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 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 ssize_t ecc_notice_size
;
140 struct ramoops_context
*cxt
= psi
->data
;
141 struct persistent_ram_zone
*prz
;
143 prz
= ramoops_get_next_prz(cxt
->przs
, &cxt
->dump_read_cnt
,
144 cxt
->max_dump_cnt
, id
, type
,
145 PSTORE_TYPE_DMESG
, 1);
147 prz
= ramoops_get_next_prz(&cxt
->cprz
, &cxt
->console_read_cnt
,
148 1, id
, type
, PSTORE_TYPE_CONSOLE
, 0);
150 prz
= ramoops_get_next_prz(&cxt
->fprz
, &cxt
->ftrace_read_cnt
,
151 1, id
, type
, PSTORE_TYPE_FTRACE
, 0);
155 /* TODO(kees): Bogus time for the moment. */
159 size
= persistent_ram_old_size(prz
);
161 /* ECC correction notice */
162 ecc_notice_size
= persistent_ram_ecc_string(prz
, NULL
, 0);
164 *buf
= kmalloc(size
+ ecc_notice_size
+ 1, GFP_KERNEL
);
168 memcpy(*buf
, persistent_ram_old(prz
), size
);
169 persistent_ram_ecc_string(prz
, *buf
+ size
, ecc_notice_size
+ 1);
171 return size
+ ecc_notice_size
;
174 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone
*prz
)
177 struct timespec timestamp
;
180 /* Report zeroed timestamp if called before timekeeping has resumed. */
181 if (__getnstimeofday(×tamp
)) {
182 timestamp
.tv_sec
= 0;
183 timestamp
.tv_nsec
= 0;
185 hdr
= kasprintf(GFP_ATOMIC
, RAMOOPS_KERNMSG_HDR
"%lu.%lu\n",
186 (long)timestamp
.tv_sec
, (long)(timestamp
.tv_nsec
/ 1000));
188 len
= hdr
? strlen(hdr
) : 0;
189 persistent_ram_write(prz
, hdr
, len
);
195 static int notrace
ramoops_pstore_write_buf(enum pstore_type_id type
,
196 enum kmsg_dump_reason reason
,
197 u64
*id
, unsigned int part
,
199 size_t hsize
, size_t size
,
200 struct pstore_info
*psi
)
202 struct ramoops_context
*cxt
= psi
->data
;
203 struct persistent_ram_zone
*prz
;
206 if (type
== PSTORE_TYPE_CONSOLE
) {
209 persistent_ram_write(cxt
->cprz
, buf
, size
);
211 } else if (type
== PSTORE_TYPE_FTRACE
) {
214 persistent_ram_write(cxt
->fprz
, buf
, size
);
218 if (type
!= PSTORE_TYPE_DMESG
)
221 /* Out of the various dmesg dump types, ramoops is currently designed
222 * to only store crash logs, rather than storing general kernel logs.
224 if (reason
!= KMSG_DUMP_OOPS
&&
225 reason
!= KMSG_DUMP_PANIC
)
228 /* Skip Oopes when configured to do so. */
229 if (reason
== KMSG_DUMP_OOPS
&& !cxt
->dump_oops
)
232 /* Explicitly only take the first part of any new crash.
233 * If our buffer is larger than kmsg_bytes, this can never happen,
234 * and if our buffer is smaller than kmsg_bytes, we don't want the
235 * report split across multiple records.
