[HWASan] Add files missing in r330624

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@330628 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 244 insertions, 0 deletions

diff --git a/lib/hwasan/hwasan_dynamic_shadow.cc b/lib/hwasan/hwasan_dynamic_shadow.cc
new file mode 100644
index 000000000..17338003a
--- /dev/null
+++ b/lib/hwasan/hwasan_dynamic_shadow.cc
@@ -0,0 +1,132 @@
+//===-- hwasan_dynamic_shadow.cc --------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file is a part of HWAddressSanitizer. It reserves dynamic shadow memory
+/// region and handles ifunc resolver case, when necessary.
+///
+//===----------------------------------------------------------------------===//
+
+#include "hwasan_dynamic_shadow.h"
+#include "hwasan_mapping.h"
+#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_posix.h"
+
+// The code in this file needs to run in an unrelocated binary. It should not
+// access any external symbol, including its own non-hidden globals.
+
+namespace __hwasan {
+
+static void UnmapFromTo(uptr from, uptr to) {
+  if (to == from)
+    return;
+  CHECK(to >= from);
+  uptr res = internal_munmap(reinterpret_cast<void *>(from), to - from);
+  if (UNLIKELY(internal_iserror(res))) {
+    Report("ERROR: %s failed to unmap 0x%zx (%zd) bytes at address %p\n",
+           SanitizerToolName, to - from, to - from, from);
+    CHECK("unable to unmap" && 0);
+  }
+}
+
+// Returns an address aligned to 8 pages, such that one page on the left and
+// shadow_size_bytes bytes on the right of it are mapped r/o.
+static uptr MapDynamicShadow(uptr shadow_size_bytes) {
+  const uptr granularity = GetMmapGranularity();
+  const uptr alignment = granularity * SHADOW_GRANULARITY;
+  const uptr left_padding = granularity;
+  const uptr shadow_size =
+      RoundUpTo(shadow_size_bytes, granularity);
+  const uptr map_size = shadow_size + left_padding + alignment;
+
+  const uptr map_start = (uptr)MmapNoAccess(map_size);
+  CHECK_NE(map_start, ~(uptr)0);
+
+  const uptr shadow_start = RoundUpTo(map_start + left_padding, alignment);
+
+  UnmapFromTo(map_start, shadow_start - left_padding);
+  UnmapFromTo(shadow_start + shadow_size, map_start + map_size);
+
+  return shadow_start;
+}
+
+}  // namespace __hwasan
+
+#if HWASAN_PREMAP_SHADOW
+
+extern "C" {
+
+INTERFACE_ATTRIBUTE void __hwasan_shadow();
+decltype(__hwasan_shadow)* __hwasan_premap_shadow();
+
+}  // extern "C"
+
+namespace __hwasan {
+
+// Conservative upper limit.
+static uptr PremapShadowSize() {
+  return RoundUpTo(GetMaxVirtualAddress() >> kShadowScale,
+                   GetMmapGranularity());
+}
+
+static uptr PremapShadow() {
+  return MapDynamicShadow(PremapShadowSize());
+}
+
+static bool IsPremapShadowAvailable() {
+  const uptr shadow = reinterpret_cast<uptr>(&__hwasan_shadow);
+  const uptr resolver = reinterpret_cast<uptr>(&__hwasan_premap_shadow);
+  // shadow == resolver is how Android KitKat and older handles ifunc.
+  // shadow == 0 just in case.
+  return shadow != 0 && shadow != resolver;
+}
+
+static uptr FindPremappedShadowStart(uptr shadow_size_bytes) {
+  const uptr granularity = GetMmapGranularity();
+  const uptr shadow_start = reinterpret_cast<uptr>(&__hwasan_shadow);
+  const uptr premap_shadow_size = PremapShadowSize();
+  const uptr shadow_size = RoundUpTo(shadow_size_bytes, granularity);
+
+  // We may have mapped too much. Release extra memory.
+  UnmapFromTo(shadow_start + shadow_size, shadow_start + premap_shadow_size);
+  return shadow_start;
+}
+
+}  // namespace __hwasan
+
+extern "C" {
+
+decltype(__hwasan_shadow)* __hwasan_premap_shadow() {
+  // The resolver might be called multiple times. Map the shadow just once.
+  static __sanitizer::uptr shadow = 0;
+  if (!shadow)
+    shadow = __hwasan::PremapShadow();
+  return reinterpret_cast<decltype(__hwasan_shadow)*>(shadow);
+}
+
+// __hwasan_shadow is a "function" that has the same address as the first byte
+// of the shadow mapping.
