Hi!
I've committed the following cherry-pick of upstream change for tsan
atomics after bootstrapping/regtesting it on x86_64-linux and i686-linux.
2017-03-22 Jakub Jelinek <ja...@redhat.com>
PR sanitizer/78158
* tsan/tsan_interface_atomic.cc: Cherry-pick upstream r298378.
--- libsanitizer/tsan/tsan_interface_atomic.cc (revision 298377)
+++ libsanitizer/tsan/tsan_interface_atomic.cc (revision 298378)
@@ -448,10 +448,27 @@ static void AtomicFence(ThreadState *thr
// C/C++
+static morder covert_morder(morder mo) {
+ if (flags()->force_seq_cst_atomics)
+ return (morder)mo_seq_cst;
+
+ // Filter out additional memory order flags:
+ // MEMMODEL_SYNC = 1 << 15
+ // __ATOMIC_HLE_ACQUIRE = 1 << 16
+ // __ATOMIC_HLE_RELEASE = 1 << 17
+ //
+ // HLE is an optimization, and we pretend that elision always fails.
+ // MEMMODEL_SYNC is used when lowering __sync_ atomics,
+ // since we use __sync_ atomics for actual atomic operations,
+ // we can safely ignore it as well. It also subtly affects semantics,
+ // but we don't model the difference.
+ return (morder)(mo & 0x7fff);
+}
+
#define SCOPED_ATOMIC(func, ...) \
const uptr callpc = (uptr)__builtin_return_address(0); \
uptr pc = StackTrace::GetCurrentPc(); \
- mo = flags()->force_seq_cst_atomics ? (morder)mo_seq_cst : mo; \
+ mo = covert_morder(mo); \
ThreadState *const thr = cur_thread(); \
if (thr->ignore_interceptors) \
return NoTsanAtomic##func(__VA_ARGS__); \
Jakub