243 prz
= cxt
->przs
[cxt
->dump_write_cnt
];
245 hlen
= ramoops_write_kmsg_hdr(prz
);
246 if (size
+ hlen
> prz
->buffer_size
)
247 size
= prz
->buffer_size
- hlen
;
248 persistent_ram_write(prz
, buf
, size
);
250 cxt
->dump_write_cnt
= (cxt
->dump_write_cnt
+ 1) % cxt
->max_dump_cnt
;
255 static int ramoops_pstore_erase(enum pstore_type_id type
, u64 id
, int count
,
256 struct timespec time
, struct pstore_info
*psi
)
258 struct ramoops_context
*cxt
= psi
->data
;
259 struct persistent_ram_zone
*prz
;
262 case PSTORE_TYPE_DMESG
:
263 if (id
>= cxt
->max_dump_cnt
)
267 case PSTORE_TYPE_CONSOLE
:
270 case PSTORE_TYPE_FTRACE
:
277 persistent_ram_free_old(prz
);
278 persistent_ram_zap(prz
);
283 static struct ramoops_context oops_cxt
= {
285 .owner
= THIS_MODULE
,
287 .open
= ramoops_pstore_open
,
288 .read
= ramoops_pstore_read
,
289 .write_buf
= ramoops_pstore_write_buf
,
290 .erase
= ramoops_pstore_erase
,
294 static void ramoops_free_przs(struct ramoops_context
*cxt
)
301 for (i
= 0; !IS_ERR_OR_NULL(cxt
->przs
[i
]); i
++)
302 persistent_ram_free(cxt
->przs
[i
]);
306 static int ramoops_init_przs(struct device
*dev
, struct ramoops_context
*cxt
,
307 phys_addr_t
*paddr
, size_t dump_mem_sz
)
312 if (!cxt
->record_size
)
315 if (*paddr
+ dump_mem_sz
- cxt
->phys_addr
> cxt
->size
) {
316 dev_err(dev
, "no room for dumps\n");
320 cxt
->max_dump_cnt
= dump_mem_sz
/ cxt
->record_size
;
321 if (!cxt
->max_dump_cnt
)
324 cxt
->przs
= kzalloc(sizeof(*cxt
->przs
) * cxt
->max_dump_cnt
,
327 dev_err(dev
, "failed to initialize a prz array for dumps\n");
331 for (i
= 0; i
< cxt
->max_dump_cnt
; i
++) {
332 size_t sz
= cxt
->record_size
;
334 cxt
->przs
[i
] = persistent_ram_new(*paddr
, sz
, 0,
336 if (IS_ERR(cxt
->przs
[i
])) {
337 err
= PTR_ERR(cxt
->przs
[i
]);
338 dev_err(dev
, "failed to request mem region (0x%zx@0x%llx): %d\n",
339 sz
, (unsigned long long)*paddr
, err
);
347 ramoops_free_przs(cxt
);
351 static int ramoops_init_prz(struct device
*dev
, struct ramoops_context
*cxt
,
352 struct persistent_ram_zone
**prz
,
353 phys_addr_t
*paddr
, size_t sz
, u32 sig
)
358 if (*paddr
+ sz
- cxt
->phys_addr
> cxt
->size
) {
359 dev_err(dev
, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
360 sz
, (unsigned long long)*paddr
,
361 cxt
->size
, (unsigned long long)cxt
->phys_addr
);
365 *prz
= persistent_ram_new(*paddr
, sz
, sig
, &cxt
->ecc_info
);
367 int err
= PTR_ERR(*prz
);
369 dev_err(dev
, "failed to request mem region (0x%zx@0x%llx): %d\n",
370 sz
, (unsigned long long)*paddr
, err
);
374 persistent_ram_zap(*prz
);
381 static int ramoops_probe(struct platform_device
*pdev
)
383 struct device
*dev
= &pdev
->dev
;
384 struct ramoops_platform_data
*pdata
= pdev
->dev
.platform_data
;
385 struct ramoops_context
*cxt
= &oops_cxt
;
390 /* Only a single ramoops area allowed at a time, so fail extra
393 if (cxt
->max_dump_cnt
)
396 if (!pdata
->mem_size
|| (!pdata
->record_size
&& !pdata
->console_size
&&
397 !pdata
->ftrace_size
)) {
398 pr_err("The memory size and the record/console size must be "
403 if (!is_power_of_2(pdata
->record_size
))
404 pdata
->record_size
= rounddown_pow_of_two(pdata
->record_size
);
405 if (!is_power_of_2(pdata
->console_size
))
406 pdata
->console_size
= rounddown_pow_of_two(pdata
->console_size
);
407 if (!is_power_of_2(pdata
->ftrace_size
))
408 pdata
->ftrace_size
= rounddown_pow_of_two(pdata
->ftrace_size
);
410 cxt
->dump_read_cnt
= 0;
411 cxt
->size
= pdata
->mem_size
;
412 cxt
->phys_addr
= pdata
->mem_address
;
413 cxt
->record_size
= pdata
->record_size
;
414 cxt
->console_size
= pdata
->console_size
;
415 cxt
->ftrace_size
= pdata
->ftrace_size
;
416 cxt
->dump_oops
