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 ulong mem_address; 59 module_param(mem_address, ulong, 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; 190 int header_length; 191 192 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt, 193 cxt->max_dump_cnt, id, type, 194 PSTORE_TYPE_DMESG, 1); 195 if (!prz_ok(prz)) 196 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt, 197 1, id, type, PSTORE_TYPE_CONSOLE, 0); 198 if (!prz_ok(prz)) 199 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt, 200 1, id, type, PSTORE_TYPE_FTRACE, 0); 201 if (!prz_ok(prz)) 202 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt, 203 1, id, type, PSTORE_TYPE_PMSG, 0); 204 if (!prz_ok(prz)) 205 return 0; 206 207 if (!persistent_ram_old(prz)) 208 return 0; 209 210 size = persistent_ram_old_size(prz); 211 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time, 212 compressed); 213 size -= header_length; 214 215 /* ECC correction notice */ 216 ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0); 217 218 *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL); 219 if (*buf == NULL) 220 return -ENOMEM; 221 222 memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size); 223 persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1); 224 225 return size + ecc_notice_size; 226 } 227 228 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz, 229 bool compressed) 230 { 231 char *hdr; 232 struct timespec timestamp; 233 size_t len; 234 235 /* Report zeroed timestamp if called before timekeeping has resumed. */ 236 if (__getnstimeofday(×tamp)) { 237 timestamp.tv_sec = 0; 238 timestamp.tv_nsec = 0; 239 } 240 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n", 241 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000), 242 compressed ? 'C' : 'D'); 243 WARN_ON_ONCE(!hdr); 244 len = hdr ? strlen(hdr) : 0; 245 persistent_ram_write(prz, hdr, len); 246 kfree(hdr); 247 248 return len; 249 } 250 251 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type, 252 enum kmsg_dump_reason reason, 253 u64 *id, unsigned int part, 254 const char *buf, 255 bool compressed, size_t size, 256 struct pstore_info *psi) 257 { 258 struct ramoops_context *cxt = psi->data; 259 struct persistent_ram_zone *prz; 260 size_t hlen; 261 262 if (type == PSTORE_TYPE_CONSOLE) { 263 if (!cxt->cprz) 264 return -ENOMEM; 265 persistent_ram_write(cxt->cprz, buf, size); 266 return 0; 267 } else if (type == PSTORE_TYPE_FTRACE) { 268 if (!cxt->fprz) 269 return -ENOMEM; 270 persistent_ram_write(cxt->fprz, buf, size); 271 return 0; 272 } else if (type == PSTORE_TYPE_PMSG) { 273 if (!cxt->mprz) 274 return -ENOMEM; 275 persistent_ram_write(cxt->mprz, buf, size); 276 return 0; 277 } 278 279 if (type != PSTORE_TYPE_DMESG) 280 return -EINVAL; 281 282 /* Out of the various dmesg dump types, ramoops is currently designed 283 * to only store crash logs, rather than storing general kernel logs. 284 */ 285 if (reason != KMSG_DUMP_OOPS && 286 reason != KMSG_DUMP_PANIC) 287 return -EINVAL; 288 289 /* Skip Oopes when configured to do so. */ 290 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops) 291 return -EINVAL; 292 293 /* Explicitly only take the first part of any new crash. 294 * If our buffer is larger than kmsg_bytes, this can never happen, 295 * and if our buffer is smaller than kmsg_bytes, we don't want the 296 * report split across multiple records. 297 */ 298 if (part != 1) 299 return -ENOSPC; 300 301 if (!cxt->przs) 302 return -ENOSPC; 303 304 prz = cxt->przs[cxt->dump_write_cnt]; 305 306 hlen = ramoops_write_kmsg_hdr(prz, compressed); 307 if (size + hlen > prz->buffer_size) 308 size = prz->buffer_size - hlen; 309 persistent_ram_write(prz, buf, size); 310 311 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt; 312 313 return 0; 314 } 315 316 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count, 317 struct timespec time, struct pstore_info *psi) 318 { 319 struct ramoops_context *cxt = psi->data; 320 struct persistent_ram_zone *prz; 321 322 switch (type) { 323 case PSTORE_TYPE_DMESG: 324 if (id >= cxt->max_dump_cnt) 325 return -EINVAL; 326 prz = cxt->przs[id]; 327 break; 328 case PSTORE_TYPE_CONSOLE: 329 prz = cxt->cprz; 330 break; 331 case PSTORE_TYPE_FTRACE: 332 prz = cxt->fprz; 333 break; 334 case PSTORE_TYPE_PMSG: 