[compiler-rt] d41233e - tsan: introduce kAccessFree

[Dmitry Vyukov via llvm-commits]

Author: Dmitry Vyukov
Date: 2021-08-04T18:03:41+02:00
New Revision: d41233e9cf12b85b4f856fe6f4c881211b29534c

URL: https://github.com/llvm/llvm-project/commit/d41233e9cf12b85b4f856fe6f4c881211b29534c
DIFF: https://github.com/llvm/llvm-project/commit/d41233e9cf12b85b4f856fe6f4c881211b29534c.diff

LOG: tsan: introduce kAccessFree

Add kAccessFree memory access flag (similar to kAccessVptr).
In preparation for MemoryAccess refactoring.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D107464

Added: 
    

Modified: 
    compiler-rt/lib/tsan/rtl/tsan_rtl.h
    compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp

Removed: 
    


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diff  --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.h b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
index 483459b7646d..327590456626 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
@@ -698,7 +698,8 @@ enum : AccessType {
   kAccessWrite = 0,
   kAccessRead = 1 << 0,
   kAccessAtomic = 1 << 1,
-  kAccessVptr = 1 << 2,
+  kAccessVptr = 1 << 2,  // read or write of an object virtual table pointer
+  kAccessFree = 1 << 3,  // synthetic memory access during memory freeing
 };
 
 void MemoryAccess(ThreadState *thr, uptr pc, uptr addr,
@@ -741,9 +742,13 @@ void MemoryAccess(ThreadState *thr, uptr pc, uptr addr, uptr size,
   bool is_atomic = typ & kAccessAtomic;
   if (typ & kAccessVptr)
     thr->is_vptr_access = true;
+  if (typ & kAccessFree)
+    thr->is_freeing = true;
   MemoryAccess(thr, pc, addr, size_log, is_write, is_atomic);
   if (typ & kAccessVptr)
     thr->is_vptr_access = false;
+  if (typ & kAccessFree)
+    thr->is_freeing = false;
 }
 
 void MemoryResetRange(ThreadState *thr, uptr pc, uptr addr, uptr size);

diff  --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
index a3554725c44e..795732475f63 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
@@ -132,12 +132,8 @@ void MutexDestroy(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
   // Imitate a memory write to catch unlock-destroy races.
   // Do this outside of sync mutex, because it can report a race which locks
   // sync mutexes.
-  if (IsAppMem(addr)) {
-    CHECK(!thr->is_freeing);
-    thr->is_freeing = true;
-    MemoryAccess(thr, pc, addr, 1, kAccessWrite);
-    thr->is_freeing = false;
-  }
+  if (IsAppMem(addr))
+    MemoryAccess(thr, pc, addr, 1, kAccessWrite | kAccessFree);
   // s will be destroyed and freed in MetaMap::FreeBlock.
 }