[llvm-branch-commits] [compiler-rt] [TSan] Lock ScopedErrorReportLock before slot and thread_registry locks (PR #228614)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka updated https://github.com/llvm/llvm-project/pull/228614

>From 2d7a01735508d80bfbcd365301d826f833301f12 Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka at google.com>
Date: Fri, 2 Oct 2026 16:21:44 -0700
Subject: [PATCH 1/2] Add CheckNoLocks and keep ReportDestroyLocked
 RestoreStack in place

Created using spr 1.3.7
---
 compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp  | 29 ++++++++------------
 compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp |  2 ++
 2 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
index 80bda14d728ec..23226f86bf33c 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
@@ -574,34 +574,29 @@ void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r) {
 
 void ReportDestroyLocked(ThreadState *thr, uptr pc, uptr addr,
                          FastState last_lock, StackID creation_stack_id) {
-  Tid tid;
-  DynamicMutexSet mset;
-  uptr tag;
-  VarSizeStackTrace last_lock_stack;
-  {
-    // We need to lock the slot during RestoreStack because it protects
-    // the slot journal.
-    Lock slot_lock(&ctx->slots[static_cast<uptr>(last_lock.sid())].mtx);
-    ThreadRegistryLock l0(&ctx->thread_registry);
-    Lock slots_lock(&ctx->slot_mtx);
-    if (!RestoreStack(EventType::kLock, last_lock.sid(), last_lock.epoch(),
-                      addr, 0, kAccessWrite, &tid, &last_lock_stack, mset,
-                      &tag))
-      return;
-  }
-
   // Use alloca, because malloc during signal handling deadlocks
   ScopedReport *rep = (ScopedReport *)__builtin_alloca(sizeof(ScopedReport));
   // Release locks before symbolizing and outputting the report to avoid
   // deadlocks.
   {
     new (rep) ScopedReport(ReportTypeMutexDestroyLocked);
+    // We need to lock the slot during RestoreStack because it protects
+    // the slot journal.
+    Lock slot_lock(&ctx->slots[static_cast<uptr>(last_lock.sid())].mtx);
     ThreadRegistryLock l0(&ctx->thread_registry);
+    Lock slots_lock(&ctx->slot_mtx);
     rep->AddMutex(addr, creation_stack_id);
     VarSizeStackTrace trace;
     ObtainCurrentStack(thr, pc, &trace);
     rep->AddStack(trace, true);
-    rep->AddStack(last_lock_stack, true);
+
+    Tid tid;
+    DynamicMutexSet mset;
+    uptr tag;
+    if (!RestoreStack(EventType::kLock, last_lock.sid(), last_lock.epoch(),
+                      addr, 0, kAccessWrite, &tid, &trace, mset, &tag))
+      return;
+    rep->AddStack(trace, true);
     rep->AddLocation(addr, 1);
   }
   OutputReport(thr, *rep);
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
index 132ef718d39f5..e90d7e8851752 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
@@ -164,6 +164,7 @@ bool ShouldReport(ThreadState *thr, ReportType typ) {
 }
 
 ScopedReportBase::ScopedReportBase(ReportType typ, uptr tag) {
+  CheckedMutex::CheckNoLocks();
   rep_ = New<ReportDesc>();
   rep_->typ = typ;
   rep_->tag = tag;
@@ -676,6 +677,7 @@ static bool HandleRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2]) {
 }
 
 bool OutputReport(ThreadState *thr, ScopedReport &srep) {
+  CheckedMutex::CheckNoLocks();
   // These should have been checked in ShouldReport.
   // It's too late to check them here, we have already taken locks.
   CHECK(flags()->report_bugs);

>From a74331b81d885b13eb7365417e15239a6e181627 Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka at google.com>
Date: Fri, 2 Oct 2026 19:41:31 -0700
Subject: [PATCH 2/2] Fix clang-format

Created using spr 1.3.7
---
 compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
index e90d7e8851752..7d302955374de 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
@@ -843,7 +843,7 @@ void ReportRace(ThreadState *thr, RawShadow *shadow_mem, Shadow cur, Shadow old,
   }
 
   // Use alloca, because malloc during signal handling deadlocks
-  ScopedReport *rep = (ScopedReport *)__builtin_alloca(sizeof(ScopedReport));
+  ScopedReport* rep = (ScopedReport*)__builtin_alloca(sizeof(ScopedReport));
   // Release locks before symbolizing and outputting the report to avoid
   // deadlocks.
   {