[asan] Move memcpy, memmove, memset code out of asan_interceptors.cc

This is a pure refactoring change. It simply moves all the code and
macros related to defining the ASan interceptor versions of memcpy,
memmove, and memset into a separate file. This makes it cleaner to
disable all the other interceptor code while still using these three,
for a port that defines these but not the other common interceptors.

Reviewers: alekseyshl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35590

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@308575 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 148 insertions, 0 deletions

diff --git a/lib/asan/asan_interceptors_memintrinsics.h b/lib/asan/asan_interceptors_memintrinsics.h
new file mode 100644
index 000000000..5a8339a23
--- /dev/null
+++ b/lib/asan/asan_interceptors_memintrinsics.h
@@ -0,0 +1,148 @@
+//===-- asan_interceptors_memintrinsics.h -----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// 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.
+//
+// ASan-private header for asan_memintrin.cc
+//===---------------------------------------------------------------------===//
+#ifndef ASAN_MEMINTRIN_H
+#define ASAN_MEMINTRIN_H
+
+#include "asan_interface_internal.h"
+#include "asan_internal.h"
+#include "asan_mapping.h"
+#include "interception/interception.h"
+
+DECLARE_REAL(void*, memcpy, void *to, const void *from, uptr size)
+DECLARE_REAL(void*, memset, void *block, int c, uptr size)
+
+namespace __asan {
+
+// Return true if we can quickly decide that the region is unpoisoned.
+// We assume that a redzone is at least 16 bytes.
+static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
+  if (size == 0) return true;
+  if (size <= 32)
+    return !AddressIsPoisoned(beg) &&
+           !AddressIsPoisoned(beg + size - 1) &&
+           !AddressIsPoisoned(beg + size / 2);
+  if (size <= 64)
+    return !AddressIsPoisoned(beg) &&
+           !AddressIsPoisoned(beg + size / 4) &&
+           !AddressIsPoisoned(beg + size - 1) &&
+           !AddressIsPoisoned(beg + 3 * size / 4) &&
+           !AddressIsPoisoned(beg + size / 2);
+  return false;
+}
+
+struct AsanInterceptorContext {
+  const char *interceptor_name;
+};
+
+// We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
+// and ASAN_WRITE_RANGE as macro instead of function so
+// that no extra frames are created, and stack trace contains
+// relevant information only.
+// We check all shadow bytes.
+#define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) do {            \
+    uptr __offset = (uptr)(offset);                                     \
+    uptr __size = (uptr)(size);                                         \
+    uptr __bad = 0;                                                     \
+    if (__offset > __offset + __size) {                                 \
+      GET_STACK_TRACE_FATAL_HERE;                                       \
+      ReportStringFunctionSizeOverflow(__offset, __size, &stack);       \
+    }                                                                   \
+    if (!QuickCheckForUnpoisonedRegion(__offset, __size) &&             \
+        (__bad = __asan_region_is_poisoned(__offset, __size))) {        \
+      AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx;     \
+      bool suppressed = false;                                          \
+      if (_ctx) {                                                       \
+        suppressed = IsInterceptorSuppressed(_ctx->interceptor_name);   \
+        if (!suppressed && HaveStackTraceBasedSuppressions()) {         \
+          GET_STACK_TRACE_FATAL_HERE;                                   \
+          suppressed = IsStackTraceSuppressed(&stack);                  \
+        }                                                               \
+      }                                                                 \
+      if (!suppressed) {                                                \
+        GET_CURRENT_PC_BP_SP;                                           \
+        ReportGenericError(pc, bp, sp, __bad, isWrite, __size, 0, false);\
+      }                                                                 \
+    }                                                                   \
+  } while (0)
+
+// memcpy is called during __asan_init() from the internals of printf(...).
+// We do not treat memcpy with to==from as a bug.
+// See http://llvm.org/bugs/show_bug.cgi?id=11763.
+#define ASAN_MEMCPY_IMPL(ctx, to, from, size)                           \
+  do {                                                                  \
+    if (UNLIKELY(!asan_inited)) return internal_memcpy(to, from, size); \
+    if (asan_init_is_running) {                                         \
+      return REAL(memcpy)(to, from, size);                              \
+    }                                                                   \
+    ENSURE_ASAN_INITED();                                               \
+    if (flags()->replace_intrin) {                                      \
+      if (to != from) {                                                 \
+        CHECK_RANGES_OVERLAP("memcpy", to, size, from, size);           \
+      }                                                                 \
+      ASAN_READ_RANGE(ctx, from, size);                                 \
+      ASAN_WRITE_RANGE(ctx, to, size);                                  \
+    }                                                                   \
+    return REAL(memcpy)(to, from, size);                                \
+  } while (0)
+
+// memset is called inside Printf.
+#define ASAN_MEMSET_IMPL(ctx, block, c, size)                           \
+  do {                                                                  \
+    if (UNLIKELY(!asan_inited)) return internal_memset(block, c, size); \
+    if (asan_init_is_running) {                                         \
+      return REAL(memset)(block, c, size);                              \
+    }                                                                   \
+    ENSURE_ASAN_INITED();                                               \
+    if (flags()->replace_intrin) {                                      \
+      ASAN_WRITE_RANGE(ctx, block, size);                               \
+    }                                                                   \
+    return REAL(memset)(block, c, size);                                \
+  } while (0)
+
+#define ASAN_MEMMOVE_IMPL(ctx, to, from, size)                           \
+  do {                                                                   \
+    if (UNLIKELY(!asan_inited)) return internal_memmove(to, from, size); \
+    ENSURE_ASAN_INITED();                                                \
+    if (flags()->replace_intrin) {                                       \
+      ASAN_READ_RANGE(ctx, from, size);                                  \
+      ASAN_WRITE_RANGE(ctx, to, size);                                   \
+    }                                                                    \
+    return internal_memmove(to, from, size);                             \
+  } while (0)
+
+#define ASAN_READ_RANGE(ctx, offset, size) \
+  ACCESS_MEMORY_RANGE(ctx, offset, size, false)
+#define ASAN_WRITE_RANGE(ctx, offset, size) \
+  ACCESS_MEMORY_RANGE(ctx, offset, size, true)
+
+// Behavior of functions like "memcpy" or "strcpy" is undefined
+// if memory intervals overlap. We report error in this case.
+// Macro is used to avoid creation of new frames.
+static inline bool RangesOverlap(const char *offset1, uptr length1,
+                                 const char *offset2, uptr length2) {
+  return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
+}
+#define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2) do { \
+  const char *offset1 = (const char*)_offset1; \
+  const char *offset2 = (const char*)_offset2; \
+  if (RangesOverlap(offset1, length1, offset2, length2)) { \
+    GET_STACK_TRACE_FATAL_HERE; \
+    ReportStringFunctionMemoryRangesOverlap(name, offset1, length1, \
+                                            offset2, length2, &stack); \
+  } \
+} while (0)
+
+}  // namespace __asan
+
+#endif  // ASAN_MEMINTRIN_H