[compiler-rt] b345952 - Revert "tsan: add a test for stack init race"

[Kevin Athey via llvm-commits]

Author: Kevin Athey
Date: 2021-09-27T15:31:23-07:00
New Revision: b345952ad42655a437780e796cd0d7b6c4ccb559

URL: https://github.com/llvm/llvm-project/commit/b345952ad42655a437780e796cd0d7b6c4ccb559
DIFF: https://github.com/llvm/llvm-project/commit/b345952ad42655a437780e796cd0d7b6c4ccb559.diff

LOG: Revert "tsan: add a test for stack init race"

This reverts commit b72176b9bc06146d12e495167977effe050dc326.

Broke bot: https://lab.llvm.org/buildbot/#/builders/70/builds/12193

Added: 
    

Modified: 
    compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp

Removed: 
    compiler-rt/test/tsan/stack_race3.cpp


################################################################################
diff  --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
index 61133a4a3e7e..67b12c804fb2 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
@@ -138,8 +138,6 @@ void ThreadContext::OnCreated(void *arg) {
   creation_stack_id = CurrentStackId(args->thr, args->pc);
 }
 
-extern "C" void __tsan_stack_initialization() {}
-
 struct OnStartedArgs {
   ThreadState *thr;
   uptr stk_addr;
@@ -175,15 +173,9 @@ void ThreadStart(ThreadState *thr, Tid tid, tid_t os_id,
 #endif
 
 #if !SANITIZER_GO
-  // Don't imitate stack/TLS writes for the main thread,
-  // because its initialization is synchronized with all
-  // subsequent threads anyway.
   if (tid != kMainTid) {
-    if (stk_addr && stk_size) {
-      const uptr pc = StackTrace::GetNextInstructionPc(
-          reinterpret_cast<uptr>(__tsan_stack_initialization));
-      MemoryRangeImitateWrite(thr, pc, stk_addr, stk_size);
-    }
+    if (stk_addr && stk_size)
+      MemoryRangeImitateWrite(thr, /*pc=*/1, stk_addr, stk_size);
 
     if (tls_addr && tls_size)
       ImitateTlsWrite(thr, tls_addr, tls_size);

diff  --git a/compiler-rt/test/tsan/stack_race3.cpp b/compiler-rt/test/tsan/stack_race3.cpp
deleted file mode 100644
index 854ca1dc6eff..000000000000
--- a/compiler-rt/test/tsan/stack_race3.cpp
+++ /dev/null
@@ -1,34 +0,0 @@
-// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
-
-// Race with initial stack initialization:
-// there is no explicit second write,
-// but the stack variable is published unsafely.
-#include "test.h"
-
-long *P;
-
-void *Thread(void *a) {
-  long X;
-  __atomic_store_n(&P, &X, __ATOMIC_RELAXED);
-  barrier_wait(&barrier);
-  barrier_wait(&barrier);
-  return 0;
-}
-
-int main() {
-  barrier_init(&barrier, 2);
-  pthread_t t;
-  pthread_create(&t, NULL, Thread, NULL);
-  barrier_wait(&barrier);
-  long *p = __atomic_load_n(&P, __ATOMIC_RELAXED);
-  *p = 42;
-  barrier_wait(&barrier);
-  pthread_join(t, 0);
-}
-
-// CHECK: WARNING: ThreadSanitizer: data race
-// CHECK:   Write of size 8 at {{.*}} by main thread:
-// CHECK:     #0 main
-// CHECK:   Previous write of size 8 at {{.*}} by thread T1:
-// CHECK:     #0 __tsan_stack_initialization
-// CHECK:   Location is stack of thread T1