llvm-project/compiler-rt/lib/hwasan/hwasan_report.h

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//===-- hwasan_report.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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file is a part of HWAddressSanitizer. HWASan-private header for error
/// reporting functions.
///
//===----------------------------------------------------------------------===//
#ifndef HWASAN_REPORT_H
#define HWASAN_REPORT_H
#include "sanitizer_common/sanitizer_internal_defs.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
namespace __hwasan {
void ReportStats();
void ReportTagMismatch(StackTrace *stack, uptr addr, uptr access_size,
[HWASan] Save + print registers when tag mismatch occurs in AArch64. Summary: This change change the instrumentation to allow users to view the registers at the point at which tag mismatch occured. Most of the heavy lifting is done in the runtime library, where we save the registers to the stack and emit unwind information. This allows us to reduce the overhead, as very little additional work needs to be done in each __hwasan_check instance. In this implementation, the fast path of __hwasan_check is unmodified. There are an additional 4 instructions (16B) emitted in the slow path in every __hwasan_check instance. This may increase binary size somewhat, but as most of the work is done in the runtime library, it's manageable. The failure trace now contains a list of registers at the point of which the failure occured, in a format similar to that of Android's tombstones. It currently has the following format: Registers where the failure occurred (pc 0x0055555561b4): x0 0000000000000014 x1 0000007ffffff6c0 x2 1100007ffffff6d0 x3 12000056ffffe025 x4 0000007fff800000 x5 0000000000000014 x6 0000007fff800000 x7 0000000000000001 x8 12000056ffffe020 x9 0200007700000000 x10 0200007700000000 x11 0000000000000000 x12 0000007fffffdde0 x13 0000000000000000 x14 02b65b01f7a97490 x15 0000000000000000 x16 0000007fb77376b8 x17 0000000000000012 x18 0000007fb7ed6000 x19 0000005555556078 x20 0000007ffffff768 x21 0000007ffffff778 x22 0000000000000001 x23 0000000000000000 x24 0000000000000000 x25 0000000000000000 x26 0000000000000000 x27 0000000000000000 x28 0000000000000000 x29 0000007ffffff6f0 x30 00000055555561b4 ... and prints after the dump of memory tags around the buggy address. Every register is saved exactly as it was at the point where the tag mismatch occurs, with the exception of x16/x17. These registers are used in the tag mismatch calculation as scratch registers during __hwasan_check, and cannot be saved without affecting the fast path. As these registers are designated as scratch registers for linking, there should be no important information in them that could aid in debugging. Reviewers: pcc, eugenis Reviewed By: pcc, eugenis Subscribers: srhines, kubamracek, mgorny, javed.absar, krytarowski, kristof.beyls, hiraditya, jdoerfert, llvm-commits, #sanitizers Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D58857 llvm-svn: 355738
2019-03-09 05:22:35 +08:00
bool is_store, bool fatal, uptr *registers_frame);
void ReportInvalidFree(StackTrace *stack, uptr addr);
void ReportTailOverwritten(StackTrace *stack, uptr addr, uptr orig_size,
hwasan: Improve precision of checks using short granule tags. A short granule is a granule of size between 1 and `TG-1` bytes. The size of a short granule is stored at the location in shadow memory where the granule's tag is normally stored, while the granule's actual tag is stored in the last byte of the granule. This means that in order to verify that a pointer tag matches a memory tag, HWASAN must check for two possibilities: * the pointer tag is equal to the memory tag in shadow memory, or * the shadow memory tag is actually a short granule size, the value being loaded is in bounds of the granule and the pointer tag is equal to the last byte of the granule. Pointer tags between 1 to `TG-1` are possible and are as likely as any other tag. This means that these tags in memory have two interpretations: the full tag interpretation (where the pointer tag is between 1 and `TG-1` and the last byte of the granule is ordinary data) and the short tag interpretation (where the pointer tag is stored in the granule). When HWASAN detects an error near a memory tag between 1 and `TG-1`, it will show both the memory tag and the last byte of the granule. Currently, it is up to the user to disambiguate the two possibilities. Because this functionality obsoletes the right aligned heap feature of the HWASAN memory allocator (and because we can no longer easily test it), the feature is removed. Also update the documentation to cover both short granule tags and outlined checks. Differential Revision: https://reviews.llvm.org/D63908 llvm-svn: 365551
2019-07-10 04:22:36 +08:00
const u8 *expected);
[HWASan] Save + print registers when tag mismatch occurs in AArch64. Summary: This change change the instrumentation to allow users to view the registers at the point at which tag mismatch occured. Most of the heavy lifting is done in the runtime library, where we save the registers to the stack and emit unwind information. This allows us to reduce the overhead, as very little additional work needs to be done in each __hwasan_check instance. In this implementation, the fast path of __hwasan_check is unmodified. There are an additional 4 instructions (16B) emitted in the slow path in every __hwasan_check instance. This may increase binary size somewhat, but as most of the work is done in the runtime library, it's manageable. The failure trace now contains a list of registers at the point of which the failure occured, in a format similar to that of Android's tombstones. It currently has the following format: Registers where the failure occurred (pc 0x0055555561b4): x0 0000000000000014 x1 0000007ffffff6c0 x2 1100007ffffff6d0 x3 12000056ffffe025 x4 0000007fff800000 x5 0000000000000014 x6 0000007fff800000 x7 0000000000000001 x8 12000056ffffe020 x9 0200007700000000 x10 0200007700000000 x11 0000000000000000 x12 0000007fffffdde0 x13 0000000000000000 x14 02b65b01f7a97490 x15 0000000000000000 x16 0000007fb77376b8 x17 0000000000000012 x18 0000007fb7ed6000 x19 0000005555556078 x20 0000007ffffff768 x21 0000007ffffff778 x22 0000000000000001 x23 0000000000000000 x24 0000000000000000 x25 0000000000000000 x26 0000000000000000 x27 0000000000000000 x28 0000000000000000 x29 0000007ffffff6f0 x30 00000055555561b4 ... and prints after the dump of memory tags around the buggy address. Every register is saved exactly as it was at the point where the tag mismatch occurs, with the exception of x16/x17. These registers are used in the tag mismatch calculation as scratch registers during __hwasan_check, and cannot be saved without affecting the fast path. As these registers are designated as scratch registers for linking, there should be no important information in them that could aid in debugging. Reviewers: pcc, eugenis Reviewed By: pcc, eugenis Subscribers: srhines, kubamracek, mgorny, javed.absar, krytarowski, kristof.beyls, hiraditya, jdoerfert, llvm-commits, #sanitizers Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D58857 llvm-svn: 355738
2019-03-09 05:22:35 +08:00
void ReportRegisters(uptr *registers_frame, uptr pc);
void ReportAtExitStatistics();
} // namespace __hwasan
#endif // HWASAN_REPORT_H