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 ramoops_pmsg_size = MIN_MEM_SIZE;
  55 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
  56 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
  57
  58 static ulong mem_address;
  59 module_param(mem_address, ulong, 0400);
  60 MODULE_PARM_DESC(mem_address,
  61                 "start of reserved RAM used to store oops/panic logs");
  62
  63 static ulong mem_size;
  64 module_param(mem_size, ulong, 0400);
  65 MODULE_PARM_DESC(mem_size,
  66                 "size of reserved RAM used to store oops/panic logs");
  67
  68 static int dump_oops = 1;
  69 module_param(dump_oops, int, 0600);
  70 MODULE_PARM_DESC(dump_oops,
  71                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
  72
  73 static int ramoops_ecc;
  74 module_param_named(ecc, ramoops_ecc, int, 0600);
  75 MODULE_PARM_DESC(ramoops_ecc,
  76                 "if non-zero, the option enables ECC support and specifies "
  77                 "ECC buffer size in bytes (1 is a special value, means 16 "
  78                 "bytes ECC)");
  79
  80 struct ramoops_context {
  81         struct persistent_ram_zone **przs;
  82         struct persistent_ram_zone *cprz;
  83         struct persistent_ram_zone *fprz;
  84         struct persistent_ram_zone *mprz;
  85         phys_addr_t phys_addr;
  86         unsigned long size;
  87         size_t record_size;
  88         size_t console_size;
  89         size_t ftrace_size;
  90         size_t pmsg_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         unsigned int pmsg_read_cnt;
 100         struct pstore_info pstore;
 101 };
 102
 103 static struct platform_device *dummy;
 104 static struct ramoops_platform_data *dummy_data;
 105
 106 static int ramoops_pstore_open(struct pstore_info *psi)
 107 {
 108         struct ramoops_context *cxt = psi->data;
 109
 110         cxt->dump_read_cnt = 0;
 111         cxt->console_read_cnt = 0;
 112         cxt->ftrace_read_cnt = 0;
 113         cxt->pmsg_read_cnt = 0;
 114         return 0;
 115 }
 116
 117 static struct persistent_ram_zone *
 118 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 119                      u64 *id,
 120                      enum pstore_type_id *typep, enum pstore_type_id type,
 121                      bool update)
 122 {
 123         struct persistent_ram_zone *prz;
 124         int i = (*c)++;
 125
 126         if (i >= max)
 127                 return NULL;
 128
 129         prz = przs[i];
 130
 131         if (update) {
 132                 /* Update old/shadowed buffer. */
 133                 persistent_ram_save_old(prz);
 134                 if (!persistent_ram_old_size(prz))
 135                         return NULL;
 136         }
 137
 138         *typep = type;
 139         *id = i;
 140
 141         return prz;
 142 }
 143
 144 static bool prz_ok(struct persistent_ram_zone *prz)
 145 {
 146         return !!prz && !!(persistent_ram_old_size(prz) +
 147                            persistent_ram_ecc_string(prz, NULL, 0));
 148 }
 149
 150 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 151                                    int *count, struct timespec *time,
 152                                    char **buf, struct pstore_info *psi)
 153 {
 154         ssize_t size;
 155         ssize_t ecc_notice_size;
 156         struct ramoops_context *cxt = psi->data;
 157         struct persistent_ram_zone *prz;
 158
 159         prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
 160                                    cxt->max_dump_cnt, id, type,
 161                                    PSTORE_TYPE_DMESG, 1);
 162         if (!prz_ok(prz))
 163                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 164                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
