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 ramoops_pmsg_size = MIN_MEM_SIZE; 55 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400); 56 MODULE_PARM_DESC(pmsg_size, "size of user space message log"); 57 58 static unsigned long long mem_address; 59 module_param(mem_address, ullong, 0400); 60 MODULE_PARM_DESC(mem_address, 61 "start of reserved RAM used to store oops/panic logs"); 62 63 static ulong mem_size; 64 module_param(mem_size, ulong, 0400); 65 MODULE_PARM_DESC(mem_size, 66 "size of reserved RAM used to store oops/panic logs"); 67 68 static unsigned int mem_type; 69 module_param(mem_type, uint, 0600); 70 MODULE_PARM_DESC(mem_type, 71 "set to 1 to try to use unbuffered memory (default 0)"); 72 73 static int dump_oops = 1; 74 module_param(dump_oops, int, 0600); 75 MODULE_PARM_DESC(dump_oops, 76 "set to 1 to dump oopses, 0 to only dump panics (default 1)"); 77 78 static int ramoops_ecc; 79 module_param_named(ecc, ramoops_ecc, int, 0600); 80 MODULE_PARM_DESC(ramoops_ecc, 81 "if non-zero, the option enables ECC support and specifies " 82 "ECC buffer size in bytes (1 is a special value, means 16 " 83 "bytes ECC)"); 84 85 struct ramoops_context { 86 struct persistent_ram_zone **przs; 87 struct persistent_ram_zone *cprz; 88 struct persistent_ram_zone *fprz; 89 struct persistent_ram_zone *mprz; 90 phys_addr_t phys_addr; 91 unsigned long size; 92 unsigned int memtype; 93 size_t record_size; 94 size_t console_size; 95 size_t ftrace_size; 96 size_t pmsg_size; 97 int dump_oops; 98 struct persistent_ram_ecc_info ecc_info; 99 unsigned int max_dump_cnt; 100 unsigned int dump_write_cnt; 101 /* _read_cnt need clear on ramoops_pstore_open */ 102 unsigned int dump_read_cnt; 103 unsigned int console_read_cnt; 104 unsigned int ftrace_read_cnt; 105 unsigned int pmsg_read_cnt; 106 struct pstore_info pstore; 107 }; 108 109 static struct platform_device *dummy; 110 static struct ramoops_platform_data *dummy_data; 111 112 static int ramoops_pstore_open(struct pstore_info *psi) 113 { 114 struct ramoops_context *cxt = psi->data; 115 116 cxt->dump_read_cnt = 0; 117 cxt->console_read_cnt = 0; 118 cxt->ftrace_read_cnt = 0; 119 cxt->pmsg_read_cnt = 0; 120 return 0; 121 } 122 123 static struct persistent_ram_zone * 124 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max, 125 u64 *id, 126 enum pstore_type_id *typep, enum pstore_type_id type, 127 bool update) 128 { 129 struct persistent_ram_zone *prz; 130 int i = (*c)++; 131 132 if (i >= max) 133 return NULL; 134 135 prz = przs[i]; 136 if (!prz) 137 return NULL; 138 139 /* Update old/shadowed buffer. */ 140 if (update) 141 persistent_ram_save_old(prz); 142 143 if (!persistent_ram_old_size(prz)) 144 return NULL; 145 146 *typep = type; 147 *id = i; 148 149 return prz; 150 } 151 152 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time, 153 bool *compressed) 154 { 155 char data_type; 156 int header_length = 0; 157 158 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec, 159 &time->tv_nsec, &data_type, &header_length) == 3) { 160 if (data_type == 'C') 161 *compressed = true; 162 else 163 *compressed = false; 164 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n", 165 &time->tv_sec, &time->tv_nsec, &header_length) == 2) { 166 *compressed = false; 167 } else { 168 time->tv_sec = 0; 169 time->tv_nsec = 0; 170 *compressed = false; 171 } 172 return header_length; 173 } 174 175 static bool prz_ok(struct persistent_ram_zone *prz) 176 { 177 return !!prz && !!(persistent_ram_old_size(prz) + 178 persistent_ram_ecc_string(prz, NULL, 0)); 179 } 180 181 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, 182 int *count, struct timespec *time, 183 char **buf, bool *compressed, 184 struct pstore_info *psi) 185 { 186 ssize_t size; 187 ssize_t ecc_notice_size; 188 struct ramoops_context *cxt = psi->data; 189 struct persistent_ram_zone *prz = NULL; 190 int header_length = 0; 191 192 /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but 193 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have 194 * valid time stamps, so it is initialized to zero. 195 */ 196 time->tv_sec = 0; 197 time->tv_nsec = 0; 198 *compressed = false; 199 200 /* Find the next valid persistent_ram_zone for DMESG */ 201 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) { 