[ASan] Fix __asan_describe_address and add a test for it.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@213583 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 22 insertions, 0 deletions

diff --git a/lib/asan/asan_report.cc b/lib/asan/asan_report.cc
index 3135e1028..395cefe22 100644
--- a/lib/asan/asan_report.cc
+++ b/lib/asan/asan_report.cc
@@ -945,7 +945,10 @@ void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
 }
 
 void __asan_describe_address(uptr addr) {
+  // Thread registry must be locked while we're describing an address.
+  asanThreadRegistry().Lock();
   DescribeAddress(addr, 1);
+  asanThreadRegistry().Unlock();
 }
 
 extern "C" {
diff --git a/test/asan/TestCases/describe_address.cc b/test/asan/TestCases/describe_address.cc
new file mode 100644
index 000000000..868c0eb1c
--- /dev/null
+++ b/test/asan/TestCases/describe_address.cc
@@ -0,0 +1,19 @@
+// RUN: %clangxx_asan -O0 %s -o %t && %run %t 2>&1 | FileCheck %s
+
+#include <sanitizer/asan_interface.h>
+
+int global;
+
+int main(int argc, char *argv[]) {
+  int stack;
+  int *heap = new int[100];
+  __asan_describe_address(heap);
+  // CHECK: {{.*}} is located 0 bytes inside of 400-byte region
+  // CHECK: allocated by thread T{{.*}} here
+  __asan_describe_address(&stack);
+  // CHECK: Address {{.*}} is located in stack of thread T{{.*}} at offset {{.*}}
+  __asan_describe_address(&global);
+  // CHECK: {{.*}} is located 0 bytes inside of global variable 'global'
+  delete[] heap;
+  return 0;
+}