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
 129         if (update) {
 130                 /* Update old/shadowed buffer. */
 131                 persistent_ram_save_old(prz);
 132                 if (!persistent_ram_old_size(prz))
 133                         return NULL;
 134         }
 135
 136         *typep = type;
 137         *id = i;
 138
 139         return prz;
 140 }
 141
 142 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 143                                    int *count, struct timespec *time,
 144                                    char **buf, struct pstore_info *psi)
 145 {
 146         ssize_t size;
 147         ssize_t ecc_notice_size;
 148         struct ramoops_context *cxt = psi->data;
 149         struct persistent_ram_zone *prz;
 150
 151         prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
 152                                    cxt->max_dump_cnt, id, type,
 153                                    PSTORE_TYPE_DMESG, 1);
 154         if (!prz)
 155                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 156                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
 157         if (!prz)
 158                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
 159                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
 160         if (!prz)
 161                 return 0;
 162
 163         /* TODO(kees): Bogus time for the moment. */
 164         time->tv_sec = 0;
 165         time->tv_nsec = 0;
 166
 167         size = persistent_ram_old_size(prz);
 168
 169         /* ECC correction notice */
 170         ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 171
 172         *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL);
 173         if (*buf == NULL)
 174                 return -ENOMEM;
 175
 176         memcpy(*buf, persistent_ram_old(prz), size);
 177         persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
 178
 179         return size + ecc_notice_size;
 180 }
 181
 182 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
 183 {
 184         char *hdr;
 185         struct timespec timestamp;
 186         size_t len;
 187
 188         /* Report zeroed timestamp if called before timekeeping has resumed. */
 189         if (__getnstimeofday(&timestamp)) {
 190                 timestamp.tv_sec = 0;
 191                 timestamp.tv_nsec = 0;
 192         }
 193         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
 194                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000));
 195         WARN_ON_ONCE(!hdr);
 196         len = hdr ? strlen(hdr) : 0;
 197         persistent_ram_write(prz, hdr, len);
 198         kfree(hdr);
 199
 200         return len;
 201 }
 202
 203 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 204                                             enum kmsg_dump_reason reason,
 205                                             u64 *id, unsigned int part,
 206                                             const char *buf, size_t size,
 207                                             struct pstore_info *psi)
 208 {
 209         struct ramoops_context *cxt = psi->data;
 210         struct persistent_ram_zone *prz;
 211         size_t hlen;
 212
 213         if (type == PSTORE_TYPE_CONSOLE) {
 214                 if (!cxt->cprz)
 215                         return -ENOMEM;
 216                 persistent_ram_write(cxt->cprz, buf, size);
 217                 return 0;
 218         } else if (type == PSTORE_TYPE_FTRACE) {
 219                 if (!cxt->fprz)
 220                         return -ENOMEM;
 221                 persistent_ram_write(cxt->fprz, buf, size);
 222                 return 0;
 223         }
 224
 225         if (type != PSTORE_TYPE_DMESG)
 226                 return -EINVAL;
 227
 228         /* Out of the various dmesg dump types, ramoops is currently designed
 229          * to only store crash logs, rather than storing general kernel logs.
 230          */
 231         if (reason != KMSG_DUMP_OOPS &&
 232             reason != KMSG_DUMP_PANIC)
 233                 return -EINVAL;
 234
 235         /* Skip Oopes when configured to do so. */
 236         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 237                 return -EINVAL;
 238
 239         /* Explicitly only take the first part of any new crash.
 240          * If our buffer is larger than kmsg_bytes, this can never happen,
 241          * and if our buffer is smaller than kmsg_bytes, we don't want the
 242          * report split across multiple records.
