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 unsigned int mem_type;
  69 module_param(mem_type, uint, 0600);
  70 MODULE_PARM_DESC(mem_type,
  71                 "set to 1 to try to use unbuffered memory (default 0)");
  72
  73 static int dump_oops = 1;
  74 module_param(dump_oops, int, 0600);
  75 MODULE_PARM_DESC(dump_oops,
  76                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
  77
  78 static int ramoops_ecc;
  79 module_param_named(ecc, ramoops_ecc, int, 0600);
  80 MODULE_PARM_DESC(ramoops_ecc,
  81                 "if non-zero, the option enables ECC support and specifies "
  82                 "ECC buffer size in bytes (1 is a special value, means 16 "
  83                 "bytes ECC)");
  84
  85 struct ramoops_context {
  86         struct persistent_ram_zone **przs;
  87         struct persistent_ram_zone *cprz;
  88         struct persistent_ram_zone *fprz;
  89         struct persistent_ram_zone *mprz;
  90         phys_addr_t phys_addr;
  91         unsigned long size;
  92         unsigned int memtype;
  93         size_t record_size;
  94         size_t console_size;
  95         size_t ftrace_size;
  96         size_t pmsg_size;
  97         int dump_oops;
  98         struct persistent_ram_ecc_info ecc_info;
  99         unsigned int max_dump_cnt;
 100         unsigned int dump_write_cnt;
 101         /* _read_cnt need clear on ramoops_pstore_open */
 102         unsigned int dump_read_cnt;
 103         unsigned int console_read_cnt;
 104         unsigned int ftrace_read_cnt;
 105         unsigned int pmsg_read_cnt;
 106         struct pstore_info pstore;
 107 };
 108
 109 static struct platform_device *dummy;
 110 static struct ramoops_platform_data *dummy_data;
 111
 112 static int ramoops_pstore_open(struct pstore_info *psi)
 113 {
 114         struct ramoops_context *cxt = psi->data;
 115
 116         cxt->dump_read_cnt = 0;
 117         cxt->console_read_cnt = 0;
 118         cxt->ftrace_read_cnt = 0;
 119         cxt->pmsg_read_cnt = 0;
 120         return 0;
 121 }
 122
 123 static struct persistent_ram_zone *
 124 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 125                      u64 *id,
 126                      enum pstore_type_id *typep, enum pstore_type_id type,
 127                      bool update)
 128 {
 129         struct persistent_ram_zone *prz;
 130         int i = (*c)++;
 131
 132         if (i >= max)
 133                 return NULL;
 134
 135         prz = przs[i];
 136         if (!prz)
 137                 return NULL;
 138
 139         /* Update old/shadowed buffer. */
 140         if (update)
 141                 persistent_ram_save_old(prz);
 142
 143         if (!persistent_ram_old_size(prz))
 144                 return NULL;
 145
 146         *typep = type;
 147         *id = i;
 148
 149         return prz;
 150 }
 151
 152 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
 153                                   bool *compressed)
 154 {
 155         char data_type;
 156         int header_length = 0;
 157
 158         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
 159                         &time->tv_nsec, &data_type, &header_length) == 3) {
 160                 if (data_type == 'C')
 161                         *compressed = true;
 162                 else
 163                         *compressed = false;
 164         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
 165                         &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
 166                         *compressed = false;
 167         } else {
 168                 time->tv_sec = 0;
 169                 time->tv_nsec = 0;
 170                 *compressed = false;
 171         }
 172         return header_length;
 173 }
 174
 175 static bool prz_ok(struct persistent_ram_zone *prz)
 176 {
 177         return !!prz && !!(persistent_ram_old_size(prz) +
 178                            persistent_ram_ecc_string(prz, NULL, 0));
 179 }
 180
 181 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 182                                    int *count, struct timespec *time,
 183                                    char **buf, bool *compressed,
 184                                    struct pstore_info *psi)
 185 {
 186         ssize_t size;
 187         ssize_t ecc_notice_size;
 188         struct ramoops_context *cxt = psi->data;
 189         struct persistent_ram_zone *prz;
 190         int header_length;
 191
 192         prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
 193                                    cxt->max_dump_cnt, id, type,
 194                                    PSTORE_TYPE_DMESG, 1);
 195         if (!prz_ok(prz))
 196                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 197                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
 198         if (!prz_ok(prz))
 199                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
 200                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
 201         if (!prz_ok(prz))
 202                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 203                                            1, id, type, PSTORE_TYPE_PMSG, 0);
 204         if (!prz_ok(prz))
 205                 return 0;
 206
 207         if (!persistent_ram_old(prz))
 208                 return 0;
 209
 210         size = persistent_ram_old_size(prz);
 211         header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time,
 212                         compressed);
 213         size -= header_length;
 214
 215         /* ECC correction notice */
 216         ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 217
