1 /* 2 * RAM Oops/Panic logger 3 * 4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com> 5 * Copyright (C) 2011 Kees Cook <keescook@chromium.org> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * version 2 as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, but 12 * WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 19 * 02110-1301 USA 20 * 21 */ 22 23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 24 25 #include <linux/kernel.h> 26 #include <linux/err.h> 27 #include <linux/module.h> 28 #include <linux/version.h> 29 #include <linux/pstore.h> 30 #include <linux/time.h> 31 #include <linux/io.h> 32 #include <linux/ioport.h> 33 #include <linux/platform_device.h> 34 #include <linux/slab.h> 35 #include <linux/compiler.h> 36 #include <linux/pstore_ram.h> 37 38 #define RAMOOPS_KERNMSG_HDR "====" 39 #define MIN_MEM_SIZE 4096UL 40 41 static ulong record_size = MIN_MEM_SIZE; 42 module_param(record_size, ulong, 0400); 43 MODULE_PARM_DESC(record_size, 44 "size of each dump done on oops/panic"); 45 46 static ulong ramoops_console_size = MIN_MEM_SIZE; 47 module_param_named(console_size, ramoops_console_size, ulong, 0400); 48 MODULE_PARM_DESC(console_size, "size of kernel console log"); 49 50 static ulong ramoops_ftrace_size = MIN_MEM_SIZE; 51 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400); 52 MODULE_PARM_DESC(ftrace_size, "size of ftrace log"); 53 54 static ulong mem_address; 55 module_param(mem_address, ulong, 0400); 56 MODULE_PARM_DESC(mem_address, 57 "start of reserved RAM used to store oops/panic logs"); 58 59 static ulong mem_size; 60 module_param(mem_size, ulong, 0400); 61 MODULE_PARM_DESC(mem_size, 62 "size of reserved RAM used to store oops/panic logs"); 63 64 static int dump_oops = 1; 65 module_param(dump_oops, int, 0600); 66 MODULE_PARM_DESC(dump_oops, 67 "set to 1 to dump oopses, 0 to only dump panics (default 1)"); 68 69 static int ramoops_ecc; 70 module_param_named(ecc, ramoops_ecc, int, 0600); 71 MODULE_PARM_DESC(ramoops_ecc, 72 "if non-zero, the option enables ECC support and specifies " 73 "ECC buffer size in bytes (1 is a special value, means 16 " 74 "bytes ECC)"); 75 76 struct ramoops_context { 77 struct persistent_ram_zone **przs; 78 struct persistent_ram_zone *cprz; 79 struct persistent_ram_zone *fprz; 80 phys_addr_t phys_addr; 81 unsigned long size; 82 size_t record_size; 83 size_t console_size; 84 size_t ftrace_size; 85 int dump_oops; 86 struct persistent_ram_ecc_info ecc_info; 87 unsigned int max_dump_cnt; 88 unsigned int dump_write_cnt; 89 unsigned int dump_read_cnt; 90 unsigned int console_read_cnt; 91 unsigned int ftrace_read_cnt; 92 struct pstore_info pstore; 93 }; 94 95 static struct platform_device *dummy; 96 static struct ramoops_platform_data *dummy_data; 97 98 static int ramoops_pstore_open(struct pstore_info *psi) 99 { 100 struct ramoops_context *cxt = psi->data; 101 102 cxt->dump_read_cnt = 0; 103 cxt->console_read_cnt = 0; 104 return 0; 105 } 106 107 static struct persistent_ram_zone * 108 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max, 109 u64 *id, 110 enum pstore_type_id *typep, enum pstore_type_id type, 111 bool update) 112 { 113 struct persistent_ram_zone *prz; 114 int i = (*c)++; 115 116 if (i >= max) 117 return NULL; 118 119 prz = przs[i]; 120 121 if (update) { 122 /* Update old/shadowed buffer. */ 123 persistent_ram_save_old(prz); 124 if (!persistent_ram_old_size(prz)) 125 return NULL; 126 } 127 128 *typep = type; 129 *id = i; 130 131 return prz; 132 } 133 134 static void ramoops_read_kmsg_hdr(char *buffer, struct timespec *time, 135 bool *compressed) 136 { 137 char data_type; 138 139 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n", 140 &time->tv_sec, &time->tv_nsec, &data_type) == 3) { 141 if (data_type == 'C') 142 *compressed = true; 143 else 144 *compressed = false; 145 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n", 146 &time->tv_sec, &time->tv_nsec) == 2) { 147 *compressed = false; 148 } else { 149 time->tv_sec = 0; 150 time->tv_nsec = 0; 151 *compressed = false; 152 } 153 } 154 155 