 243          */
 244         if (part != 1)
 245                 return -ENOSPC;
 246
 247         if (!cxt->przs)
 248                 return -ENOSPC;
 249
 250         prz = cxt->przs[cxt->dump_write_cnt];
 251
 252         hlen = ramoops_write_kmsg_hdr(prz);
 253         if (size + hlen > prz->buffer_size)
 254                 size = prz->buffer_size - hlen;
 255         persistent_ram_write(prz, buf, size);
 256
 257         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 258
 259         return 0;
 260 }
 261
 262 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
 263                                 struct timespec time, struct pstore_info *psi)
 264 {
 265         struct ramoops_context *cxt = psi->data;
 266         struct persistent_ram_zone *prz;
 267
 268         switch (type) {
 269         case PSTORE_TYPE_DMESG:
 270                 if (id >= cxt->max_dump_cnt)
 271                         return -EINVAL;
 272                 prz = cxt->przs[id];
 273                 break;
 274         case PSTORE_TYPE_CONSOLE:
 275                 prz = cxt->cprz;
 276                 break;
 277         case PSTORE_TYPE_FTRACE:
 278                 prz = cxt->fprz;
 279                 break;
 280         default:
 281                 return -EINVAL;
 282         }
 283
 284         persistent_ram_free_old(prz);
 285         persistent_ram_zap(prz);
 286
 287         return 0;
 288 }
 289
 290 static struct ramoops_context oops_cxt = {
 291         .pstore = {
 292                 .owner  = THIS_MODULE,
 293                 .name   = "ramoops",
 294                 .open   = ramoops_pstore_open,
 295                 .read   = ramoops_pstore_read,
 296                 .write_buf      = ramoops_pstore_write_buf,
 297                 .erase  = ramoops_pstore_erase,
 298         },
 299 };
 300
 301 static void ramoops_free_przs(struct ramoops_context *cxt)
 302 {
 303         int i;
 304
 305         if (!cxt->przs)
 306                 return;
 307
 308         for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
 309                 persistent_ram_free(cxt->przs[i]);
 310         kfree(cxt->przs);
 311 }
 312
 313 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
 314                              phys_addr_t *paddr, size_t dump_mem_sz)
 315 {
 316         int err = -ENOMEM;
 317         int i;
 318
 319         if (!cxt->record_size)
 320                 return 0;
 321
 322         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
 323                 dev_err(dev, "no room for dumps\n");
 324                 return -ENOMEM;
 325         }
 326
 327         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
 328         if (!cxt->max_dump_cnt)
 329                 return -ENOMEM;
 330
 331         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
 332                              GFP_KERNEL);
 333         if (!cxt->przs) {
 334                 dev_err(dev, "failed to initialize a prz array for dumps\n");
 335                 return -ENOMEM;
 336         }
 337
 338         for (i = 0; i < cxt->max_dump_cnt; i++) {
 339                 size_t sz = cxt->record_size;
 340
 341                 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0,
 342                                                   &cxt->ecc_info,
 343                                                   cxt->memtype);
 344                 if (IS_ERR(cxt->przs[i])) {
 345                         err = PTR_ERR(cxt->przs[i]);
 346                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 347                                 sz, (unsigned long long)*paddr, err);
 348                         goto fail_prz;
 349                 }
 350                 *paddr += sz;
 351         }
 352
 353         return 0;
 354 fail_prz:
 355         ramoops_free_przs(cxt);
 356         return err;
 357 }
 358
 359 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
 360                             struct persistent_ram_zone **prz,
 361                             phys_addr_t *paddr, size_t sz, u32 sig)
 362 {
 363         if (!sz)
 364                 return 0;
 365
 366         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 367                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 368                         sz, (unsigned long long)*paddr,
 369                         cxt->size, (unsigned long long)cxt->phys_addr);
 370                 return -ENOMEM;
 371         }
 372
 373         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
 374         if (IS_ERR(*prz)) {
 375                 int err = PTR_ERR(*prz);
 376
 377                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 378                         sz, (unsigned long long)*paddr, err);
 379                 return err;
 380         }
 381
 382         persistent_ram_zap(*prz);
 383
 384         *paddr += sz;
 385
 386         return 0;
 387 }
 388
 389 static int ramoops_probe(struct platform_device *pdev)
 390 {
 391         struct device *dev = &pdev->dev;
 392         struct ramoops_platform_data *pdata = pdev->dev.platform_data;
 393         struct ramoops_context *cxt = &oops_cxt;
 394         size_t dump_mem_sz;
 395         phys_addr_t paddr;
 396         int err = -EINVAL;
 397
 398         /* Only a single ramoops area allowed at a time, so fail extra
 399          * probes.
 400          */
 401         if (cxt->max_dump_cnt)
 402                 goto fail_out;
 403
 404         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 405                         !pdata->ftrace_size)) {
 406                 pr_err("The memory size and the record/console size must be "
 407                         "non-zero\n");
 408                 goto fail_out;
 409         }
 410
 411         if (!is_power_of_2(pdata->mem_size))
 412                 pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
 413         if (!is_power_of_2(pdata->record_size))
 414                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 415         if (!is_power_of_2(pdata->console_size))
 416                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 417         if (!is_power_of_2(pdata->ftrace_size))
 418                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 419
 420         cxt->size = pdata->mem_size;
 421         cxt->phys_addr = pdata->mem_address;
 422         cxt->memtype = pdata->mem_type;
 423         cxt->record_size = pdata->record_size;
 424         cxt->console_size = pdata->console_size;
 425         cxt->ftrace_size = pdata->ftrace_size;
 426         cxt->dump_oops = pdata->dump_oops;
 427         cxt->ecc_info = pdata->ecc_info;
 428
 429         paddr = cxt->phys_addr;
 430
 431         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
 432         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
 433         if (err)
 434                 goto fail_out;
 435
 436         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
 437                                cxt->console_size, 0);
 438         if (err)
 439                 goto fail_init_cprz;
 440
 441         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
 442                                LINUX_VERSION_CODE);
 443         if (err)
 444                 goto fail_init_fprz;
 445
 446         if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
 447                 pr_err("memory size too small, minimum is %zu\n",
 448                         cxt->console_size + cxt->record_size +
 449                         cxt->ftrace_size);
 450                 err = -EINVAL;
 451                 goto fail_cnt;
 452         }
 453
 454         cxt->pstore.data = cxt;
 455         /*
 456          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 457          * have to handle dumps, we must have at least record_size buffer. And
 458          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 459          * ZERO_SIZE_PTR).