 218         *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL);
 219         if (*buf == NULL)
 220                 return -ENOMEM;
 221
 222         memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
 223         persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
 224
 225         return size + ecc_notice_size;
 226 }
 227
 228 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 229                                      bool compressed)
 230 {
 231         char *hdr;
 232         struct timespec timestamp;
 233         size_t len;
 234
 235         /* Report zeroed timestamp if called before timekeeping has resumed. */
 236         if (__getnstimeofday(&timestamp)) {
 237                 timestamp.tv_sec = 0;
 238                 timestamp.tv_nsec = 0;
 239         }
 240         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
 241                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
 242                 compressed ? 'C' : 'D');
 243         WARN_ON_ONCE(!hdr);
 244         len = hdr ? strlen(hdr) : 0;
 245         persistent_ram_write(prz, hdr, len);
 246         kfree(hdr);
 247
 248         return len;
 249 }
 250
 251 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 252                                             enum kmsg_dump_reason reason,
 253                                             u64 *id, unsigned int part,
 254                                             const char *buf,
 255                                             bool compressed, size_t size,
 256                                             struct pstore_info *psi)
 257 {
 258         struct ramoops_context *cxt = psi->data;
 259         struct persistent_ram_zone *prz;
 260         size_t hlen;
 261
 262         if (type == PSTORE_TYPE_CONSOLE) {
 263                 if (!cxt->cprz)
 264                         return -ENOMEM;
 265                 persistent_ram_write(cxt->cprz, buf, size);
 266                 return 0;
 267         } else if (type == PSTORE_TYPE_FTRACE) {
 268                 if (!cxt->fprz)
 269                         return -ENOMEM;
 270                 persistent_ram_write(cxt->fprz, buf, size);
 271                 return 0;
 272         } else if (type == PSTORE_TYPE_PMSG) {
 273                 if (!cxt->mprz)
 274                         return -ENOMEM;
 275                 persistent_ram_write(cxt->mprz, buf, size);
 276                 return 0;
 277         }
 278
 279         if (type != PSTORE_TYPE_DMESG)
 280                 return -EINVAL;
 281
 282         /* Out of the various dmesg dump types, ramoops is currently designed
 283          * to only store crash logs, rather than storing general kernel logs.
 284          */
 285         if (reason != KMSG_DUMP_OOPS &&
 286             reason != KMSG_DUMP_PANIC)
 287                 return -EINVAL;
 288
 289         /* Skip Oopes when configured to do so. */
 290         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 291                 return -EINVAL;
 292
 293         /* Explicitly only take the first part of any new crash.
 294          * If our buffer is larger than kmsg_bytes, this can never happen,
 295          * and if our buffer is smaller than kmsg_bytes, we don't want the
 296          * report split across multiple records.
 297          */
 298         if (part != 1)
 299                 return -ENOSPC;
 300
 301         if (!cxt->przs)
 302                 return -ENOSPC;
 303
 304         prz = cxt->przs[cxt->dump_write_cnt];
 305
 306         hlen = ramoops_write_kmsg_hdr(prz, compressed);
 307         if (size + hlen > prz->buffer_size)
 308                 size = prz->buffer_size - hlen;
 309         persistent_ram_write(prz, buf, size);
 310
 311         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 312
 313         return 0;
 314 }
 315
 316 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
 317                                 struct timespec time, struct pstore_info *psi)
 318 {
 319         struct ramoops_context *cxt = psi->data;
 320         struct persistent_ram_zone *prz;
 321
 322         switch (type) {
 323         case PSTORE_TYPE_DMESG:
 324                 if (id >= cxt->max_dump_cnt)
 325                         return -EINVAL;
 326                 prz = cxt->przs[id];
 327                 break;
 328         case PSTORE_TYPE_CONSOLE:
 329                 prz = cxt->cprz;
 330                 break;
 331         case PSTORE_TYPE_FTRACE:
 332                 prz = cxt->fprz;
 333                 break;
 334         case PSTORE_TYPE_PMSG:
 335                 prz = cxt->mprz;
 336                 break;
 337         default:
 338                 return -EINVAL;
 339         }
 340
 341         persistent_ram_free_old(prz);
 342         persistent_ram_zap(prz);
 343
 344         return 0;
 345 }
 346
 347 static struct ramoops_context oops_cxt = {
 348         .pstore = {
 349                 .owner  = THIS_MODULE,
 350                 .name   = "ramoops",
 351                 .open   = ramoops_pstore_open,
 352                 .read   = ramoops_pstore_read,
 353                 .write_buf      = ramoops_pstore_write_buf,
 354                 .erase  = ramoops_pstore_erase,
 355         },
 356 };
 357
 358 static void ramoops_free_przs(struct ramoops_context *cxt)
 359 {
 360         int i;
 361
 362         cxt->max_dump_cnt = 0;
 363         if (!cxt->przs)
 364                 return;
 365
 366         for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
 367                 persistent_ram_free(cxt->przs[i]);
 368         kfree(cxt->przs);
 369 }
 370
 371 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
