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 15 namespace gwp_asan { 16 namespace 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. 31 typedef 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. 39 typedef 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. 44 options::Backtrace_t getBacktraceFunction(); 45 46 // Returns platform-specific provided implementations of PrintBacktrace_t and 47 // SegvBacktrace_t for use in the optional SEGV handler. 48 PrintBacktrace_t getPrintBacktraceFunction(); 49 SegvBacktrace_t getSegvBacktraceFunction(); 50 } // namespace backtrace 51 } // namespace gwp_asan 52 53 #endif // GWP_ASAN_OPTIONAL_BACKTRACE_H_ 54