1 files changed, 194 insertions, 0 deletions
diff --git a/contrib/llvm-project/compiler-rt/lib/hwasan/hwasan_checks.h b/contrib/llvm-project/compiler-rt/lib/hwasan/hwasan_checks.h
new file mode 100644
index 000000000000..735d21a5db77
--- /dev/null
+++ b/contrib/llvm-project/compiler-rt/lib/hwasan/hwasan_checks.h
@@ -0,0 +1,194 @@
+//===-- hwasan_checks.h -----------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of HWAddressSanitizer.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef HWASAN_CHECKS_H
+#define HWASAN_CHECKS_H
+
+#include "hwasan_allocator.h"
+#include "hwasan_mapping.h"
+#include "hwasan_registers.h"
+#include "sanitizer_common/sanitizer_common.h"
+
+namespace __hwasan {
+
+enum class ErrorAction { Abort, Recover };
+enum class AccessType { Load, Store };
+
+// Used when the access size is known.
+constexpr unsigned SigTrapEncoding(ErrorAction EA, AccessType AT,
+                                   unsigned LogSize) {
+  return 0x20 * (EA == ErrorAction::Recover) +
+         0x10 * (AT == AccessType::Store) + LogSize;
+}
+
+// Used when the access size varies at runtime.
+constexpr unsigned SigTrapEncoding(ErrorAction EA, AccessType AT) {
+  return SigTrapEncoding(EA, AT, 0xf);
+}
+
+template <ErrorAction EA, AccessType AT, size_t LogSize>
+__attribute__((always_inline)) static void SigTrap(uptr p) {
+  // Other platforms like linux can use signals for intercepting an exception
+  // and dispatching to HandleTagMismatch. The fuchsias implementation doesn't
+  // use signals so we can call it here directly instead.
+#if CAN_GET_REGISTERS && SANITIZER_FUCHSIA
+  auto regs = GetRegisters();
+  size_t size = 2 << LogSize;
+  AccessInfo access_info = {
+      .addr = p,
+      .size = size,
+      .is_store = AT == AccessType::Store,
+      .is_load = AT == AccessType::Load,
+      .recover = EA == ErrorAction::Recover,
+  };
+  HandleTagMismatch(access_info, (uptr)__builtin_return_address(0),
+                    (uptr)__builtin_frame_address(0), /*uc=*/nullptr, regs.x);
+#elif defined(__aarch64__)
+  (void)p;
+  // 0x900 is added to do not interfere with the kernel use of lower values of
+  // brk immediate.
+  register uptr x0 asm("x0") = p;
+  asm("brk %1\n\t" ::"r"(x0), "n"(0x900 + SigTrapEncoding(EA, AT, LogSize)));
+#elif defined(__x86_64__)
+  // INT3 + NOP DWORD ptr [EAX + X] to pass X to our signal handler, 5 bytes
+  // total. The pointer is passed via rdi.
+  // 0x40 is added as a safeguard, to help distinguish our trap from others and
+  // to avoid 0 offsets in the command (otherwise it'll be reduced to a
+  // different nop command, the three bytes one).
+  asm volatile(
+      "int3\n"
+      "nopl %c0(%%rax)\n" ::"n"(0x40 + SigTrapEncoding(EA, AT, LogSize)),
+      "D"(p));
+#elif SANITIZER_RISCV64
+  // Put pointer into x10
+  // addiw contains immediate of 0x40 + X, where 0x40 is magic number and X
+  // encodes access size
+  register uptr x10 asm("x10") = p;
+  asm volatile(
+      "ebreak\n"
+      "addiw x0, x0, %1\n" ::"r"(x10),
+      "I"(0x40 + SigTrapEncoding(EA, AT, LogSize)));
+#else
+  // FIXME: not always sigill.
+  __builtin_trap();
+#endif
+  // __builtin_unreachable();
+}
+
+// Version with access size which is not power of 2
+template <ErrorAction EA, AccessType AT>
+__attribute__((always_inline)) static void SigTrap(uptr p, uptr size) {
+  // Other platforms like linux can use signals for intercepting an exception
+  // and dispatching to HandleTagMismatch. The fuchsias implementation doesn't
+  // use signals so we can call it here directly instead.