 372                              phys_addr_t *paddr, size_t dump_mem_sz)
 373 {
 374         int err = -ENOMEM;
 375         int i;
 376
 377         if (!cxt->record_size)
 378                 return 0;
 379
 380         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
 381                 dev_err(dev, "no room for dumps\n");
 382                 return -ENOMEM;
 383         }
 384
 385         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
 386         if (!cxt->max_dump_cnt)
 387                 return -ENOMEM;
 388
 389         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
 390                              GFP_KERNEL);
 391         if (!cxt->przs) {
 392                 dev_err(dev, "failed to initialize a prz array for dumps\n");
 393                 goto fail_prz;
 394         }
 395
 396         for (i = 0; i < cxt->max_dump_cnt; i++) {
 397                 size_t sz = cxt->record_size;
 398
 399                 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0,
 400                                                   &cxt->ecc_info,
 401                                                   cxt->memtype);
 402                 if (IS_ERR(cxt->przs[i])) {
 403                         err = PTR_ERR(cxt->przs[i]);
 404                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 405                                 sz, (unsigned long long)*paddr, err);
 406                         goto fail_prz;
 407                 }
 408                 *paddr += sz;
 409         }
 410
 411         return 0;
 412 fail_prz:
 413         ramoops_free_przs(cxt);
 414         return err;
 415 }
 416
 417 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
 418                             struct persistent_ram_zone **prz,
 419                             phys_addr_t *paddr, size_t sz, u32 sig)
 420 {
 421         if (!sz)
 422                 return 0;
 423
 424         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 425                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 426                         sz, (unsigned long long)*paddr,
 427                         cxt->size, (unsigned long long)cxt->phys_addr);
 428                 return -ENOMEM;
 429         }
 430
 431         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
 432         if (IS_ERR(*prz)) {
 433                 int err = PTR_ERR(*prz);
 434
 435                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 436                         sz, (unsigned long long)*paddr, err);
 437                 return err;
 438         }
 439
 440         persistent_ram_zap(*prz);
 441
 442         *paddr += sz;
 443
 444         return 0;
 445 }
 446
 447 static int ramoops_probe(struct platform_device *pdev)
 448 {
 449         struct device *dev = &pdev->dev;
 450         struct ramoops_platform_data *pdata = pdev->dev.platform_data;
 451         struct ramoops_context *cxt = &oops_cxt;
 452         size_t dump_mem_sz;
 453         phys_addr_t paddr;
 454         int err = -EINVAL;
 455
 456         /* Only a single ramoops area allowed at a time, so fail extra
 457          * probes.
 458          */
 459         if (cxt->max_dump_cnt)
 460                 goto fail_out;
 461
 462         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 463                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 464                 pr_err("The memory size and the record/console size must be "
 465                         "non-zero\n");
 466                 goto fail_out;
 467         }
 468
 469         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 470                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 471         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 472                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 473         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 474                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 475         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 476                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 477
 478         cxt->size = pdata->mem_size;
 479         cxt->phys_addr = pdata->mem_address;
 480         cxt->memtype = pdata->mem_type;
 481         cxt->record_size = pdata->record_size;
 482         cxt->console_size = pdata->console_size;
 483         cxt->ftrace_size = pdata->ftrace_size;
 484         cxt->pmsg_size = pdata->pmsg_size;
 485         cxt->dump_oops = pdata->dump_oops;
 486         cxt->ecc_info = pdata->ecc_info;
 487
 488         paddr = cxt->phys_addr;
 489
 490         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 491                         - cxt->pmsg_size;
 492         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
 493         if (err)
 494                 goto fail_out;
 495
 496         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
 497                                cxt->console_size, 0);
 498         if (err)
 499                 goto fail_init_cprz;
 500
 501         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
 502                                LINUX_VERSION_CODE);
 503         if (err)
 504                 goto fail_init_fprz;
 505
 506         err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
 507         if (err)
 508                 goto fail_init_mprz;
 509
 510         cxt->pstore.data = cxt;
 511         /*
 512          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 513          * have to handle dumps, we must have at least record_size buffer. And
 514          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 515          * ZERO_SIZE_PTR).
