[asan] Avoid hooking memchr() on Windows64

[wang0109]

Summary

There is not enough padding in front of memchr(), and, the first 6 bytes
contains a branch instruction. Basically the current interception will
not work on memchr().

It was disabled before, but was missing the part to disable it for
INTERCEPT_LIBRARY_FUNCTION.

[etienneb]

This is fine to me.

But, in practice this error will occur again if someone disable an other hook.

#define SANITIZER_INTERCEPT_MEMSET 1
#define SANITIZER_INTERCEPT_MEMMOVE 1
#define SANITIZER_INTERCEPT_MEMCPY 1
#define SANITIZER_INTERCEPT_MEMCMP 1
#define SANITIZER_INTERCEPT_MEMCHR 1

But. we can postpone this fix.

[wang0109]

Yes, I think the correct behavior is to let SANITIZER_INTERCEPTER_XXXX macros to control both library and non-library interceptions, meaning, we should surround those interceptions in lib/asan/asan_win_dll_thunk.cc with these macros. That is, another CL, since this one is about memchr() in particular.

[rnk]

lgtm

compiler-rt/trunk/lib/asan/asan_win_dll_thunk.cc

 //===----------------------------------------------------------------------===//
 
 // Only compile this code when buidling asan_dll_thunk.lib
 // Using #ifdef rather than relying on Makefiles etc.
 // simplifies the build procedure.
 #ifdef ASAN_DLL_THUNK
 #include "asan_init_version.h"
 #include "interception/interception.h"
+#include "sanitizer_common/sanitizer_platform_interceptors.h"
 
 // ---------- Function interception helper functions and macros ----------- {{{1
 extern "C" {
 void *__stdcall GetModuleHandleA(const char *module_name);
 void *__stdcall GetProcAddress(void *module, const char *proc_name);
 void abort();
 }
 

 // can't use INTERCEPT_LIBRARY_FUNCTION(_except_handler4).
 INTERCEPTOR(int, _except_handler4, void *a, void *b, void *c, void *d) {
   __asan_handle_no_return();
   return REAL(_except_handler4)(a, b, c, d);
 }
 
 INTERCEPT_LIBRARY_FUNCTION(frexp);
 INTERCEPT_LIBRARY_FUNCTION(longjmp);
+#if SANITIZER_INTERCEPT_MEMCHR
 INTERCEPT_LIBRARY_FUNCTION(memchr);
+#endif
 INTERCEPT_LIBRARY_FUNCTION(memcmp);
 INTERCEPT_LIBRARY_FUNCTION(memcpy);
 INTERCEPT_LIBRARY_FUNCTION(memmove);
 INTERCEPT_LIBRARY_FUNCTION(memset);
 INTERCEPT_LIBRARY_FUNCTION(strcat);  // NOLINT
 INTERCEPT_LIBRARY_FUNCTION(strchr);
 INTERCEPT_LIBRARY_FUNCTION(strcmp);
 INTERCEPT_LIBRARY_FUNCTION(strcpy);  // NOLINT

compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_interceptors.h

 #define SANITIZER_INTERCEPT_STRSPN 1
 #define SANITIZER_INTERCEPT_STRPBRK 1
 #define SANITIZER_INTERCEPT_TEXTDOMAIN SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_STRCASECMP SI_NOT_WINDOWS
 #define SANITIZER_INTERCEPT_MEMSET 1
 #define SANITIZER_INTERCEPT_MEMMOVE 1
 #define SANITIZER_INTERCEPT_MEMCPY 1
 #define SANITIZER_INTERCEPT_MEMCMP 1
-// TODO(wwchrome): Re-enable intercepting memchr() when ready.
 // The function memchr() contains a jump in the first 6 bytes
 // that is problematic to intercept correctly on Win64.
-// Disable memchr() interception for Win64 temporarily.
+// Disable memchr() interception for Win64.
 #if SANITIZER_WINDOWS64
 #define SANITIZER_INTERCEPT_MEMCHR 0
 #else
 #define SANITIZER_INTERCEPT_MEMCHR 1
 #endif
 #define SANITIZER_INTERCEPT_MEMRCHR SI_FREEBSD || SI_LINUX
 
 #define SANITIZER_INTERCEPT_READ   SI_NOT_WINDOWS