]> git.openfabrics.org - ~shefty/rdma-dev.git/blob - drivers/char/ramoops.c
RAMOOPS: Don't overflow over non-allocated regions
[~shefty/rdma-dev.git] / drivers / char / ramoops.c
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 #include <linux/platform_device.h>
29 #include <linux/ramoops.h>
30
31 #define RAMOOPS_KERNMSG_HDR "===="
32
33 #define RECORD_SIZE 4096
34
35 static ulong mem_address;
36 module_param(mem_address, ulong, 0400);
37 MODULE_PARM_DESC(mem_address,
38                 "start of reserved RAM used to store oops/panic logs");
39
40 static ulong mem_size;
41 module_param(mem_size, ulong, 0400);
42 MODULE_PARM_DESC(mem_size,
43                 "size of reserved RAM used to store oops/panic logs");
44
45 static int dump_oops = 1;
46 module_param(dump_oops, int, 0600);
47 MODULE_PARM_DESC(dump_oops,
48                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
49
50 static struct ramoops_context {
51         struct kmsg_dumper dump;
52         void *virt_addr;
53         phys_addr_t phys_addr;
54         unsigned long size;
55         int count;
56         int max_count;
57 } oops_cxt;
58
59 static void ramoops_do_dump(struct kmsg_dumper *dumper,
60                 enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
61                 const char *s2, unsigned long l2)
62 {
63         struct ramoops_context *cxt = container_of(dumper,
64                         struct ramoops_context, dump);
65         unsigned long s1_start, s2_start;
66         unsigned long l1_cpy, l2_cpy;
67         int res, hdr_size;
68         char *buf, *buf_orig;
69         struct timeval timestamp;
70
71         /* Only dump oopses if dump_oops is set */
72         if (reason == KMSG_DUMP_OOPS && !dump_oops)
73                 return;
74
75         buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE));
76         buf_orig = buf;
77
78         memset(buf, '\0', RECORD_SIZE);
79         res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR);
80         buf += res;
81         do_gettimeofday(&timestamp);
82         res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec);
83         buf += res;
84
85         hdr_size = buf - buf_orig;
86         l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - hdr_size));
87         l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - hdr_size) - l2_cpy);
88
89         s2_start = l2 - l2_cpy;
90         s1_start = l1 - l1_cpy;
91
92         memcpy(buf, s1 + s1_start, l1_cpy);
93         memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
94
95         cxt->count = (cxt->count + 1) % cxt->max_count;
96 }
97
98 static int __init ramoops_probe(struct platform_device *pdev)
99 {
100         struct ramoops_platform_data *pdata = pdev->dev.platform_data;
101         struct ramoops_context *cxt = &oops_cxt;
102         int err = -EINVAL;
103
104         if (pdata) {
105                 mem_size = pdata->mem_size;
106                 mem_address = pdata->mem_address;
107         }
108
109         if (!mem_size) {
110                 printk(KERN_ERR "ramoops: invalid size specification");
111                 goto fail3;
112         }
113
114         rounddown_pow_of_two(mem_size);
115
116         if (mem_size < RECORD_SIZE) {
117                 printk(KERN_ERR "ramoops: size too small");
118                 goto fail3;
119         }
120
121         cxt->max_count = mem_size / RECORD_SIZE;
122         cxt->count = 0;
123         cxt->size = mem_size;
124         cxt->phys_addr = mem_address;
125
126         if (!request_mem_region(cxt->phys_addr, cxt->size, "ramoops")) {
127                 printk(KERN_ERR "ramoops: request mem region failed");
128                 err = -EINVAL;
129                 goto fail3;
130         }
131
132         cxt->virt_addr = ioremap(cxt->phys_addr,  cxt->size);
133         if (!cxt->virt_addr) {
134                 printk(KERN_ERR "ramoops: ioremap failed");
135                 goto fail2;
136         }
137
138         cxt->dump.dump = ramoops_do_dump;
139         err = kmsg_dump_register(&cxt->dump);
140         if (err) {
141                 printk(KERN_ERR "ramoops: registering kmsg dumper failed");
142                 goto fail1;
143         }
144
145         return 0;
146
147 fail1:
148         iounmap(cxt->virt_addr);
149 fail2:
150         release_mem_region(cxt->phys_addr, cxt->size);
151 fail3:
152         return err;
153 }
154
155 static int __exit ramoops_remove(struct platform_device *pdev)
156 {
157         struct ramoops_context *cxt = &oops_cxt;
158
159         if (kmsg_dump_unregister(&cxt->dump) < 0)
160                 printk(KERN_WARNING "ramoops: could not unregister kmsg_dumper");
161
162         iounmap(cxt->virt_addr);
163         release_mem_region(cxt->phys_addr, cxt->size);
164         return 0;
165 }
166
167 static struct platform_driver ramoops_driver = {
168         .remove         = __exit_p(ramoops_remove),
169         .driver         = {
170                 .name   = "ramoops",
171                 .owner  = THIS_MODULE,
172         },
173 };
174
175 static int __init ramoops_init(void)
176 {
177         return platform_driver_probe(&ramoops_driver, ramoops_probe);
178 }
179
180 static void __exit ramoops_exit(void)
181 {
182         platform_driver_unregister(&ramoops_driver);
183 }
184
185 module_init(ramoops_init);
186 module_exit(ramoops_exit);
187
188 MODULE_LICENSE("GPL");
189 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
190 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");