 516          */
 517         if (cxt->console_size)
 518                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 519         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 520         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 521         spin_lock_init(&cxt->pstore.buf_lock);
 522         if (!cxt->pstore.buf) {
 523                 pr_err("cannot allocate pstore buffer\n");
 524                 err = -ENOMEM;
 525                 goto fail_clear;
 526         }
 527
 528         err = pstore_register(&cxt->pstore);
 529         if (err) {
 530                 pr_err("registering with pstore failed\n");
 531                 goto fail_buf;
 532         }
 533
 534         /*
 535          * Update the module parameter variables as well so they are visible
 536          * through /sys/module/ramoops/parameters/
 537          */
 538         mem_size = pdata->mem_size;
 539         mem_address = pdata->mem_address;
 540         record_size = pdata->record_size;
 541         dump_oops = pdata->dump_oops;
 542
 543         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 544                 cxt->size, (unsigned long long)cxt->phys_addr,
 545                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 546
 547         return 0;
 548
 549 fail_buf:
 550         kfree(cxt->pstore.buf);
 551 fail_clear:
 552         cxt->pstore.bufsize = 0;
 553         kfree(cxt->mprz);
 554 fail_init_mprz:
 555         kfree(cxt->fprz);
 556 fail_init_fprz:
 557         kfree(cxt->cprz);
 558 fail_init_cprz:
 559         ramoops_free_przs(cxt);
 560 fail_out:
 561         return err;
 562 }
 563
 564 static int __exit ramoops_remove(struct platform_device *pdev)
 565 {
 566 #if 0
 567         /* TODO(kees): We cannot unload ramoops since pstore doesn't support
 568          * unregistering yet.
 569          */
 570         struct ramoops_context *cxt = &oops_cxt;
 571
 572         iounmap(cxt->virt_addr);
 573         release_mem_region(cxt->phys_addr, cxt->size);
 574         cxt->max_dump_cnt = 0;
 575
 576         /* TODO(kees): When pstore supports unregistering, call it here. */
 577         kfree(cxt->pstore.buf);
 578         cxt->pstore.bufsize = 0;
 579
 580         return 0;
 581 #endif
 582         return -EBUSY;
 583 }
 584
 585 static struct platform_driver ramoops_driver = {
 586         .probe          = ramoops_probe,
 587         .remove         = __exit_p(ramoops_remove),
 588         .driver         = {
 589                 .name   = "ramoops",
 590         },
 591 };
 592
 593 static void ramoops_register_dummy(void)
 594 {
 595         if (!mem_size)
 596                 return;
 597
 598         pr_info("using module parameters\n");
 599
 600         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 601         if (!dummy_data) {
 602                 pr_info("could not allocate pdata\n");
 603                 return;
 604         }
 605
 606         dummy_data->mem_size = mem_size;
 607         dummy_data->mem_address = mem_address;
 608         dummy_data->mem_type = 0;
 609         dummy_data->record_size = record_size;
 610         dummy_data->console_size = ramoops_console_size;
 611         dummy_data->ftrace_size = ramoops_ftrace_size;
 612         dummy_data->pmsg_size = ramoops_pmsg_size;
 613         dummy_data->dump_oops = dump_oops;
 614         /*
 615          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 616          * (using 1 byte for ECC isn't much of use anyway).
 617          */
 618         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 619
 620         dummy = platform_device_register_data(NULL, "ramoops", -1,
 621                         dummy_data, sizeof(struct ramoops_platform_data));
 622         if (IS_ERR(dummy)) {
 623                 pr_info("could not create platform device: %ld\n",
 624                         PTR_ERR(dummy));
 625         }
 626 }
 627
 628 static int __init ramoops_init(void)
 629 {
 630         ramoops_register_dummy();
 631         return platform_driver_register(&ramoops_driver);
 632 }
 633 postcore_initcall(ramoops_init);
 634
 635 static void __exit ramoops_exit(void)
 636 {
 637         platform_driver_unregister(&ramoops_driver);
 638         platform_device_unregister(dummy);
 639         kfree(dummy_data);
 640 }
 641 module_exit(ramoops_exit);
 642
 643 MODULE_LICENSE("GPL");
 644 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 645 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");