Support pthread_key_create symbol alias in MSan/NetBSD

[krytarowski]

Summary

NetBSD uses indirection symbol for a set of threading functions.

Add alias to handle __libc_thr_keycreate the same way as pthread_key_create.

Sponsored by <The NetBSD Foundation>

[krytarowski]

While there.. is lib/sanitizer_common/sanitizer_common_syscalls.inc required for MSan?

[vitalybuka]

lib/msan/msan_interceptors.cc

1530

NetBSD header contains following:
#define pthread_key_create __libc_thr_keycreate

Should you instead pthread_key_create interceptor define __libc_thr_keycreate?

[krytarowski]

lib/msan/msan_interceptors.cc

1530

pthread_key_create(3) can be called internally in libpthread() or some other way without symbol mangling, this is why I want to intercept both symbol names.

This was the case in TSan in functions like pthread_mutex_lock(3).

Long term NetBSD will likely drop the symbol indirection and remove names like __libc_thr_keycreate.

[vitalybuka]

lib/msan/msan_interceptors.cc

1651

could you please move this and interceptor itself next to corresponding pthread_key_create lines

[krytarowski]

Just reminding about my side question:

While there.. is lib/sanitizer_common/sanitizer_common_syscalls.inc required for MSan?

I will try to port it to NetBSD and see whether it helps MSan to work better.

lib/msan/msan_interceptors.cc

INTERCEPTOR(int, pthread_key_create, __sanitizer_pthread_key_t *key,
   if (msan_init_is_running) return REAL(pthread_key_create)(key, dtor);
   ENSURE_MSAN_INITED();
   int res = REAL(pthread_key_create)(key, dtor);
   if (!res && key)
     __msan_unpoison(key, sizeof(*key));
   return res;
 }
 
+#if SANITIZER_NETBSD
+INTERCEPTOR(void, __libc_thr_keycreate, void *m, void (*dtor)(void *value)) \
+  ALIAS(WRAPPER_NAME(pthread_key_create));
+#endif
+
 INTERCEPTOR(int, pthread_join, void *th, void **retval) {
   ENSURE_MSAN_INITED();
   int res = REAL(pthread_join)(th, retval);
   if (!res && retval)
     __msan_unpoison(retval, sizeof(*retval));
   return res;
 }
 

 }
 
 void __msan_unpoison_string(const char* s) {
   if (!MEM_IS_APP(s)) return;
   __msan_unpoison(s, REAL(strlen)(s) + 1);
 }
 
 namespace __msan {
 
 void InitializeInterceptors() {
   static int inited = 0;
   CHECK_EQ(inited, 0);
   InitializeCommonInterceptors();
   InitializeSignalInterceptors();
 
   INTERCEPT_FUNCTION(mmap);
   MSAN_MAYBE_INTERCEPT_MMAP64;
#endif
   INTERCEPT_FUNCTION(pthread_join);
   INTERCEPT_FUNCTION(tzset);
   INTERCEPT_FUNCTION(__cxa_atexit);
   INTERCEPT_FUNCTION(shmat);
   INTERCEPT_FUNCTION(fork);
   INTERCEPT_FUNCTION(openpty);
   INTERCEPT_FUNCTION(forkpty);
 
+#if SANITIZER_NETBSD
+  INTERCEPT_FUNCTION(__libc_thr_keycreate);
+#endif
+
   inited = 1;
 }
 } // namespace __msan