335 prz = cxt->mprz; 336 break; 337 default: 338 return -EINVAL; 339 } 340 341 persistent_ram_free_old(prz); 342 persistent_ram_zap(prz); 343 344 return 0; 345 } 346 347 static struct ramoops_context oops_cxt = { 348 .pstore = { 349 .owner = THIS_MODULE, 350 .name = "ramoops", 351 .open = ramoops_pstore_open, 352 .read = ramoops_pstore_read, 353 .write_buf = ramoops_pstore_write_buf, 354 .erase = ramoops_pstore_erase, 355 }, 356 }; 357 358 static void ramoops_free_przs(struct ramoops_context *cxt) 359 { 360 int i; 361 362 cxt->max_dump_cnt = 0; 363 if (!cxt->przs) 364 return; 365 366 for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++) 367 persistent_ram_free(cxt->przs[i]); 368 kfree(cxt->przs); 369 } 370 371 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt, 372 phys_addr_t *paddr, size_t dump_mem_sz) 373 { 374 int err = -ENOMEM; 375 int i; 376 377 if (!cxt->record_size) 378 return 0; 379 380 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) { 381 dev_err(dev, "no room for dumps\n"); 382 return -ENOMEM; 383 } 384 385 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size; 386 if (!cxt->max_dump_cnt) 387 return -ENOMEM; 388 389 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt, 390 GFP_KERNEL); 391 if (!cxt->przs) { 392 dev_err(dev, "failed to initialize a prz array for dumps\n"); 393 goto fail_prz; 394 } 395 396 for (i = 0; i < cxt->max_dump_cnt; i++) { 397 size_t sz = cxt->record_size; 398 399 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, 400 &cxt->ecc_info, 401 cxt->memtype); 402 if (IS_ERR(cxt->przs[i])) { 403 err = PTR_ERR(cxt->przs[i]); 404 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", 405 sz, (unsigned long long)*paddr, err); 406 goto fail_prz; 407 } 408 *paddr += sz; 409 } 410 411 return 0; 412 fail_prz: 413 ramoops_free_przs(cxt); 414 return err; 415 } 416 417 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt, 418 struct persistent_ram_zone **prz, 419 phys_addr_t *paddr, size_t sz, u32 sig) 420 { 421 if (!sz) 422 return 0; 423 424 if (*paddr + sz - cxt->phys_addr > cxt->size) { 425 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n", 426 sz, (unsigned long long)*paddr, 427 cxt->size, (unsigned long long)cxt->phys_addr); 428 return -ENOMEM; 429 } 430 431 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype); 432 if (IS_ERR(*prz)) { 433 int err = PTR_ERR(*prz); 434 435 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n", 436 sz, (unsigned long long)*paddr, err); 437 return err; 438 } 439 440 persistent_ram_zap(*prz); 441 442 *paddr += sz; 443 444 return 0; 445 } 446 447 static int ramoops_probe(struct platform_device *pdev) 448 { 449 struct device *dev = &pdev->dev; 450 struct ramoops_platform_data *pdata = pdev->dev.platform_data; 451 struct ramoops_context *cxt = &oops_cxt; 452 size_t dump_mem_sz; 453 phys_addr_t paddr; 454 int err = -EINVAL; 455 456 /* Only a single ramoops area allowed at a time, so fail extra 457 * probes. 458 */ 459 if (cxt->max_dump_cnt) 460 goto fail_out; 461 462 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size && 463 !pdata->ftrace_size && !pdata->pmsg_size)) { 464 pr_err("The memory size and the record/console size must be " 465 "non-zero\n"); 466 goto fail_out; 467 } 468 469 if (pdata->record_size && !is_power_of_2(pdata->record_size)) 470 pdata->record_size = rounddown_pow_of_two(pdata->record_size); 471 if (pdata->console_size && !is_power_of_2(pdata->console_size)) 472 pdata->console_size = rounddown_pow_of_two(pdata->console_size); 473 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size)) 474 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); 475 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size)) 476 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size); 477 478 cxt->size = pdata->mem_size; 479 cxt->phys_addr = pdata->mem_address; 480 cxt->memtype = pdata->mem_type; 481 cxt->record_size = pdata->record_size; 482 cxt->console_size = pdata->console_size; 483 cxt->ftrace_size = pdata->ftrace_size; 484 cxt->pmsg_size = pdata->pmsg_size; 485 cxt->dump_oops = pdata->dump_oops; 486 cxt->ecc_info = pdata->ecc_info; 487 488 paddr = cxt->phys_addr; 489 490 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size 491 - cxt->pmsg_size; 492 