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 unsigned long long mem_address
;
59 module_param(mem_address
, ullong
, 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 ssize_t
*ecc_notice_size
,
185 struct pstore_info
*psi
)
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);
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
];
322 hlen
= ramoops_write_kmsg_hdr(prz
, compressed
);
323 if (size
+ hlen
> prz
->buffer_size
)
324 size
= prz
->buffer_size
- hlen
;
325 persistent_ram_write(prz
, buf
, size
);
327 cxt
->dump_write_cnt
= (cxt
->dump_write_cnt
+ 1) % cxt
->max_dump_cnt
;
332 static int ramoops_pstore_erase(enum pstore_type_id type
, u64 id
, int count
,
333 struct timespec time
, struct pstore_info
*psi
)
335 struct ramoops_context
*cxt
= psi
->data
;
336 struct persistent_ram_zone
*prz
;
339 case PSTORE_TYPE_DMESG
:
340 if (id
>= cxt
->max_dump_cnt
)
344 case PSTORE_TYPE_CONSOLE
:
347 case PSTORE_TYPE_FTRACE
:
350 case PSTORE_TYPE_PMSG
:
357 persistent_ram_free_old(prz
);
358 persistent_ram_zap(prz
);
363 static struct ramoops_context oops_cxt
= {
365 .owner
= THIS_MODULE
,
367 .open
= ramoops_pstore_open
,
368 .read
= ramoops_pstore_read
,
369 .write_buf
= ramoops_pstore_write_buf
,
370 .erase
= ramoops_pstore_erase
,
374 static void ramoops_free_przs(struct ramoops_context
*cxt
)
378 cxt
->max_dump_cnt
= 0;
382 for (i
= 0; !IS_ERR_OR_NULL(cxt
->przs
[i
]); i
++)
383 persistent_ram_free(cxt
->przs
[i
]);
387 static int ramoops_init_przs(struct device
*dev
, struct ramoops_context
*cxt
,
388 phys_addr_t
*paddr
, size_t dump_mem_sz
)
393 if (!cxt
->record_size
)
396 if (*paddr
+ dump_mem_sz
- cxt
->phys_addr
> cxt
->size
) {
397 dev_err(dev
, "no room for dumps\n");
401 cxt
->max_dump_cnt
= dump_mem_sz
/ cxt
->record_size
;
402 if (!cxt
->max_dump_cnt
)
405 cxt
->przs
= kzalloc(sizeof(*cxt
->przs
) * cxt
->max_dump_cnt
,
408 dev_err(dev
, "failed to initialize a prz array for dumps\n");
412 for (i
= 0; i
< cxt
->max_dump_cnt
; i
++) {
413 cxt
->przs
[i
] = persistent_ram_new(*paddr
, cxt
->record_size
, 0,
416 if (IS_ERR(cxt
->przs
[i
])) {
417 err
= PTR_ERR(cxt
->przs
[i
]);
418 dev_err(dev
, "failed to request mem region (0x%zx@0x%llx): %d\n",
419 cxt
->record_size
, (unsigned long long)*paddr
, err
);
422 *paddr
+= cxt
->record_size
;
427 ramoops_free_przs(cxt
);
431 static int ramoops_init_prz(struct device
*dev
, struct ramoops_context
*cxt
,
432 struct persistent_ram_zone
**prz
,
433 phys_addr_t
*paddr
, size_t sz
, u32 sig
)
438 if (*paddr
+ sz
- cxt
->phys_addr
> cxt
->size
) {
439 dev_err(dev
, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
440 sz
, (unsigned long long)*paddr
,
441 cxt
->size
, (unsigned long long)cxt
->phys_addr
);
445 *prz
= persistent_ram_new(*paddr
, sz
, sig
, &cxt
->ecc_info
, cxt
->memtype
);
447 int err
= PTR_ERR(*prz
);
449 dev_err(dev
, "failed to request mem region (0x%zx@0x%llx): %d\n",
450 sz
, (unsigned long long)*paddr
, err
);
454 persistent_ram_zap(*prz
);
461 static int ramoops_probe(struct platform_device
*pdev
)
463 struct device
*dev
= &pdev
->dev
;
464 struct ramoops_platform_data
*pdata
= pdev
->dev
.platform_data
;
465 struct ramoops_context
*cxt
= &oops_cxt
;
470 /* Only a single ramoops area allowed at a time, so fail extra
473 if (cxt
->max_dump_cnt
)
476 if (!pdata
->mem_size
|| (!pdata
->record_size
&& !pdata
->console_size
&&
477 !pdata
->ftrace_size
&& !pdata
->pmsg_size
)) {
478 pr_err("The memory size and the record/console size must be "
483 if (pdata
->record_size
&& !is_power_of_2(pdata
->record_size
))
484 pdata
->record_size
= rounddown_pow_of_two(pdata
->record_size
);
485 if (pdata
->console_size
&& !is_power_of_2(pdata
->console_size
))
486 pdata
->console_size
= rounddown_pow_of_two(pdata
->console_size
);
487 if (pdata
->ftrace_size
&& !is_power_of_2(pdata
->ftrace_size
))
488 pdata
->ftrace_size
= rounddown_pow_of_two(pdata
->ftrace_size
);
489 if (pdata
->pmsg_size
&& !is_power_of_2(pdata
->pmsg_size
))
490 pdata
->pmsg_size
= rounddown_pow_of_two(pdata
->pmsg_size
