1 //===-- backtrace_linux_libc.cpp --------------------------------*- 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 #include <assert.h> 10 #include <execinfo.h> 11 #include <stddef.h> 12 #include <stdint.h> 13 #include <stdlib.h> 14 #include <string.h> 15 16 #include "gwp_asan/optional/backtrace.h" 17 #include "gwp_asan/options.h" 18 19 namespace { 20 size_t Backtrace(uintptr_t *TraceBuffer, size_t Size) { 21 static_assert(sizeof(uintptr_t) == sizeof(void *), "uintptr_t is not void*"); 22 23 return backtrace(reinterpret_cast<void **>(TraceBuffer), Size); 24 } 25 26 // We don't need any custom handling for the Segv backtrace - the libc unwinder 27 // has no problems with unwinding through a signal handler. Force inlining here 28 // to avoid the additional frame. 29 GWP_ASAN_ALWAYS_INLINE size_t SegvBacktrace(uintptr_t *TraceBuffer, size_t Size, 30 void * /*Context*/) { 31 return Backtrace(TraceBuffer, Size); 32 } 33 34 static void PrintBacktrace(uintptr_t *Trace, size_t TraceLength, 35 gwp_asan::crash_handler::Printf_t Printf) { 36 if (TraceLength == 0) { 37 Printf(" <not found (does your allocator support backtracing?)>\n\n"); 38 return; 39 } 40 41 char **BacktraceSymbols = 42 backtrace_symbols(reinterpret_cast<void **>(Trace), TraceLength); 43 44 for (size_t i = 0; i < TraceLength; ++i) { 45 if (!BacktraceSymbols) 46 Printf(" #%zu %p\n", i, Trace[i]); 47 else 48 Printf(" #%zu %s\n", i, BacktraceSymbols[i]); 49 } 50 51 Printf("\n"); 52 if (BacktraceSymbols) 53 free(BacktraceSymbols); 54 } 55 } // anonymous namespace 56 57 namespace gwp_asan { 58 namespace options { 59 Backtrace_t getBacktraceFunction() { return Backtrace; } 60 crash_handler::PrintBacktrace_t getPrintBacktraceFunction() { 61 return PrintBacktrace; 62 } 63 } // namespace options 64 65 namespace crash_handler { 66 SegvBacktrace_t getSegvBacktraceFunction() { return SegvBacktrace; } 67 } // namespace crash_handler 68 } // namespace gwp_asan 69