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