[compiler-rt] r350258 - [TSan] Enable detection of lock-order-inversions for Objective-C @synchronized
Julian Lettner via llvm-commits
llvm-commits at lists.llvm.org
Wed Jan 2 12:10:30 PST 2019
Author: yln
Date: Wed Jan 2 12:10:30 2019
New Revision: 350258
URL: http://llvm.org/viewvc/llvm-project?rev=350258&view=rev
Log:
[TSan] Enable detection of lock-order-inversions for Objective-C @synchronized
Summary:
@synchronized semantics can be synthesized by using existing mutex_[un]lock operations.
```
@synchronized(obj) {
// ...
}
=>
{
mutex_lock(obj);
// ...
mutex_unlock(obj);
}
```
Let me know whether you think this a good idea.
Reviewers: dcoughlin, dvyukov, kubamracek, delcypher
Reviewed By: dvyukov
Subscribers: llvm-commits, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D55959
Added:
compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle-tagged.mm
compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle.mm
compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-nested-recursive.mm
Modified:
compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors_mac.cc
Modified: compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors_mac.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors_mac.cc?rev=350258&r1=350257&r2=350258&view=diff
==============================================================================
--- compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors_mac.cc (original)
+++ compiler-rt/trunk/lib/tsan/rtl/tsan_interceptors_mac.cc Wed Jan 2 12:10:30 2019
@@ -21,6 +21,7 @@
#include "tsan_interface_ann.h"
#include <libkern/OSAtomic.h>
+#include <objc/objc-sync.h>
#if defined(__has_include) && __has_include(<xpc/xpc.h>)
#include <xpc/xpc.h>
@@ -318,17 +319,25 @@ static uptr SyncAddressForObjCObject(voi
return (uptr)obj;
}
-TSAN_INTERCEPTOR(int, objc_sync_enter, void *obj) {
+TSAN_INTERCEPTOR(int, objc_sync_enter, id obj) {
SCOPED_TSAN_INTERCEPTOR(objc_sync_enter, obj);
+ if (!obj) return REAL(objc_sync_enter)(obj);
+ uptr addr = SyncAddressForObjCObject(obj);
+ MutexPreLock(thr, pc, addr, MutexFlagWriteReentrant);
int result = REAL(objc_sync_enter)(obj);
- if (obj) Acquire(thr, pc, SyncAddressForObjCObject(obj));
+ CHECK_EQ(result, OBJC_SYNC_SUCCESS);
+ MutexPostLock(thr, pc, addr, MutexFlagWriteReentrant);
return result;
}
-TSAN_INTERCEPTOR(int, objc_sync_exit, void *obj) {
+TSAN_INTERCEPTOR(int, objc_sync_exit, id obj) {
SCOPED_TSAN_INTERCEPTOR(objc_sync_exit, obj);
- if (obj) Release(thr, pc, SyncAddressForObjCObject(obj));
- return REAL(objc_sync_exit)(obj);
+ if (!obj) return REAL(objc_sync_exit)(obj);
+ uptr addr = SyncAddressForObjCObject(obj);
+ MutexUnlock(thr, pc, addr);
+ int result = REAL(objc_sync_exit)(obj);
+ if (result != OBJC_SYNC_SUCCESS) MutexInvalidAccess(thr, pc, addr);
+ return result;
}
// On macOS, libc++ is always linked dynamically, so intercepting works the
Added: compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle-tagged.mm
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle-tagged.mm?rev=350258&view=auto
==============================================================================
--- compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle-tagged.mm (added)
+++ compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle-tagged.mm Wed Jan 2 12:10:30 2019
@@ -0,0 +1,43 @@
