freebsd-skq/contrib/compiler-rt/lib/hwasan/hwasan_checks.h

81 lines
2.7 KiB
C++

//===-- hwasan_checks.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 HWAddressSanitizer.
//
//===----------------------------------------------------------------------===//
#ifndef HWASAN_CHECKS_H
#define HWASAN_CHECKS_H
#include "hwasan_mapping.h"
namespace __hwasan {
template <unsigned X>
__attribute__((always_inline)) static void SigTrap(uptr p) {
#if defined(__aarch64__)
(void)p;
// 0x900 is added to do not interfere with the kernel use of lower values of
// brk immediate.
// FIXME: Add a constraint to put the pointer into x0, the same as x86 branch.
asm("brk %0\n\t" ::"n"(0x900 + X));
#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 + X),
"D"(p));
#else
// FIXME: not always sigill.
__builtin_trap();
#endif
// __builtin_unreachable();
}
enum class ErrorAction { Abort, Recover };
enum class AccessType { Load, Store };
template <ErrorAction EA, AccessType AT, unsigned LogSize>
__attribute__((always_inline, nodebug)) static void CheckAddress(uptr p) {
tag_t ptr_tag = GetTagFromPointer(p);
uptr ptr_raw = p & ~kAddressTagMask;
tag_t mem_tag = *(tag_t *)MemToShadow(ptr_raw);
if (UNLIKELY(ptr_tag != mem_tag)) {
SigTrap<0x20 * (EA == ErrorAction::Recover) +
0x10 * (AT == AccessType::Store) + 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)
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 - 1);
for (tag_t *t = shadow_first; t <= shadow_last; ++t)
if (UNLIKELY(ptr_tag != *t)) {
SigTrap<0x20 * (EA == ErrorAction::Recover) +
0x10 * (AT == AccessType::Store) + 0xf>(p);
if (EA == ErrorAction::Abort)
__builtin_unreachable();
}
}
} // end namespace __hwasan
#endif // HWASAN_CHECKS_H