1 files changed, 10 insertions, 3 deletions
diff --git a/libsanitizer/asan/asan_poisoning.cc b/libsanitizer/asan/asan_poisoning.cc
index 1343dfbd39e..35409baf612 100644
--- a/libsanitizer/asan/asan_poisoning.cc
+++ b/libsanitizer/asan/asan_poisoning.cc
@@ -30,7 +30,7 @@ bool CanPoisonMemory() {
 }
 
 void PoisonShadow(uptr addr, uptr size, u8 value) {
-  if (!CanPoisonMemory()) return;
+  if (value && !CanPoisonMemory()) return;
   CHECK(AddrIsAlignedByGranularity(addr));
   CHECK(AddrIsInMem(addr));
   CHECK(AddrIsAlignedByGranularity(addr + size));
@@ -180,8 +180,15 @@ int __asan_address_is_poisoned(void const volatile *addr) {
 uptr __asan_region_is_poisoned(uptr beg, uptr size) {
   if (!size) return 0;
   uptr end = beg + size;
-  if (!AddrIsInMem(beg)) return beg;
-  if (!AddrIsInMem(end)) return end;
+  if (SANITIZER_MYRIAD2) {
+    // On Myriad, address not in DRAM range need to be treated as
+    // unpoisoned.
+    if (!AddrIsInMem(beg) && !AddrIsInShadow(beg)) return 0;
+    if (!AddrIsInMem(end) && !AddrIsInShadow(end)) return 0;
+  } else {
+    if (!AddrIsInMem(beg)) return beg;
+    if (!AddrIsInMem(end)) return end;
+  }
   CHECK_LT(beg, end);
   uptr aligned_b = RoundUpTo(beg, SHADOW_GRANULARITY);
   uptr aligned_e = RoundDownTo(end, SHADOW_GRANULARITY);