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, 156 int *count, struct timespec *time, 157 char **buf, bool *compressed, 158 struct pstore_info *psi) 159 { 160 ssize_t size; 161 ssize_t ecc_notice_size; 162 struct ramoops_context *cxt = psi->data; 163 struct persistent_ram_zone *prz; 164 165 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt, 166 cxt->max_dump_cnt, id, type, 167 PSTORE_TYPE_DMESG, 1); 168 if (!prz) 169 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt, 170 1, id, type, PSTORE_TYPE_CONSOLE, 0); 171 if (!prz) 172 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt, 173 1, id, type, PSTORE_TYPE_FTRACE, 0); 174 if (!prz) 175 return 0; 176 177 size = persistent_ram_old_size(prz); 178 179 /* ECC correction notice */ 180 ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0); 181 182 *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL); 183 if (*buf == NULL) 184 return -ENOMEM; 185 186 memcpy(*buf, persistent_ram_old(prz), size); 187 ramoops_read_kmsg_hdr(*buf, time, compressed); 188 persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1); 189 190 return size + ecc_notice_size; 191 } 192 193 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz, 194 bool compressed) 195 { 196 char *hdr; 197 struct timespec timestamp; 198 size_t len; 199 200 /* Report zeroed timestamp if called before timekeeping has resumed. */ 201 if (__getnstimeofday(×tamp)) { 202 timestamp.tv_sec = 0; 203 timestamp.tv_nsec = 0; 204 } 205 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n", 206 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000), 207 compressed ? 'C' : 'D'); 208 WARN_ON_ONCE(!hdr); 209 len = hdr ? strlen(hdr) : 0; 210 persistent_ram_write(prz, hdr, len); 211 kfree(hdr); 212 213 return len; 214 } 215 216 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type, 217 enum kmsg_dump_reason reason, 218 u64 *id, unsigned int part, 219 const char *buf, 220 bool compressed, size_t size, 221 struct pstore_info *psi) 222 { 223 struct ramoops_context *cxt = psi->data; 224 struct persistent_ram_zone *prz; 225 size_t hlen; 226 227 if (type == PSTORE_TYPE_CONSOLE) { 228 if (!cxt->cprz) 229 return -ENOMEM; 230 persistent_ram_write(cxt->cprz, buf, size); 231 return 0; 232 } else if (type == PSTORE_TYPE_FTRACE) { 233 if (!cxt->fprz) 234 return -ENOMEM; 235 persistent_ram_write(cxt->fprz, buf, size); 236 return 0; 237 } 238 239 if (type != PSTORE_TYPE_DMESG) 240 return -EINVAL; 241 242 /* Out of the various dmesg dump types, ramoops is currently designed 243 * to only store crash logs, rather than storing general kernel logs. 244 */ 245 if (reason != KMSG_DUMP_OOPS && 246 reason != KMSG_DUMP_PANIC) 247 return -EINVAL; 248 249 /* Skip Oopes when configured to do so. */ 250 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops) 251 return -EINVAL; 252 253 /* Explicitly only take the first part of any new crash. 254 * If our buffer is larger than kmsg_bytes, this can never happen, 255 * and if our buffer is smaller than kmsg_bytes, we don't want the 256 * report split across multiple records. 257 */ 258 if (part != 1) 259 return -ENOSPC; 260 261 if (!cxt->przs) 262 return -ENOSPC; 263 264 prz = cxt->przs[cxt->dump_write_cnt]; 265 266 hlen = ramoops_write_kmsg_hdr(prz, compressed); 267 if (size + hlen > prz->buffer_size) 268 size = prz->buffer_size - hlen; 269 persistent_ram_write(prz, buf, size); 270 271 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt; 272 273 return 0; 274 } 275 276 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count, 277 struct timespec time, struct pstore_info *psi) 278 { 279 struct ramoops_context *cxt = psi->data; 280 struct persistent_ram_zone *prz; 281 282 switch (type) { 283 case PSTORE_TYPE_DMESG: 284 if (id >= cxt->max_dump_cnt) 285 return -EINVAL; 286 prz = cxt->przs[id]; 287 break; 288 case PSTORE_TYPE_CONSOLE: 289 prz = cxt->cprz; 290 break; 291 case PSTORE_TYPE_FTRACE: 292 prz = cxt->fprz; 293 break; 294 default: 295 return -EINVAL; 296 } 297 298 persistent_ram_free_old(prz); 299 persistent_ram_zap(prz); 300 301 return 0; 302 } 303 304 static struct