[compiler-rt] [compiler-rt][TSan] fix crash caused by intercpting pthread_detach on Android (PR #161596)

[Fei Peng via llvm-commits]

https://github.com/airpfei created https://github.com/llvm/llvm-project/pull/161596

In Bionic, pthread_detach calls pthread_join, so the thread has already been consumed by the pthread_detach interceptor.

https://android.googlesource.com/platform/bionic/+/refs/heads/android16-release/libc/bionic/pthread_detach.cpp


>From a35a95d88d6f2e5eb2331398fd8ad49d2e7d6d6e Mon Sep 17 00:00:00 2001
From: Fei Peng <pengfei.02 at bytedance.com>
Date: Wed, 1 Oct 2025 15:16:36 -0700
Subject: [PATCH] [compiler-rt][TSan] fix crash caused by intercpting
 pthread_detach on Android

---
 .../lib/tsan/rtl/tsan_interceptors_posix.cpp       | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
index b46a81031258c..40bd7e217f4f7 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -1130,6 +1130,20 @@ TSAN_INTERCEPTOR(int, pthread_create,
 
 TSAN_INTERCEPTOR(int, pthread_join, void *th, void **ret) {
   SCOPED_INTERCEPTOR_RAW(pthread_join, th, ret);
+#if SANITIZER_ANDROID
+  {
+    // In Bionic, pthread_detach calls pthread_join, so the thread has already
+    // been consumed by the pthread_detach interceptor.
+    Tid tid = ctx->thread_registry.FindThread(
+        [](ThreadContextBase *tctx, void *arg) {
+          return tctx->user_id == (uptr)arg;
+        },
+        th);
+    if (tid == kInvalidTid) {
+      return REAL(pthread_join)(th, ret);
+    }
+  }
+#endif
   Tid tid = ThreadConsumeTid(thr, pc, (uptr)th);
   ThreadIgnoreBegin(thr, pc);
   int res = BLOCK_REAL(pthread_join)(th, ret);