+INTERFACE_ATTRIBUTE __attribute__((ifunc("__hwasan_premap_shadow")))
+void __hwasan_shadow();
+
+}  // extern "C"
+
+#endif  // HWASAN_PREMAP_SHADOW
+
+namespace __hwasan {
+
+uptr FindDynamicShadowStart(uptr shadow_size_bytes) {
+#if HWASAN_PREMAP_SHADOW
+  if (IsPremapShadowAvailable())
+    return FindPremappedShadowStart(shadow_size_bytes);
+#endif
+  return MapDynamicShadow(shadow_size_bytes);
+}
+
+}  // namespace __hwasan
diff --git a/lib/hwasan/hwasan_dynamic_shadow.h b/lib/hwasan/hwasan_dynamic_shadow.h
new file mode 100644
index 000000000..b5e9e1dd6
--- /dev/null
+++ b/lib/hwasan/hwasan_dynamic_shadow.h
@@ -0,0 +1,27 @@
+//===-- hwasan_dynamic_shadow.h ---------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file is a part of HWAddressSanitizer. It reserves dynamic shadow memory
+/// region.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef HWASAN_PREMAP_SHADOW_H
+#define HWASAN_PREMAP_SHADOW_H
+
+#include "sanitizer_common/sanitizer_internal_defs.h"
+
+namespace __hwasan {
+
+uptr FindDynamicShadowStart(uptr shadow_size_bytes);
+
+}  // namespace __hwasan
+
+#endif  // HWASAN_PREMAP_SHADOW_H
diff --git a/lib/hwasan/hwasan_mapping.h b/lib/hwasan/hwasan_mapping.h
new file mode 100644
index 000000000..4650532e7
--- /dev/null
+++ b/lib/hwasan/hwasan_mapping.h
@@ -0,0 +1,85 @@
+//===-- hwasan_mapping.h ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file is a part of HWAddressSanitizer and defines memory mapping.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef HWASAN_MAPPING_H
+#define HWASAN_MAPPING_H
+
+#include "sanitizer_common/sanitizer_internal_defs.h"
+
+// Typical mapping on Linux/x86_64 with fixed shadow mapping:
+// || [0x080000000000, 0x7fffffffffff] || HighMem    ||
+// || [0x008000000000, 0x07ffffffffff] || HighShadow ||
+// || [0x000100000000, 0x007fffffffff] || ShadowGap  ||
+// || [0x000010000000, 0x0000ffffffff] || LowMem     ||
+// || [0x000001000000, 0x00000fffffff] || LowShadow  ||
+// || [0x000000000000, 0x000000ffffff] || ShadowGap  ||
+//
+// and with dynamic shadow mapped at [0x770d59f40000, 0x7f0d59f40000]:
+// || [0x7f0d59f40000, 0x7fffffffffff] || HighMem    ||
+// || [0x7efe2f934000, 0x7f0d59f3ffff] || HighShadow ||
+// || [0x7e7e2f934000, 0x7efe2f933fff] || ShadowGap  ||
+// || [0x770d59f40000, 0x7e7e2f933fff] || LowShadow  ||
+// || [0x000000000000, 0x770d59f3ffff] || LowMem     ||
+
+// Typical mapping on Android/AArch64 (39-bit VMA):
+// || [0x001000000000, 0x007fffffffff] || HighMem    ||
+// || [0x000800000000, 0x000fffffffff] || ShadowGap  ||
+// || [0x000100000000, 0x0007ffffffff] || HighShadow ||
+// || [0x000010000000, 0x0000ffffffff] || LowMem     ||
+// || [0x000001000000, 0x00000fffffff] || LowShadow  ||
+// || [0x000000000000, 0x000000ffffff] || ShadowGap  ||
+//
+// and with dynamic shadow mapped: [0x007477480000, 0x007c77480000]:
+// || [0x007c77480000, 0x007fffffffff] || HighMem    ||
+// || [0x007c3ebc8000, 0x007c7747ffff] || HighShadow ||
+// || [0x007bbebc8000, 0x007c3ebc7fff] || ShadowGap  ||
+// || [0x007477480000, 0x007bbebc7fff] || LowShadow  ||
+// || [0x000000000000, 0x00747747ffff] || LowMem     ||
+
+static constexpr __sanitizer::u64 kDefaultShadowSentinel = ~(__sanitizer::u64)0;
+
+// Reasonable values are 4 (for 1/16th shadow) and 6 (for 1/64th).
+constexpr __sanitizer::uptr kShadowScale = 4;
+constexpr __sanitizer::uptr kShadowAlignment = 1ULL << kShadowScale;
+
+#if defined(__x86_64__)
+# define HWASAN_FIXED_MAPPING 1
+#else
+# define HWASAN_FIXED_MAPPING 0
+#endif
+
+#if HWASAN_FIXED_MAPPING
+# define SHADOW_OFFSET (0)
+# define HWASAN_PREMAP_SHADOW 0
+#else
+# define SHADOW_OFFSET (__hwasan_shadow_memory_dynamic_address)
+# define HWASAN_PREMAP_SHADOW 1
+#endif
+
+#define SHADOW_GRANULARITY (1ULL << kShadowScale)
+
+#define MEM_TO_SHADOW(mem) (((uptr)(mem) >> kShadowScale) + SHADOW_OFFSET)
+#define SHADOW_TO_MEM(shadow) (((uptr)(shadow) - SHADOW_OFFSET) << kShadowScale)
+
+#define MEM_TO_SHADOW_SIZE(size) ((uptr)(size) >> kShadowScale)
+
+#define MEM_IS_APP(mem) MemIsApp((uptr)(mem))
+
+namespace __hwasan {
+
+bool MemIsApp(uptr p);
+
+}  // namespace __hwasan
+
+#endif  // HWASAN_MAPPING_H