Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1/*
2 * RAM Oops/Panic logger
3 *
4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
18 * 02110-1301 USA
19 *
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/kmsg_dump.h>
25#include <linux/time.h>
26#include <linux/io.h>
27#include <linux/ioport.h>
28
29#define RAMOOPS_KERNMSG_HDR "===="
30#define RAMOOPS_HEADER_SIZE (5 + sizeof(struct timeval))
31
32#define RECORD_SIZE 4096
33
34static ulong mem_address;
35module_param(mem_address, ulong, 0400);
36MODULE_PARM_DESC(mem_address,
37 "start of reserved RAM used to store oops/panic logs");
38
39static ulong mem_size;
40module_param(mem_size, ulong, 0400);
41MODULE_PARM_DESC(mem_size,
42 "size of reserved RAM used to store oops/panic logs");
43
44static int dump_oops = 1;
45module_param(dump_oops, int, 0600);
46MODULE_PARM_DESC(dump_oops,
47 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
48
49static struct ramoops_context {
50 struct kmsg_dumper dump;
51 void *virt_addr;
52 phys_addr_t phys_addr;
53 unsigned long size;
54 int count;
55 int max_count;
56} oops_cxt;
57
58static void ramoops_do_dump(struct kmsg_dumper *dumper,
59 enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
60 const char *s2, unsigned long l2)
61{
62 struct ramoops_context *cxt = container_of(dumper,
63 struct ramoops_context, dump);
64 unsigned long s1_start, s2_start;
65 unsigned long l1_cpy, l2_cpy;
66 int res;
67 char *buf;
68 struct timeval timestamp;
69
70 /* Only dump oopses if dump_oops is set */
71 if (reason == KMSG_DUMP_OOPS && !dump_oops)
72 return;
73
74 buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE));
75 memset(buf, '\0', RECORD_SIZE);
76 res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
77 buf += res;
78 do_gettimeofday(×tamp);
79 res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
80 buf += res;
81
82 l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE));
83 l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE) - l2_cpy);
84
85 s2_start = l2 - l2_cpy;
86 s1_start = l1 - l1_cpy;
87
88 memcpy(buf, s1 + s1_start, l1_cpy);
89 memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
90
91 cxt->count = (cxt->count + 1) % cxt->max_count;
92}
93
94static int __init ramoops_init(void)
95{
96 struct ramoops_context *cxt = &oops_cxt;
97 int err = -EINVAL;
98
99 if (!mem_size) {
100 printk(KERN_ERR "ramoops: invalid size specification");
101 goto fail3;
102 }
103
104 rounddown_pow_of_two(mem_size);
105
106 if (mem_size < RECORD_SIZE) {
107 printk(KERN_ERR "ramoops: size too small");
108 goto fail3;
109 }
110
111 cxt->max_count = mem_size / RECORD_SIZE;
112 cxt->count = 0;
113 cxt->size = mem_size;
114 cxt->phys_addr = mem_address;
115
116 if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
117 printk(KERN_ERR "ramoops: request mem region failed");
118 err = -EINVAL;
119 goto fail3;
120 }
121
122 cxt->virt_addr = ioremap(cxt->phys_addr, cxt->size);
123 if (!cxt->virt_addr) {
124 printk(KERN_ERR "ramoops: ioremap failed");
125 goto fail2;
126 }
127
128 cxt->dump.dump = ramoops_do_dump;
129 err = kmsg_dump_register(&cxt->dump);
130 if (err) {
131 printk(KERN_ERR "ramoops: registering kmsg dumper failed");
132 goto fail1;
133 }
134
135 return 0;
136
137fail1:
138 iounmap(cxt->virt_addr);
139fail2:
140 release_mem_region(cxt->phys_addr, cxt->size);
141fail3:
142 return err;
143}
144
145static void __exit ramoops_exit(void)
146{
147 struct ramoops_context *cxt = &oops_cxt;
148
149 if (kmsg_dump_unregister(&cxt->dump) < 0)
150 printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
151
152 iounmap(cxt->virt_addr);
153 release_mem_region(cxt->phys_addr, cxt->size);
154}
155
156
157module_init(ramoops_init);
158module_exit(ramoops_exit);
159
160MODULE_LICENSE("GPL");
161MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
162MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");