Version:  2.0.40 2.2.26 2.4.37 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 3.15 3.16 3.17 3.18

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

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