+#if CAN_GET_REGISTERS && SANITIZER_FUCHSIA
+  auto regs = GetRegisters();
+  AccessInfo access_info = {
+      .addr = p,
+      .size = size,
+      .is_store = AT == AccessType::Store,
+      .is_load = AT == AccessType::Load,
+      .recover = EA == ErrorAction::Recover,
+  };
+  HandleTagMismatch(access_info, (uptr)__builtin_return_address(0),
+                    (uptr)__builtin_frame_address(0), /*uc=*/nullptr, regs.x);
+#elif defined(__aarch64__)
+  register uptr x0 asm("x0") = p;
+  register uptr x1 asm("x1") = size;
+  asm("brk %2\n\t" ::"r"(x0), "r"(x1), "n"(0x900 + SigTrapEncoding(EA, AT)));
+#elif defined(__x86_64__)
+  // Size is stored in rsi.
+  asm volatile(
+      "int3\n"
+      "nopl %c0(%%rax)\n" ::"n"(0x40 + SigTrapEncoding(EA, AT)),
+      "D"(p), "S"(size));
+#elif SANITIZER_RISCV64
+  // Put access size into x11
+  register uptr x10 asm("x10") = p;
+  register uptr x11 asm("x11") = size;
+  asm volatile(
+      "ebreak\n"
+      "addiw x0, x0, %2\n" ::"r"(x10),
+      "r"(x11), "I"(0x40 + SigTrapEncoding(EA, AT)));
+#else
+  __builtin_trap();
+#endif
+  // __builtin_unreachable();
+}
+
+__attribute__((always_inline, nodebug)) static inline uptr ShortTagSize(
+    tag_t mem_tag, uptr ptr) {
+  DCHECK(IsAligned(ptr, kShadowAlignment));
+  tag_t ptr_tag = GetTagFromPointer(ptr);
+  if (ptr_tag == mem_tag)
+    return kShadowAlignment;
+  if (!mem_tag || mem_tag >= kShadowAlignment)
+    return 0;
+  if (*(u8 *)(ptr | (kShadowAlignment - 1)) != ptr_tag)
+    return 0;
+  return mem_tag;
+}
+
+__attribute__((always_inline, nodebug)) static inline bool
+PossiblyShortTagMatches(tag_t mem_tag, uptr ptr, uptr sz) {
+  tag_t ptr_tag = GetTagFromPointer(ptr);
+  if (ptr_tag == mem_tag)
+    return true;
+  if (mem_tag >= kShadowAlignment)
+    return false;
+  if ((ptr & (kShadowAlignment - 1)) + sz > mem_tag)
+    return false;
+  return *(u8 *)(ptr | (kShadowAlignment - 1)) == ptr_tag;
+}
+
+template <ErrorAction EA, AccessType AT, unsigned LogSize>
+__attribute__((always_inline, nodebug)) static void CheckAddress(uptr p) {
+  if (!InTaggableRegion(p))
+    return;
+  uptr ptr_raw = p & ~kAddressTagMask;
+  tag_t mem_tag = *(tag_t *)MemToShadow(ptr_raw);
+  if (UNLIKELY(!PossiblyShortTagMatches(mem_tag, p, 1 << LogSize))) {
+    SigTrap<EA, AT, LogSize>(p);
+    if (EA == ErrorAction::Abort)
+      __builtin_unreachable();
+  }
+}
+
+template <ErrorAction EA, AccessType AT>
+__attribute__((always_inline, nodebug)) static void CheckAddressSized(uptr p,
+                                                                      uptr sz) {
+  if (sz == 0 || !InTaggableRegion(p))
+    return;
+  tag_t ptr_tag = GetTagFromPointer(p);
+  uptr ptr_raw = p & ~kAddressTagMask;
+  tag_t *shadow_first = (tag_t *)MemToShadow(ptr_raw);
+  tag_t *shadow_last = (tag_t *)MemToShadow(ptr_raw + sz);
+  for (tag_t *t = shadow_first; t < shadow_last; ++t)
+    if (UNLIKELY(ptr_tag != *t)) {
+      SigTrap<EA, AT>(p, sz);
+      if (EA == ErrorAction::Abort)
+        __builtin_unreachable();
+    }
+  uptr end = p + sz;
+  uptr tail_sz = end & (kShadowAlignment - 1);
+  if (UNLIKELY(tail_sz != 0 &&
+               !PossiblyShortTagMatches(
+                   *shadow_last, end & ~(kShadowAlignment - 1), tail_sz))) {
+    SigTrap<EA, AT>(p, sz);
+    if (EA == ErrorAction::Abort)
+      __builtin_unreachable();
+  }
+}
+
+}  // end namespace __hwasan
+
+#endif  // HWASAN_CHECKS_H