 165         if (!prz_ok(prz))
 166                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
 167                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
 168         if (!prz_ok(prz))
 169                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 170                                            1, id, type, PSTORE_TYPE_PMSG, 0);
 171         if (!prz_ok(prz))
 172                 return 0;
 173
 174         /* TODO(kees): Bogus time for the moment. */
 175         time->tv_sec = 0;
 176         time->tv_nsec = 0;
 177
 178         size = persistent_ram_old_size(prz);
 179
 180         /* ECC correction notice */
 181         ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 182
 183         *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL);
 184         if (*buf == NULL)
 185                 return -ENOMEM;
 186
 187         memcpy(*buf, persistent_ram_old(prz), size);
 188         persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
 189
 190         return size + ecc_notice_size;
 191 }
 192
 193 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
 194 {
 195         char *hdr;
 196         struct timespec timestamp;
 197         size_t len;
 198
 199         /* Report zeroed timestamp if called before timekeeping has resumed. */
 200         if (__getnstimeofday(&timestamp)) {
 201                 timestamp.tv_sec = 0;
 202                 timestamp.tv_nsec = 0;
 203         }
 204         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
 205                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000));
 206         WARN_ON_ONCE(!hdr);
 207         len = hdr ? strlen(hdr) : 0;
 208         persistent_ram_write(prz, hdr, len);
 209         kfree(hdr);
 210
 211         return len;
 212 }
 213
 214 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 215                                             enum kmsg_dump_reason reason,
 216                                             u64 *id, unsigned int part,
 217                                             const char *buf, size_t size,
 218                                             struct pstore_info *psi)
 219 {
 220         struct ramoops_context *cxt = psi->data;
 221         struct persistent_ram_zone *prz;
 222         size_t hlen;
 223
 224         if (type == PSTORE_TYPE_CONSOLE) {
 225                 if (!cxt->cprz)
 226                         return -ENOMEM;
 227                 persistent_ram_write(cxt->cprz, buf, size);
 228                 return 0;
 229         } else if (type == PSTORE_TYPE_FTRACE) {
 230                 if (!cxt->fprz)
 231                         return -ENOMEM;
 232                 persistent_ram_write(cxt->fprz, buf, size);
 233                 return 0;
 234         } else if (type == PSTORE_TYPE_PMSG) {
 235                 if (!cxt->mprz)
 236                         return -ENOMEM;
 237                 persistent_ram_write(cxt->mprz, buf, size);
 238                 return 0;
 239         }
 240
 241         if (type != PSTORE_TYPE_DMESG)
 242                 return -EINVAL;
 243
 244         /* Out of the various dmesg dump types, ramoops is currently designed
 245          * to only store crash logs, rather than storing general kernel logs.
 246          */
 247         if (reason != KMSG_DUMP_OOPS &&
 248             reason != KMSG_DUMP_PANIC)
 249                 return -EINVAL;
 250
 251         /* Skip Oopes when configured to do so. */
 252         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 253                 return -EINVAL;
 254
 255         /* Explicitly only take the first part of any new crash.
 256          * If our buffer is larger than kmsg_bytes, this can never happen,
 257          * and if our buffer is smaller than kmsg_bytes, we don't want the
 258          * report split across multiple records.
