1 files changed, 57 insertions, 0 deletions
diff --git a/libsanitizer/asan/asan_poisoning.h b/libsanitizer/asan/asan_poisoning.h
new file mode 100644
index 00000000000..866c0a57c7e
--- /dev/null
+++ b/libsanitizer/asan/asan_poisoning.h
@@ -0,0 +1,57 @@
+//===-- asan_poisoning.h ----------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// Shadow memory poisoning by ASan RTL and by user application.
+//===----------------------------------------------------------------------===//
+
+#include "asan_interceptors.h"
+#include "asan_internal.h"
+#include "asan_mapping.h"
+
+namespace __asan {
+
+// Poisons the shadow memory for "size" bytes starting from "addr".
+void PoisonShadow(uptr addr, uptr size, u8 value);
+
+// Poisons the shadow memory for "redzone_size" bytes starting from
+// "addr + size".
+void PoisonShadowPartialRightRedzone(uptr addr,
+                                     uptr size,
+                                     uptr redzone_size,
+                                     u8 value);
+
+// Fast versions of PoisonShadow and PoisonShadowPartialRightRedzone that
+// assume that memory addresses are properly aligned. Use in
+// performance-critical code with care.
+ALWAYS_INLINE void FastPoisonShadow(uptr aligned_beg, uptr aligned_size,
+                                    u8 value) {
+  DCHECK(flags()->poison_heap);
+  uptr shadow_beg = MEM_TO_SHADOW(aligned_beg);
+  uptr shadow_end = MEM_TO_SHADOW(
+      aligned_beg + aligned_size - SHADOW_GRANULARITY) + 1;
+  REAL(memset)((void*)shadow_beg, value, shadow_end - shadow_beg);
+}
+
+ALWAYS_INLINE void FastPoisonShadowPartialRightRedzone(
+    uptr aligned_addr, uptr size, uptr redzone_size, u8 value) {
+  DCHECK(flags()->poison_heap);
+  u8 *shadow = (u8*)MEM_TO_SHADOW(aligned_addr);
+  for (uptr i = 0; i < redzone_size; i += SHADOW_GRANULARITY, shadow++) {
+    if (i + SHADOW_GRANULARITY <= size) {
+      *shadow = 0;  // fully addressable
+    } else if (i >= size) {
+      *shadow = (SHADOW_GRANULARITY == 128) ? 0xff : value;  // unaddressable
+    } else {
+      // first size-i bytes are addressable
+      *shadow = static_cast<u8>(size - i);
+    }
+  }
+}
+
+}  // namespace __asan