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 #include <linux/of_address.h>
40 #define RAMOOPS_KERNMSG_HDR "===="
41 #define MIN_MEM_SIZE 4096UL
43 static ulong record_size = MIN_MEM_SIZE;
44 module_param(record_size, ulong, 0400);
45 MODULE_PARM_DESC(record_size,
46 "size of each dump done on oops/panic");
48 static ulong ramoops_console_size = MIN_MEM_SIZE;
49 module_param_named(console_size, ramoops_console_size, ulong, 0400);
50 MODULE_PARM_DESC(console_size, "size of kernel console log");
52 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
53 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
54 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
56 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
57 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
58 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
60 static unsigned long long mem_address;
61 module_param(mem_address, ullong, 0400);
62 MODULE_PARM_DESC(mem_address,
63 "start of reserved RAM used to store oops/panic logs");
65 static ulong mem_size;
66 module_param(mem_size, ulong, 0400);
67 MODULE_PARM_DESC(mem_size,
68 "size of reserved RAM used to store oops/panic logs");
70 static unsigned int mem_type;
71 module_param(mem_type, uint, 0600);
72 MODULE_PARM_DESC(mem_type,
73 "set to 1 to try to use unbuffered memory (default 0)");
75 static int dump_oops = 1;
76 module_param(dump_oops, int, 0600);
77 MODULE_PARM_DESC(dump_oops,
78 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
80 static int ramoops_ecc;
81 module_param_named(ecc, ramoops_ecc, int, 0600);
82 MODULE_PARM_DESC(ramoops_ecc,
83 "if non-zero, the option enables ECC support and specifies "
84 "ECC buffer size in bytes (1 is a special value, means 16 "
87 struct ramoops_context {
88 struct persistent_ram_zone **przs;
89 struct persistent_ram_zone *cprz;
90 struct persistent_ram_zone *fprz;
91 struct persistent_ram_zone *mprz;
92 phys_addr_t phys_addr;
100 struct persistent_ram_ecc_info ecc_info;
101 unsigned int max_dump_cnt;
102 unsigned int dump_write_cnt;
103 /* _read_cnt need clear on ramoops_pstore_open */
104 unsigned int dump_read_cnt;
105 unsigned int console_read_cnt;
106 unsigned int ftrace_read_cnt;
107 unsigned int pmsg_read_cnt;
108 struct pstore_info pstore;
111 static struct platform_device *dummy;
112 static struct ramoops_platform_data *dummy_data;
114 static int ramoops_pstore_open(struct pstore_info *psi)
116 struct ramoops_context *cxt = psi->data;
118 cxt->dump_read_cnt = 0;
119 cxt->console_read_cnt = 0;
120 cxt->ftrace_read_cnt = 0;
121 cxt->pmsg_read_cnt = 0;
125 static struct persistent_ram_zone *
126 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
128 enum pstore_type_id *typep, enum pstore_type_id type,
131 struct persistent_ram_zone *prz;
141 /* Update old/shadowed buffer. */
143 persistent_ram_save_old(prz);
145 if (!persistent_ram_old_size(prz))
154 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
158 int header_length = 0;
160 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
161 &time->tv_nsec, &data_type, &header_length) == 3) {
162 if (data_type == 'C')
166 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
167 &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
174 return header_length;
177 static bool prz_ok(struct persistent_ram_zone *prz)
179 return !!prz && !!(persistent_ram_old_size(prz) +
180 persistent_ram_ecc_string(prz, NULL, 0));
183 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
184 int *count, struct timespec *time,
185 char **buf, bool *compressed,
186 ssize_t *ecc_notice_size,
187 struct pstore_info *psi)
190 struct ramoops_context *cxt = psi->data;
191 struct persistent_ram_zone *prz = NULL;
192 int header_length = 0;
194 /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
195 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
196 * valid time stamps, so it is initialized to zero.
