1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
/*
* Persistent Storage - platform driver interface parts.
*
* Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/atomic.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kmsg_dump.h>
#include <linux/module.h>
#include <linux/pstore.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include "internal.h"
/*
* pstore_lock just protects "psinfo" during
* calls to pstore_register()
*/
static DEFINE_SPINLOCK(pstore_lock);
static struct pstore_info *psinfo;
/* How much of the console log to snapshot. /sys/fs/pstore/kmsg_bytes */
static unsigned long kmsg_bytes = 10240;
static ssize_t b_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return snprintf(buf, PAGE_SIZE, "%lu\n", kmsg_bytes);
}
static ssize_t b_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
return (sscanf(buf, "%lu", &kmsg_bytes) > 0) ? count : 0;
}
struct kobj_attribute pstore_kmsg_bytes_attr =
__ATTR(kmsg_bytes, S_IRUGO | S_IWUSR, b_show, b_store);
/* Tag each group of saved records with a sequence number */
static int oopscount;
/*
* callback from kmsg_dump. (s2,l2) has the most recently
* written bytes, older bytes are in (s1,l1). Save as much
* as we can from the end of the buffer.
*/
static void pstore_dump(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason,
const char *s1, unsigned long l1,
const char *s2, unsigned long l2)
{
unsigned long s1_start, s2_start;
unsigned long l1_cpy, l2_cpy;
unsigned long size, total = 0;
char *dst;
u64 id;
int hsize, part = 1;
mutex_lock(&psinfo->buf_mutex);
oopscount++;
while (total < kmsg_bytes) {
dst = psinfo->buf;
hsize = sprintf(dst, "Oops#%d Part%d\n", oopscount, part++);
size = psinfo->bufsize - hsize;
dst += hsize;
l2_cpy = min(l2, size);
l1_cpy = min(l1, size - l2_cpy);
if (l1_cpy + l2_cpy == 0)
break;
s2_start = l2 - l2_cpy;
s1_start = l1 - l1_cpy;
memcpy(dst, s1 + s1_start, l1_cpy);
memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy);
id = psinfo->write(PSTORE_TYPE_DMESG, hsize + l1_cpy + l2_cpy);
if (pstore_is_mounted())
pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id,
psinfo->buf, hsize + l1_cpy + l2_cpy,
CURRENT_TIME, psinfo->erase);
l1 -= l1_cpy;
l2 -= l2_cpy;
total += l1_cpy + l2_cpy;
}
mutex_unlock(&psinfo->buf_mutex);
}
static struct kmsg_dumper pstore_dumper = {
.dump = pstore_dump,
};
/*
* platform specific persistent storage driver registers with
* us here. If pstore is already mounted, call the platform
* read function right away to populate the file system. If not
* then the pstore mount code will call us later to fill out
* the file system.
*
* Register with kmsg_dump to save last part of console log on panic.
*/
int pstore_register(struct pstore_info *psi)
{
struct module *owner = psi->owner;
spin_lock(&pstore_lock);
if (psinfo) {
spin_unlock(&pstore_lock);
return -EBUSY;
}
psinfo = psi;
spin_unlock(&pstore_lock);
if (owner && !try_module_get(owner)) {
psinfo = NULL;
return -EINVAL;
}
if (pstore_is_mounted())
pstore_get_records();
kmsg_dump_register(&pstore_dumper);
return 0;
}
EXPORT_SYMBOL_GPL(pstore_register);
/*
* Read all the records from the persistent store. Create and
* file files in our filesystem.
*/
void pstore_get_records(void)
{
struct pstore_info *psi = psinfo;
size_t size;
u64 id;
enum pstore_type_id type;
struct timespec time;
int failed = 0;
if (!psi)
return;
mutex_lock(&psinfo->buf_mutex);
while ((size = psi->read(&id, &type, &time)) > 0) {
if (pstore_mkfile(type, psi->name, id, psi->buf, size,
time, psi->erase))
failed++;
}
mutex_unlock(&psinfo->buf_mutex);
if (failed)
printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n",
failed, psi->name);
}
/*
* Call platform driver to write a record to the
* persistent store.
*/
int pstore_write(enum pstore_type_id type, char *buf, size_t size)
{
u64 id;
if (!psinfo)
return -ENODEV;
if (size > psinfo->bufsize)
return -EFBIG;
mutex_lock(&psinfo->buf_mutex);
memcpy(psinfo->buf, buf, size);
id = psinfo->write(type, size);
if (pstore_is_mounted())
pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id, psinfo->buf,
size, CURRENT_TIME, psinfo->erase);
mutex_unlock(&psinfo->buf_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(pstore_write);
|
