build: ASAN fixes for glibc (JuliaLang#51755)

For the `sigsetjmp` bypass; looks like glibc removed the `__libc_siglongjmp` symbol in glibc 2.34, so change to using the approach taking by our `dlopen` wrapper instead. Adopts topolarity's fixes from JuliaLang#50170 Resolves JuliaLang#47698 Co-authored-by: Jameson Nash <[email protected]>
inkydragon · Nov 20, 2023 · 5cb0e51 · 5cb0e51
1 parent 7327a8f
commit 5cb0e51
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Showing 3 changed files with 22 additions and 5 deletions.
diff --git a/src/dlload.c b/src/dlload.c
@@ -188,7 +188,7 @@ JL_DLLEXPORT JL_NO_SANITIZE void *jl_dlopen(const char *filename, unsigned flags
  dlopen = (dlopen_prototype*)dlsym(RTLD_NEXT, "dlopen");
  if (!dlopen)
  return NULL;
- void *libdl_handle = dlopen("libdl.so", RTLD_NOW | RTLD_NOLOAD);
+ void *libdl_handle = dlopen("libdl.so.2", RTLD_NOW | RTLD_NOLOAD);
  assert(libdl_handle);
  dlopen = (dlopen_prototype*)dlsym(libdl_handle, "dlopen");
  dlclose(libdl_handle);

diff --git a/src/julia.h b/src/julia.h
@@ -2287,10 +2287,9 @@ void (ijl_longjmp)(jmp_buf _Buf, int _Value);
 #define jl_setjmp_name "sigsetjmp"
 #endif
 #define jl_setjmp(a,b) sigsetjmp(a,b)
-#if defined(_COMPILER_ASAN_ENABLED_) && __GLIBC__
-// Bypass the ASAN longjmp wrapper - we're unpoisoning the stack ourselves.
-JL_DLLIMPORT int __attribute__ ((nothrow)) (__libc_siglongjmp)(jl_jmp_buf buf, int val);
-#define jl_longjmp(a,b) __libc_siglongjmp(a,b)
+#if defined(_COMPILER_ASAN_ENABLED_) && defined(__GLIBC__)
+extern void (*real_siglongjmp)(jmp_buf _Buf, int _Value);
+#define jl_longjmp(a,b) real_siglongjmp(a,b)
 #else
 #define jl_longjmp(a,b) siglongjmp(a,b)
 #endif

diff --git a/src/task.c b/src/task.c
@@ -42,6 +42,13 @@ extern "C" {
 #endif
 
 #if defined(_COMPILER_ASAN_ENABLED_)
+#if __GLIBC__
+#include <dlfcn.h>
+// Bypass the ASAN longjmp wrapper - we are unpoisoning the stack ourselves,
+// since ASAN normally unpoisons far too much.
+// c.f. interceptor in jl_dlopen as well
+void (*real_siglongjmp)(jmp_buf _Buf, int _Value) = NULL;
+#endif
 static inline void sanitizer_start_switch_fiber(jl_ptls_t ptls, jl_task_t *from, jl_task_t *to) {
  if (to->copy_stack)
  __sanitizer_start_switch_fiber(&from->ctx.asan_fake_stack, (char*)ptls->stackbase-ptls->stacksize, ptls->stacksize);
@@ -1226,6 +1233,17 @@ void jl_init_tasks(void) JL_GC_DISABLED
  exit(1);
  }
 #endif
+#if defined(_COMPILER_ASAN_ENABLED_) && __GLIBC__
+ void *libc_handle = dlopen("libc.so.6", RTLD_NOW | RTLD_NOLOAD);
+ if (libc_handle) {
+ *(void**)&real_siglongjmp = dlsym(libc_handle, "siglongjmp");
+ dlclose(libc_handle);
+ }
+ if (real_siglongjmp == NULL) {
+ jl_safe_printf("failed to get real siglongjmp\n");
+ exit(1);
+ }
+#endif
 }
 
 #if defined(_COMPILER_ASAN_ENABLED_)