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz); 493 if (err) 494 goto fail_out; 495 496 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr, 497 cxt->console_size, 0); 498 if (err) 499 goto fail_init_cprz; 500 501 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size, 502 LINUX_VERSION_CODE); 503 if (err) 504 goto fail_init_fprz; 505 506 err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0); 507 if (err) 508 goto fail_init_mprz; 509 510 cxt->pstore.data = cxt; 511 /* 512 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we 513 * have to handle dumps, we must have at least record_size buffer. And 514 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be 515 * ZERO_SIZE_PTR). 516 */ 517 if (cxt->console_size) 518 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */ 519 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize); 520 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL); 521 spin_lock_init(&cxt->pstore.buf_lock); 522 if (!cxt->pstore.buf) { 523 pr_err("cannot allocate pstore buffer\n"); 524 err = -ENOMEM; 525 goto fail_clear; 526 } 527 528 err = pstore_register(&cxt->pstore); 529 if (err) { 530 pr_err("registering with pstore failed\n"); 531 goto fail_buf; 532 } 533 534 /* 535 * Update the module parameter variables as well so they are visible 536 * through /sys/module/ramoops/parameters/ 537 */ 538 mem_size = pdata->mem_size; 539 mem_address = pdata->mem_address; 540 record_size = pdata->record_size; 541 dump_oops = pdata->dump_oops; 542 543 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n", 544 cxt->size, (unsigned long long)cxt->phys_addr, 545 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size); 546 547 return 0; 548 549 fail_buf: 550 kfree(cxt->pstore.buf); 551 fail_clear: 552 cxt->pstore.bufsize = 0; 553 kfree(cxt->mprz); 554 fail_init_mprz: 555 kfree(cxt->fprz); 556 fail_init_fprz: 557 kfree(cxt->cprz); 558 fail_init_cprz: 559 ramoops_free_przs(cxt); 560 fail_out: 561 return err; 562 } 563 564 static int __exit ramoops_remove(struct platform_device *pdev) 565 { 566 #if 0 567 /* TODO(kees): We cannot unload ramoops since pstore doesn't support 568 * unregistering yet. 569 */ 570 struct ramoops_context *cxt = &oops_cxt; 571 572 iounmap(cxt->virt_addr); 573 release_mem_region(cxt->phys_addr, cxt->size); 574 cxt->max_dump_cnt = 0; 575 576 /* TODO(kees): When pstore supports unregistering, call it here. */ 577 kfree(cxt->pstore.buf); 578 cxt->pstore.bufsize = 0; 579 580 return 0; 581 #endif 582 return -EBUSY; 583 } 584 585 static struct platform_driver ramoops_driver = { 586 .probe = ramoops_probe, 587 .remove = __exit_p(ramoops_remove), 588 .driver = { 589 .name = "ramoops", 590 }, 591 }; 592 593 static void ramoops_register_dummy(void) 594 { 595 if (!mem_size) 596 return; 597 598 pr_info("using module parameters\n"); 599 600 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL); 601 if (!dummy_data) { 602 pr_info("could not allocate pdata\n"); 603 return; 604 } 605 606 dummy_data->mem_size = mem_size; 607 dummy_data->mem_address = mem_address; 608 dummy_data->mem_type = 0; 609 dummy_data->record_size = record_size; 610 dummy_data->console_size = ramoops_console_size; 611 dummy_data->ftrace_size = ramoops_ftrace_size; 612 dummy_data->pmsg_size = ramoops_pmsg_size; 613 dummy_data->dump_oops = dump_oops; 614 /* 615 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC 616 * (using 1 byte for ECC isn't much of use anyway). 617 */ 618 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc; 619 620 dummy = platform_device_register_data(NULL, "ramoops", -1, 621 dummy_data, sizeof(struct ramoops_platform_data)); 622 if (IS_ERR(dummy)) { 623 pr_info("could not create platform device: %ld\n", 624 PTR_ERR(dummy)); 625 } 626 } 627 628 static int __init ramoops_init(void) 629 { 630 ramoops_register_dummy(); 631 return platform_driver_register(&ramoops_driver); 632 } 633 postcore_initcall(ramoops_init); 634 635 static void __exit ramoops_exit(void) 636 { 637 platform_driver_unregister(&ramoops_driver); 638 platform_device_unregister(dummy); 639 kfree(dummy_data); 640 } 641 module_exit(ramoops_exit); 642 643 MODULE_LICENSE("GPL"); 644 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>"); 645 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver"); 646