diff --git a/compiler-rt/lib/tsan/rtl/tsan_platform.h b/compiler-rt/lib/tsan/rtl/tsan_platform.h
index 354f6da6a64a..ada594bc11fc 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_platform.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_platform.h
@@ -931,7 +931,7 @@ bool IsAppMem(uptr mem) { return SelectMapping<IsAppMemImpl>(mem); }
 struct IsShadowMemImpl {
   template <typename Mapping>
   static bool Apply(uptr mem) {
-    return mem >= Mapping::kShadowBeg && mem <= Mapping::kShadowEnd;
+    return mem >= Mapping::kShadowBeg && mem < Mapping::kShadowEnd;
   }
 };
 
@@ -943,7 +943,7 @@ bool IsShadowMem(RawShadow *p) {
 struct IsMetaMemImpl {
   template <typename Mapping>
   static bool Apply(uptr mem) {
-    return mem >= Mapping::kMetaShadowBeg && mem <= Mapping::kMetaShadowEnd;
+    return mem >= Mapping::kMetaShadowBeg && mem < Mapping::kMetaShadowEnd;
   }
 };
 
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp
index cf07686d968d..dbdc6359d92a 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp
@@ -525,7 +525,7 @@ SECOND:
 void ShadowSet(RawShadow* p, RawShadow* end, RawShadow v) {
   DCHECK_LE(p, end);
   DCHECK(IsShadowMem(p));
-  DCHECK(IsShadowMem(end));
+  DCHECK(p == end || IsShadowMem(end - 1));
   UNUSED const uptr kAlign = kShadowCnt * kShadowSize;
   DCHECK_EQ(reinterpret_cast<uptr>(p) % kAlign, 0);
   DCHECK_EQ(reinterpret_cast<uptr>(end) % kAlign, 0);
@@ -669,7 +669,7 @@ void MemoryAccessRangeT(ThreadState* thr, uptr pc, uptr addr, uptr size) {
   RawShadow* shadow_mem = MemToShadow(addr);
   DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_read=%d\n", thr->tid,
            (void*)pc, (void*)addr, (int)size, is_read);
-
+  DCHECK_NE(size, 0);
 #if SANITIZER_DEBUG
   if (!IsAppMem(addr)) {
     Printf("Access to non app mem start: %p\n", (void*)addr);