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