1//===-- backtrace.h ---------------------------------------------*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8 9#ifndef GWP_ASAN_OPTIONAL_BACKTRACE_H_ 10#define GWP_ASAN_OPTIONAL_BACKTRACE_H_ 11 12#include "gwp_asan/optional/printf.h" 13#include "gwp_asan/options.h" 14 15namespace gwp_asan { 16namespace backtrace { 17// ================================ Description ================================ 18// This function shall take the backtrace provided in `TraceBuffer`, and print 19// it in a human-readable format using `Print`. Generally, this function shall 20// resolve raw pointers to section offsets and print them with the following 21// sanitizer-common format: 22// " #{frame_number} {pointer} in {function name} ({binary name}+{offset}" 23// e.g. " #5 0x420459 in _start (/tmp/uaf+0x420459)" 24// This format allows the backtrace to be symbolized offline successfully using 25// llvm-symbolizer. 26// =================================== Notes =================================== 27// This function may directly or indirectly call malloc(), as the 28// GuardedPoolAllocator contains a reentrancy barrier to prevent infinite 29// recursion. Any allocation made inside this function will be served by the 30// supporting allocator, and will not have GWP-ASan protections. 31typedef void (*PrintBacktrace_t)(uintptr_t *TraceBuffer, size_t TraceLength, 32 Printf_t Print); 33 34// Returns a function pointer to a backtrace function that's suitable for 35// unwinding through a signal handler. This is important primarily for frame- 36// pointer based unwinders, DWARF or other unwinders can simply provide the 37// normal backtrace function as the implementation here. On POSIX, SignalContext 38// should be the `ucontext_t` from the signal handler. 39typedef size_t (*SegvBacktrace_t)(uintptr_t *TraceBuffer, size_t Size, 40 void *SignalContext); 41 42// Returns platform-specific provided implementations of Backtrace_t for use 43// inside the GWP-ASan core allocator. 44options::Backtrace_t getBacktraceFunction(); 45 46// Returns platform-specific provided implementations of PrintBacktrace_t and 47// SegvBacktrace_t for use in the optional SEGV handler. 48PrintBacktrace_t getPrintBacktraceFunction(); 49SegvBacktrace_t getSegvBacktraceFunction(); 50} // namespace backtrace 51} // namespace gwp_asan 52 53#endif // GWP_ASAN_OPTIONAL_BACKTRACE_H_ 54