Index: compiler-rt/lib/asan/asan_errors.cc
===================================================================
--- compiler-rt/lib/asan/asan_errors.cc
+++ compiler-rt/lib/asan/asan_errors.cc
@@ -296,6 +296,12 @@
       if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY) shadow_addr++;
       // If we are in the partial right redzone, look at the next shadow byte.
       if (*shadow_addr > 0 && *shadow_addr < 128) shadow_addr++;
+      // For large shadow granularity, skip pass all partial right redzones.
+      if (SHADOW_GRANULARITY >= 32) {
+        while (AddrIsInShadow((uptr)shadow_addr) && *shadow_addr > 0 &&
+               *shadow_addr < 128)
+          shadow_addr++;
+      }
       bool far_from_bounds = false;
       shadow_val = *shadow_addr;
       int bug_type_score = 0;
Index: llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp
===================================================================
--- llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp
+++ llvm/lib/Transforms/Utils/ASanStackFrameLayout.cpp
@@ -81,6 +81,9 @@
     size_t NextAlignment = IsLast ? Granularity
                    : std::max(Granularity, Vars[i + 1].Alignment);
     size_t SizeWithRedzone = VarAndRedzoneSize(Size, NextAlignment);
+    // Add a sentinel to end of stack.
+    if (IsLast && SizeWithRedzone == Granularity)
+      SizeWithRedzone += Granularity;
     Vars[i].Offset = Offset;
     Offset += SizeWithRedzone;
   }
Index: llvm/unittests/Transforms/Utils/ASanStackFrameLayoutTest.cpp
===================================================================
--- llvm/unittests/Transforms/Utils/ASanStackFrameLayoutTest.cpp
+++ llvm/unittests/Transforms/Utils/ASanStackFrameLayoutTest.cpp
@@ -70,7 +70,7 @@
   VAR(a, 105, 103, 1, 0);
 
   TEST_LAYOUT({a1_1}, 8, 16, "1 16 1 4 a1_1", "LL1R", "LL1R");
-  TEST_LAYOUT({a1_1}, 64, 64, "1 64 1 4 a1_1", "L1", "L1");
+  TEST_LAYOUT({a1_1}, 64, 64, "1 64 1 4 a1_1", "L1R", "L1R");
   TEST_LAYOUT({p1_32}, 8, 32, "1 32 1 8 p1_32:15", "LLLL1RRR", "LLLL1RRR");
   TEST_LAYOUT({p1_32}, 8, 64, "1 64 1 8 p1_32:15", "LLLLLLLL1RRRRRRR",
               "LLLLLLLL1RRRRRRR");