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/pstore_ram.h>
37 #define RAMOOPS_KERNMSG_HDR "===="
38 #define MIN_MEM_SIZE 4096UL
40 static ulong record_size = MIN_MEM_SIZE;
41 module_param(record_size, ulong, 0400);
42 MODULE_PARM_DESC(record_size,
43 "size of each dump done on oops/panic");
45 static ulong ramoops_console_size = MIN_MEM_SIZE;
46 module_param_named(console_size, ramoops_console_size, ulong, 0400);
47 MODULE_PARM_DESC(console_size, "size of kernel console log");
49 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
50 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
51 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
53 static ulong mem_address;
54 module_param(mem_address, ulong, 0400);
55 MODULE_PARM_DESC(mem_address,
56 "start of reserved RAM used to store oops/panic logs");
58 static ulong mem_size;
59 module_param(mem_size, ulong, 0400);
60 MODULE_PARM_DESC(mem_size,
61 "size of reserved RAM used to store oops/panic logs");
63 static int dump_oops = 1;
64 module_param(dump_oops, int, 0600);
65 MODULE_PARM_DESC(dump_oops,
66 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
68 static int ramoops_ecc;
69 module_param_named(ecc, ramoops_ecc, int, 0600);
70 MODULE_PARM_DESC(ramoops_ecc,
71 "if non-zero, the option enables ECC support and specifies "
72 "ECC buffer size in bytes (1 is a special value, means 16 "
75 struct ramoops_context {
76 struct persistent_ram_zone **przs;
77 struct persistent_ram_zone *cprz;
78 struct persistent_ram_zone *fprz;
79 phys_addr_t phys_addr;
86 unsigned int max_dump_cnt;
87 unsigned int dump_write_cnt;
88 unsigned int dump_read_cnt;
89 unsigned int console_read_cnt;
90 unsigned int ftrace_read_cnt;
91 struct pstore_info pstore;
94 static struct platform_device *dummy;
95 static struct ramoops_platform_data *dummy_data;
97 static int ramoops_pstore_open(struct pstore_info *psi)
99 struct ramoops_context *cxt = psi->data;
101 cxt->dump_read_cnt = 0;
102 cxt->console_read_cnt = 0;
106 static struct persistent_ram_zone *
107 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
109 enum pstore_type_id *typep, enum pstore_type_id type,
112 struct persistent_ram_zone *prz;
121 /* Update old/shadowed buffer. */
122 persistent_ram_save_old(prz);
123 if (!persistent_ram_old_size(prz))
133 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
134 struct timespec *time,
136 struct pstore_info *psi)
139 struct ramoops_context *cxt = psi->data;
140 struct persistent_ram_zone *prz;
142 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
143 cxt->max_dump_cnt, id, type,
144 PSTORE_TYPE_DMESG, 1);
146 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
147 1, id, type, PSTORE_TYPE_CONSOLE, 0);
149 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
150 1, id, type, PSTORE_TYPE_FTRACE, 0);
154 /* TODO(kees): Bogus time for the moment. */
158 size = persistent_ram_old_size(prz);
159 *buf = kmalloc(size, GFP_KERNEL);
162 memcpy(*buf, persistent_ram_old(prz), size);
167 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
170 struct timeval timestamp;
173 do_gettimeofday(×tamp);
174 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
175 (long)timestamp.tv_sec, (long)timestamp.tv_usec);
177 len = hdr ? strlen(hdr) : 0;
178 persistent_ram_write(prz, hdr, len);
185 static int ramoops_pstore_write_buf(enum pstore_type_id type,
186 enum kmsg_dump_reason reason,
187 u64 *id, unsigned int part,
188 const char *buf, size_t size,
189 struct pstore_info *psi)
191 struct ramoops_context *cxt = psi->data;
192 struct persistent_ram_zone *prz = cxt->przs[cxt->dump_write_cnt];
195 if (type == PSTORE_TYPE_CONSOLE) {
198 persistent_ram_write(cxt->cprz, buf, size);
200 } else if (type == PSTORE_TYPE_FTRACE) {
203 persistent_ram_write(cxt->fprz, buf, size);
207 if (type != PSTORE_TYPE_DMESG)
210 /* Out of the various dmesg dump types, ramoops is currently designed
211 * to only store crash logs, rather than storing general kernel logs.
213 if (reason != KMSG_DUMP_OOPS &&
214 reason != KMSG_DUMP_PANIC)
217 /* Skip Oopes when configured to do so. */
218 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
221 /* Explicitly only take the first part of any new crash.
222 * If our buffer is larger than kmsg_bytes, this can never happen,
223 * and if our buffer is smaller than kmsg_bytes, we don't want the
224 * report split across multiple records.
