squiid/llvm
1
0
Fork 0
Code Issues Pull requests Activity

Revert "tsan: fix and test detection of TLS races"

Browse source 
This reverts commit b4c1e5cb73.

Reverting this as it contains a test that is currently failing on the PPC BE bots.
This commit is contained in:
Amy Kwan 2021-10-01 16:38:20 -05:00
parent 8b1984bb8c
commit 103c1bd118
3 changed files with 10 additions and 51 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
compiler-rt/lib/tsan/rtl/tsan_platform_linux.cpp
View file

@ -453,8 +453,6 @@ static void InitializeLongjmpXorKey() {
}
#endif
extern "C" void __tsan_tls_initialization() {}
void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
// Check that the thr object is in tls;
const uptr thr_beg = (uptr)thr;
@ -464,10 +462,9 @@ void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
CHECK_GE(thr_end, tls_addr);
CHECK_LE(thr_end, tls_addr + tls_size);
// Since the thr object is huge, skip it.
const uptr pc = StackTrace::GetNextInstructionPc(
reinterpret_cast<uptr>(__tsan_tls_initialization));
MemoryRangeImitateWrite(thr, pc, tls_addr, thr_beg - tls_addr);
MemoryRangeImitateWrite(thr, pc, thr_end, tls_addr + tls_size - thr_end);
MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr);
MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end,
tls_addr + tls_size - thr_end);
}
// Note: this function runs with async signals enabled,

17
compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
View file

@ -156,6 +156,13 @@ void ThreadStart(ThreadState *thr, Tid tid, tid_t os_id,
if (thread_type != ThreadType::Fiber)
GetThreadStackAndTls(tid == kMainTid, &stk_addr, &stk_size, &tls_addr,
&tls_size);
if (tid != kMainTid) {
if (stk_addr && stk_size)
MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size);
if (tls_addr && tls_size) ImitateTlsWrite(thr, tls_addr, tls_size);
}
#endif
ThreadRegistry *tr = &ctx->thread_registry;
@ -171,16 +178,6 @@ void ThreadStart(ThreadState *thr, Tid tid, tid_t os_id,
ThreadIgnoreSyncBegin(thr, 0);
}
#endif
#if !SANITIZER_GO
if (tid != kMainTid) {
if (stk_addr && stk_size)
MemoryRangeImitateWrite(thr, /*pc=*/1, stk_addr, stk_size);
if (tls_addr && tls_size)
ImitateTlsWrite(thr, tls_addr, tls_size);
}
#endif
}
void ThreadContext::OnStarted(void *arg) {

35
compiler-rt/test/tsan/tls_race3.cpp
View file

@ -1,35 +0,0 @@
// RUN: %clangxx_tsan %darwin_min_target_with_tls_support -O1 %s -o %t && \
// RUN: %deflake %run %t | FileCheck %s
// Race with initial TLS initialization:
// there is no explicit second write,
// but the TLS variable is published unsafely.
#include "test.h"
__thread long X;
long *P;
void *Thread(void *a) {
__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_tls_initialization
// CHECK: Location is TLS of thread T1.