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;
87 unsigned int max_dump_cnt;
88 unsigned int dump_write_cnt;
89 unsigned int dump_read_cnt;
90 unsigned int console_read_cnt;
91 unsigned int ftrace_read_cnt;
92 struct pstore_info pstore;
95 static struct platform_device *dummy;
96 static struct ramoops_platform_data *dummy_data;
98 static int ramoops_pstore_open(struct pstore_info *psi)
100 struct ramoops_context *cxt = psi->data;
102 cxt->dump_read_cnt = 0;
103 cxt->console_read_cnt = 0;
107 static struct persistent_ram_zone *
108 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
110 enum pstore_type_id *typep, enum pstore_type_id type,
113 struct persistent_ram_zone *prz;
122 /* Update old/shadowed buffer. */
123 persistent_ram_save_old(prz);
124 if (!persistent_ram_old_size(prz))
134 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
135 int *count, struct timespec *time,
136 char **buf, 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);
184 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
185 enum kmsg_dump_reason reason,
186 u64 *id, unsigned int part,
187 const char *buf, size_t size,
188 struct pstore_info *psi)
190 struct ramoops_context *cxt = psi->data;
191 struct persistent_ram_zone *prz;
194 if (type == PSTORE_TYPE_CONSOLE) {
197 persistent_ram_write(cxt->cprz, buf, size);
199 } else if (type == PSTORE_TYPE_FTRACE) {
202 persistent_ram_write(cxt->fprz, buf, size);
206 if (type != PSTORE_TYPE_DMESG)
209 /* Out of the various dmesg dump types, ramoops is currently designed
210 * to only store crash logs, rather than storing general kernel logs.
212 if (reason != KMSG_DUMP_OOPS &&
213 reason != KMSG_DUMP_PANIC)
216 /* Skip Oopes when configured to do so. */
217 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
220 /* Explicitly only take the first part of any new crash.
221 * If our buffer is larger than kmsg_bytes, this can never happen,
222 * and if our buffer is smaller than kmsg_bytes, we don't want the
223 * report split across multiple records.
231 prz = cxt->przs[cxt->dump_write_cnt];
233 hlen = ramoops_write_kmsg_hdr(prz);
234 if (size + hlen > prz->buffer_size)
235 size = prz->buffer_size - hlen;
236 persistent_ram_write(prz, buf, size);
238 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
243 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
244 struct timespec time, struct pstore_info *psi)
246 struct ramoops_context *cxt = psi->data;
247 struct persistent_ram_zone *prz;
250 case PSTORE_TYPE_DMESG:
251 if (id >= cxt->max_dump_cnt)
255 case PSTORE_TYPE_CONSOLE:
258 case PSTORE_TYPE_FTRACE:
265 persistent_ram_free_old(prz);
266 persistent_ram_zap(prz);
271 static struct ramoops_context oops_cxt = {
273 .owner = THIS_MODULE,
275 .open = ramoops_pstore_open,
276 .read = ramoops_pstore_read,
277 .write_buf = ramoops_pstore_write_buf,
278 .erase = ramoops_pstore_erase,
282 static void ramoops_free_przs(struct ramoops_context *cxt)
289 for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
290 persistent_ram_free(cxt->przs[i]);
294 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
295 phys_addr_t *paddr, size_t dump_mem_sz)
300 if (!cxt->record_size)
303 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
304 dev_err(dev, "no room for dumps\n");
308 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
309 if (!cxt->max_dump_cnt)
312 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
315 dev_err(dev, "failed to initialize a prz array for dumps\n");
319 for (i = 0; i < cxt->max_dump_cnt; i++) {
320 size_t sz = cxt->record_size;
322 cxt->przs[i] = persistent_ram_new(*paddr, sz, 0, cxt->ecc_size);
323 if (IS_ERR(cxt->przs[i])) {
324 err = PTR_ERR(cxt->przs[i]);
325 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
326 sz, (unsigned long long)*paddr, err);
334 ramoops_free_przs(cxt);
338 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
339 struct persistent_ram_zone **prz,
340 phys_addr_t *paddr, size_t sz, u32 sig)
345 if (*paddr + sz - cxt->phys_addr > cxt->size) {
346 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
347 sz, (unsigned long long)*paddr,
348 cxt->size, (unsigned long long)cxt->phys_addr);
352 *prz = persistent_ram_new(*paddr, sz, sig, cxt->ecc_size);
354 int err = PTR_ERR(*prz);
356 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
357 sz, (unsigned long long)*paddr, err);
361 persistent_ram_zap(*prz);
368 static int ramoops_probe(struct platform_device *pdev)
370 struct device *dev = &pdev->dev;
