Version:  2.6.34 2.6.35 2.6.36 2.6.37 2.6.38 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14

Linux/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 int dump_oops = 1;
 65 module_param(dump_oops, int, 0600);
 66 MODULE_PARM_DESC(dump_oops,
 67                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
 68 
 69 static int ramoops_ecc;
 70 module_param_named(ecc, ramoops_ecc, int, 0600);
 71 MODULE_PARM_DESC(ramoops_ecc,
 72                 "if non-zero, the option enables ECC support and specifies "
 73                 "ECC buffer size in bytes (1 is a special value, means 16 "
 74                 "bytes ECC)");
 75 
 76 struct ramoops_context {
 77         struct persistent_ram_zone **przs;
 78         struct persistent_ram_zone *cprz;
 79         struct persistent_ram_zone *fprz;
 80         phys_addr_t phys_addr;
 81         unsigned long size;
 82         size_t record_size;
 83         size_t console_size;
 84         size_t ftrace_size;
 85         int dump_oops;
 86         struct persistent_ram_ecc_info ecc_info;
 87         unsigned int max_dump_cnt;
 88         unsigned int dump_write_cnt;
 89         unsigned int dump_read_cnt;
 90         unsigned int console_read_cnt;
 91         unsigned int ftrace_read_cnt;
 92         struct pstore_info pstore;
 93 };
 94 
 95 static struct platform_device *dummy;
 96 static struct ramoops_platform_data *dummy_data;
 97 
 98 static int ramoops_pstore_open(struct pstore_info *psi)
 99 {
100         struct ramoops_context *cxt = psi->data;
101 
102         cxt->dump_read_cnt = 0;
103         cxt->console_read_cnt = 0;
104         return 0;
105 }
106 
107 static struct persistent_ram_zone *
108 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
109                      u64 *id,
110                      enum pstore_type_id *typep, enum pstore_type_id type,
111                      bool update)
112 {
113         struct persistent_ram_zone *prz;
114         int i = (*c)++;
115 
116         if (i >= max)
117                 return NULL;
118 
119         prz = przs[i];
120 
121         if (update) {
122                 /* Update old/shadowed buffer. */
123                 persistent_ram_save_old(prz);
124                 if (!persistent_ram_old_size(prz))
125                         return NULL;
126         }
127 
128         *typep = type;
129         *id = i;
130 
131         return prz;
132 }
133 
134 static void ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
135                                   bool *compressed)
136 {
137         char data_type;
138 
139         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
140                         &time->tv_sec, &time->tv_nsec, &data_type) == 3) {
141                 if (data_type == 'C')
142                         *compressed = true;
143                 else
144                         *compressed = false;
145         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
146                         &time->tv_sec, &time->tv_nsec) == 2) {
147                         *compressed = false;
148         } else {
149                 time->tv_sec = 0;
150                 time->tv_nsec = 0;
151                 *compressed = false;
152         }
153 }
154 
155 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
156                                    int *count, struct timespec *time,
157                                    char **buf, bool *compressed,
158                                    struct pstore_info *psi)
159 {
160         ssize_t size;
161         ssize_t ecc_notice_size;
162         struct ramoops_context *cxt = psi->data;
163         struct persistent_ram_zone *prz;
164 
165         prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
166                                    cxt->max_dump_cnt, id, type,
167                                    PSTORE_TYPE_DMESG, 1);
168         if (!prz)
169                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
170                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
171         if (!prz)
172                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
173                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
174         if (!prz)
175                 return 0;
176 
177         size = persistent_ram_old_size(prz);
178 
179         /* ECC correction notice */
180         ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
181 
182         *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL);
183         if (*buf == NULL)
184                 return -ENOMEM;
185 
186         memcpy(*buf, persistent_ram_old(prz), size);
187         ramoops_read_kmsg_hdr(*buf, time, compressed);
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                                      bool compressed)
195 {
196         char *hdr;
197         struct timespec timestamp;
198         size_t len;
199 
200         /* Report zeroed timestamp if called before timekeeping has resumed. */
201         if (__getnstimeofday(&timestamp)) {