 460          */
 461         if (cxt->console_size)
 462                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 463         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 464         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 465         spin_lock_init(&cxt->pstore.buf_lock);
 466         if (!cxt->pstore.buf) {
 467                 pr_err("cannot allocate pstore buffer\n");
 468                 err = -ENOMEM;
 469                 goto fail_clear;
 470         }
 471
 472         err = pstore_register(&cxt->pstore);
 473         if (err) {
 474                 pr_err("registering with pstore failed\n");
 475                 goto fail_buf;
 476         }
 477
 478         /*
 479          * Update the module parameter variables as well so they are visible
 480          * through /sys/module/ramoops/parameters/
 481          */
 482         mem_size = pdata->mem_size;
 483         mem_address = pdata->mem_address;
 484         record_size = pdata->record_size;
 485         dump_oops = pdata->dump_oops;
 486
 487         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 488                 cxt->size, (unsigned long long)cxt->phys_addr,
 489                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 490
 491         return 0;
 492
 493 fail_buf:
 494         kfree(cxt->pstore.buf);
 495 fail_clear:
 496         cxt->pstore.bufsize = 0;
 497         cxt->max_dump_cnt = 0;
 498 fail_cnt:
 499         kfree(cxt->fprz);
 500 fail_init_fprz:
 501         kfree(cxt->cprz);
 502 fail_init_cprz:
 503         ramoops_free_przs(cxt);
 504 fail_out:
 505         return err;
 506 }
 507
 508 static int __exit ramoops_remove(struct platform_device *pdev)
 509 {
 510 #if 0
 511         /* TODO(kees): We cannot unload ramoops since pstore doesn't support
 512          * unregistering yet.
 513          */
 514         struct ramoops_context *cxt = &oops_cxt;
 515
 516         iounmap(cxt->virt_addr);
 517         release_mem_region(cxt->phys_addr, cxt->size);
 518         cxt->max_dump_cnt = 0;
 519
 520         /* TODO(kees): When pstore supports unregistering, call it here. */
 521         kfree(cxt->pstore.buf);
 522         cxt->pstore.bufsize = 0;
 523
 524         return 0;
 525 #endif
 526         return -EBUSY;
 527 }
 528
 529 static struct platform_driver ramoops_driver = {
 530         .probe          = ramoops_probe,
 531         .remove         = __exit_p(ramoops_remove),
 532         .driver         = {
 533                 .name   = "ramoops",
 534                 .owner  = THIS_MODULE,
 535         },
 536 };
 537
 538 static void ramoops_register_dummy(void)
 539 {
 540         if (!mem_size)
 541                 return;
 542
 543         pr_info("using module parameters\n");
 544
 545         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 546         if (!dummy_data) {
 547                 pr_info("could not allocate pdata\n");
 548                 return;
 549         }
 550
 551         dummy_data->mem_size = mem_size;
 552         dummy_data->mem_address = mem_address;
 553         dummy_data->mem_type = 0;
 554         dummy_data->record_size = record_size;
 555         dummy_data->console_size = ramoops_console_size;
 556         dummy_data->ftrace_size = ramoops_ftrace_size;
 557         dummy_data->dump_oops = dump_oops;
 558         /*
 559          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 560          * (using 1 byte for ECC isn't much of use anyway).
 561          */
 562         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 563
 564         dummy = platform_device_register_data(NULL, "ramoops", -1,
 565                         dummy_data, sizeof(struct ramoops_platform_data));
 566         if (IS_ERR(dummy)) {
 567                 pr_info("could not create platform device: %ld\n",
 568                         PTR_ERR(dummy));
 569         }
 570 }
 571
 572 static int __init ramoops_init(void)
 573 {
 574         ramoops_register_dummy();
 575         return platform_driver_register(&ramoops_driver);
 576 }
 577 postcore_initcall(ramoops_init);
 578
 579 static void __exit ramoops_exit(void)
 580 {
 581         platform_driver_unregister(&ramoops_driver);
 582         platform_device_unregister(dummy);
 583         kfree(dummy_data);
 584 }
 585 module_exit(ramoops_exit);
 586
 587 MODULE_LICENSE("GPL");
 588 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 589 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");