ramoops_context oops_cxt = { 305 .pstore = { 306 .owner = THIS_MODULE, 307 .name = "ramoops", 308 .open = ramoops_pstore_open, 309 .read = ramoops_pstore_read, 310 .write_buf = ramoops_pstore_write_buf, 311 .erase = ramoops_pstore_erase, 312 }, 313 }; 314 315 static void ramoops_free_przs(struct ramoops_context *cxt) 316 { 317 int i; 318 319 if (!cxt->przs) 320 return; 321 322 for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++) 323 persistent_ram_free(cxt->przs[i]); 324 kfree(cxt->przs); 325 } 326 327 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt, 328 phys_addr_t *paddr, size_t dump_mem_sz) 329 { 330 int err = -ENOMEM; 331 int i; 332 333 if (!cxt->record_size) 334 return 0; 335 336 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) { 337 dev_err(dev, "no room for dumps\n"); 338 return -ENOMEM; 339 } 340 341 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size; 342 if (!cxt->max_dump_cnt) 343 return -ENOMEM; 344 345 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt, 346 GFP_KERNEL); 347 if (!cxt->przs) { 348 dev_err(dev, "failed to initialize a prz array for dumps\n"); 349 return -ENOMEM; 350 } 351 352 for (i = 0; i < cxt->max_dump_cnt; i++) { 353 size_t sz = cxt->record_size; 354 355 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, 356 &cxt->ecc_info); 357 if (IS_ERR(cxt->przs[i])) { 358 err = PTR_ERR(cxt->przs[i]); 359 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", 360 sz, (unsigned long long)*paddr, err); 361 goto fail_prz; 362 } 363 *paddr += sz; 364 } 365 366 return 0; 367 fail_prz: 368 ramoops_free_przs(cxt); 369 return err; 370 } 371 372 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, 373 struct persistent_ram_zone **prz, 374 phys_addr_t *paddr, size_t sz, u32 sig) 375 { 376 if (!sz) 377 return 0; 378 379 if (*paddr + sz - cxt->phys_addr > cxt->size) { 380 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n", 381 sz, (unsigned long long)*paddr, 382 cxt->size, (unsigned long long)cxt->phys_addr); 383 return -ENOMEM; 384 } 385 386 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info); 387 if (IS_ERR(*prz)) { 388 int err = PTR_ERR(*prz); 389 390 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", 391 sz, (unsigned long long)*paddr, err); 392 return err; 393 } 394 395 persistent_ram_zap(*prz); 396 397 *paddr += sz; 398 399 return 0; 400 } 401 402 static int ramoops_probe(struct platform_device *pdev) 403 { 404 struct device *dev = &pdev->dev; 405 struct ramoops_platform_data *pdata = pdev->dev.platform_data; 406 struct ramoops_context *cxt = &oops_cxt; 407 size_t dump_mem_sz; 408 phys_addr_t paddr; 409 int err = -EINVAL; 410 411 /* Only a single ramoops area allowed at a time, so fail extra 412 * probes. 413 */ 414 if (cxt->max_dump_cnt) 415 goto fail_out; 416 417 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size && 418 !pdata->ftrace_size)) { 419 pr_err("The memory size and the record/console size must be " 420 "non-zero\n"); 421 goto fail_out; 422 } 423 424 if (pdata->record_size && !is_power_of_2(pdata->record_size)) 425 pdata->record_size = rounddown_pow_of_two(pdata->record_size); 426 if (pdata->console_size && !is_power_of_2(pdata->console_size)) 427 pdata->console_size = rounddown_pow_of_two(pdata->console_size); 428 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size)) 429 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); 430 431 cxt->dump_read_cnt = 0; 432 cxt->size = pdata->mem_size; 433 cxt->phys_addr = pdata->mem_address; 434 cxt->record_size = pdata->record_size; 435 cxt->console_size = pdata->console_size; 436 cxt->ftrace_size = pdata->ftrace_size; 437 cxt->dump_oops = pdata->dump_oops; 438 cxt->ecc_info = pdata->ecc_info; 439 440 paddr = cxt->phys_addr; 441 442 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size; 443 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz); 444 if (err) 445 goto fail_out; 446 447 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr, 448 cxt->console_size, 0); 449 if (err) 450 goto fail_init_cprz; 451 452 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size, 453 LINUX_VERSION_CODE); 454 if (err) 455 goto fail_init_fprz; 456 457 if (!cxt->przs && !cxt->cprz && !cxt->fprz) { 458 pr_err("memory size too small, minimum is %zu\n", 459 cxt->console_size + cxt->record_size + 460 cxt->ftrace_size); 461 err = -EINVAL; 462 goto fail_cnt; 463 } 464 465 cxt->pstore.data = cxt; 466 /* 467 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we 468 * have to handle dumps, we must have at least record_size buffer. And 469 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be 470 * ZERO_SIZE_PTR). 