[compiler-rt] r201304 - [asan] Avoid deadlock in CovDump.

[Evgeniy Stepanov]

Author: eugenis
Date: Thu Feb 13 02:50:36 2014
New Revision: 201304

URL: http://llvm.org/viewvc/llvm-project?rev=201304&view=rev
Log:
[asan] Avoid deadlock in CovDump.

Modified:
    compiler-rt/trunk/lib/asan/lit_tests/TestCases/Linux/coverage.cc
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_coverage.cc

Modified: compiler-rt/trunk/lib/asan/lit_tests/TestCases/Linux/coverage.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/lit_tests/TestCases/Linux/coverage.cc?rev=201304&r1=201303&r2=201304&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/lit_tests/TestCases/Linux/coverage.cc (original)
+++ compiler-rt/trunk/lib/asan/lit_tests/TestCases/Linux/coverage.cc Thu Feb 13 02:50:36 2014
@@ -6,6 +6,9 @@
 // RUN: %t bar 2>&1     | FileCheck %s --check-prefix=CHECK-bar
 // RUN: %t foo bar 2>&1 | FileCheck %s --check-prefix=CHECK-foo-bar
 // RUN: not %t foo bar 1 2  2>&1 | FileCheck %s --check-prefix=CHECK-report
+//
+// https://code.google.com/p/address-sanitizer/issues/detail?id=263
+// XFAIL: android
 
 #include <stdio.h>
 #include <string.h>

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_coverage.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_coverage.cc?rev=201304&r1=201303&r2=201304&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_coverage.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_coverage.cc Thu Feb 13 02:50:36 2014
@@ -43,9 +43,10 @@
 struct CovData {
   BlockingMutex mu;
   InternalMmapVector<uptr> v;
+  atomic_uint32_t guard;
 };
 
-static uptr cov_data_placeholder[sizeof(CovData) / sizeof(uptr)];
+static uptr cov_data_placeholder[(sizeof(CovData) / sizeof(uptr)) + 1];
 COMPILER_CHECK(sizeof(cov_data_placeholder) >= sizeof(CovData));
 static CovData *cov_data = reinterpret_cast<CovData*>(cov_data_placeholder);
 
@@ -65,6 +66,7 @@ static inline bool CompareLess(const upt
 // Dump the coverage on disk.
 void CovDump() {
 #if !SANITIZER_WINDOWS
+  if (atomic_fetch_add(&cov_data->guard, 1, memory_order_relaxed) != 0) return;
   BlockingMutexLock lock(&cov_data->mu);
   InternalMmapVector<uptr> &v = cov_data->v;
   InternalSort(&v, v.size(), CompareLess);