singlefilehost doesn't link to system libunwind #42661

singlefilehost doesn't link to system libunwind #42661

Comments

omajid commented Sep 24, 2020

Configuration

Regression?

Other information

ghost commented Sep 24, 2020

omajid commented Sep 24, 2020

ghost commented Sep 24, 2020

janvorli commented Sep 24, 2020

omajid commented Sep 24, 2020

janvorli commented Sep 24, 2020