 259          */
 260         if (part != 1)
 261                 return -ENOSPC;
 262
 263         if (!cxt->przs)
 264                 return -ENOSPC;
 265
 266         prz = cxt->przs[cxt->dump_write_cnt];
 267
 268         hlen = ramoops_write_kmsg_hdr(prz);
 269         if (size + hlen > prz->buffer_size)
 270                 size = prz->buffer_size - hlen;
 271         persistent_ram_write(prz, buf, size);
 272
 273         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 274
 275         return 0;
 276 }
 277
 278 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
 279                                 struct timespec time, struct pstore_info *psi)
 280 {
 281         struct ramoops_context *cxt = psi->data;
 282         struct persistent_ram_zone *prz;
 283
 284         switch (type) {
 285         case PSTORE_TYPE_DMESG:
 286                 if (id >= cxt->max_dump_cnt)
 287                         return -EINVAL;
 288                 prz = cxt->przs[id];
 289                 break;
 290         case PSTORE_TYPE_CONSOLE:
 291                 prz = cxt->cprz;
 292                 break;
 293         case PSTORE_TYPE_FTRACE:
 294                 prz = cxt->fprz;
 295                 break;
 296         case PSTORE_TYPE_PMSG:
 297                 prz = cxt->mprz;
 298                 break;
 299         default:
 300                 return -EINVAL;
 301         }
 302
 303         persistent_ram_free_old(prz);
 304         persistent_ram_zap(prz);
 305
 306         return 0;
 307 }
 308
 309 static struct ramoops_context oops_cxt = {
 310         .pstore = {
 311                 .owner  = THIS_MODULE,
 312                 .name   = "ramoops",
 313                 .open   = ramoops_pstore_open,
 314                 .read   = ramoops_pstore_read,
 315                 .write_buf      = ramoops_pstore_write_buf,
 316                 .erase  = ramoops_pstore_erase,
 317         },
 318 };
 319
 320 static void ramoops_free_przs(struct ramoops_context *cxt)
 321 {
 322         int i;
 323
 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                 return -ENOMEM;
 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 void notrace ramoops_console_write_buf(const char *buf, size_t size)
 408 {
 409         struct ramoops_context *cxt = &oops_cxt;
 410         persistent_ram_write(cxt->cprz, buf, size);
 411 }
 412
 413 static int ramoops_probe(struct platform_device *pdev)
 414 {
 415         struct device *dev = &pdev->dev;
 416         struct ramoops_platform_data *pdata = pdev->dev.platform_data;
 417         struct ramoops_context *cxt = &oops_cxt;
 418         size_t dump_mem_sz;
 419         phys_addr_t paddr;
 420         int err = -EINVAL;
 421
 422         /* Only a single ramoops area allowed at a time, so fail extra
 423          * probes.
 424          */
 425         if (cxt->max_dump_cnt)
 426                 goto fail_out;
 427
 428         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 429                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 430                 pr_err("The memory size and the record/console size must be "
 431                         "non-zero\n");
 432                 goto fail_out;
 433         }
 434
 435         if (!is_power_of_2(pdata->mem_size))
 436                 pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
 437         if (!is_power_of_2(pdata->record_size))
 438                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 439         if (!is_power_of_2(pdata->console_size))
 440                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 441         if (!is_power_of_2(pdata->ftrace_size))
 442                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 443         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 444                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 445
 446         cxt->size = pdata->mem_size;
 447         cxt->phys_addr = pdata->mem_address;
 448         cxt->record_size = pdata->record_size;
 449         cxt->console_size = pdata->console_size;
 450         cxt->ftrace_size = pdata->ftrace_size;
 451         cxt->pmsg_size = pdata->pmsg_size;
 452         cxt->dump_oops = pdata->dump_oops;
 453         cxt->ecc_info = pdata->ecc_info;
 454
 455         paddr = cxt->phys_addr;
 456
 457         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 458                         - cxt->pmsg_size;
 459         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
 460         if (err)
 461                 goto fail_out;
 462
 463         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
 464                                cxt->console_size, 0);
 465         if (err)
 466                 goto fail_init_cprz;
 467
 468         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
 469                                LINUX_VERSION_CODE);
 470         if (err)
 471                 goto fail_init_fprz;
 472
 473         err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
 474         if (err)
 475                 goto fail_init_mprz;
 476
 477         cxt->pstore.data = cxt;
 478         /*
 479          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 480          * have to handle dumps, we must have at least record_size buffer. And
 481          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 482          * ZERO_SIZE_PTR).
