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");