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