202 /* Find the next valid persistent_ram_zone for DMESG */
203 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
204 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
205 cxt->max_dump_cnt, id, type,
206 PSTORE_TYPE_DMESG, 1);
209 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
211 /* Clear and skip this DMESG record if it has no valid header */
212 if (!header_length) {
213 persistent_ram_free_old(prz);
214 persistent_ram_zap(prz);
220 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
221 1, id, type, PSTORE_TYPE_CONSOLE, 0);
223 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
224 1, id, type, PSTORE_TYPE_FTRACE, 0);
226 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
227 1, id, type, PSTORE_TYPE_PMSG, 0);
231 size = persistent_ram_old_size(prz) - header_length;
233 /* ECC correction notice */
234 *ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
236 *buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
240 memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
241 persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
246 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
250 struct timespec timestamp;
253 /* Report zeroed timestamp if called before timekeeping has resumed. */
254 if (__getnstimeofday(×tamp)) {
255 timestamp.tv_sec = 0;
256 timestamp.tv_nsec = 0;
258 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
259 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
260 compressed ? 'C' : 'D');
262 len = hdr ? strlen(hdr) : 0;
263 persistent_ram_write(prz, hdr, len);
269 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
270 enum kmsg_dump_reason reason,
271 u64 *id, unsigned int part,
273 bool compressed, size_t size,
274 struct pstore_info *psi)
276 struct ramoops_context *cxt = psi->data;
277 struct persistent_ram_zone *prz;
280 if (type == PSTORE_TYPE_CONSOLE) {
283 persistent_ram_write(cxt->cprz, buf, size);
285 } else if (type == PSTORE_TYPE_FTRACE) {
288 persistent_ram_write(cxt->fprz, buf, size);
290 } else if (type == PSTORE_TYPE_PMSG) {
293 persistent_ram_write(cxt->mprz, buf, size);
297 if (type != PSTORE_TYPE_DMESG)
300 /* Out of the various dmesg dump types, ramoops is currently designed
301 * to only store crash logs, rather than storing general kernel logs.
303 if (reason != KMSG_DUMP_OOPS &&
304 reason != KMSG_DUMP_PANIC)
307 /* Skip Oopes when configured to do so. */
308 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
311 /* Explicitly only take the first part of any new crash.
312 * If our buffer is larger than kmsg_bytes, this can never happen,
313 * and if our buffer is smaller than kmsg_bytes, we don't want the
314 * report split across multiple records.
322 prz = cxt->przs[cxt->dump_write_cnt];
325 * Since this is a new crash dump, we need to reset the buffer in
326 * case it still has an old dump present. Without this, the new dump
327 * will get appended, which would seriously confuse anything trying
328 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
329 * expects to find a dump header in the beginning of buffer data, so
330 * we must to reset the buffer values, in order to ensure that the
331 * header will be written to the beginning of the buffer.
