Merge pull request #1008 from Qwinci/dladdr1

options/posix: Implement dladdr1
managarm · Feb 24, 2024 · 147eb24 · 147eb24
2 parents dfc0aea + ffdd971
commit 147eb24
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Showing 4 changed files with 51 additions and 7 deletions.
diff --git a/options/posix/generic/dlfcn-stubs.cpp b/options/posix/generic/dlfcn-stubs.cpp
@@ -9,6 +9,8 @@ struct __dlapi_symbol {
 	void *base;
 	const char *symbol;
 	void *address;
+	const void *elf_symbol;
+	void *link_map;
 };
 
 extern "C" const char *__dlapi_error();
@@ -45,6 +47,9 @@ void *dlvsym(void *__restrict handle, const char *__restrict string, const char
 }
 
 //gnu extensions
+
+#if __MLIBC_GLIBC_OPTION
+
 int dladdr(const void *ptr, Dl_info *out) {
 	__dlapi_symbol info;
 	if(__dlapi_reverse(ptr, &info))
@@ -57,8 +62,34 @@ int dladdr(const void *ptr, Dl_info *out) {
 	return 1;
 }
 
-int dlinfo(void *, int, void *) {
+int dladdr1(const void *ptr, Dl_info *out, void **extra, int flags) {
+	__dlapi_symbol info;
+	if(__dlapi_reverse(ptr, &info)) {
+		return 0;
+	}
+
+	out->dli_fname = info.file;
+	out->dli_fbase = info.base;
+	out->dli_sname = info.symbol;
+	out->dli_saddr = info.address;
+
+	switch(flags) {
+	case RTLD_DL_SYMENT:
+		*const_cast<const void **>(extra) = info.elf_symbol;
+		break;
+	case RTLD_DL_LINKMAP:
+		*extra = info.link_map;
+		break;
+	default:
+		break;
+	}
+
+	return 1;
+}
+
+int dlinfo(void *__restrict, int, void *__restrict) {
 	__ensure(!"dlinfo() not implemented");
 	__builtin_unreachable();
 }
 
+#endif // __MLIBC_GLIBC_OPTION
diff --git a/options/posix/include/dlfcn.h b/options/posix/include/dlfcn.h
@@ -2,6 +2,8 @@
 #ifndef _DLFCN_H
 #define _DLFCN_H
 
+#include <mlibc-config.h>
+
 #define RTLD_LOCAL 0
 #define RTLD_NOW 1
 #define RTLD_GLOBAL 2
@@ -13,6 +15,9 @@
 #define RTLD_NEXT ((void *)-1)
 #define RTLD_DEFAULT ((void *)0)
 
+#define RTLD_DL_SYMENT 1
+#define RTLD_DL_LINKMAP 2
+
 #define RTLD_DI_LINKMAP 2
 
 #ifdef __cplusplus
@@ -29,6 +34,8 @@ void *dlvsym(void *__restrict, const char *__restrict, const char *__restrict);
 
 #endif /* !__MLIBC_ABI_ONLY */
 
+#if defined(_GNU_SOURCE) && __MLIBC_GLIBC_OPTION
+
 //gnu extension
 typedef struct {
 	const char *dli_fname;
@@ -39,11 +46,14 @@ typedef struct {
 
 #ifndef __MLIBC_ABI_ONLY
 
-int dladdr(const void *, Dl_info *);
-int dlinfo(void *, int, void *);
+int dladdr(const void *__ptr, Dl_info *__out);
+int dladdr1(const void *__ptr, Dl_info *__out, void **__extra, int __flags);
+int dlinfo(void *__restrict __handle, int __request, void *__restrict __info);
 
 #endif /* !__MLIBC_ABI_ONLY */
 
+#endif /* defined(_GNU_SOURCE) && __MLIBC_GLIBC_OPTION */
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/options/rtdl/generic/main.cpp b/options/rtdl/generic/main.cpp
@@ -691,6 +691,8 @@ struct __dlapi_symbol {
 	void *base;
 	const char *symbol;
 	void *address;
+	const void *elf_symbol;
+	void *link_map;
 };
 
 extern "C" [[ gnu::visibility("default") ]]
@@ -726,6 +728,8 @@ int __dlapi_reverse(const void *ptr, __dlapi_symbol *info) {
 				info->base = reinterpret_cast<void *>(object->baseAddress);
 				info->symbol = cand.getString();
 				info->address = reinterpret_cast<void *>(cand.virtualAddress());
+				info->elf_symbol = cand.symbol();
+				info->link_map = &object->linkMap;
 				return 0;
 			}
 		}
@@ -748,6 +752,8 @@ int __dlapi_reverse(const void *ptr, __dlapi_symbol *info) {
 				info->base = reinterpret_cast<void *>(object->baseAddress);
 				info->symbol = nullptr;
 				info->address = 0;
+				info->elf_symbol = nullptr;
+				info->link_map = &object->linkMap;
 				return 0;
 			}
 		}

diff --git a/tests/meson.build b/tests/meson.build
@@ -142,12 +142,9 @@ extra_cflags_test_cases = {
 
 test_sources = []
 test_link_args = []
-test_c_args = []
+test_c_args = ['-D_GNU_SOURCE']
 use_pie = false
 
-test_c_args = []
-test_link_args = []
-
 # Our ubsan implementation can't be used by the tests themselves,
 # since it is internal to libc.so and ld.so.
 test_override_options = ['b_sanitize=none']