);
492 cxt
->size
= pdata
->mem_size
;
493 cxt
->phys_addr
= pdata
->mem_address
;
494 cxt
->memtype
= pdata
->mem_type
;
495 cxt
->record_size
= pdata
->record_size
;
496 cxt
->console_size
= pdata
->console_size
;
497 cxt
->ftrace_size
= pdata
->ftrace_size
;
498 cxt
->pmsg_size
= pdata
->pmsg_size
;
499 cxt
->dump_oops
= pdata
->dump_oops
;
500 cxt
->ecc_info
= pdata
->ecc_info
;
502 paddr
= cxt
->phys_addr
;
504 dump_mem_sz
= cxt
->size
- cxt
->console_size
- cxt
->ftrace_size
506 err
= ramoops_init_przs(dev
, cxt
, &paddr
, dump_mem_sz
);
510 err
= ramoops_init_prz(dev
, cxt
, &cxt
->cprz
, &paddr
,
511 cxt
->console_size
, 0);
515 err
= ramoops_init_prz(dev
, cxt
, &cxt
->fprz
, &paddr
, cxt
->ftrace_size
,
520 err
= ramoops_init_prz(dev
, cxt
, &cxt
->mprz
, &paddr
, cxt
->pmsg_size
, 0);
524 cxt
->pstore
.data
= cxt
;
526 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
527 * have to handle dumps, we must have at least record_size buffer. And
528 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
531 if (cxt
->console_size
)
532 cxt
->pstore
.bufsize
= 1024; /* LOG_LINE_MAX */
533 cxt
->pstore
.bufsize
= max(cxt
->record_size
, cxt
->pstore
.bufsize
);
534 cxt
->pstore
.buf
= kmalloc(cxt
->pstore
.bufsize
, GFP_KERNEL
);
535 spin_lock_init(&cxt
->pstore
.buf_lock
);
536 if (!cxt
->pstore
.buf
) {
537 pr_err("cannot allocate pstore buffer\n");
542 err
= pstore_register(&cxt
->pstore
);
544 pr_err("registering with pstore failed\n");
549 * Update the module parameter variables as well so they are visible
550 * through /sys/module/ramoops/parameters/
552 mem_size
= pdata
->mem_size
;
553 mem_address
= pdata
->mem_address
;
554 record_size
= pdata
->record_size
;
555 dump_oops
= pdata
->dump_oops
;
556 ramoops_console_size
= pdata
->console_size
;
557 ramoops_pmsg_size
= pdata
->pmsg_size
;
558 ramoops_ftrace_size
= pdata
->ftrace_size
;
560 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
561 cxt
->size
, (unsigned long long)cxt
->phys_addr
,
562 cxt
->ecc_info
.ecc_size
, cxt
->ecc_info
.block_size
);
567 kfree(cxt
->pstore
.buf
);
569 cxt
->pstore
.bufsize
= 0;
576 ramoops_free_przs(cxt
);
581 static int ramoops_remove(struct platform_device
*pdev
)
583 struct ramoops_context
*cxt
= &oops_cxt
;
585 pstore_unregister(&cxt
->pstore
);
586 cxt
->max_dump_cnt
= 0;
588 kfree(cxt
->pstore
.buf
);
589 cxt
->pstore
.bufsize
= 0;
591 persistent_ram_free(cxt
->mprz
);
592 persistent_ram_free(cxt
->fprz
);
593 persistent_ram_free(cxt
->cprz
);
594 ramoops_free_przs(cxt
);
599 static struct platform_driver ramoops_driver
= {
600 .probe
= ramoops_probe
,
601 .remove
= ramoops_remove
,
607 static void ramoops_register_dummy(void)
612 pr_info("using module parameters\n");
614 dummy_data
= kzalloc(sizeof(*dummy_data
), GFP_KERNEL
);
616 pr_info("could not allocate pdata\n");
620 dummy_data
->mem_size
= mem_size
;
621 dummy_data
->mem_address
= mem_address
;
622 dummy_data
->mem_type
= mem_type
;
623 dummy_data
->record_size
= record_size
;
624 dummy_data
->console_size
= ramoops_console_size
;
625 dummy_data
->ftrace_size
= ramoops_ftrace_size
;
626 dummy_data
->pmsg_size
= ramoops_pmsg_size
;
627 dummy_data
->dump_oops
= dump_oops
;
629 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
630 * (using 1 byte for ECC isn't much of use anyway).
632 dummy_data
->ecc_info
.ecc_size
= ramoops_ecc
== 1 ? 16 : ramoops_ecc
;
634 dummy
= platform_device_register_data(NULL
, "ramoops", -1,
635 dummy_data
, sizeof(struct ramoops_platform_data
));
637 pr_info("could not create platform device: %ld\n",
642 static int __init
ramoops_init(void)
644 ramoops_register_dummy();
645 return platform_driver_register(&ramoops_driver
);
647 postcore_initcall(ramoops_init
);
649 static void __exit
ramoops_exit(void)
651 platform_driver_unregister(&ramoops_driver
);
652 platform_device_unregister(dummy
);
655 module_exit(ramoops_exit
);
657 MODULE_LICENSE("GPL");
658 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
659 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");