+// RUN: %clangxx_tsan %s -o %t -framework Foundation -fobjc-arc %darwin_min_target_with_full_runtime_arc_support
+// RUN: %run %t 6 2>&1 | FileCheck %s --check-prefix=SIX
+// RUN: not %run %t 7 2>&1 | FileCheck %s --check-prefix=SEVEN
+// XFAIL: *
+
+#import <Foundation/Foundation.h>
+
+static bool isTaggedPtr(id obj) {
+ uintptr_t ptr = (uintptr_t) obj;
+ return (ptr & 0x8000000000000001ull) != 0;
+}
+
+int main(int argc, char* argv[]) {
+ assert(argc == 2);
+ int arg = atoi(argv[0]);
+
+ @autoreleasepool {
+ NSObject* obj = [NSObject new];
+ NSObject* num1 = @7;
+ NSObject* num2 = [NSNumber numberWithInt:arg];
+
+ assert(!isTaggedPtr(obj));
+ assert(isTaggedPtr(num1) && isTaggedPtr(num2));
+
+ // obj -> num1 (includes num2)
+ @synchronized(obj) {
+ @synchronized(num1) {
+ }
+ }
+
+ // num2 -> obj1
+ @synchronized(num2) {
+ @synchronized(obj) {
+// SEVEN: ThreadSanitizer: lock-order-inversion (potential deadlock)
+ }
+ }
+ }
+
+ NSLog(@"PASS");
+// SIX-NOT: ThreadSanitizer
+// SIX: PASS
+ return 0;
+}
Added: compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle.mm
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle.mm?rev=350258&view=auto
==============================================================================
--- compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle.mm (added)
+++ compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-cycle.mm Wed Jan 2 12:10:30 2019
@@ -0,0 +1,31 @@
+// RUN: %clangxx_tsan %s -o %t -framework Foundation -fobjc-arc %darwin_min_target_with_full_runtime_arc_support
+// RUN: not %run %t 2>&1 | FileCheck %s
+// RUN: %env_tsan_opts=detect_deadlocks=1 not %run %t 2>&1 | FileCheck %s
+// RUN: %env_tsan_opts=detect_deadlocks=0 %run %t 2>&1 | FileCheck %s --check-prefix=DISABLED
+
+#import <Foundation/Foundation.h>
+
+int main() {
+ @autoreleasepool {
+ NSObject* obj1 = [NSObject new];
+ NSObject* obj2 = [NSObject new];
+
+ // obj1 -> obj2
+ @synchronized(obj1) {
+ @synchronized(obj2) {
+ }
+ }
+
+ // obj1 -> obj1
+ @synchronized(obj2) {
+ @synchronized(obj1) {
+// CHECK: ThreadSanitizer: lock-order-inversion (potential deadlock)
+ }
+ }
+ }
+
+ NSLog(@"PASS");
+// DISABLED-NOT: ThreadSanitizer
+// DISABLED: PASS
+ return 0;
+}
Added: compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-nested-recursive.mm
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-nested-recursive.mm?rev=350258&view=auto
==============================================================================
--- compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-nested-recursive.mm (added)
+++ compiler-rt/trunk/test/tsan/Darwin/objc-synchronize-nested-recursive.mm Wed Jan 2 12:10:30 2019
@@ -0,0 +1,35 @@
+// RUN: %clangxx_tsan %s -o %t -framework Foundation -fobjc-arc %darwin_min_target_with_full_runtime_arc_support
+// RUN: %run %t 2>&1 | FileCheck %s
+
+#import <Foundation/Foundation.h>
+
+int main() {
+ @autoreleasepool {
+ NSObject* obj1 = [NSObject new];
+ NSObject* obj2 = [NSObject new];
+
+ @synchronized(obj1) {
+ @synchronized(obj1) {
+ NSLog(@"nested 1-1");
+// CHECK: nested 1-1
+ }
+ }
+
+ @synchronized(obj1) {
+ @synchronized(obj2) {
+ @synchronized(obj1) {
+ @synchronized(obj2) {
+ NSLog(@"nested 1-2-1-2");
+// CHECK: nested 1-2-1-2
+ }
+ }
+ }
+ }
+
+ }
+
+ NSLog(@"PASS");
+// CHECK-NOT: ThreadSanitizer
+// CHECK: PASS
+ return 0;
+}
More information about the llvm-commits
mailing list