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 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");
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");
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)");
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 "
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;
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;
96 static struct platform_device *dummy;
97 static struct ramoops_platform_data *dummy_data;
99 static int ramoops_pstore_open(struct pstore_info *psi)
101 struct ramoops_context *cxt = psi->data;
103 cxt->dump_read_cnt = 0;
104 cxt->console_read_cnt = 0;
105 cxt->ftrace_read_cnt = 0;
109 static struct persistent_ram_zone *
110 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
112 enum pstore_type_id *typep, enum pstore_type_id type,
115 struct persistent_ram_zone *prz;
125 /* Update old/shadowed buffer. */
127 persistent_ram_save_old(prz);
129 if (!persistent_ram_old_size(prz))
138 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
142 int header_length = 0;
144 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
145 &time->tv_nsec, &data_type, &header_length) == 3) {
146 if (data_type == 'C')
150 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
151 &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
158 return header_length;
161 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
162 int *count, struct timespec *time,
163 char **buf, bool *compressed,
164 struct pstore_info *psi)
167 ssize_t ecc_notice_size;
168 struct ramoops_context *cxt = psi->data;
169 struct persistent_ram_zone *prz;
172 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
173 cxt->max_dump_cnt, id, type,
174 PSTORE_TYPE_DMESG, 1);
176 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
177 1, id, type, PSTORE_TYPE_CONSOLE, 0);
179 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
180 1, id, type, PSTORE_TYPE_FTRACE, 0);
184 if (!persistent_ram_old(prz))
187 size = persistent_ram_old_size(prz);
188 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time,
190 size -= header_length;
192 /* ECC correction notice */
193 ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
195 *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL);
199 memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
200 persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
202 return size + ecc_notice_size;
205 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
209 struct timespec timestamp;
212 /* Report zeroed timestamp if called before timekeeping has resumed. */
213 if (__getnstimeofday(×tamp)) {
214 timestamp.tv_sec = 0;
215 timestamp.tv_nsec = 0;
217 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
218 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
219 compressed ? 'C' : 'D');
221 len = hdr ? strlen(hdr) : 0;
222 persistent_ram_write(prz, hdr, len);
228 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
229 enum kmsg_dump_reason reason,
230 u64 *id, unsigned int part,
232 bool compressed, size_t size,
233 struct pstore_info *psi)
235 struct ramoops_context *cxt = psi->data;
236 struct persistent_ram_zone *prz;
239 if (type == PSTORE_TYPE_CONSOLE) {
242 persistent_ram_write(cxt->cprz, buf, size);
244 } else if (type == PSTORE_TYPE_FTRACE) {
247 persistent_ram_write(cxt->fprz, buf, size);
251 if (type != PSTORE_TYPE_DMESG)
254 /* Out of the various dmesg dump types, ramoops is currently designed
255 * to only store crash logs, rather than storing general kernel logs.
257 if (reason != KMSG_DUMP_OOPS &&
258 reason != KMSG_DUMP_PANIC)
261 /* Skip Oopes when configured to do so. */
262 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
265 /* Explicitly only take the first part of any new crash.
266 * If our buffer is larger than kmsg_bytes, this can never happen,
267 * and if our buffer is smaller than kmsg_bytes, we don't want the
268 * report split across multiple records.
276 prz = cxt->przs[cxt->dump_write_cnt];
278 hlen = ramoops_write_kmsg_hdr(prz, compressed);
279 if (size + hlen > prz->buffer_size)
280 size = prz->buffer_size - hlen;
281 persistent_ram_write(prz, buf, size);
283 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
288 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
289 struct timespec time, struct pstore_info *psi)
291 struct ramoops_context *cxt = psi->data;
292 struct persistent_ram_zone *prz;
295 case PSTORE_TYPE_DMESG:
296 if (id >= cxt->max_dump_cnt)
300 case PSTORE_TYPE_CONSOLE:
303 case PSTORE_TYPE_FTRACE:
310 persistent_ram_free_old(prz);
311 persistent_ram_zap(prz);
316 static struct ramoops_context oops_cxt = {
318 .owner = THIS_MODULE,
320 .open = ramoops_pstore_open,
321 .read = ramoops_pstore_read,
322 .write_buf = ramoops_pstore_write_buf,
323 .erase = ramoops_pstore_erase,
327 static void ramoops_free_przs(struct ramoops_context *cxt)
331 cxt->max_dump_cnt = 0;
335 for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
336 persistent_ram_free(cxt->przs[i]);
340 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
341 phys_addr_t *paddr, size_t dump_mem_sz)
346 if (!cxt->record_size)
349 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
350 dev_err(dev, "no room for dumps\n");
354 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
355 if (!cxt->max_dump_cnt)
358 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
361 dev_err(dev, "failed to initialize a prz array for dumps\n");
