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
];
324 hlen
= ramoops_write_kmsg_hdr(prz
, compressed
);
325 if (size
+ hlen
> prz
->buffer_size
)
326 size
= prz
->buffer_size
- hlen
;
327 persistent_ram_write(prz
, buf
, size
);
329 cxt
->dump_write_cnt
= (cxt
->dump_write_cnt
+ 1) % cxt
->max_dump_cnt
;
334 static int notrace
ramoops_pstore_write_buf_user(enum pstore_type_id type
,
335 enum kmsg_dump_reason reason
,
336 u64
*id
, unsigned int part
,
337 const char __user
*buf
,
338 bool compressed
, size_t size
,
339 struct pstore_info
*psi
)
341 if (type
== PSTORE_TYPE_PMSG
) {
342 struct ramoops_context
*cxt
= psi
->data
;
346 return persistent_ram_write_user(cxt
->mprz
, buf
, size
);
352 static int ramoops_pstore_erase(enum pstore_type_id type
, u64 id
, int count
,
353 struct timespec time
, struct pstore_info
*psi
)
355 struct ramoops_context
*cxt
= psi
->data
;
356 struct persistent_ram_zone
*prz
;
359 case PSTORE_TYPE_DMESG
:
360 if (id
>= cxt
->max_dump_cnt
)
364 case PSTORE_TYPE_CONSOLE
:
367 case PSTORE_TYPE_FTRACE
:
370 case PSTORE_TYPE_PMSG
:
377 persistent_ram_free_old(prz
);
378 persistent_ram_zap(prz
);
383 static struct ramoops_context oops_cxt
= {
385 .owner
= THIS_MODULE
,
387 .open
= ramoops_pstore_open
,
388 .read
= ramoops_pstore_read
,
389 .write_buf
= ramoops_pstore_write_buf
,
390 .write_buf_user
= ramoops_pstore_write_buf_user
,
391 .erase
= ramoops_pstore_erase
,
395 static void ramoops_free_przs(struct ramoops_context
*cxt
)
402 for (i
= 0; i
< cxt
->max_dump_cnt
; i
++)
403 persistent_ram_free(cxt
->przs
[i
]);
406 cxt
->max_dump_cnt
= 0;
409 static int ramoops_init_przs(struct device
*dev
, struct ramoops_context
*cxt
,
410 phys_addr_t
*paddr
, size_t dump_mem_sz
)
415 if (!cxt
->record_size
)
418 if (*paddr
+ dump_mem_sz
- cxt
->phys_addr
> cxt
->size
) {
419 dev_err(dev
, "no room for dumps\n");
423 cxt
->max_dump_cnt
= dump_mem_sz
/ cxt
->record_size
;
424 if (!cxt
->max_dump_cnt
)
427 cxt
->przs
= kzalloc(sizeof(*cxt
->przs
) * cxt
->max_dump_cnt
,
430 dev_err(dev
, "failed to initialize a prz array for dumps\n");
434 for (i
= 0; i
< cxt
->max_dump_cnt
; i
++) {
435 cxt
->przs
[i
] = persistent_ram_new(*paddr
, cxt
->record_size
, 0,
438 if (IS_ERR(cxt
->przs
[i
])) {
439 err
= PTR_ERR(cxt
->przs
[i
]);
440 dev_err(dev
, "failed to request mem region (0x%zx@0x%llx): %d\n",
441 cxt
->record_size
, (unsigned long long)*paddr
, err
);
445 persistent_ram_free(cxt
->przs
[i
]);
449 *paddr
+= cxt
->record_size
;
456 cxt
->max_dump_cnt
= 0;
460 static int ramoops_init_prz(struct device
*dev
, struct ramoops_context
*cxt
,
461 struct persistent_ram_zone
**prz
,
462 phys_addr_t
*paddr
, size_t sz
, u32 sig
)
467 if (*paddr
+ sz
- cxt
->phys_addr
> cxt
->size
) {
468 dev_err(dev
, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
469 sz
, (unsigned long long)*paddr
,
470 cxt
->size
, (unsigned long long)cxt
->phys_addr
);
474 *prz
= persistent_ram_new(*paddr
, sz
, sig
, &cxt
->ecc_info
,
477 int err
= PTR_ERR(*prz
);
479 dev_err(dev
, "failed to request mem region (0x%zx@0x%llx): %d\n",
480 sz
, (unsigned long long)*paddr
, err
);
484 persistent_ram_zap(*prz
);
491 static int ramoops_parse_dt_size(struct platform_device
*pdev
,
492 const char *propname
, u32
*value
)
497 ret
= of_property_read_u32(pdev
->dev
.of_node
, propname
, &val32
);
498 if (ret
< 0 && ret
!= -EINVAL
) {
499 dev_err(&pdev