229 hlen = ramoops_write_kmsg_hdr(prz);
230 if (size + hlen > prz->buffer_size)
231 size = prz->buffer_size - hlen;
232 persistent_ram_write(prz, buf, size);
234 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
239 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id,
240 struct pstore_info *psi)
242 struct ramoops_context *cxt = psi->data;
243 struct persistent_ram_zone *prz;
246 case PSTORE_TYPE_DMESG:
247 if (id >= cxt->max_dump_cnt)
251 case PSTORE_TYPE_CONSOLE:
254 case PSTORE_TYPE_FTRACE:
261 persistent_ram_free_old(prz);
262 persistent_ram_zap(prz);
267 static struct ramoops_context oops_cxt = {
269 .owner = THIS_MODULE,
271 .open = ramoops_pstore_open,
272 .read = ramoops_pstore_read,
273 .write_buf = ramoops_pstore_write_buf,
274 .erase = ramoops_pstore_erase,
278 static void ramoops_free_przs(struct ramoops_context *cxt)
285 for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
286 persistent_ram_free(cxt->przs[i]);
290 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
291 phys_addr_t *paddr, size_t dump_mem_sz)
296 if (!cxt->record_size)
299 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
300 if (!cxt->max_dump_cnt)
303 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
306 dev_err(dev, "failed to initialize a prz array for dumps\n");
310 for (i = 0; i < cxt->max_dump_cnt; i++) {
311 size_t sz = cxt->record_size;
313 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, cxt->ecc_size);
314 if (IS_ERR(cxt->przs[i])) {
315 err = PTR_ERR(cxt->przs[i]);
316 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
317 sz, (unsigned long long)*paddr, err);
325 ramoops_free_przs(cxt);
329 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
330 struct persistent_ram_zone **prz,
331 phys_addr_t *paddr, size_t sz, u32 sig)
336 if (*paddr + sz > *paddr + cxt->size)
339 *prz = persistent_ram_new(*paddr, sz, sig, cxt->ecc_size);
341 int err = PTR_ERR(*prz);
343 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
344 sz, (unsigned long long)*paddr, err);
348 persistent_ram_zap(*prz);
355 static int __devinit ramoops_probe(struct platform_device *pdev)
357 struct device *dev = &pdev->dev;
358 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
359 struct ramoops_context *cxt = &oops_cxt;
364 /* Only a single ramoops area allowed at a time, so fail extra
367 if (cxt->max_dump_cnt)
370 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
371 !pdata->ftrace_size)) {
372 pr_err("The memory size and the record/console size must be "
377 pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
378 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
379 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
380 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
382 cxt->dump_read_cnt = 0;
383 cxt->size = pdata->mem_size;
384 cxt->phys_addr = pdata->mem_address;
385 cxt->record_size = pdata->record_size;
386 cxt->console_size = pdata->console_size;
387 cxt->ftrace_size = pdata->ftrace_size;
388 cxt->dump_oops = pdata->dump_oops;
389 cxt->ecc_size = pdata->ecc_size;
391 paddr = cxt->phys_addr;
393 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
394 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
398 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
399 cxt->console_size, 0);
403 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
408 if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
409 pr_err("memory size too small, minimum is %lu\n",
410 cxt->console_size + cxt->record_size +
415 cxt->pstore.data = cxt;
417 * Console can handle any buffer size, so prefer dumps buffer
418 * size since usually it is smaller.
421 cxt->pstore.bufsize = cxt->przs[0]->buffer_size;
423 cxt->pstore.bufsize = cxt->cprz->buffer_size;
424 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
425 spin_lock_init(&cxt->pstore.buf_lock);
426 if (!cxt->pstore.buf) {
427 pr_err("cannot allocate pstore buffer\n");
431 err = pstore_register(&cxt->pstore);
433 pr_err("registering with pstore failed\n");
438 * Update the module parameter variables as well so they are visible
439 * through /sys/module/ramoops/parameters/
441 mem_size = pdata->mem_size;
442 mem_address = pdata->mem_address;
443 record_size = pdata->record_size;
444 dump_oops = pdata->dump_oops;
446 pr_info("attached 0x%lx@0x%llx, ecc: %d\n",
447 cxt->size, (unsigned long long)cxt->phys_addr,
453 kfree(cxt->pstore.buf);
455 cxt->pstore.bufsize = 0;
456 cxt->max_dump_cnt = 0;
462 ramoops_free_przs(cxt);
467 static int __exit ramoops_remove(struct platform_device *pdev)
470 /* TODO(kees): We cannot unload ramoops since pstore doesn't support
473 struct ramoops_context *cxt = &oops_cxt;
475 iounmap(cxt->virt_addr);
476 release_mem_region(cxt->phys_addr, cxt->size);
477 cxt->max_dump_cnt = 0;
479 /* TODO(kees): When pstore supports unregistering, call it here. */
480 kfree(cxt->pstore.buf);
481 cxt->pstore.bufsize = 0;
488 static struct platform_driver ramoops_driver = {
489 .probe = ramoops_probe,
490 .remove = __exit_p(ramoops_remove),
493 .owner = THIS_MODULE,
497 static void ramoops_register_dummy(void)
502 pr_info("using module parameters\n");
504 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
506 pr_info("could not allocate pdata\n");
510 dummy_data->mem_size = mem_size;
511 dummy_data->mem_address = mem_address;
512 dummy_data->record_size = record_size;
513 dummy_data->console_size = ramoops_console_size;
514 dummy_data->ftrace_size = ramoops_ftrace_size;
515 dummy_data->dump_oops = dump_oops;
517 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
518 * (using 1 byte for ECC isn't much of use anyway).
520 dummy_data->ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
522 dummy = platform_device_register_data(NULL, "ramoops", -1,
523 dummy_data, sizeof(struct ramoops_platform_data));
525 pr_info("could not create platform device: %ld\n",
530 static int __init ramoops_init(void)
532 ramoops_register_dummy();
533 return platform_driver_register(&ramoops_driver);
535 postcore_initcall(ramoops_init);
537 static void __exit ramoops_exit(void)
539 platform_driver_unregister(&ramoops_driver);
542 module_exit(ramoops_exit);
544 MODULE_LICENSE("GPL");
545 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
546 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");