compiler-rt/lib/gwp_asan/optional/backtrace_linux_libc.cpp

   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