333 persistent_ram_zap(prz);
335 hlen = ramoops_write_kmsg_hdr(prz, compressed);
336 if (size + hlen > prz->buffer_size)
337 size = prz->buffer_size - hlen;
338 persistent_ram_write(prz, buf, size);
340 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
345 static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
346 enum kmsg_dump_reason reason,
347 u64 *id, unsigned int part,
348 const char __user *buf,
349 bool compressed, size_t size,
350 struct pstore_info *psi)
352 if (type == PSTORE_TYPE_PMSG) {
353 struct ramoops_context *cxt = psi->data;
357 return persistent_ram_write_user(cxt->mprz, buf, size);
363 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
364 struct timespec time, struct pstore_info *psi)
366 struct ramoops_context *cxt = psi->data;
367 struct persistent_ram_zone *prz;
370 case PSTORE_TYPE_DMESG:
371 if (id >= cxt->max_dump_cnt)
375 case PSTORE_TYPE_CONSOLE:
378 case PSTORE_TYPE_FTRACE:
381 case PSTORE_TYPE_PMSG:
388 persistent_ram_free_old(prz);
389 persistent_ram_zap(prz);
394 static struct ramoops_context oops_cxt = {
396 .owner = THIS_MODULE,
398 .open = ramoops_pstore_open,
399 .read = ramoops_pstore_read,
400 .write_buf = ramoops_pstore_write_buf,
401 .write_buf_user = ramoops_pstore_write_buf_user,
402 .erase = ramoops_pstore_erase,
406 static void ramoops_free_przs(struct ramoops_context *cxt)
413 for (i = 0; i < cxt->max_dump_cnt; i++)
414 persistent_ram_free(cxt->przs[i]);
417 cxt->max_dump_cnt = 0;
420 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
421 phys_addr_t *paddr, size_t dump_mem_sz)
426 if (!cxt->record_size)
429 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
430 dev_err(dev, "no room for dumps\n");
434 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
435 if (!cxt->max_dump_cnt)
438 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
441 dev_err(dev, "failed to initialize a prz array for dumps\n");
445 for (i = 0; i < cxt->max_dump_cnt; i++) {
446 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
449 if (IS_ERR(cxt->przs[i])) {
450 err = PTR_ERR(cxt->przs[i]);
451 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
452 cxt->record_size, (unsigned long long)*paddr, err);
456 persistent_ram_free(cxt->przs[i]);
460 *paddr += cxt->record_size;
467 cxt->max_dump_cnt = 0;
471 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
472 struct persistent_ram_zone **prz,
473 phys_addr_t *paddr, size_t sz, u32 sig)
478 if (*paddr + sz - cxt->phys_addr > cxt->size) {
479 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
480 sz, (unsigned long long)*paddr,
481 cxt->size, (unsigned long long)cxt->phys_addr);
485 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
488 int err = PTR_ERR(*prz);
490 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
491 sz, (unsigned long long)*paddr, err);
495 persistent_ram_zap(*prz);
502 static int ramoops_parse_dt_size(struct platform_device *pdev,
503 const char *propname, u32 *value)
508 ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
509 if (ret < 0 && ret != -EINVAL) {
510 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
515 if (val32 > INT_MAX) {
516 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
524 static int ramoops_parse_dt(struct platform_device *pdev,
525 struct ramoops_platform_data *pdata)
527 struct device_node *of_node = pdev->dev.of_node;
528 struct resource *res;
532 dev_dbg(&pdev->dev, "using Device Tree\n");
534 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
537 "failed to locate DT /reserved-memory resource\n");
541 pdata->mem_size = resource_size(res);
542 pdata->mem_address = res->start;
543 pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
544 pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
546 #define parse_size(name, field) { \
547 ret = ramoops_parse_dt_size(pdev, name, &value); \
553 parse_size("record-size", pdata->record_size);
554 parse_size("console-size", pdata->console_size);
555 parse_size("ftrace-size", pdata->ftrace_size);
556 parse_size("pmsg-size", pdata->pmsg_size);
557 parse_size("ecc-size", pdata->ecc_info.ecc_size);
564 static int ramoops_probe(struct platform_device *pdev)
566 struct device *dev = &pdev->dev;
567 struct ramoops_platform_data *pdata = dev->platform_data;
568 struct ramoops_context *cxt = &oops_cxt;
573 if (dev_of_node(dev) && !pdata) {
574 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
580 err = ramoops_parse_dt(pdev, pdata);
585 /* Only a single ramoops area allowed at a time, so fail extra
588 if (cxt->max_dump_cnt)
591 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
592 !pdata->ftrace_size && !pdata->pmsg_size)) {
593 pr_err("The memory size and the record/console size must be "
598 if (pdata->record_size && !is_power_of_2(pdata->record_size))
