From 173c690a618287d06fe7f29175675af12dbe3a6a Mon Sep 17 00:00:00 2001 From: Kuba Brecka Date: Thu, 14 Apr 2016 09:05:19 +0000 Subject: [PATCH] [tsan] Fix size reporting for OS X zone allocator with 0-sized allocations 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 --- compiler-rt/lib/tsan/rtl/tsan_malloc_mac.cc | 3 ++- compiler-rt/test/tsan/Darwin/malloc_size.mm | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 compiler-rt/test/tsan/Darwin/malloc_size.mm diff --git a/compiler-rt/lib/tsan/rtl/tsan_malloc_mac.cc b/compiler-rt/lib/tsan/rtl/tsan_malloc_mac.cc index 7fd9427..1366384 100644 --- a/compiler-rt/lib/tsan/rtl/tsan_malloc_mac.cc +++ b/compiler-rt/lib/tsan/rtl/tsan_malloc_mac.cc @@ -53,7 +53,8 @@ using namespace __tsan; 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; \ diff --git a/compiler-rt/test/tsan/Darwin/malloc_size.mm b/compiler-rt/test/tsan/Darwin/malloc_size.mm new file mode 100644 index 0000000..da18305 --- /dev/null +++ b/compiler-rt/test/tsan/Darwin/malloc_size.mm @@ -0,0 +1,23 @@ +// 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 +#include + +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 -- 2.7.4