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