Version:  2.0.40 2.2.26 2.4.37 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 3.19

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

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