471 */ 472 if (cxt->console_size) 473 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */ 474 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize); 475 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL); 476 spin_lock_init(&cxt->pstore.buf_lock); 477 if (!cxt->pstore.buf) { 478 pr_err("cannot allocate pstore buffer\n"); 479 err = -ENOMEM; 480 goto fail_clear; 481 } 482 483 err = pstore_register(&cxt->pstore); 484 if (err) { 485 pr_err("registering with pstore failed\n"); 486 goto fail_buf; 487 } 488 489 /* 490 * Update the module parameter variables as well so they are visible 491 * through /sys/module/ramoops/parameters/ 492 */ 493 mem_size = pdata->mem_size; 494 mem_address = pdata->mem_address; 495 record_size = pdata->record_size; 496 dump_oops = pdata->dump_oops; 497 498 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n", 499 cxt->size, (unsigned long long)cxt->phys_addr, 500 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size); 501 502 return 0; 503 504 fail_buf: 505 kfree(cxt->pstore.buf); 506 fail_clear: 507 cxt->pstore.bufsize = 0; 508 cxt->max_dump_cnt = 0; 509 fail_cnt: 510 kfree(cxt->fprz); 511 fail_init_fprz: 512 kfree(cxt->cprz); 513 fail_init_cprz: 514 ramoops_free_przs(cxt); 515 fail_out: 516 return err; 517 } 518 519 static int __exit ramoops_remove(struct platform_device *pdev) 520 { 521 #if 0 522 /* TODO(kees): We cannot unload ramoops since pstore doesn't support 523 * unregistering yet. 524 */ 525 struct ramoops_context *cxt = &oops_cxt; 526 527 iounmap(cxt->virt_addr); 528 release_mem_region(cxt->phys_addr, cxt->size); 529 cxt->max_dump_cnt = 0; 530 531 /* TODO(kees): When pstore supports unregistering, call it here. */ 532 kfree(cxt->pstore.buf); 533 cxt->pstore.bufsize = 0; 534 535 return 0; 536 #endif 537 return -EBUSY; 538 } 539 540 static struct platform_driver ramoops_driver = { 541 .probe = ramoops_probe, 542 .remove = __exit_p(ramoops_remove), 543 .driver = { 544 .name = "ramoops", 545 .owner = THIS_MODULE, 546 }, 547 }; 548 549 static void ramoops_register_dummy(void) 550 { 551 if (!mem_size) 552 return; 553 554 pr_info("using module parameters\n"); 555 556 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL); 557 if (!dummy_data) { 558 pr_info("could not allocate pdata\n"); 559 return; 560 } 561 562 dummy_data->mem_size = mem_size; 563 dummy_data->mem_address = mem_address; 564 dummy_data->record_size = record_size; 565 dummy_data->console_size = ramoops_console_size; 566 dummy_data->ftrace_size = ramoops_ftrace_size; 567 dummy_data->dump_oops = dump_oops; 568 /* 569 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC 570 * (using 1 byte for ECC isn't much of use anyway). 571 */ 572 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc; 573 574 dummy = platform_device_register_data(NULL, "ramoops", -1, 575 dummy_data, sizeof(struct ramoops_platform_data)); 576 if (IS_ERR(dummy)) { 577 pr_info("could not create platform device: %ld\n", 578 PTR_ERR(dummy)); 579 } 580 } 581 582 static int __init ramoops_init(void) 583 { 584 ramoops_register_dummy(); 585 return platform_driver_register(&ramoops_driver); 586 } 587 postcore_initcall(ramoops_init); 588 589 static void __exit ramoops_exit(void) 590 { 591 platform_driver_unregister(&ramoops_driver); 592 platform_device_unregister(dummy); 593 kfree(dummy_data); 594 } 595 module_exit(ramoops_exit); 596 597 MODULE_LICENSE("GPL"); 598 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>"); 599 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver"); 600