fs/pstore/ram.c

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