202                 timestamp.tv_sec = 0;
203                 timestamp.tv_nsec = 0;
204         }
205         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
206                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
207                 compressed ? 'C' : 'D');
208         WARN_ON_ONCE(!hdr);
209         len = hdr ? strlen(hdr) : 0;
210         persistent_ram_write(prz, hdr, len);
211         kfree(hdr);
212 
213         return len;
214 }
215 
216 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
217                                             enum kmsg_dump_reason reason,
218                                             u64 *id, unsigned int part,
219                                             const char *buf,
220                                             bool compressed, size_t size,
221                                             struct pstore_info *psi)
222 {
223         struct ramoops_context *cxt = psi->data;
224         struct persistent_ram_zone *prz;
225         size_t hlen;
226 
227         if (type == PSTORE_TYPE_CONSOLE) {
228                 if (!cxt->cprz)
229                         return -ENOMEM;
230                 persistent_ram_write(cxt->cprz, buf, size);
231                 return 0;
232         } else if (type == PSTORE_TYPE_FTRACE) {
233                 if (!cxt->fprz)
234                         return -ENOMEM;
235                 persistent_ram_write(cxt->fprz, buf, size);
236                 return 0;
237         }
238 
239         if (type != PSTORE_TYPE_DMESG)
240                 return -EINVAL;
241 
242         /* Out of the various dmesg dump types, ramoops is currently designed
243          * to only store crash logs, rather than storing general kernel logs.
244          */
245         if (reason != KMSG_DUMP_OOPS &&
246             reason != KMSG_DUMP_PANIC)
247                 return -EINVAL;
248 
249         /* Skip Oopes when configured to do so. */
250         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
251                 return -EINVAL;
252 
253         /* Explicitly only take the first part of any new crash.
254          * If our buffer is larger than kmsg_bytes, this can never happen,
255          * and if our buffer is smaller than kmsg_bytes, we don't want the
256          * report split across multiple records.
257          */
258         if (part != 1)
259                 return -ENOSPC;
260 
261         if (!cxt->przs)
262                 return -ENOSPC;
263 
264         prz = cxt->przs[cxt->dump_write_cnt];
265 
266         hlen = ramoops_write_kmsg_hdr(prz, compressed);
267         if (size + hlen > prz->buffer_size)
268                 size = prz->buffer_size - hlen;
269         persistent_ram_write(prz, buf, size);
270 
271         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
272 
273         return 0;
274 }
275 
276 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
277                                 struct timespec time, struct pstore_info *psi)
278 {
279         struct ramoops_context *cxt = psi->data;
280         struct persistent_ram_zone *prz;
281 
282         switch (type) {
283         case PSTORE_TYPE_DMESG:
284                 if (id >= cxt->max_dump_cnt)
285                         return -EINVAL;
286                 prz = cxt->przs[id];
287                 break;
288         case PSTORE_TYPE_CONSOLE:
289                 prz = cxt->cprz;
290                 break;
291         case PSTORE_TYPE_FTRACE:
292                 prz = cxt->fprz;
293                 break;
294         default:
295                 return -EINVAL;
296         }
297 
298         persistent_ram_free_old(prz);
299         persistent_ram_zap(prz);
300 
301         return 0;
302 }
303 
304 static struct ramoops_context oops_cxt = {
305         .pstore = {
306                 .owner  = THIS_MODULE,
307                 .name   = "ramoops",
308                 .open   = ramoops_pstore_open,
309                 .read   = ramoops_pstore_read,
310                 .write_buf      = ramoops_pstore_write_buf,
311                 .erase  = ramoops_pstore_erase,
312         },
313 };
314 
315 static void ramoops_free_przs(struct ramoops_context *cxt)
316 {
317         int i;
318 
319         if (!cxt->przs)
320                 return;
321 
322         for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
323                 persistent_ram_free(cxt->przs[i]);
324         kfree(cxt->przs);
325 }
326 
327 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
328                              phys_addr_t *paddr, size_t dump_mem_sz)
329 {
330         int err = -ENOMEM;
331         int i;
332 
333         if (!cxt->record_size)
334                 return 0;
335 
336         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
337                 dev_err(dev, "no room for dumps\n");
338                 return -ENOMEM;
339         }
340 
341         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
342         if (!cxt->max_dump_cnt)
