diff options
Diffstat (limited to 'lib/hwasan/hwasan_flags.inc')
| -rw-r--r-- | lib/hwasan/hwasan_flags.inc | 46 |
1 files changed, 16 insertions, 30 deletions
diff --git a/lib/hwasan/hwasan_flags.inc b/lib/hwasan/hwasan_flags.inc index b450ab9503f9..2dff2b9aca6e 100644 --- a/lib/hwasan/hwasan_flags.inc +++ b/lib/hwasan/hwasan_flags.inc @@ -1,9 +1,8 @@ //===-- hwasan_flags.inc ------------------------------------------*- C++ -*-===// // -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. +// 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 // //===----------------------------------------------------------------------===// // @@ -38,32 +37,6 @@ HWASAN_FLAG( "HWASan allocator flag. max_malloc_fill_size is the maximal amount of " "bytes that will be filled with malloc_fill_byte on malloc.") -// Rules for malloc alignment on aarch64: -// * If the size is 16-aligned, then malloc should return 16-aligned memory. -// * Otherwise, malloc should return 8-alignment memory. -// So, -// * If the size is 16-aligned, we don't need to do anything. -// * Otherwise we don't have to obey 16-alignment, just the 8-alignment. -// * We may want to break the 8-alignment rule to catch more buffer overflows -// but this will break valid code in some rare cases, like this: -// struct Foo { -// // accessed via atomic instructions that require 8-alignment. -// std::atomic<int64_t> atomic_stuff; -// ... -// char vla[1]; // the actual size of vla could be anything. -// } -// Which means that the safe values for malloc_align_right are 0, 8, 9, -// and the values 1 and 2 may require changes in otherwise valid code. - -HWASAN_FLAG( - int, malloc_align_right, 0, // off by default - "HWASan allocator flag. " - "0 (default): allocations are always aligned left to 16-byte boundary; " - "1: allocations are sometimes aligned right to 1-byte boundary (risky); " - "2: allocations are always aligned right to 1-byte boundary (risky); " - "8: allocations are sometimes aligned right to 8-byte boundary; " - "9: allocations are always aligned right to 8-byte boundary." - ) HWASAN_FLAG(bool, free_checks_tail_magic, 1, "If set, free() will check the magic values " "to the right of the allocated object " @@ -86,3 +59,16 @@ HWASAN_FLAG(int, stack_history_size, 1024, "The number of stack frames remembered per thread. " "Affects the quality of stack-related reports, but not the ability " "to find bugs.") + +// Malloc / free bisection. Only tag malloc and free calls when a hash of +// allocation size and stack trace is between malloc_bisect_left and +// malloc_bisect_right (both inclusive). [0, 0] range is special and disables +// bisection (i.e. everything is tagged). Once the range is narrowed down +// enough, use malloc_bisect_dump to see interesting allocations. +HWASAN_FLAG(uptr, malloc_bisect_left, 0, + "Left bound of malloc bisection, inclusive.") +HWASAN_FLAG(uptr, malloc_bisect_right, 0, + "Right bound of malloc bisection, inclusive.") +HWASAN_FLAG(bool, malloc_bisect_dump, false, + "Print all allocations within [malloc_bisect_left, " + "malloc_bisect_right] range ") |