src/util/bt.c (raw)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 |
/************************************************************************** * * Tint2 : backtrace * * Copyright (C) 2007 Pål Staurland (staura@gmail.com) * Modified (C) 2008 thierry lorthiois (lorthiois@bbsoft.fr) from Omega distribution * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. **************************************************************************/ #include <stdint.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <unistd.h> #include <stdio.h> #include "bt.h" #include "bool.h" #if defined(HAS_BACKTRACE) || defined(HAS_LIBUNWIND) || defined(HAS_EXECINFO) static void bt_add_frame(struct backtrace *bt, const char *fname) { if (bt->frame_count >= BT_MAX_FRAMES) return; struct backtrace_frame *frame = &bt->frames[bt->frame_count]; if (fname && *fname) { strncpy(frame->name, fname, BT_FRAME_SIZE); } else { strncpy(frame->name, "??", BT_FRAME_SIZE); } bt->frame_count++; } #endif #ifdef HAS_BACKTRACE #include <backtrace.h> static const char *get_exe() { static char buf[256] = {0}; ssize_t ret = readlink("/proc/self/exe", buf, sizeof(buf)-1); if (ret > 0) return buf; ret = readlink("/proc/curproc/file", buf, sizeof(buf)-1); if (ret > 0) return buf; return buf; } static void bt_error_callback(void *data, const char *msg, int errnum) { } static int bt_full_callback(void *data, uintptr_t pc, const char *filename, int lineno, const char *function) { struct backtrace *bt = (struct backtrace *)data; bt_add_frame(bt, function); return 0; } void get_backtrace(struct backtrace *bt, int skip) { static struct backtrace_state *state = NULL; if (!state) { const char *exe = get_exe(); if (exe) state = backtrace_create_state(exe, 1, bt_error_callback, NULL); } bzero(bt, sizeof(*bt)); if (state) { backtrace_full(state, skip + 1, bt_full_callback, bt_error_callback, bt); } } #elif HAS_LIBUNWIND #define UNW_LOCAL_ONLY #include <libunwind.h> struct bt_mapping { unw_word_t ip; char fname[BT_FRAME_SIZE]; }; #define BT_BUCKET_SIZE 3 struct bt_bucket { struct bt_mapping mappings[BT_BUCKET_SIZE]; }; struct bt_cache { struct bt_bucket *buckets; size_t count; size_t size; }; static unsigned oat_hash(void *key, int len) { unsigned char *p = key; unsigned h = 0; int i; for (i = 0; i < len; i++) { h += p[i]; h += (h << 10); h ^= (h >> 6); } h += (h << 3); h ^= (h >> 11); h += (h << 15); return h; } static struct bt_bucket *cached_proc_name_bucket(struct bt_cache *cache, unw_word_t ip) { if (!cache->size) return NULL; unsigned h = oat_hash(&ip, sizeof(ip)); return &cache->buckets[h % cache->size]; } static void bt_cache_init(struct bt_cache *cache) { if (!cache->size) { cache->size = 119; cache->buckets = calloc(cache->size, sizeof(*cache->buckets)); if (!cache->buckets) cache->size = 0; cache->count = 0; } } static void cached_proc_name_store(struct bt_cache *cache, unw_word_t ip, const char *fname); static void bt_cache_rebalance(struct bt_cache *cache) { struct bt_cache bigger = {}; bigger.size = cache->size * 2 + 1337; bigger.buckets = calloc(bigger.size, sizeof(*bigger.buckets)); bigger.count = 0; for (size_t b = 0; b < cache->size; b++) { for (size_t i = 0; i < BT_BUCKET_SIZE; i++) { struct bt_mapping *map = &cache->buckets[b].mappings[i]; if (map->ip) { cached_proc_name_store(&bigger, map->ip, map->fname); } } } free(cache->buckets); *cache = bigger; } static void cached_proc_name_store(struct bt_cache *cache, unw_word_t ip, const char *fname) { bt_cache_init(cache); if (!cache->size) return; struct bt_bucket *bucket = cached_proc_name_bucket(cache, ip); bool stored = false; for (size_t i = 0; i < BT_BUCKET_SIZE; i++) { if (bucket->mappings[i].ip == ip) return; if (bucket->mappings[i].ip != 0) continue; bucket->mappings[i].ip = ip; strncpy(bucket->mappings[i].fname, fname, sizeof(bucket->mappings[i].fname)); cache->count++; stored = true; break; } if (cache->count > cache->size / 4 || !stored) { bt_cache_rebalance(cache); fprintf(stderr, "tint2: proc_name cache: ratio %f, count %lu, size %lu, (%lu bytes)\n", cache->count / (double)cache->size, cache->count, (size_t)cache->size, cache->size * sizeof(*cache->buckets)); } } const char *cached_proc_name_get(struct bt_cache *cache, unw_word_t ip) { struct bt_bucket *bucket = cached_proc_name_bucket(cache, ip); if (!bucket) return NULL; for (size_t i = 0; i < BT_BUCKET_SIZE; i++) { if (bucket->mappings[i].ip != ip) continue; return bucket->mappings[i].fname; } return NULL; } void get_backtrace(struct backtrace *bt, int skip) { static struct bt_cache bt_cache = {}; bzero(bt, sizeof(*bt)); unw_cursor_t cursor; unw_context_t context; unw_getcontext(&context); unw_init_local(&cursor, &context); while (unw_step(&cursor) > 0) { if (skip > 0) { skip--; continue; } unw_word_t offset; char fname[BT_FRAME_SIZE] = {0}; unw_word_t ip; unw_get_reg(&cursor, UNW_REG_IP, &ip); const char *fname_cached = cached_proc_name_get(&bt_cache, ip); if (fname_cached) { bt_add_frame(bt, fname_cached); } else { unw_get_proc_name(&cursor, fname, sizeof(fname), &offset); cached_proc_name_store(&bt_cache, ip, fname); bt_add_frame(bt, fname); } } } #elif HAS_EXECINFO #include <execinfo.h> void get_backtrace(struct backtrace *bt, int skip) { bzero(bt, sizeof(*bt)); void *array[BT_MAX_FRAMES]; int size = backtrace(array, BT_MAX_FRAMES); char **strings = backtrace_symbols(array, size); for (int i = 0; i < size; i++) { bt_add_frame(bt, strings[i]); } free(strings); } #else void get_backtrace(struct backtrace *bt, int skip) { bzero(bt, sizeof(*bt)); } #endif |