1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/compiler.h> 3 #include <linux/kernel.h> 4 #include <linux/string.h> 5 #include <linux/zalloc.h> 6 #include <sys/types.h> 7 #include <sys/stat.h> 8 #include <errno.h> 9 #include <fcntl.h> 10 #include <unistd.h> 11 #include <string.h> 12 #include <asm/bug.h> 13 #include <dirent.h> 14 15 #include "data.h" 16 #include "util.h" // rm_rf_perf_data() 17 #include "debug.h" 18 #include "header.h" 19 #include <internal/lib.h> 20 21 static void close_dir(struct perf_data_file *files, int nr) 22 { 23 while (--nr >= 1) { 24 close(files[nr].fd); 25 zfree(&files[nr].path); 26 } 27 free(files); 28 } 29 30 void perf_data__close_dir(struct perf_data *data) 31 { 32 close_dir(data->dir.files, data->dir.nr); 33 } 34 35 int perf_data__create_dir(struct perf_data *data, int nr) 36 { 37 struct perf_data_file *files = NULL; 38 int i, ret = -1; 39 40 if (WARN_ON(!data->is_dir)) 41 return -EINVAL; 42 43 files = zalloc(nr * sizeof(*files)); 44 if (!files) 45 return -ENOMEM; 46 47 data->dir.version = PERF_DIR_VERSION; 48 data->dir.files = files; 49 data->dir.nr = nr; 50 51 for (i = 0; i < nr; i++) { 52 struct perf_data_file *file = &files[i]; 53 54 if (asprintf(&file->path, "%s/data.%d", data->path, i) < 0) 55 goto out_err; 56 57 ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR); 58 if (ret < 0) 59 goto out_err; 60 61 file->fd = ret; 62 } 63 64 return 0; 65 66 out_err: 67 close_dir(files, i); 68 return ret; 69 } 70 71 int perf_data__open_dir(struct perf_data *data) 72 { 73 struct perf_data_file *files = NULL; 74 struct dirent *dent; 75 int ret = -1; 76 DIR *dir; 77 int nr = 0; 78 79 /* 80 * Directory containing a single regular perf data file which is already 81 * open, means there is nothing more to do here. 82 */ 83 if (perf_data__is_single_file(data)) 84 return 0; 85 86 if (WARN_ON(!data->is_dir)) 87 return -EINVAL; 88 89 /* The version is provided by DIR_FORMAT feature. */ 90 if (WARN_ON(data->dir.version != PERF_DIR_VERSION)) 91 return -1; 92 93 dir = opendir(data->path); 94 if (!dir) 95 return -EINVAL; 96 97 while ((dent = readdir(dir)) != NULL) { 98 struct perf_data_file *file; 99 char path[PATH_MAX]; 100 struct stat st; 101 102 snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name); 103 if (stat(path, &st)) 104 continue; 105 106 if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5)) 107 continue; 108 109 ret = -ENOMEM; 110 111 file = realloc(files, (nr + 1) * sizeof(*files)); 112 if (!file) 113 goto out_err; 114 115 files = file; 116 file = &files[nr++]; 117 118 file->path = strdup(path); 119 if (!file->path) 120 goto out_err; 121 122 ret = open(file->path, O_RDONLY); 123 if (ret < 0) 124 goto out_err; 125 126 file->fd = ret; 127 file->size = st.st_size; 128 } 129 130 if (!files) 131 return -EINVAL; 132 133 data->dir.files = files; 134 data->dir.nr = nr; 135 return 0; 136 137 out_err: 138 close_dir(files, nr); 139 return ret; 140 } 141 142 int perf_data__update_dir(struct perf_data *data) 143 { 144 int i; 145 146 if (WARN_ON(!data->is_dir)) 147 return -EINVAL; 148 149 for (i = 0; i < data->dir.nr; i++) { 150 struct perf_data_file *file = &data->dir.files[i]; 151 struct stat st; 152 153 if (fstat(file->fd, &st)) 154 return -1; 155 156 file->size = st.st_size; 157 } 158 159 return 0; 160 } 161 162 static bool check_pipe(struct perf_data *data) 163 { 164 struct stat st; 165 bool is_pipe = false; 166 int fd = perf_data__is_read(data) ? 167 STDIN_FILENO : STDOUT_FILENO; 168 169 if (!data->path) { 170 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) 171 is_pipe = true; 172 } else { 173 if (!strcmp(data->path, "-")) 174 is_pipe = true; 175 } 176 177 if (is_pipe) 178 data->file.fd = fd; 179 180 return data->is_pipe = is_pipe; 181 } 182 183 static int check_backup(struct perf_data *data) 184 { 185 struct stat st; 186 187 if (perf_data__is_read(data)) 188 return 0; 189 190 if (!stat(data->path, &st) && st.st_size) { 191 char oldname[PATH_MAX]; 192 int ret; 193 194 snprintf(oldname, sizeof(oldname), "%s.old", 195 data->path); 196 197 ret = rm_rf_perf_data(oldname); 198 if (ret) { 199 pr_err("Can't remove old data: %s (%s)\n", 200 ret == -2 ? 201 "Unknown file found" : strerror(errno), 202 oldname); 203 return -1; 204 } 205 206 if (rename(data->path, oldname)) { 207 pr_err("Can't move data: %s (%s to %s)\n", 208 strerror(errno), 209 data->path, oldname); 210 return -1; 211 } 212 } 213 214 return 0; 215 } 216 217 static bool is_dir(struct perf_data *data) 218 { 219 struct stat st; 220 221 if (stat(data->path, &st)) 222 return false; 223 224 return (st.st_mode & S_IFMT) == S_IFDIR; 225 } 226 227 static int open_file_read(struct perf_data *data) 228 { 229 struct stat st; 230 int fd; 231 char sbuf[STRERR_BUFSIZE]; 232 233 fd = open(data->file.path, O_RDONLY); 234 if (fd < 0) { 235 int err = errno; 236 237 pr_err("failed to open %s: %s", data->file.path, 238 str_error_r(err, sbuf, sizeof(sbuf))); 239 if (err == ENOENT && !strcmp(data->file.path, "perf.data")) 240 pr_err(" (try 'perf record' first)"); 241 pr_err("\n"); 242 return -err; 243 } 244 245 if (fstat(fd, &st) < 0) 246 goto out_close; 247 248 if (!data->force && st.st_uid && (st.st_uid != geteuid())) { 249 pr_err("File %s not owned by current user or root (use -f to override)\n", 250 data->file.path); 251 goto out_close; 252 } 253 254 if (!st.st_size) { 255 pr_info("zero-sized data (%s), nothing to do!