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