343                 return -ENOMEM;
344 
345         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
346                              GFP_KERNEL);
347         if (!cxt->przs) {
348                 dev_err(dev, "failed to initialize a prz array for dumps\n");
349                 return -ENOMEM;
350         }
351 
352         for (i = 0; i < cxt->max_dump_cnt; i++) {
353                 size_t sz = cxt->record_size;
354 
355                 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0,
356                                                   &cxt->ecc_info);
357                 if (IS_ERR(cxt->przs[i])) {
358                         err = PTR_ERR(cxt->przs[i]);
359                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
360                                 sz, (unsigned long long)*paddr, err);
361                         goto fail_prz;
362                 }
363                 *paddr += sz;
364         }
365 
366         return 0;
367 fail_prz:
368         ramoops_free_przs(cxt);
369         return err;
370 }
371 
372 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
373                             struct persistent_ram_zone **prz,
374                             phys_addr_t *paddr, size_t sz, u32 sig)
375 {
376         if (!sz)
377                 return 0;
378 
379         if (*paddr + sz - cxt->phys_addr > cxt->size) {
380                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
381                         sz, (unsigned long long)*paddr,
382                         cxt->size, (unsigned long long)cxt->phys_addr);
383                 return -ENOMEM;
384         }
385 
386         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info);
387         if (IS_ERR(*prz)) {
388                 int err = PTR_ERR(*prz);
389 
390                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
391                         sz, (unsigned long long)*paddr, err);
392                 return err;
393         }
394 
395         persistent_ram_zap(*prz);
396 
397         *paddr += sz;
398 
399         return 0;
400 }
401 
402 static int ramoops_probe(struct platform_device *pdev)
403 {
404         struct device *dev = &pdev->dev;
405         struct ramoops_platform_data *pdata = pdev->dev.platform_data;
406         struct ramoops_context *cxt = &oops_cxt;
407         size_t dump_mem_sz;
408         phys_addr_t paddr;
409         int err = -EINVAL;
410 
411         /* Only a single ramoops area allowed at a time, so fail extra
412          * probes.
413          */
414         if (cxt->max_dump_cnt)
415                 goto fail_out;
416 
417         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
418                         !pdata->ftrace_size)) {
419                 pr_err("The memory size and the record/console size must be "
420                         "non-zero\n");
421                 goto fail_out;
422         }
423 
424         if (pdata->record_size && !is_power_of_2(pdata->record_size))
425                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
426         if (pdata->console_size && !is_power_of_2(pdata->console_size))
427                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
428         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
429                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
430 
431         cxt->dump_read_cnt = 0;
432         cxt->size = pdata->mem_size;
433         cxt->phys_addr = pdata->mem_address;
434         cxt->record_size = pdata->record_size;
435         cxt->console_size = pdata->console_size;
436         cxt->ftrace_size = pdata->ftrace_size;
437         cxt->dump_oops = pdata->dump_oops;
438         cxt->ecc_info = pdata->ecc_info;
439 
440         paddr = cxt->phys_addr;
441 
442         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
443         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
444         if (err)
445                 goto fail_out;
446 
447         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
448                                cxt->console_size, 0);
449         if (err)
450                 goto fail_init_cprz;
451 
452         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
453                                LINUX_VERSION_CODE);
454         if (err)
455                 goto fail_init_fprz;
456 
457         if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
458                 pr_err("memory size too small, minimum is %zu\n",
459                         cxt->console_size + cxt->record_size +
460                         cxt->ftrace_size);
461                 err = -EINVAL;
462                 goto fail_cnt;
463         }
464 
465         cxt->pstore.data = cxt;
466         /*
467          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
468          * have to handle dumps, we must have at least record_size buffer. And
469          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
470          * ZERO_SIZE_PTR).