->dev
, "failed to parse property %s: %d\n",
504 if (val32
> INT_MAX
) {
505 dev_err(&pdev
->dev
, "%s %u > INT_MAX\n", propname
, val32
);
513 static int ramoops_parse_dt(struct platform_device
*pdev
,
514 struct ramoops_platform_data
*pdata
)
516 struct device_node
*of_node
= pdev
->dev
.of_node
;
517 struct resource
*res
;
521 dev_dbg(&pdev
->dev
, "using Device Tree\n");
523 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
526 "failed to locate DT /reserved-memory resource\n");
530 pdata
->mem_size
= resource_size(res
);
531 pdata
->mem_address
= res
->start
;
532 pdata
->mem_type
= of_property_read_bool(of_node
, "unbuffered");
533 pdata
->dump_oops
= !of_property_read_bool(of_node
, "no-dump-oops");
535 #define parse_size(name, field) { \
536 ret = ramoops_parse_dt_size(pdev, name, &value); \
542 parse_size("record-size", pdata
->record_size
);
543 parse_size("console-size", pdata
->console_size
);
544 parse_size("ftrace-size", pdata
->ftrace_size
);
545 parse_size("pmsg-size", pdata
->pmsg_size
);
546 parse_size("ecc-size", pdata
->ecc_info
.ecc_size
);
553 static int ramoops_probe(struct platform_device
*pdev
)
555 struct device
*dev
= &pdev
->dev
;
556 struct ramoops_platform_data
*pdata
= dev
->platform_data
;
557 struct ramoops_context
*cxt
= &oops_cxt
;
562 if (dev_of_node(dev
) && !pdata
) {
563 pdata
= devm_kzalloc(&pdev
->dev
, sizeof(*pdata
), GFP_KERNEL
);
569 err
= ramoops_parse_dt(pdev
, pdata
);
574 /* Only a single ramoops area allowed at a time, so fail extra
577 if (cxt
->max_dump_cnt
)
580 if (!pdata
->mem_size
|| (!pdata
->record_size
&& !pdata
->console_size
&&
581 !pdata
->ftrace_size
&& !pdata
->pmsg_size
)) {
582 pr_err("The memory size and the record/console size must be "
587 if (pdata
->record_size
&& !is_power_of_2(pdata
->record_size
))
588 pdata
->record_size
= rounddown_pow_of_two(pdata
->record_size
);
589 if (pdata
->console_size
&& !is_power_of_2(pdata
->console_size
))
590 pdata
->console_size
= rounddown_pow_of_two(pdata
->console_size
);
591 if (pdata
->ftrace_size
&& !is_power_of_2(pdata
->ftrace_size
))
592 pdata
->ftrace_size
= rounddown_pow_of_two(pdata
->ftrace_size
);
593 if (pdata
->pmsg_size
&& !is_power_of_2(pdata
->pmsg_size
))
594 pdata
->pmsg_size
= rounddown_pow_of_two(pdata
->pmsg_size
);
596 cxt
->size
= pdata
->mem_size
;
597 cxt
->phys_addr
= pdata
->mem_address
;
598 cxt
->memtype
= pdata
->mem_type
;
599 cxt
->record_size
= pdata
->record_size
;
600 cxt
->console_size
= pdata
->console_size
;
601 cxt
->ftrace_size
= pdata
->ftrace_size
;
602 cxt
->pmsg_size
= pdata
->pmsg_size
;
603 cxt
->dump_oops
= pdata
->dump_oops
;
604 cxt
->ecc_info
= pdata
->ecc_info
;
606 paddr
= cxt
->phys_addr
;
608 dump_mem_sz
= cxt
->size
- cxt
->console_size
- cxt
->ftrace_size
610 err
= ramoops_init_przs(dev
, cxt
, &paddr
, dump_mem_sz
);
614 err
= ramoops_init_prz(dev
, cxt
, &cxt
->cprz
, &paddr
,
615 cxt
->console_size
, 0);
619 err
= ramoops_init_prz(dev
, cxt
, &cxt
->fprz
, &paddr
, cxt
->ftrace_size
,
624 err
= ramoops_init_prz(dev
, cxt
, &cxt
->mprz
, &paddr
, cxt
->pmsg_size
, 0);
628 cxt
->pstore
.data
= cxt
;
630 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
631 * have to handle dumps, we must have at least record_size buffer. And
632 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
635 if (cxt
->console_size
)
636 cxt
->pstore
.bufsize
= 1024; /* LOG_LINE_MAX */