202 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt, 203 cxt->max_dump_cnt, id, type, 204 PSTORE_TYPE_DMESG, 1); 205 if (!prz_ok(prz)) 206 continue; 207 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), 208 time, compressed); 209 /* Clear and skip this DMESG record if it has no valid header */ 210 if (!header_length) { 211 persistent_ram_free_old(prz); 212 persistent_ram_zap(prz); 213 prz = NULL; 214 } 215 } 216 217 if (!prz_ok(prz)) 218 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt, 219 1, id, type, PSTORE_TYPE_CONSOLE, 0); 220 if (!prz_ok(prz)) 221 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt, 222 1, id, type, PSTORE_TYPE_FTRACE, 0); 223 if (!prz_ok(prz)) 224 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt, 225 1, id, type, PSTORE_TYPE_PMSG, 0); 226 if (!prz_ok(prz)) 227 return 0; 228 229 size = persistent_ram_old_size(prz) - header_length; 230 231 /* ECC correction notice */ 232 ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0); 233 234 *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL); 235 if (*buf == NULL) 236 return -ENOMEM; 237 238 memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size); 239 persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1); 240 241 return size + ecc_notice_size; 242 } 243 244 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz, 245 bool compressed) 246 { 247 char *hdr; 248 struct timespec timestamp; 249 size_t len; 250 251 /* Report zeroed timestamp if called before timekeeping has resumed. */ 252 if (__getnstimeofday(×tamp)) { 253 timestamp.tv_sec = 0; 254 timestamp.tv_nsec = 0; 255 } 256 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n", 257 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000), 258 compressed ? 'C' : 'D'); 259 WARN_ON_ONCE(!hdr); 260 len = hdr ? strlen(hdr) : 0; 261 persistent_ram_write(prz, hdr, len); 262 kfree(hdr); 263 264 return len; 265 } 266 267 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type, 268 enum kmsg_dump_reason reason, 269 u64 *id, unsigned int part, 270 const char *buf, 271 bool compressed, size_t size, 272 struct pstore_info *psi) 273 { 274 struct ramoops_context *cxt = psi->data; 275 struct persistent_ram_zone *prz; 276 size_t hlen; 277 278 if (type == PSTORE_TYPE_CONSOLE) { 279 if (!cxt->cprz) 280 return -ENOMEM; 281 persistent_ram_write(cxt->cprz, buf, size); 282 return 0; 283 } else if (type == PSTORE_TYPE_FTRACE) { 284 if (!cxt->fprz) 285 return -ENOMEM; 286 persistent_ram_write(cxt->fprz, buf, size); 287 return 0; 288 } else if (type == PSTORE_TYPE_PMSG) { 289 if (!cxt->mprz) 290 return -ENOMEM; 291 persistent_ram_write(cxt->mprz, buf, size); 292 return 0; 293 } 294 295 if (type != PSTORE_TYPE_DMESG) 296 return -EINVAL; 297 298 /* Out of the various dmesg dump types, ramoops is currently designed 299 * to only store crash logs, rather than storing general kernel logs. 300 */ 301 if (reason != KMSG_DUMP_OOPS && 302 reason != KMSG_DUMP_PANIC) 303 return -EINVAL; 304 305 /* Skip Oopes when configured to do so. */ 306 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops) 307 return -EINVAL; 308 309 /* Explicitly only take the first part of any new crash. 310 * If our buffer is larger than kmsg_bytes, this can never happen, 311 * and if our buffer is smaller than kmsg_bytes, we don't want the 312 * report split across multiple records. 313 */ 314 if (part != 1) 315 return -ENOSPC; 316 317 if (!cxt->przs) 318 return -ENOSPC; 319 320 prz = cxt->przs[cxt->dump_write_cnt]; 321 322 hlen = ramoops_write_kmsg_hdr(prz, compressed); 323 if (size + hlen > prz->buffer_size) 324 size = prz->buffer_size - hlen; 325 persistent_ram_write(prz, buf, size); 326 327 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt; 328 329 return 0; 330 } 331 332 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count, 333 struct timespec time, struct pstore_info *psi) 334 { 335 struct ramoops_context *cxt = psi->data; 336 struct persistent_ram_zone *prz; 337 338 switch (type) { 339 case PSTORE_TYPE_DMESG: 340 if (id >= cxt->max_dump_cnt) 341 return -EINVAL; 342 prz = cxt->przs[id]; 343 break; 344 case PSTORE_TYPE_CONSOLE: 345 prz = cxt->cprz; 346 break; 347 case PSTORE_TYPE_FTRACE: 348 prz = cxt->fprz; 349 break; 350 case PSTORE_TYPE_PMSG: 351 