From 2e7f29f042eb203215eb0ccb12ebc5b811fa4c7a Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Mon, 18 Mar 2013 15:49:07 +0000
Subject: [PATCH] tsan: mark shadow for thread stack as "don't need" when
 thread exits

llvm-svn: 177288
---
 compiler-rt/lib/tsan/rtl/tsan_interceptors.cc |  6 +-----
 compiler-rt/lib/tsan/rtl/tsan_mman.cc         |  5 +----
 compiler-rt/lib/tsan/rtl/tsan_rtl.cc          |  6 ++++++
 compiler-rt/lib/tsan/rtl/tsan_rtl.h           |  1 +
 compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc   | 16 ++++------------
 5 files changed, 13 insertions(+), 21 deletions(-)

diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
index 0bc4c73..5c84989 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
@@ -619,11 +619,7 @@ TSAN_INTERCEPTOR(void*, mmap64, void *addr, long_t sz, int prot,
 
 TSAN_INTERCEPTOR(int, munmap, void *addr, long_t sz) {
   SCOPED_TSAN_INTERCEPTOR(munmap, addr, sz);
-  // We are about to unmap a chunk of user memory.
-  // Mark the corresponding shadow memory as not needed.
-  uptr shadow_beg = MemToShadow((uptr)addr);
-  uptr shadow_end = MemToShadow((uptr)addr + sz);
-  FlushUnneededShadowMemory(shadow_beg, shadow_end - shadow_beg);
+  DontNeedShadowFor((uptr)addr, sz);
   int res = REAL(munmap)(addr, sz);
   return res;
 }
diff --git a/compiler-rt/lib/tsan/rtl/tsan_mman.cc b/compiler-rt/lib/tsan/rtl/tsan_mman.cc
index 355d93b..1d887c6 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_mman.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_mman.cc
@@ -34,10 +34,7 @@ struct MapUnmapCallback {
   void OnUnmap(uptr p, uptr size) const {
     // We are about to unmap a chunk of user memory.
     // Mark the corresponding shadow memory as not needed.
-    uptr shadow_beg = MemToShadow(p);
-    uptr shadow_end = MemToShadow(p + size);
-    CHECK(IsAligned(shadow_end|shadow_beg, GetPageSizeCached()));
-    FlushUnneededShadowMemory(shadow_beg, shadow_end - shadow_beg);
+    DontNeedShadowFor(p, size);
   }
 };
 
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl.cc
index 2e9a36b..9ed3a4c 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.cc
@@ -125,6 +125,12 @@ static void InitializeMemoryProfile() {
   internal_start_thread(&MemoryProfileThread, (void*)(uptr)fd);
 }
 
+void DontNeedShadowFor(uptr addr, uptr size) {
+  uptr shadow_beg = MemToShadow(addr);
+  uptr shadow_end = MemToShadow(addr + size);
+  FlushUnneededShadowMemory(shadow_beg, shadow_end - shadow_beg);
+}
+
 static void MemoryFlushThread(void *arg) {
   ScopedInRtl in_rtl;
   for (int i = 0; ; i++) {
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.h b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
index 02d4edd..3db1a89 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
@@ -527,6 +527,7 @@ void ALWAYS_INLINE INLINE StatSet(ThreadState *thr, StatType typ, u64 n) {
 
 void MapShadow(uptr addr, uptr size);
 void MapThreadTrace(uptr addr, uptr size);
+void DontNeedShadowFor(uptr addr, uptr size);
 void InitializeShadowMemory();
 void InitializeInterceptors();
 void InitializeDynamicAnnotations();
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
index 238baef..0372bb5 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
@@ -200,9 +200,8 @@ void ThreadStart(ThreadState *thr, int tid, uptr os_id) {
   GetThreadStackAndTls(tid == 0, &stk_addr, &stk_size, &tls_addr, &tls_size);
 
   if (tid) {
-    if (stk_addr && stk_size) {
+    if (stk_addr && stk_size)
       MemoryResetRange(thr, /*pc=*/ 1, stk_addr, stk_size);
-    }
 
     if (tls_addr && tls_size) {
       // Check that the thr object is in tls;
@@ -225,17 +224,10 @@ void ThreadStart(ThreadState *thr, int tid, uptr os_id) {
 void ThreadFinish(ThreadState *thr) {
   CHECK_GT(thr->in_rtl, 0);
   StatInc(thr, StatThreadFinish);
-  // FIXME: Treat it as write.
   if (thr->stk_addr && thr->stk_size)
-    MemoryResetRange(thr, /*pc=*/ 3, thr->stk_addr, thr->stk_size);
-  if (thr->tls_addr && thr->tls_size) {
-    const uptr thr_beg = (uptr)thr;
-    const uptr thr_end = (uptr)thr + sizeof(*thr);
-    // Since the thr object is huge, skip it.
-    MemoryResetRange(thr, /*pc=*/ 4, thr->tls_addr, thr_beg - thr->tls_addr);
-    MemoryResetRange(thr, /*pc=*/ 5,
-        thr_end, thr->tls_addr + thr->tls_size - thr_end);
-  }
+    DontNeedShadowFor(thr->stk_addr, thr->stk_size);
+  if (thr->tls_addr && thr->tls_size)
+    DontNeedShadowFor(thr->tls_addr, thr->tls_size);
   thr->is_alive = false;
   Context *ctx = CTX();
   ctx->thread_registry->FinishThread(thr->tid);
-- 
2.7.4