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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 | ||
34 | static ulong mem_address; | |
35 | module_param(mem_address, ulong, 0400); | |
36 | MODULE_PARM_DESC(mem_address, | |
37 | "start of reserved RAM used to store oops/panic logs"); | |
38 | ||
39 | static ulong mem_size; | |
40 | module_param(mem_size, ulong, 0400); | |
41 | MODULE_PARM_DESC(mem_size, | |
42 | "size of reserved RAM used to store oops/panic logs"); | |
43 | ||
44 | static int dump_oops = 1; | |
45 | module_param(dump_oops, int, 0600); | |
46 | MODULE_PARM_DESC(dump_oops, | |
47 | "set to 1 to dump oopses, 0 to only dump panics (default 1)"); | |
48 | ||
49 | static 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 | ||
58 | static 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 | ||
94 | static 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 | ||
137 | fail1: | |
138 | iounmap(cxt->virt_addr); | |
139 | fail2: | |
140 | release_mem_region(cxt->phys_addr, cxt->size); | |
141 | fail3: | |
142 | return err; | |
143 | } | |
144 | ||
145 | static 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 | ||
157 | module_init(ramoops_init); | |
158 | module_exit(ramoops_exit); | |
159 | ||
160 | MODULE_LICENSE("GPL"); | |
161 | MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>"); | |
162 | MODULE_DESCRIPTION("RAM Oops/Panic logger/driver"); |