 483          */
 484         if (cxt->console_size)
 485                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 486         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 487         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 488         spin_lock_init(&cxt->pstore.buf_lock);
 489         if (!cxt->pstore.buf) {
 490                 pr_err("cannot allocate pstore buffer\n");
 491                 err = -ENOMEM;
 492                 goto fail_clear;
 493         }
 494
 495         err = pstore_register(&cxt->pstore);
 496         if (err) {
 497                 pr_err("registering with pstore failed\n");
 498                 goto fail_buf;
 499         }
 500
 501         /*
 502          * Update the module parameter variables as well so they are visible
 503          * through /sys/module/ramoops/parameters/
 504          */
 505         mem_size = pdata->mem_size;
 506         mem_address = pdata->mem_address;
 507         record_size = pdata->record_size;
 508         dump_oops = pdata->dump_oops;
 509
 510         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 511                 cxt->size, (unsigned long long)cxt->phys_addr,
 512                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 513
 514         return 0;
 515
 516 fail_buf:
 517         kfree(cxt->pstore.buf);
 518 fail_clear:
 519         cxt->pstore.bufsize = 0;
 520         cxt->max_dump_cnt = 0;
 521         kfree(cxt->mprz);
 522 fail_init_mprz:
 523         kfree(cxt->fprz);
 524 fail_init_fprz:
 525         kfree(cxt->cprz);
 526 fail_init_cprz:
 527         ramoops_free_przs(cxt);
 528 fail_out:
 529         return err;
 530 }
 531
 532 static int __exit ramoops_remove(struct platform_device *pdev)
 533 {
 534 #if 0
 535         /* TODO(kees): We cannot unload ramoops since pstore doesn't support
 536          * unregistering yet.
 537          */
 538         struct ramoops_context *cxt = &oops_cxt;
 539
 540         iounmap(cxt->virt_addr);
 541         release_mem_region(cxt->phys_addr, cxt->size);
 542         cxt->max_dump_cnt = 0;
 543
 544         /* TODO(kees): When pstore supports unregistering, call it here. */
 545         kfree(cxt->pstore.buf);
 546         cxt->pstore.bufsize = 0;
 547
 548         return 0;
 549 #endif
 550         return -EBUSY;
 551 }
 552
 553 static struct platform_driver ramoops_driver = {
 554         .probe          = ramoops_probe,
 555         .remove         = __exit_p(ramoops_remove),
 556         .driver         = {
 557                 .name   = "ramoops",
 558                 .owner  = THIS_MODULE,
 559         },
 560 };
 561
 562 static void ramoops_register_dummy(void)
 563 {
 564         if (!mem_size)
 565                 return;
 566
 567         pr_info("using module parameters\n");
 568
 569         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 570         if (!dummy_data) {
 571                 pr_info("could not allocate pdata\n");
 572                 return;
 573         }
 574
 575         dummy_data->mem_size = mem_size;
 576         dummy_data->mem_address = mem_address;
 577         dummy_data->record_size = record_size;
 578         dummy_data->console_size = ramoops_console_size;
 579         dummy_data->ftrace_size = ramoops_ftrace_size;
 580         dummy_data->pmsg_size = ramoops_pmsg_size;
 581         dummy_data->dump_oops = dump_oops;
 582         /*
 583          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 584          * (using 1 byte for ECC isn't much of use anyway).
 585          */
 586         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 587
 588         dummy = platform_device_register_data(NULL, "ramoops", -1,
 589                         dummy_data, sizeof(struct ramoops_platform_data));
 590         if (IS_ERR(dummy)) {
 591                 pr_info("could not create platform device: %ld\n",
 592                         PTR_ERR(dummy));
 593         }
 594 }
 595
 596 static int __init ramoops_init(void)
 597 {
 598         ramoops_register_dummy();
 599         return platform_driver_register(&ramoops_driver);
 600 }
 601 postcore_initcall(ramoops_init);
 602
 603 static void __exit ramoops_exit(void)
 604 {
 605         platform_driver_unregister(&ramoops_driver);
 606         platform_device_unregister(dummy);
 607         kfree(dummy_data);
 608 }
 609 module_exit(ramoops_exit);
 610
 611 MODULE_LICENSE("GPL");
 612 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 613 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");