prz = cxt->mprz; 352 break; 353 default: 354 return -EINVAL; 355 } 356 357 persistent_ram_free_old(prz); 358 persistent_ram_zap(prz); 359 360 return 0; 361 } 362 363 static struct ramoops_context oops_cxt = { 364 .pstore = { 365 .owner = THIS_MODULE, 366 .name = "ramoops", 367 .open = ramoops_pstore_open, 368 .read = ramoops_pstore_read, 369 .write_buf = ramoops_pstore_write_buf, 370 .erase = ramoops_pstore_erase, 371 }, 372 }; 373 374 static void ramoops_free_przs(struct ramoops_context *cxt) 375 { 376 int i; 377 378 cxt->max_dump_cnt = 0; 379 if (!cxt->przs) 380 return; 381 382 for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++) 383 persistent_ram_free(cxt->przs[i]); 384 kfree(cxt->przs); 385 } 386 387 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt, 388 phys_addr_t *paddr, size_t dump_mem_sz) 389 { 390 int err = -ENOMEM; 391 int i; 392 393 if (!cxt->record_size) 394 return 0; 395 396 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) { 397 dev_err(dev, "no room for dumps\n"); 398 return -ENOMEM; 399 } 400 401 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size; 402 if (!cxt->max_dump_cnt) 403 return -ENOMEM; 404 405 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt, 406 GFP_KERNEL); 407 if (!cxt->przs) { 408 dev_err(dev, "failed to initialize a prz array for dumps\n"); 409 goto fail_prz; 410 } 411 412 for (i = 0; i < cxt->max_dump_cnt; i++) { 413 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0, 414 &cxt->ecc_info, 415 cxt->memtype); 416 if (IS_ERR(cxt->przs[i])) { 417 err = PTR_ERR(cxt->przs[i]); 418 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", 419 cxt->record_size, (unsigned long long)*paddr, err); 420 goto fail_prz; 421 } 422 *paddr += cxt->record_size; 423 } 424 425 return 0; 426 fail_prz: 427 ramoops_free_przs(cxt); 428 return err; 429 } 430 431 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, 432 struct persistent_ram_zone **prz, 433 phys_addr_t *paddr, size_t sz, u32 sig) 434 { 435 if (!sz) 436 return 0; 437 438 if (*paddr + sz - cxt->phys_addr > cxt->size) { 439 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n", 440 sz, (unsigned long long)*paddr, 441 cxt->size, (unsigned long long)cxt->phys_addr); 442 return -ENOMEM; 443 } 444 445 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype); 446 if (IS_ERR(*prz)) { 447 int err = PTR_ERR(*prz); 448 449 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", 450 sz, (unsigned long long)*paddr, err); 451 return err; 452 } 453 454 persistent_ram_zap(*prz); 455 456 *paddr += sz; 457 458 return 0; 459 } 460 461 static int ramoops_probe(struct platform_device *pdev) 462 { 463 struct device *dev = &pdev->dev; 464 struct ramoops_platform_data *pdata = pdev->dev.platform_data; 465 struct ramoops_context *cxt = &oops_cxt; 466 size_t dump_mem_sz; 467 phys_addr_t paddr; 468 int err = -EINVAL; 469 470 /* Only a single ramoops area allowed at a time, so fail extra 471 * probes. 472 */ 473 if (cxt->max_dump_cnt) 474 goto fail_out; 475 476 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size && 477 !pdata->ftrace_size && !pdata->pmsg_size)) { 478 pr_err("The memory size and the record/console size must be " 479 "non-zero\n"); 480 goto fail_out; 481 } 482 483 if (pdata->record_size && !is_power_of_2(pdata->record_size)) 484 pdata->record_size = rounddown_pow_of_two(pdata->record_size); 485 if (pdata->console_size && !is_power_of_2(pdata->console_size)) 486 pdata->console_size = rounddown_pow_of_two(pdata->console_size); 487 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size)) 488 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); 489 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size)) 490 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size); 491 492 cxt->size = pdata->mem_size; 493 cxt->phys_addr = pdata->mem_address; 494 cxt->memtype = pdata->mem_type; 495 cxt->record_size = pdata->record_size; 496 cxt->console_size = pdata->console_size; 497 cxt->ftrace_size = pdata->ftrace_size; 498 cxt->pmsg_size = pdata->pmsg_size; 499 cxt->dump_oops = pdata->dump_oops; 500 cxt->ecc_info = pdata->ecc_info; 501 502 paddr = cxt->phys_addr; 503 504 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size 505 - cxt->pmsg_size; 506 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz); 