1// Test for potential deadlock in LeakSanitizer+AddressSanitizer.
2// REQUIRES: leak-detection
3//
4// RUN: %clangxx_asan -O0 %s -o %t
5// RUN: %env_asan_opts=detect_leaks=1 not %run %t 2>&1 | FileCheck %s
6
7// FIXME: Hangs for unknown reasons on all platforms. We can re-enable it when
8// its either deterministic, or we solve the deadlock between asan and lsan.
9// UNSUPPORTED: true
10
11/*
12 * Purpose: Verify deadlock prevention between ASan error reporting and LSan leak checking.
13 *
14 * Test Design:
15 * 1. Creates contention scenario between:
16 * - ASan's error reporting (requires lock B -> lock A ordering)
17 * - LSan's leak check (requires lock A -> lock B ordering)
18 * 2. Thread timing:
19 * - Main thread: Holds 'in' mutex -> Triggers LSan check (lock A then B)
20 * - Worker thread: Triggers ASan OOB error (lock B then A via symbolization)
21 *
22 * Deadlock Condition (if unfixed):
23 * Circular lock dependency forms when:
24 * [Main Thread] LSan: lock A -> requests lock B
25 * [Worker Thread] ASan: lock B -> requests lock A
26 *
27 * Success Criteria:
28 * With proper lock ordering enforcement, watchdog should NOT trigger - test exits with Asan report.
29 */
30
31#include <mutex>
32#include <sanitizer/lsan_interface.h>
33#include <stdio.h>
34#include <thread>
35#include <unistd.h>
36
37void Watchdog() {
38 // Safety mechanism: Turn infinite deadlock into finite test failure
39 sleep(seconds: 60);
40 // Unexpected. "not" in RUN will fail if we reached here.
41 _exit(status: 0);
42}
43
44int main(int argc, char **argv) {
45 int arr[1] = {0};
46 std::mutex in;
47 in.lock();
48
49 std::thread w(Watchdog);
50 w.detach();
51
52 std::thread t([&]() {
53 in.unlock();
54 /*
55 * Provoke ASan error: ASan's error reporting acquires:
56 * 1. ASan's thread registry lock (B) during the reporting
57 * 2. dl_iterate_phdr lock (A) during symbolization
58 */
59 // CHECK: SUMMARY: AddressSanitizer: stack-buffer-overflow
60 arr[argc] = 1; // Deliberate OOB access
61 });
62
63 in.lock();
64 /*
65 * Critical section: LSan's check acquires:
66 * 1. dl_iterate_phdr lock (A)
67 * 2. ASan's thread registry lock (B)
68 * before Stop The World.
69 */
70 __lsan_do_leak_check();
71 t.join();
72 return 0;
73}
74

source code of compiler-rt/test/asan/TestCases/asan_lsan_deadlock.cpp