599 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
600 if (pdata->console_size && !is_power_of_2(pdata->console_size))
601 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
602 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
603 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
604 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
605 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
607 cxt->size = pdata->mem_size;
608 cxt->phys_addr = pdata->mem_address;
609 cxt->memtype = pdata->mem_type;
610 cxt->record_size = pdata->record_size;
611 cxt->console_size = pdata->console_size;
612 cxt->ftrace_size = pdata->ftrace_size;
613 cxt->pmsg_size = pdata->pmsg_size;
614 cxt->dump_oops = pdata->dump_oops;
615 cxt->ecc_info = pdata->ecc_info;
617 paddr = cxt->phys_addr;
619 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
621 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
625 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
626 cxt->console_size, 0);
630 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
635 err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
639 cxt->pstore.data = cxt;
641 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
642 * have to handle dumps, we must have at least record_size buffer. And
643 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
646 if (cxt->console_size)
647 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
648 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
649 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
650 if (!cxt->pstore.buf) {
651 pr_err("cannot allocate pstore buffer\n");
655 spin_lock_init(&cxt->pstore.buf_lock);
657 cxt->pstore.flags = PSTORE_FLAGS_DMESG;
658 if (cxt->console_size)
659 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
660 if (cxt->ftrace_size)
661 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
663 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
665 err = pstore_register(&cxt->pstore);
667 pr_err("registering with pstore failed\n");
672 * Update the module parameter variables as well so they are visible
673 * through /sys/module/ramoops/parameters/
675 mem_size = pdata->mem_size;
676 mem_address = pdata->mem_address;
677 record_size = pdata->record_size;
678 dump_oops = pdata->dump_oops;
679 ramoops_console_size = pdata->console_size;
680 ramoops_pmsg_size = pdata->pmsg_size;
681 ramoops_ftrace_size = pdata->ftrace_size;
683 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
684 cxt->size, (unsigned long long)cxt->phys_addr,
685 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
690 kfree(cxt->pstore.buf);
692 cxt->pstore.bufsize = 0;
693 persistent_ram_free(cxt->mprz);
695 persistent_ram_free(cxt->fprz);
697 persistent_ram_free(cxt->cprz);
699 ramoops_free_przs(cxt);
704 static int ramoops_remove(struct platform_device *pdev)
706 struct ramoops_context *cxt = &oops_cxt;
708 pstore_unregister(&cxt->pstore);
710 kfree(cxt->pstore.buf);
711 cxt->pstore.bufsize = 0;
713 persistent_ram_free(cxt->mprz);
714 persistent_ram_free(cxt->fprz);
715 persistent_ram_free(cxt->cprz);
716 ramoops_free_przs(cxt);
721 static const struct of_device_id dt_match[] = {
722 { .compatible = "ramoops" },
726 static struct platform_driver ramoops_driver = {
727 .probe = ramoops_probe,
728 .remove = ramoops_remove,
731 .of_match_table = dt_match,
735 static void ramoops_register_dummy(void)
740 pr_info("using module parameters\n");
742 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
744 pr_info("could not allocate pdata\n");
748 dummy_data->mem_size = mem_size;
749 dummy_data->mem_address = mem_address;
750 dummy_data->mem_type = mem_type;
751 dummy_data->record_size = record_size;
752 dummy_data->console_size = ramoops_console_size;
753 dummy_data->ftrace_size = ramoops_ftrace_size;
754 dummy_data->pmsg_size = ramoops_pmsg_size;
755 dummy_data->dump_oops = dump_oops;
757 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
758 * (using 1 byte for ECC isn't much of use anyway).
760 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
762 dummy = platform_device_register_data(NULL, "ramoops", -1,
763 dummy_data, sizeof(struct ramoops_platform_data));
765 pr_info("could not create platform device: %ld\n",
770 static int __init ramoops_init(void)
772 ramoops_register_dummy();
773 return platform_driver_register(&ramoops_driver);
775 postcore_initcall(ramoops_init);
777 static void __exit ramoops_exit(void)
779 platform_driver_unregister(&ramoops_driver);
780 platform_device_unregister(dummy);
783 module_exit(ramoops_exit);
785 MODULE_LICENSE("GPL");
786 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
787 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");