[compiler-rt] r194573 - [ASan] Don't call __asan_init() from certain interceptors on Darwin.

[Alexander Potapenko]

Author: glider
Date: Wed Nov 13 07:34:53 2013
New Revision: 194573

URL: http://llvm.org/viewvc/llvm-project?rev=194573&view=rev
Log:
[ASan] Don't call __asan_init() from certain interceptors on Darwin.

Fixes http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58994, which hadn't
manifested in LLVM because libclang_rt.asan_osx_dynamic.dylib used to depend on
the Foundation framework.
Without that dependency some interceptors may be called from the system
libraries before libSystem_initializer() is called, which lead to assertion
failures in sanitizer_mac.cc (_NSGetEnviron() returns NULL).

To fix the problem we fall back to the original functions in the common
libsanitizer interceptors and the __cxa_atexit() interceptor on Darwin.

This patch also prints a better error message in the case _NSGetEnviron()
returns NULL.


Modified:
    compiler-rt/trunk/lib/asan/asan_interceptors.cc
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc

Modified: compiler-rt/trunk/lib/asan/asan_interceptors.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_interceptors.cc?rev=194573&r1=194572&r2=194573&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_interceptors.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_interceptors.cc Wed Nov 13 07:34:53 2013
@@ -126,12 +126,13 @@ DECLARE_REAL_AND_INTERCEPTOR(void, free,
 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
   ASAN_WRITE_RANGE(ptr, size)
 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) ASAN_READ_RANGE(ptr, size)
-#define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)              \
-  do {                                                        \
-    if (asan_init_is_running) return REAL(func)(__VA_ARGS__); \
-    ctx = 0;                                                  \
-    (void) ctx;                                               \
-    ENSURE_ASAN_INITED();                                     \
+#define COMMON_INTERCEPTOR_ENTER(ctx, func, ...)                       \
+  do {                                                                 \
+    if (asan_init_is_running) return REAL(func)(__VA_ARGS__);          \
+    ctx = 0;                                                           \
+    (void) ctx;                                                        \
+    if (SANITIZER_MAC && !asan_inited) return REAL(func)(__VA_ARGS__); \
+    ENSURE_ASAN_INITED();                                              \
   } while (false)
 #define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
   do {                                         \
@@ -659,6 +660,9 @@ static void AtCxaAtexit(void *unused) {
 #if ASAN_INTERCEPT___CXA_ATEXIT
 INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
             void *dso_handle) {
+#if SANITIZER_MAC
+  if (!asan_inited) return REAL(__cxa_atexit)(func, arg, dso_handle);
+#endif
   ENSURE_ASAN_INITED();
   int res = REAL(__cxa_atexit)(func, arg, dso_handle);
   REAL(__cxa_atexit)(AtCxaAtexit, 0, 0);

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc?rev=194573&r1=194572&r2=194573&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_mac.cc Wed Nov 13 07:34:53 2013
@@ -145,7 +145,11 @@ void GetThreadStackTopAndBottom(bool at_
 
 const char *GetEnv(const char *name) {
   char ***env_ptr = _NSGetEnviron();
-  CHECK(env_ptr);
+  if (!env_ptr) {
+    Report("_NSGetEnviron() returned NULL. Please make sure __asan_init() is "
+           "called after libSystem_initializer().\n");
+    CHECK(env_ptr);
+  }
   char **environ = *env_ptr;
   CHECK(environ);
   uptr name_len = internal_strlen(name);