2 * RAM Oops/Panic logger
4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
5 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
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.
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.
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
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
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>
38 #define RAMOOPS_KERNMSG_HDR "===="
39 #define MIN_MEM_SIZE 4096UL
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");
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");
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");
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");
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");
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");
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)");
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)");
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 "
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;
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;
109 static struct platform_device *dummy;
110 static struct ramoops_platform_data *dummy_data;
112 static int ramoops_pstore_open(struct pstore_info *psi)
114 struct ramoops_context *cxt = psi->data;
116 cxt->dump_read_cnt = 0;
117 cxt->console_read_cnt = 0;
118 cxt->ftrace_read_cnt = 0;
119 cxt->pmsg_read_cnt = 0;
123 static struct persistent_ram_zone *
124 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
126 enum pstore_type_id *typep, enum pstore_type_id type,
129 struct persistent_ram_zone *prz;
139 /* Update old/shadowed buffer. */
141 persistent_ram_save_old(prz);
143 if (!persistent_ram_old_size(prz))
152 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
156 int header_length = 0;
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')
164 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
165 &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
172 return header_length;
175 static bool prz_ok(struct persistent_ram_zone *prz)
177 return !!prz && !!(persistent_ram_old_size(prz) +
178 persistent_ram_ecc_string(prz, NULL, 0));
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)
187 ssize_t ecc_notice_size;
188 struct ramoops_context *cxt = psi->data;
189 struct persistent_ram_zone *prz = NULL;
190 int header_length = 0;
192 /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
193 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
194 * valid time stamps, so it is initialized to zero.
200 /* Find the next valid persistent_ram_zone for DMESG */
201 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
202 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
203 cxt->max_dump_cnt, id, type,
204 PSTORE_TYPE_DMESG, 1);
207 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
209 /* Clear and skip this DMESG record if it has no valid header */
210 if (!header_length) {
211 persistent_ram_free_old(prz);
212 persistent_ram_zap(prz);
218 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
219 1, id, type, PSTORE_TYPE_CONSOLE, 0);
221 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
222 1, id, type, PSTORE_TYPE_FTRACE, 0);
224 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
225 1, id, type, PSTORE_TYPE_PMSG, 0);
229 size = persistent_ram_old_size(prz) - header_length;
231 /* ECC correction notice */
232 ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
234 *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL);
238 memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
239 persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
241 return size + ecc_notice_size;
244 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
248 struct timespec timestamp;
251 /* Report zeroed timestamp if called before timekeeping has resumed. */
252 if (__getnstimeofday(×tamp)) {
253 timestamp.tv_sec = 0;
254 timestamp.tv_nsec = 0;
256 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
257 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
258 compressed ? 'C' : 'D');
260 len = hdr ? strlen(hdr) : 0;
261 persistent_ram_write(prz, hdr, len);
267 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
268 enum kmsg_dump_reason reason,
269 u64 *id, unsigned int part,
271 bool compressed, size_t size,
272 struct pstore_info *psi)
274 struct ramoops_context *cxt = psi->data;
275 struct persistent_ram_zone *prz;
278 if (type == PSTORE_TYPE_CONSOLE) {
281 persistent_ram_write(cxt->cprz, buf, size);
283 } else if (type == PSTORE_TYPE_FTRACE) {
286 persistent_ram_write(cxt->fprz, buf, size);
288 } else if (type == PSTORE_TYPE_PMSG) {
291 persistent_ram_write(cxt->mprz, buf, size);
295 if (type != PSTORE_TYPE_DMESG)
298 /* Out of the various dmesg dump types, ramoops is currently designed
299 * to only store crash logs, rather than storing general kernel logs.
301 if (reason != KMSG_DUMP_OOPS &&
302 reason != KMSG_DUMP_PANIC)
305 /* Skip Oopes when configured to do so. */
306 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
309 /* Explicitly only take the first part of any new crash.
310 * If our buffer is larger than kmsg_bytes, this can never happen,
311 * and if our buffer is smaller than kmsg_bytes, we don't want the
312 * report split across multiple records.
320 prz = cxt->przs[cxt->dump_write_cnt];
323 * Since this is a new crash dump, we need to reset the buffer in
324 * case it still has an old dump present. Without this, the new dump
325 * will get appended, which would seriously confuse anything trying
326 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
327 * expects to find a dump header in the beginning of buffer data, so
328 * we must to reset the buffer values, in order to ensure that the
329 * header will be written to the beginning of the buffer.
