llvm-project/compiler-rt/lib/hwasan/hwasan_flags.inc

88 lines
3.9 KiB
C++

//===-- hwasan_flags.inc ------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// Hwasan runtime flags.
//
//===----------------------------------------------------------------------===//
#ifndef HWASAN_FLAG
# error "Define HWASAN_FLAG prior to including this file!"
#endif
// HWASAN_FLAG(Type, Name, DefaultValue, Description)
// See COMMON_FLAG in sanitizer_flags.inc for more details.
HWASAN_FLAG(bool, verbose_threads, false,
"inform on thread creation/destruction")
HWASAN_FLAG(bool, tag_in_malloc, true, "")
HWASAN_FLAG(bool, tag_in_free, true, "")
HWASAN_FLAG(bool, print_stats, false, "")
HWASAN_FLAG(bool, halt_on_error, true, "")
HWASAN_FLAG(bool, atexit, false, "")
// Test only flag to disable malloc/realloc/free memory tagging on startup.
// Tagging can be reenabled with __hwasan_enable_allocator_tagging().
HWASAN_FLAG(bool, disable_allocator_tagging, false, "")
// If false, use simple increment of a thread local counter to generate new
// tags.
HWASAN_FLAG(bool, random_tags, true, "")
HWASAN_FLAG(
int, max_malloc_fill_size, 0x1000, // By default, fill only the first 4K.
"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 "
"if the allocation size is not a divident of the granule size")
HWASAN_FLAG(
int, max_free_fill_size, 0,
"HWASan allocator flag. max_free_fill_size is the maximal amount of "
"bytes that will be filled with free_fill_byte during free.")
HWASAN_FLAG(int, malloc_fill_byte, 0xbe,
"Value used to fill the newly allocated memory.")
HWASAN_FLAG(int, free_fill_byte, 0x55,
"Value used to fill deallocated memory.")
HWASAN_FLAG(int, heap_history_size, 1023,
"The number of heap (de)allocations remembered per thread. "
"Affects the quality of heap-related reports, but not the ability "
"to find bugs.")
HWASAN_FLAG(bool, export_memory_stats, true,
"Export up-to-date memory stats through /proc")
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.")