[LSAN] Fix pthread_create interceptor to ignore leaks in real pthread_create.

[vitalybuka]

compiler-rt/lib/hwasan/hwasan_interceptors.cpp

49

Comment why, something like "See ASAN version" is OK

[kstoimenov]

Addressed comments.

[kstoimenov]

Reason to revert is that it broke the GCC bot: https://lab.llvm.org/buildbot/#/builders/247/builds/1408

[kstoimenov]

Re-disable leak_check_before_thread_started.cpp.

compiler-rt/lib/hwasan/hwasan_interceptors.cpp

static void *HwasanThreadStartFunc(void *arg) {
   ThreadStartArg A = *reinterpret_cast<ThreadStartArg*>(arg);
   UnmapOrDie(arg, GetPageSizeCached());
   return A.callback(A.param);
 }
 
 INTERCEPTOR(int, pthread_create, void *th, void *attr, void *(*callback)(void*),
             void * param) {
   EnsureMainThreadIDIsCorrect();
-  ScopedTaggingDisabler disabler;
+  ScopedTaggingDisabler tagging_disabler;
   ThreadStartArg *A = reinterpret_cast<ThreadStartArg *> (MmapOrDie(
       GetPageSizeCached(), "pthread_create"));
   *A = {callback, param};
-  int res = REAL(pthread_create)(th, attr, &HwasanThreadStartFunc, A);
+  int res;
+  {
+    // ASAN uses the same approach to disable leaks from pthread_create.
+#    if CAN_SANITIZE_LEAKS
+    __lsan::ScopedInterceptorDisabler lsan_disabler;
+#    endif
+    res = REAL(pthread_create)(th, attr, &HwasanThreadStartFunc, A);
+  }
   return res;
 }
 
 INTERCEPTOR(int, pthread_join, void *t, void **arg) {
   return REAL(pthread_join)(t, arg);
 }
 
 DEFINE_REAL_PTHREAD_FUNCTIONS

compiler-rt/test/lsan/TestCases/Linux/disabler_in_tsd_destructor.c

 // Regression test. Disabler should not depend on TSD validity.
 // RUN: %clang_lsan %s -o %t
 // RUN: %env_lsan_opts="report_objects=1:use_registers=0:use_stacks=0:use_tls=1:use_ld_allocations=0" %run %t
 
-// Fixme: remove once test passes with hwasan
-// UNSUPPORTED: hwasan
-
 #include <assert.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 
 #include "sanitizer/lsan_interface.h"
 
 pthread_key_t key;

compiler-rt/test/lsan/TestCases/high_allocator_contention.cpp

 // A benchmark that executes malloc/free pairs in parallel.
 // Usage: ./a.out number_of_threads total_number_of_allocations
 // RUN: %clangxx_lsan %s -o %t
 // RUN: %env_lsan_opts=use_ld_allocations=0 %run %t 5 1000000 2>&1
-
-// Fixme: remove once test passes with hwasan
-// UNSUPPORTED: hwasan
 #include <assert.h>
 #include <pthread.h>
 #include <stdlib.h>
 #include <stdio.h>
 
 int num_threads;
 int total_num_alloc;
 const int kMaxNumThreads = 5000;