371 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
372 struct ramoops_context *cxt = &oops_cxt;
377 /* Only a single ramoops area allowed at a time, so fail extra
380 if (cxt->max_dump_cnt)
383 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
384 !pdata->ftrace_size)) {
385 pr_err("The memory size and the record/console size must be "
390 if (!is_power_of_2(pdata->mem_size))
391 pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
392 if (!is_power_of_2(pdata->record_size))
393 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
394 if (!is_power_of_2(pdata->console_size))
395 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
396 if (!is_power_of_2(pdata->ftrace_size))
397 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
399 cxt->dump_read_cnt = 0;
400 cxt->size = pdata->mem_size;
401 cxt->phys_addr = pdata->mem_address;
402 cxt->record_size = pdata->record_size;
403 cxt->console_size = pdata->console_size;
404 cxt->ftrace_size = pdata->ftrace_size;
405 cxt->dump_oops = pdata->dump_oops;
406 cxt->ecc_size = pdata->ecc_size;
408 paddr = cxt->phys_addr;
410 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size;
411 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
415 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
416 cxt->console_size, 0);
420 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
425 if (!cxt->przs && !cxt->cprz && !cxt->fprz) {
426 pr_err("memory size too small, minimum is %zu\n",
427 cxt->console_size + cxt->record_size +
432 cxt->pstore.data = cxt;
434 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
435 * have to handle dumps, we must have at least record_size buffer. And
436 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
439 if (cxt->console_size)
440 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
441 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
442 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
443 spin_lock_init(&cxt->pstore.buf_lock);
444 if (!cxt->pstore.buf) {
445 pr_err("cannot allocate pstore buffer\n");
449 err = pstore_register(&cxt->pstore);
451 pr_err("registering with pstore failed\n");
456 * Update the module parameter variables as well so they are visible
457 * through /sys/module/ramoops/parameters/
459 mem_size = pdata->mem_size;
460 mem_address = pdata->mem_address;
461 record_size = pdata->record_size;
462 dump_oops = pdata->dump_oops;
464 pr_info("attached 0x%lx@0x%llx, ecc: %d\n",
465 cxt->size, (unsigned long long)cxt->phys_addr,
471 kfree(cxt->pstore.buf);
473 cxt->pstore.bufsize = 0;
474 cxt->max_dump_cnt = 0;
480 ramoops_free_przs(cxt);
485 static int __exit ramoops_remove(struct platform_device *pdev)
488 /* TODO(kees): We cannot unload ramoops since pstore doesn't support
491 struct ramoops_context *cxt = &oops_cxt;
493 iounmap(cxt->virt_addr);
494 release_mem_region(cxt->phys_addr, cxt->size);
495 cxt->max_dump_cnt = 0;
497 /* TODO(kees): When pstore supports unregistering, call it here. */
498 kfree(cxt->pstore.buf);
499 cxt->pstore.bufsize = 0;
506 static struct platform_driver ramoops_driver = {
507 .probe = ramoops_probe,
508 .remove = __exit_p(ramoops_remove),
511 .owner = THIS_MODULE,
515 static void ramoops_register_dummy(void)
520 pr_info("using module parameters\n");
522 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
524 pr_info("could not allocate pdata\n");
528 dummy_data->mem_size = mem_size;
529 dummy_data->mem_address = mem_address;
530 dummy_data->record_size = record_size;
531 dummy_data->console_size = ramoops_console_size;
532 dummy_data->ftrace_size = ramoops_ftrace_size;
533 dummy_data->dump_oops = dump_oops;
535 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
536 * (using 1 byte for ECC isn't much of use anyway).
538 dummy_data->ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
540 dummy = platform_device_register_data(NULL, "ramoops", -1,
541 dummy_data, sizeof(struct ramoops_platform_data));
543 pr_info("could not create platform device: %ld\n",
548 static int __init ramoops_init(void)
550 ramoops_register_dummy();
551 return platform_driver_register(&ramoops_driver);
553 postcore_initcall(ramoops_init);
555 static void __exit ramoops_exit(void)
557 platform_driver_unregister(&ramoops_driver);
558 platform_device_unregister(dummy);
561 module_exit(ramoops_exit);
563 MODULE_LICENSE("GPL");
564 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
565 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");