The custom zone implementation for OS X must not return 0 (even for 0-sized allocations). Returning 0 indicates that the pointer doesn't belong to the zone. This can break existing applications. The underlaying allocator allocates 1 byte for 0-sized allocations anyway, so returning 1 in this case is okay.
Differential Revision: http://reviews.llvm.org/D19100
llvm-svn: 266283
SCOPED_INTERCEPTOR_RAW(free, ptr); \
user_free(thr, pc, ptr)
#define COMMON_MALLOC_SIZE(ptr) \
- uptr size = user_alloc_usable_size(ptr);
+ uptr size = user_alloc_usable_size(ptr); \
+ if (size == 0) size = 1;
#define COMMON_MALLOC_FILL_STATS(zone, stats)
#define COMMON_MALLOC_REPORT_UNKNOWN_REALLOC(ptr, zone_ptr, zone_name) \
(void)zone_name; \
--- /dev/null
+// Test that malloc_zone_from_ptr returns a valid zone for a 0-sized allocation.
+
+// RUN: %clang_tsan %s -o %t -framework Foundation
+// RUN: %run %t 2>&1 | FileCheck %s
+
+#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);
+
+ malloc_zone_t *z = malloc_zone_from_ptr(p);
+ if (z)
+ printf("z = %p\n", z);
+ else
+ printf("no zone\n");
+}
+
+// CHECK: z = 0x{{[0-9a-f]+}}
+// CHECK-NOT: no zone