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