tsan: partially restore COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED check

[dvyukov]

Summary

PPC64 buildbots crashes after D112446:
https://lab.llvm.org/buildbot#builders/52/builds/11811
Restore the old check for most platforms,
let's see if it can be disabled at least for Linux/x86_64.

Depends on D112538.

[melver]

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

158

Is there an explanation for this?
Is it the .preinit_array that isn't supported?

It would be good to explain it, otherwise it makes me think that this can equally break on other platforms.

[melver]

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

158

s/break on other platforms/break on other Linux-based x86-64 configurations/
... which might depend on libc being used?

I also see SANITIZER_CAN_USE_PREINIT_ARRAY, which should be set correctly though. But again, .preinit_array may not be the problem and it's something else.

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

 const int SA_SIGINFO = 8;
 const int SIG_SETMASK = 3;
 #else
 const int SA_SIGINFO = 4;
 const int SIG_SETMASK = 2;
 #endif
 
 // All tsan interceptors check for initialization and/or initialize things
-// as necessary lazily, so we can pretend everything is initialized in this
-// check to avoid double-checking for initialization (this is only necessary for
-// sanitizers that don't handle initialization on common grounds).
-#define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED false
+// as necessary lazily later, so for some platforms this additional check
+// is not necessary. But tread carefully since it's also know to be necessary
+// at least for ppc64 (buildbots fail w/o the check).
+#if SANITIZER_LINUX && !SANITIZER_ANDROID && defined(__x86_64__)
+#  define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED false
+#else
+#  define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED \
+    (!cur_thread_init()->is_inited)
+#endif
 
 namespace __tsan {
 struct SignalDesc {
   bool armed;
   __sanitizer_siginfo siginfo;
   ucontext_t ctx;
 };