471          */
472         if (cxt->console_size)
473                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
474         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
475         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
476         spin_lock_init(&cxt->pstore.buf_lock);
477         if (!cxt->pstore.buf) {
478                 pr_err("cannot allocate pstore buffer\n");
479                 err = -ENOMEM;
480                 goto fail_clear;
481         }
482 
483         err = pstore_register(&cxt->pstore);
484         if (err) {
485                 pr_err("registering with pstore failed\n");
486                 goto fail_buf;
487         }
488 
489         /*
490          * Update the module parameter variables as well so they are visible
491          * through /sys/module/ramoops/parameters/
492          */
493         mem_size = pdata->mem_size;
494         mem_address = pdata->mem_address;
495         record_size = pdata->record_size;
496         dump_oops = pdata->dump_oops;
497 
498         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
499                 cxt->size, (unsigned long long)cxt->phys_addr,
500                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
501 
502         return 0;
503 
504 fail_buf:
505         kfree(cxt->pstore.buf);
506 fail_clear:
507         cxt->pstore.bufsize = 0;
508         cxt->max_dump_cnt = 0;
509 fail_cnt:
510         kfree(cxt->fprz);
511 fail_init_fprz:
512         kfree(cxt->cprz);
513 fail_init_cprz:
514         ramoops_free_przs(cxt);
515 fail_out:
516         return err;
517 }
518 
519 static int __exit ramoops_remove(struct platform_device *pdev)
520 {
521 #if 0
522         /* TODO(kees): We cannot unload ramoops since pstore doesn't support
523          * unregistering yet.
524          */
525         struct ramoops_context *cxt = &oops_cxt;
526 
527         iounmap(cxt->virt_addr);
528         release_mem_region(cxt->phys_addr, cxt->size);
529         cxt->max_dump_cnt = 0;
530 
531         /* TODO(kees): When pstore supports unregistering, call it here. */
532         kfree(cxt->pstore.buf);
533         cxt->pstore.bufsize = 0;
534 
535         return 0;
536 #endif
537         return -EBUSY;
538 }
539 
540 static struct platform_driver ramoops_driver = {
541         .probe          = ramoops_probe,
542         .remove         = __exit_p(ramoops_remove),
543         .driver         = {
544                 .name   = "ramoops",
545                 .owner  = THIS_MODULE,
546         },
547 };
548 
549 static void ramoops_register_dummy(void)
550 {
551         if (!mem_size)
552                 return;
553 
554         pr_info("using module parameters\n");
555 
556         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
557         if (!dummy_data) {
558                 pr_info("could not allocate pdata\n");
559                 return;
560         }
561 
562         dummy_data->mem_size = mem_size;
563         dummy_data->mem_address = mem_address;
564         dummy_data->record_size = record_size;
565         dummy_data->console_size = ramoops_console_size;
566         dummy_data->ftrace_size = ramoops_ftrace_size;
567         dummy_data->dump_oops = dump_oops;
568         /*
569          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
570          * (using 1 byte for ECC isn't much of use anyway).
571          */
572         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
573 
574         dummy = platform_device_register_data(NULL, "ramoops", -1,
575                         dummy_data, sizeof(struct ramoops_platform_data));
576         if (IS_ERR(dummy)) {
577                 pr_info("could not create platform device: %ld\n",
578                         PTR_ERR(dummy));
579         }
580 }
581 
582 static int __init ramoops_init(void)
583 {
584         ramoops_register_dummy();
585         return platform_driver_register(&ramoops_driver);
586 }
587 postcore_initcall(ramoops_init);
588 
589 static void __exit ramoops_exit(void)
590 {
591         platform_driver_unregister(&ramoops_driver);
592         platform_device_unregister(dummy);
593         kfree(dummy_data);
594 }
595 module_exit(ramoops_exit);
596 
597 MODULE_LICENSE("GPL");
598 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
599 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
600 

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