= pdata
->dump_oops
;
417 cxt
->ecc_info
= pdata
->ecc_info
;
419 paddr
= cxt
->phys_addr
;
421 dump_mem_sz
= cxt
->size
- cxt
->console_size
- cxt
->ftrace_size
;
422 err
= ramoops_init_przs(dev
, cxt
, &paddr
, dump_mem_sz
);
426 err
= ramoops_init_prz(dev
, cxt
, &cxt
->cprz
, &paddr
,
427 cxt
->console_size
, 0);
431 err
= ramoops_init_prz(dev
, cxt
, &cxt
->fprz
, &paddr
, cxt
->ftrace_size
,
436 if (!cxt
->przs
&& !cxt
->cprz
&& !cxt
->fprz
) {
437 pr_err("memory size too small, minimum is %zu\n",
438 cxt
->console_size
+ cxt
->record_size
+
444 cxt
->pstore
.data
= cxt
;
446 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
447 * have to handle dumps, we must have at least record_size buffer. And
448 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
451 if (cxt
->console_size
)
452 cxt
->pstore
.bufsize
= 1024; /* LOG_LINE_MAX */
453 cxt
->pstore
.bufsize
= max(cxt
->record_size
, cxt
->pstore
.bufsize
);
454 cxt
->pstore
.buf
= kmalloc(cxt
->pstore
.bufsize
, GFP_KERNEL
);
455 spin_lock_init(&cxt
->pstore
.buf_lock
);
456 if (!cxt
->pstore
.buf
) {
457 pr_err("cannot allocate pstore buffer\n");
462 err
= pstore_register(&cxt
->pstore
);
464 pr_err("registering with pstore failed\n");
469 * Update the module parameter variables as well so they are visible
470 * through /sys/module/ramoops/parameters/
472 mem_size
= pdata
->mem_size
;
473 mem_address
= pdata
->mem_address
;
474 record_size
= pdata
->record_size
;
475 dump_oops
= pdata
->dump_oops
;
477 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
478 cxt
->size
, (unsigned long long)cxt
->phys_addr
,
479 cxt
->ecc_info
.ecc_size
, cxt
->ecc_info
.block_size
);
484 kfree(cxt
->pstore
.buf
);
486 cxt
->pstore
.bufsize
= 0;
487 cxt
->max_dump_cnt
= 0;
493 ramoops_free_przs(cxt
);
498 static int __exit
ramoops_remove(struct platform_device
*pdev
)
501 /* TODO(kees): We cannot unload ramoops since pstore doesn't support
504 struct ramoops_context
*cxt
= &oops_cxt
;
506 iounmap(cxt
->virt_addr
);
507 release_mem_region(cxt
->phys_addr
, cxt
->size
);
508 cxt
->max_dump_cnt
= 0;
510 /* TODO(kees): When pstore supports unregistering, call it here. */
511 kfree(cxt
->pstore
.buf
);
512 cxt
->pstore
.bufsize
= 0;
519 static struct platform_driver ramoops_driver
= {
520 .probe
= ramoops_probe
,
521 .remove
= __exit_p(ramoops_remove
),
524 .owner
= THIS_MODULE
,
528 static void ramoops_register_dummy(void)
533 pr_info("using module parameters\n");
535 dummy_data
= kzalloc(sizeof(*dummy_data
), GFP_KERNEL
);
537 pr_info("could not allocate pdata\n");
541 dummy_data
->mem_size
= mem_size
;
542 dummy_data
->mem_address
= mem_address
;
543 dummy_data
->record_size
= record_size
;
544 dummy_data
->console_size
= ramoops_console_size
;
545 dummy_data
->ftrace_size
= ramoops_ftrace_size
;
546 dummy_data
->dump_oops
= dump_oops
;
548 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
549 * (using 1 byte for ECC isn't much of use anyway).
551 dummy_data
->ecc_info
.ecc_size
= ramoops_ecc
== 1 ? 16 : ramoops_ecc
;
553 dummy
= platform_device_register_data(NULL
, "ramoops", -1,
554 dummy_data
, sizeof(struct ramoops_platform_data
));
556 pr_info("could not create platform device: %ld\n",
561 static int __init
ramoops_init(void)
563 ramoops_register_dummy();
564 return platform_driver_register(&ramoops_driver
);
566 postcore_initcall(ramoops_init
);
568 static void __exit
ramoops_exit(void)
570 platform_driver_unregister(&ramoops_driver
);
571 platform_device_unregister(dummy
);
574 module_exit(ramoops_exit
);
576 MODULE_LICENSE("GPL");
577 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
578 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");