\n", 256 data->file.path); 257 goto out_close; 258 } 259 260 data->file.size = st.st_size; 261 return fd; 262 263 out_close: 264 close(fd); 265 return -1; 266 } 267 268 static int open_file_write(struct perf_data *data) 269 { 270 int fd; 271 char sbuf[STRERR_BUFSIZE]; 272 273 fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, 274 S_IRUSR|S_IWUSR); 275 276 if (fd < 0) 277 pr_err("failed to open %s : %s\n", data->file.path, 278 str_error_r(errno, sbuf, sizeof(sbuf))); 279 280 return fd; 281 } 282 283 static int open_file(struct perf_data *data) 284 { 285 int fd; 286 287 fd = perf_data__is_read(data) ? 288 open_file_read(data) : open_file_write(data); 289 290 if (fd < 0) { 291 zfree(&data->file.path); 292 return -1; 293 } 294 295 data->file.fd = fd; 296 return 0; 297 } 298 299 static int open_file_dup(struct perf_data *data) 300 { 301 data->file.path = strdup(data->path); 302 if (!data->file.path) 303 return -ENOMEM; 304 305 return open_file(data); 306 } 307 308 static int open_dir(struct perf_data *data) 309 { 310 int ret; 311 312 /* 313 * So far we open only the header, so we can read the data version and 314 * layout. 315 */ 316 if (asprintf(&data->file.path, "%s/data", data->path) < 0) 317 return -1; 318 319 if (perf_data__is_write(data) && 320 mkdir(data->path, S_IRWXU) < 0) 321 return -1; 322 323 ret = open_file(data); 324 325 /* Cleanup whatever we managed to create so far. */ 326 if (ret && perf_data__is_write(data)) 327 rm_rf_perf_data(data->path); 328 329 return ret; 330 } 331 332 int perf_data__open(struct perf_data *data) 333 { 334 if (check_pipe(data)) 335 return 0; 336 337 if (!data->path) 338 data->path = "perf.data"; 339 340 if (check_backup(data)) 341 return -1; 342 343 if (perf_data__is_read(data)) 344 data->is_dir = is_dir(data); 345 346 return perf_data__is_dir(data) ? 347 open_dir(data) : open_file_dup(data); 348 } 349 350 void perf_data__close(struct perf_data *data) 351 { 352 if (perf_data__is_dir(data)) 353 perf_data__close_dir(data); 354 355 zfree(&data->file.path); 356 close(data->file.fd); 357 } 358 359 ssize_t perf_data_file__write(struct perf_data_file *file, 360 void *buf, size_t size) 361 { 362 return writen(file->fd, buf, size); 363 } 364 365 ssize_t perf_data__write(struct perf_data *data, 366 void *buf, size_t size) 367 { 368 return perf_data_file__write(&data->file, buf, size); 369 } 370 371 int perf_data__switch(struct perf_data *data, 372 const char *postfix, 373 size_t pos, bool at_exit, 374 char **new_filepath) 375 { 376 int ret; 377 378 if (check_pipe(data)) 379 return -EINVAL; 380 if (perf_data__is_read(data)) 381 return -EINVAL; 382 383 if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0) 384 return -ENOMEM; 385 386 /* 387 * Only fire a warning, don't return error, continue fill 388 * original file. 389 */ 390 if (rename(data->path, *new_filepath)) 391 pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath); 392 393 if (!at_exit) { 394 close(data->file.fd); 395 ret = perf_data__open(data); 396 if (ret < 0) 397 goto out; 398 399 if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) { 400 ret = -errno; 401 pr_debug("Failed to lseek to %zu: %s", 402 pos, strerror(errno)); 403 goto out; 404 } 405 } 406 ret = data->file.fd; 407 out: 408 return ret; 409 } 410 411 unsigned long perf_data__size(struct perf_data *data) 412 { 413 u64 size = data->file.size; 414 int i; 415 416 if (perf_data__is_single_file(data)) 417 return size; 418 419 for (i = 0; i < data->dir.nr; i++) { 420 struct perf_data_file *file = &data->dir.files[i]; 421 422 size += file->size; 423 } 424 425 return size; 426 } 427 428 int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz) 429 { 430 int ret; 431 432 if (!data->is_dir) 433 return -1; 434 435 ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path); 436 if (ret < 0 || (size_t)ret >= buf_sz) 437 return -1; 438 439 return mkdir(buf, S_IRWXU); 440 } 441 442 char *perf_data__kallsyms_name(struct perf_data *data) 443 { 444 char *kallsyms_name; 445 struct stat st; 446 447 if (!data->is_dir) 448 return NULL; 449 450 if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0) 451 return NULL; 452 453 if (stat(kallsyms_name, &st)) { 454 free(kallsyms_name); 455 return NULL; 456 } 457 458 return kallsyms_name; 459 } 460