| Austin Schuh | 906616c | 2019-01-21 20:25:11 -0800 | [diff] [blame] | 1 | // Copyright (c) 2005 - 2007, Google Inc. |
| 2 | // All rights reserved. |
| 3 | // |
| 4 | // Redistribution and use in source and binary forms, with or without |
| 5 | // modification, are permitted provided that the following conditions are |
| 6 | // met: |
| 7 | // |
| 8 | // * Redistributions of source code must retain the above copyright |
| 9 | // notice, this list of conditions and the following disclaimer. |
| 10 | // * Redistributions in binary form must reproduce the above |
| 11 | // copyright notice, this list of conditions and the following disclaimer |
| 12 | // in the documentation and/or other materials provided with the |
| 13 | // distribution. |
| 14 | // * Neither the name of Google Inc. nor the names of its |
| 15 | // contributors may be used to endorse or promote products derived from |
| 16 | // this software without specific prior written permission. |
| 17 | // |
| 18 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 22 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 23 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 24 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | // |
| 30 | // Author: Arun Sharma |
| 31 | // |
| 32 | // Produce stack trace using libunwind |
| 33 | |
| 34 | #include "utilities.h" |
| 35 | |
| 36 | extern "C" { |
| 37 | #define UNW_LOCAL_ONLY |
| 38 | #include <libunwind.h> |
| 39 | } |
| 40 | #include "glog/raw_logging.h" |
| 41 | #include "stacktrace.h" |
| 42 | |
| 43 | _START_GOOGLE_NAMESPACE_ |
| 44 | |
| 45 | // Sometimes, we can try to get a stack trace from within a stack |
| 46 | // trace, because libunwind can call mmap (maybe indirectly via an |
| 47 | // internal mmap based memory allocator), and that mmap gets trapped |
| 48 | // and causes a stack-trace request. If were to try to honor that |
| 49 | // recursive request, we'd end up with infinite recursion or deadlock. |
| 50 | // Luckily, it's safe to ignore those subsequent traces. In such |
| 51 | // cases, we return 0 to indicate the situation. |
| 52 | static bool g_now_entering = false; |
| 53 | |
| 54 | // If you change this function, also change GetStackFrames below. |
| 55 | int GetStackTrace(void** result, int max_depth, int skip_count) { |
| 56 | void *ip; |
| 57 | int n = 0; |
| 58 | unw_cursor_t cursor; |
| 59 | unw_context_t uc; |
| 60 | |
| 61 | if (sync_val_compare_and_swap(&g_now_entering, false, true)) { |
| 62 | return 0; |
| 63 | } |
| 64 | |
| 65 | unw_getcontext(&uc); |
| 66 | RAW_CHECK(unw_init_local(&cursor, &uc) >= 0, "unw_init_local failed"); |
| 67 | skip_count++; // Do not include the "GetStackTrace" frame |
| 68 | |
| 69 | while (n < max_depth) { |
| 70 | int ret = unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip); |
| 71 | if (ret < 0) |
| 72 | break; |
| 73 | if (skip_count > 0) { |
| 74 | skip_count--; |
| 75 | } else { |
| 76 | result[n++] = ip; |
| 77 | } |
| 78 | ret = unw_step(&cursor); |
| 79 | if (ret <= 0) |
| 80 | break; |
| 81 | } |
| 82 | |
| 83 | g_now_entering = false; |
| 84 | return n; |
| 85 | } |
| 86 | |
| 87 | _END_GOOGLE_NAMESPACE_ |