507 if (err) 508 goto fail_out; 509 510 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr, 511 cxt->console_size, 0); 512 if (err) 513 goto fail_init_cprz; 514 515 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size, 516 LINUX_VERSION_CODE); 517 if (err) 518 goto fail_init_fprz; 519 520 err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0); 521 if (err) 522 goto fail_init_mprz; 523 524 cxt->pstore.data = cxt; 525 /* 526 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we 527 * have to handle dumps, we must have at least record_size buffer. And 528 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be 529 * ZERO_SIZE_PTR). 530 */ 531 if (cxt->console_size) 532 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */ 533 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize); 534 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL); 535 spin_lock_init(&cxt->pstore.buf_lock); 536 if (!cxt->pstore.buf) { 537 pr_err("cannot allocate pstore buffer\n"); 538 err = -ENOMEM; 539 goto fail_clear; 540 } 541 542 err = pstore_register(&cxt->pstore); 543 if (err) { 544 pr_err("registering with pstore failed\n"); 545 goto fail_buf; 546 } 547 548 /* 549 * Update the module parameter variables as well so they are visible 550 * through /sys/module/ramoops/parameters/ 551 */ 552 mem_size = pdata->mem_size; 553 mem_address = pdata->mem_address; 554 record_size = pdata->record_size; 555 dump_oops = pdata->dump_oops; 556 ramoops_console_size = pdata->console_size; 557 ramoops_pmsg_size = pdata->pmsg_size; 558 ramoops_ftrace_size = pdata->ftrace_size; 559 560 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n", 561 cxt->size, (unsigned long long)cxt->phys_addr, 562 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size); 563 564 return 0; 565 566 fail_buf: 567 kfree(cxt->pstore.buf); 568 fail_clear: 569 cxt->pstore.bufsize = 0; 570 kfree(cxt->mprz); 571 fail_init_mprz: 572 kfree(cxt->fprz); 573 fail_init_fprz: 574 kfree(cxt->cprz); 575 fail_init_cprz: 576 ramoops_free_przs(cxt); 577 fail_out: 578 return err; 579 } 580 581 static int ramoops_remove(struct platform_device *pdev) 582 { 583 struct ramoops_context *cxt = &oops_cxt; 584 585 pstore_unregister(&cxt->pstore); 586 cxt->max_dump_cnt = 0; 587 588 kfree(cxt->pstore.buf); 589 cxt->pstore.bufsize = 0; 590 591 persistent_ram_free(cxt->mprz); 592 persistent_ram_free(cxt->fprz); 593 persistent_ram_free(cxt->cprz); 594 ramoops_free_przs(cxt); 595 596 return 0; 597 } 598 599 static struct platform_driver ramoops_driver = { 600 .probe = ramoops_probe, 601 .remove = ramoops_remove, 602 .driver = { 603 .name = "ramoops", 604 }, 605 }; 606 607 static void ramoops_register_dummy(void) 608 { 609 if (!mem_size) 610 return; 611 612 pr_info("using module parameters\n"); 613 614 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL); 615 if (!dummy_data) { 616 pr_info("could not allocate pdata\n"); 617 return; 618 } 619 620 dummy_data->mem_size = mem_size; 621 dummy_data->mem_address = mem_address; 622 dummy_data->mem_type = mem_type; 623 dummy_data->record_size = record_size; 624 dummy_data->console_size = ramoops_console_size; 625 dummy_data->ftrace_size = ramoops_ftrace_size; 626 dummy_data->pmsg_size = ramoops_pmsg_size; 627 dummy_data->dump_oops = dump_oops; 628 /* 629 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC 630 * (using 1 byte for ECC isn't much of use anyway). 631 */ 632 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc; 633 634 dummy = platform_device_register_data(NULL, "ramoops", -1, 635 dummy_data, sizeof(struct ramoops_platform_data)); 636 if (IS_ERR(dummy)) { 637 pr_info("could not create platform device: %ld\n", 638 PTR_ERR(dummy)); 639 } 640 } 641 642 static int __init ramoops_init(void) 643 { 644 ramoops_register_dummy(); 645 return platform_driver_register(&ramoops_driver); 646 } 647 postcore_initcall(ramoops_init); 648 649 static void __exit ramoops_exit(void) 650 { 651 platform_driver_unregister(&ramoops_driver); 652 platform_device_unregister(dummy); 653 kfree(dummy_data); 654 } 655 module_exit(ramoops_exit); 656 657 MODULE_LICENSE("GPL"); 658 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>"); 659 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver"); 660