365 for (i = 0; i < cxt->max_dump_cnt; i++) {
366 size_t sz = cxt->record_size;
368 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0,
370 if (IS_ERR(cxt->przs[i])) {
371 err = PTR_ERR(cxt->przs[i]);
372 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
373 sz, (unsigned long long)*paddr, err);
381 ramoops_free_przs(cxt);
385 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
386 struct persistent_ram_zone **prz,
387 phys_addr_t *paddr, size_t sz, u32 sig)
392 if (*paddr + sz - cxt->phys_addr > cxt->size) {
393 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
394 sz, (unsigned long long)*paddr,
395 cxt->size, (unsigned long long)cxt->phys_addr);
399 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info);
401 int err = PTR_ERR(*prz);
403 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
404 sz, (unsigned long long)*paddr, err);
408 persistent_ram_zap(*prz);
415 static int ramoops_probe(struct platform_device *pdev)
417 struct device *dev = &pdev->dev;
418 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
419 struct ramoops_context *cxt = &oops_cxt;
424 /* Only a single ramoops area allowed at a time, so fail extra
427 if (cxt->max_dump_cnt)
430 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
431 !pdata->ftrace_size)) {
432 pr_err("The memory size and the record/console size must be "
437 if (pdata->record_size && !is_power_of_2(pdata->record_size))
438 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
439 if (pdata->console_size && !is_power_of_2(pdata->console_size))
440 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
441 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
442 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
444 cxt->size = pdata->mem_size;
445 cxt->phys_addr = pdata->mem_address;
446 cxt->record_size = pdata->record_size;
447 cxt->console_size = pdata->console_size;
448 cxt->ftrace_size = pdata->ftrace_size;
449 cxt->dump_oops = pdata->dump_oops;
450 cxt->ecc_info = pdata->ecc_info;
452 paddr = cxt->phys_addr;
454 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
455 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
459 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
460 cxt->console_size, 0);
464 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
469 if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
470 pr_err("memory size too small, minimum is %zu\n",
471 cxt->console_size + cxt->record_size +
477 cxt->pstore.data = cxt;
479 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
480 * have to handle dumps, we must have at least record_size buffer. And
481 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
484 if (cxt->console_size)
485 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
486 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
487 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
488 spin_lock_init(&cxt->pstore.buf_lock);
489 if (!cxt->pstore.buf) {
490 pr_err("cannot allocate pstore buffer\n");
495 err = pstore_register(&cxt->pstore);
497 pr_err("registering with pstore failed\n");
502 * Update the module parameter variables as well so they are visible
503 * through /sys/module/ramoops/parameters/
505 mem_size = pdata->mem_size;
506 mem_address = pdata->mem_address;
507 record_size = pdata->record_size;
508 dump_oops = pdata->dump_oops;
510 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
511 cxt->size, (unsigned long long)cxt->phys_addr,
512 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
517 kfree(cxt->pstore.buf);
519 cxt->pstore.bufsize = 0;
525 ramoops_free_przs(cxt);
530 static int __exit ramoops_remove(struct platform_device *pdev)
533 /* TODO(kees): We cannot unload ramoops since pstore doesn't support
536 struct ramoops_context *cxt = &oops_cxt;
538 iounmap(cxt->virt_addr);
539 release_mem_region(cxt->phys_addr, cxt->size);
540 cxt->max_dump_cnt = 0;
542 /* TODO(kees): When pstore supports unregistering, call it here. */
543 kfree(cxt->pstore.buf);
544 cxt->pstore.bufsize = 0;
551 static struct platform_driver ramoops_driver = {
552 .probe = ramoops_probe,
553 .remove = __exit_p(ramoops_remove),
556 .owner = THIS_MODULE,
560 static void ramoops_register_dummy(void)
565 pr_info("using module parameters\n");
567 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
569 pr_info("could not allocate pdata\n");
573 dummy_data->mem_size = mem_size;
574 dummy_data->mem_address = mem_address;
575 dummy_data->record_size = record_size;
576 dummy_data->console_size = ramoops_console_size;
577 dummy_data->ftrace_size = ramoops_ftrace_size;
578 dummy_data->dump_oops = dump_oops;
580 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
581 * (using 1 byte for ECC isn't much of use anyway).
583 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
585 dummy = platform_device_register_data(NULL, "ramoops", -1,
586 dummy_data, sizeof(struct ramoops_platform_data));
588 pr_info("could not create platform device: %ld\n",
593 static int __init ramoops_init(void)
595 ramoops_register_dummy();
596 return platform_driver_register(&ramoops_driver);
598 postcore_initcall(ramoops_init);
600 static void __exit ramoops_exit(void)
602 platform_driver_unregister(&ramoops_driver);
603 platform_device_unregister(dummy);
606 module_exit(ramoops_exit);
608 MODULE_LICENSE("GPL");
609 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
610 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");