[compiler-rt] r255019 - [tsan] Fix memcmp interceptor to correctly use COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED

[Kuba Brecka via llvm-commits]

Author: kuba.brecka
Date: Tue Dec  8 08:48:21 2015
New Revision: 255019

URL: http://llvm.org/viewvc/llvm-project?rev=255019&view=rev
Log:
[tsan] Fix memcmp interceptor to correctly use COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED

The memcmp interceptor checks COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED only after it calls COMMON_INTERCEPTOR_ENTER, which causes an early process launch crash when running TSan in iOS simulator. Let's fix this by checking COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED as the very first thing in the interceptor.

Differential Revision: http://reviews.llvm.org/D15287


Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc?rev=255019&r1=255018&r2=255019&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc Tue Dec  8 08:48:21 2015
@@ -403,10 +403,10 @@ DECLARE_WEAK_INTERCEPTOR_HOOK(__sanitize
                               const void *s1, const void *s2, uptr n)
 
 INTERCEPTOR(int, memcmp, const void *a1, const void *a2, uptr size) {
-  void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, memcmp, a1, a2, size);
   if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)
     return internal_memcmp(a1, a2, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, memcmp, a1, a2, size);
   CALL_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_memcmp, GET_CALLER_PC(), a1,
                              a2, size);
   if (common_flags()->intercept_memcmp) {