637 cxt
->pstore
.bufsize
= max(cxt
->record_size
, cxt
->pstore
.bufsize
);
638 cxt
->pstore
.buf
= kmalloc(cxt
->pstore
.bufsize
, GFP_KERNEL
);
639 if (!cxt
->pstore
.buf
) {
640 pr_err("cannot allocate pstore buffer\n");
644 spin_lock_init(&cxt
->pstore
.buf_lock
);
646 cxt
->pstore
.flags
= PSTORE_FLAGS_DMESG
;
647 if (cxt
->console_size
)
648 cxt
->pstore
.flags
|= PSTORE_FLAGS_CONSOLE
;
649 if (cxt
->ftrace_size
)
650 cxt
->pstore
.flags
|= PSTORE_FLAGS_FTRACE
;
652 cxt
->pstore
.flags
|= PSTORE_FLAGS_PMSG
;
654 err
= pstore_register(&cxt
->pstore
);
656 pr_err("registering with pstore failed\n");
661 * Update the module parameter variables as well so they are visible
662 * through /sys/module/ramoops/parameters/
664 mem_size
= pdata
->mem_size
;
665 mem_address
= pdata
->mem_address
;
666 record_size
= pdata
->record_size
;
667 dump_oops
= pdata
->dump_oops
;
668 ramoops_console_size
= pdata
->console_size
;
669 ramoops_pmsg_size
= pdata
->pmsg_size
;
670 ramoops_ftrace_size
= pdata
->ftrace_size
;
672 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
673 cxt
->size
, (unsigned long long)cxt
->phys_addr
,
674 cxt
->ecc_info
.ecc_size
, cxt
->ecc_info
.block_size
);
679 kfree(cxt
->pstore
.buf
);
681 cxt
->pstore
.bufsize
= 0;
682 persistent_ram_free(cxt
->mprz
);
684 persistent_ram_free(cxt
->fprz
);
686 persistent_ram_free(cxt
->cprz
);
688 ramoops_free_przs(cxt
);
693 static int ramoops_remove(struct platform_device
*pdev
)
695 struct ramoops_context
*cxt
= &oops_cxt
;
697 pstore_unregister(&cxt
->pstore
);
699 kfree(cxt
->pstore
.buf
);
700 cxt
->pstore
.bufsize
= 0;
702 persistent_ram_free(cxt
->mprz
);
703 persistent_ram_free(cxt
->fprz
);
704 persistent_ram_free(cxt
->cprz
);
705 ramoops_free_przs(cxt
);
710 static const struct of_device_id dt_match
[] = {
711 { .compatible
= "ramoops" },
715 static struct platform_driver ramoops_driver
= {
716 .probe
= ramoops_probe
,
717 .remove
= ramoops_remove
,
720 .of_match_table
= dt_match
,
724 static void ramoops_register_dummy(void)
729 pr_info("using module parameters\n");
731 dummy_data
= kzalloc(sizeof(*dummy_data
), GFP_KERNEL
);
733 pr_info("could not allocate pdata\n");
737 dummy_data
->mem_size
= mem_size
;
738 dummy_data
->mem_address
= mem_address
;
739 dummy_data
->mem_type
= mem_type
;
740 dummy_data
->record_size
= record_size
;
741 dummy_data
->console_size
= ramoops_console_size
;
742 dummy_data
->ftrace_size
= ramoops_ftrace_size
;
743 dummy_data
->pmsg_size
= ramoops_pmsg_size
;
744 dummy_data
->dump_oops
= dump_oops
;
746 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
747 * (using 1 byte for ECC isn't much of use anyway).
749 dummy_data
->ecc_info
.ecc_size
= ramoops_ecc
== 1 ? 16 : ramoops_ecc
;
751 dummy
= platform_device_register_data(NULL
, "ramoops", -1,
752 dummy_data
, sizeof(struct ramoops_platform_data
));
754 pr_info("could not create platform device: %ld\n",
759 static int __init
ramoops_init(void)
761 ramoops_register_dummy();
762 return platform_driver_register(&ramoops_driver
);
764 postcore_initcall(ramoops_init
);
766 static void __exit
ramoops_exit(void)
768 platform_driver_unregister(&ramoops_driver
);
769 platform_device_unregister(dummy
);
772 module_exit(ramoops_exit
);
774 MODULE_LICENSE("GPL");
775 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
776 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");