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