331 persistent_ram_zap(prz);
333 hlen = ramoops_write_kmsg_hdr(prz, compressed);
334 if (size + hlen > prz->buffer_size)
335 size = prz->buffer_size - hlen;
336 persistent_ram_write(prz, buf, size);
338 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
343 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
344 struct timespec time, struct pstore_info *psi)
346 struct ramoops_context *cxt = psi->data;
347 struct persistent_ram_zone *prz;
350 case PSTORE_TYPE_DMESG:
351 if (id >= cxt->max_dump_cnt)
355 case PSTORE_TYPE_CONSOLE:
358 case PSTORE_TYPE_FTRACE:
361 case PSTORE_TYPE_PMSG:
368 persistent_ram_free_old(prz);
369 persistent_ram_zap(prz);
374 static struct ramoops_context oops_cxt = {
376 .owner = THIS_MODULE,
378 .open = ramoops_pstore_open,
379 .read = ramoops_pstore_read,
380 .write_buf = ramoops_pstore_write_buf,
381 .erase = ramoops_pstore_erase,
385 static void ramoops_free_przs(struct ramoops_context *cxt)
392 for (i = 0; i < cxt->max_dump_cnt; i++)
393 persistent_ram_free(cxt->przs[i]);
396 cxt->max_dump_cnt = 0;
399 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
400 phys_addr_t *paddr, size_t dump_mem_sz)
405 if (!cxt->record_size)
408 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
409 dev_err(dev, "no room for dumps\n");
413 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
414 if (!cxt->max_dump_cnt)
417 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
420 dev_err(dev, "failed to initialize a prz array for dumps\n");
424 for (i = 0; i < cxt->max_dump_cnt; i++) {
425 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
428 if (IS_ERR(cxt->przs[i])) {
429 err = PTR_ERR(cxt->przs[i]);
430 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
431 cxt->record_size, (unsigned long long)*paddr, err);
435 persistent_ram_free(cxt->przs[i]);
439 *paddr += cxt->record_size;
446 cxt->max_dump_cnt = 0;
450 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
451 struct persistent_ram_zone **prz,
452 phys_addr_t *paddr, size_t sz, u32 sig)
457 if (*paddr + sz - cxt->phys_addr > cxt->size) {
458 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
459 sz, (unsigned long long)*paddr,
460 cxt->size, (unsigned long long)cxt->phys_addr);
464 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
467 int err = PTR_ERR(*prz);
469 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
470 sz, (unsigned long long)*paddr, err);
474 persistent_ram_zap(*prz);
481 static int ramoops_probe(struct platform_device *pdev)
483 struct device *dev = &pdev->dev;
484 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
485 struct ramoops_context *cxt = &oops_cxt;
490 /* Only a single ramoops area allowed at a time, so fail extra
493 if (cxt->max_dump_cnt)
496 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
497 !pdata->ftrace_size && !pdata->pmsg_size)) {
498 pr_err("The memory size and the record/console size must be "
503 if (pdata->record_size && !is_power_of_2(pdata->record_size))
504 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
505 if (pdata->console_size && !is_power_of_2(pdata->console_size))
506 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
507 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
508 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
509 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
510 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
512 cxt->size = pdata->mem_size;
513 cxt->phys_addr = pdata->mem_address;
514 cxt->memtype = pdata->mem_type;
515 cxt->record_size = pdata->record_size;
516 cxt->console_size = pdata->console_size;
517 cxt->ftrace_size = pdata->ftrace_size;
518 cxt->pmsg_size = pdata->pmsg_size;
519 cxt->dump_oops = pdata->dump_oops;
520 cxt->ecc_info = pdata->ecc_info;
522 paddr = cxt->phys_addr;
524 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
526 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
530 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
531 cxt->console_size, 0);
535 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
540 err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
544 cxt->pstore.data = cxt;
546 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
547 * have to handle dumps, we must have at least record_size buffer. And
548 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
551 if (cxt->console_size)
552 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
553 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
554 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
555 spin_lock_init(&cxt->pstore.buf_lock);
556 if (!cxt->pstore.buf) {
557 pr_err("cannot allocate pstore buffer\n");
562 err = pstore_register(&cxt->pstore);
564 pr_err("registering with pstore failed\n");
569 * Update the module parameter variables as well so they are visible
570 * through /sys/module/ramoops/parameters/
572 mem_size = pdata->mem_size;
573 mem_address = pdata->mem_address;
574 record_size = pdata->record_size;
575 dump_oops = pdata->dump_oops;
576 ramoops_console_size = pdata->console_size;
577 ramoops_pmsg_size = pdata->pmsg_size;
578 ramoops_ftrace_size = pdata->ftrace_size;
580 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
581 cxt->size, (unsigned long long)cxt->phys_addr,
582 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
587 kfree(cxt->pstore.buf);
589 cxt->pstore.bufsize = 0;
596 ramoops_free_przs(cxt);
601 static int ramoops_remove(struct platform_device *pdev)
603 struct ramoops_context *cxt = &oops_cxt;
605 pstore_unregister(&cxt->pstore);
607 kfree(cxt->pstore.buf);
608 cxt->pstore.bufsize = 0;
610 persistent_ram_free(cxt->mprz);
611 persistent_ram_free(cxt->fprz);
612 persistent_ram_free(cxt->cprz);
613 ramoops_free_przs(cxt);
618 static struct platform_driver ramoops_driver = {
619 .probe = ramoops_probe,
620 .remove = ramoops_remove,
626 static void ramoops_register_dummy(void)
631 pr_info("using module parameters\n");
633 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
635 pr_info("could not allocate pdata\n");
639 dummy_data->mem_size = mem_size;
640 dummy_data->mem_address = mem_address;
641 dummy_data->mem_type = mem_type;
642 dummy_data->record_size = record_size;
643 dummy_data->console_size = ramoops_console_size;
644 dummy_data->ftrace_size = ramoops_ftrace_size;
645 dummy_data->pmsg_size = ramoops_pmsg_size;
646 dummy_data->dump_oops = dump_oops;
648 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
649 * (using 1 byte for ECC isn't much of use anyway).
651 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
653 dummy = platform_device_register_data(NULL, "ramoops", -1,
654 dummy_data, sizeof(struct ramoops_platform_data));
656 pr_info("could not create platform device: %ld\n",
661 static int __init ramoops_init(void)
663 ramoops_register_dummy();
664 return platform_driver_register(&ramoops_driver);
666 postcore_initcall(ramoops_init);
668 static void __exit ramoops_exit(void)
670 platform_driver_unregister(&ramoops_driver);
671 platform_device_unregister(dummy);
674 module_exit(ramoops_exit);
676 MODULE_LICENSE("GPL");
677 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
678 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");