1 files changed, 26 insertions, 13 deletions

diff --git a/lib/tsan/rtl/tsan_rtl.cc b/lib/tsan/rtl/tsan_rtl.cc
index b3320aad8038..b76f3e05dde6 100644
--- a/lib/tsan/rtl/tsan_rtl.cc
+++ b/lib/tsan/rtl/tsan_rtl.cc
@@ -67,8 +67,17 @@ static char thread_registry_placeholder[sizeof(ThreadRegistry)];
 static ThreadContextBase *CreateThreadContext(u32 tid) {
   // Map thread trace when context is created.
   MapThreadTrace(GetThreadTrace(tid), TraceSize() * sizeof(Event));
-  MapThreadTrace(GetThreadTraceHeader(tid), sizeof(Trace));
-  new(ThreadTrace(tid)) Trace();
+  const uptr hdr = GetThreadTraceHeader(tid);
+  MapThreadTrace(hdr, sizeof(Trace));
+  new((void*)hdr) Trace();
+  // We are going to use only a small part of the trace with the default
+  // value of history_size. However, the constructor writes to the whole trace.
+  // Unmap the unused part.
+  uptr hdr_end = hdr + sizeof(Trace);
+  hdr_end -= sizeof(TraceHeader) * (kTraceParts - TraceParts());
+  hdr_end = RoundUp(hdr_end, GetPageSizeCached());
+  if (hdr_end < hdr + sizeof(Trace))
+    UnmapOrDie((void*)hdr_end, hdr + sizeof(Trace) - hdr_end);
   void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadContext));
   return new(mem) ThreadContext(tid);
 }
@@ -117,6 +126,7 @@ ThreadState::ThreadState(Context *ctx, int tid, int unique_id, u64 epoch,
 {
 }
 
+#ifndef SANITIZER_GO
 static void MemoryProfiler(Context *ctx, fd_t fd, int i) {
   uptr n_threads;
   uptr n_running_threads;
@@ -127,13 +137,11 @@ static void MemoryProfiler(Context *ctx, fd_t fd, int i) {
 }
 
 static void BackgroundThread(void *arg) {
-#ifndef SANITIZER_GO
   // This is a non-initialized non-user thread, nothing to see here.
   // We don't use ScopedIgnoreInterceptors, because we want ignores to be
   // enabled even when the thread function exits (e.g. during pthread thread
   // shutdown code).
   cur_thread()->ignore_interceptors++;
-#endif
   const u64 kMs2Ns = 1000 * 1000;
 
   fd_t mprof_fd = kInvalidFd;
@@ -191,7 +199,6 @@ static void BackgroundThread(void *arg) {
     if (mprof_fd != kInvalidFd)
       MemoryProfiler(ctx, mprof_fd, i);
 
-#ifndef SANITIZER_GO
     // Flush symbolizer cache if requested.
     if (flags()->flush_symbolizer_ms > 0) {
       u64 last = atomic_load(&ctx->last_symbolize_time_ns,
@@ -203,7 +210,6 @@ static void BackgroundThread(void *arg) {
         atomic_store(&ctx->last_symbolize_time_ns, 0, memory_order_relaxed);
       }
     }
-#endif
   }
 }
 
@@ -211,13 +217,14 @@ static void StartBackgroundThread() {
   ctx->background_thread = internal_start_thread(&BackgroundThread, 0);
 }
 
-#ifndef SANITIZER_GO
+#ifndef __mips__
 static void StopBackgroundThread() {
   atomic_store(&ctx->stop_background_thread, 1, memory_order_relaxed);
   internal_join_thread(ctx->background_thread);
   ctx->background_thread = 0;
 }
 #endif
+#endif
 
 void DontNeedShadowFor(uptr addr, uptr size) {
   uptr shadow_beg = MemToShadow(addr);
@@ -282,11 +289,11 @@ static void CheckShadowMapping() {
         if (p < beg || p >= end)
           continue;
         const uptr s = MemToShadow(p);
-        VPrintf(3, "  checking pointer %p -> %p\n", p, s);
+        const uptr m = (uptr)MemToMeta(p);
+        VPrintf(3, "  checking pointer %p: shadow=%p meta=%p\n", p, s, m);
         CHECK(IsAppMem(p));
         CHECK(IsShadowMem(s));
         CHECK_EQ(p & ~(kShadowCell - 1), ShadowToMem(s));
-        const uptr m = (uptr)MemToMeta(p);
         CHECK(IsMetaMem(m));
       }
     }
@@ -325,11 +332,14 @@ void Initialize(ThreadState *thr) {
 #ifndef SANITIZER_GO
   InitializeLibIgnore();
   Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
-#endif
+  // On MIPS, TSan initialization is run before
+  // __pthread_initialize_minimal_internal() is finished, so we can not spawn
+  // new threads.
+#ifndef __mips__
   StartBackgroundThread();
-#ifndef SANITIZER_GO
   SetSandboxingCallback(StopBackgroundThread);
 #endif
+#endif
   if (common_flags()->detect_deadlocks)
     ctx->dd = DDetector::Create(flags());
 
@@ -394,8 +404,11 @@ int Finalize(ThreadState *thr) {
 
   failed = OnFinalize(failed);
 
+#if TSAN_COLLECT_STATS
   StatAggregate(ctx->stat, thr->stat);
   StatOutput(ctx->stat);
+#endif
+
   return failed ? flags()->exitcode : 0;
 }
 
@@ -419,7 +432,7 @@ void ForkChildAfter(ThreadState *thr, uptr pc) {
   VPrintf(1, "ThreadSanitizer: forked new process with pid %d,"
       " parent had %d threads\n", (int)internal_getpid(), (int)nthread);
   if (nthread == 1) {
-    internal_start_thread(&BackgroundThread, 0);
+    StartBackgroundThread();
   } else {
     // We've just forked a multi-threaded process. We cannot reasonably function
     // after that (some mutexes may be locked before fork). So just enable
@@ -826,7 +839,7 @@ static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
     }
   } else {
     // The region is big, reset only beginning and end.
-    const uptr kPageSize = 4096;
+    const uptr kPageSize = GetPageSizeCached();
     u64 *begin = (u64*)MemToShadow(addr);
     u64 *end = begin + size / kShadowCell * kShadowCnt;
     u64 *p = begin;