[tsan] Return 0 from malloc_size for non-malloc'd pointers

In http://reviews.llvm.org/D19100, I introduced a bug: On OS X, existing programs rely on malloc_size() to detect whether a pointer comes from heap memory (malloc_size returns non-zero) or not. We have to distinguish between a zero-sized allocation (where we need to return 1 from malloc_size, due to other binary compatibility reasons, see http://reviews.llvm.org/D19100), and pointers that are not returned from malloc at all.

Differential Revision: http://reviews.llvm.org/D19653

llvm-svn: 268157

1 files changed, 43 insertions, 11 deletions

diff --git a/compiler-rt/test/tsan/Darwin/malloc_size.mm b/compiler-rt/test/tsan/Darwin/malloc_size.mm
index da1830529dd..3d3629b73e7 100644
--- a/compiler-rt/test/tsan/Darwin/malloc_size.mm
+++ b/compiler-rt/test/tsan/Darwin/malloc_size.mm
@@ -6,18 +6,50 @@
 #import <Foundation/Foundation.h>
 #include <malloc/malloc.h>
 
-int main() {
-  void *p = malloc(0);
-
-  size_t s = malloc_size(p);
-  printf("size = 0x%zx\n", s);
+int some_global;
 
+void describe_zone(void *p) {
   malloc_zone_t *z = malloc_zone_from_ptr(p);
-  if (z)
-    printf("z = %p\n", z);
-  else
-    printf("no zone\n");
+  if (z) {
+    fprintf(stderr, "zone = %p\n", z);
+  }	else {
+  	fprintf(stderr, "zone = no zone\n");
+  }
 }
 
-// CHECK: z = 0x{{[0-9a-f]+}}
-// CHECK-NOT: no zone
+int main() {
+  void *p;
+  size_t s;
+
+  p = malloc(0x40);
+  s = malloc_size(p);
+  fprintf(stderr, "size = 0x%zx\n", s);
+  // CHECK: size = 0x40
+  describe_zone(p);
+  // CHECK: zone = 0x{{[0-9a-f]+}}
+
+  p = malloc(0);
+  s = malloc_size(p);
+  fprintf(stderr, "size = 0x%zx\n", s);
+  // CHECK: size = 0x1
+  describe_zone(p);
+  // CHECK: zone = 0x{{[0-9a-f]+}}
+
+  p = &some_global;
+  s = malloc_size(p);
+  fprintf(stderr, "size = 0x%zx\n", s);
+  // CHECK: size = 0x0
+  describe_zone(p);
+  // CHECK: zone = no zone
+
+  p = mmap(0, 0x1000, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
+  if (!p) {
+  	fprintf(stderr, "mmap failed\n");
+  	exit(1);
+  }
+  s = malloc_size(p);
+  fprintf(stderr, "size = 0x%zx\n", s);
+  // CHECK: size = 0x0
+  describe_zone(p);
+  // CHECK: zone = no zone
+}