]>
Commit | Line | Data |
---|---|---|
2ff729d5 HY |
1 | /* |
2 | * APEI Error Record Serialization Table debug support | |
3 | * | |
4 | * ERST is a way provided by APEI to save and retrieve hardware error | |
5 | * infomation to and from a persistent store. This file provide the | |
6 | * debugging/testing support for ERST kernel support and firmware | |
7 | * implementation. | |
8 | * | |
9 | * Copyright 2010 Intel Corp. | |
10 | * Author: Huang Ying <ying.huang@intel.com> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License version | |
14 | * 2 as published by the Free Software Foundation. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, | |
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 | * GNU General Public License for more details. | |
20 | * | |
21 | * You should have received a copy of the GNU General Public License | |
22 | * along with this program; if not, write to the Free Software | |
23 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
24 | */ | |
25 | ||
26 | #include <linux/kernel.h> | |
27 | #include <linux/module.h> | |
28 | #include <linux/uaccess.h> | |
29 | #include <acpi/apei.h> | |
30 | #include <linux/miscdevice.h> | |
31 | ||
32 | #include "apei-internal.h" | |
33 | ||
34 | #define ERST_DBG_PFX "ERST DBG: " | |
35 | ||
36 | #define ERST_DBG_RECORD_LEN_MAX 4096 | |
37 | ||
38 | static void *erst_dbg_buf; | |
39 | static unsigned int erst_dbg_buf_len; | |
40 | ||
41 | /* Prevent erst_dbg_read/write from being invoked concurrently */ | |
42 | static DEFINE_MUTEX(erst_dbg_mutex); | |
43 | ||
44 | static int erst_dbg_open(struct inode *inode, struct file *file) | |
45 | { | |
46 | if (erst_disable) | |
47 | return -ENODEV; | |
48 | ||
49 | return nonseekable_open(inode, file); | |
50 | } | |
51 | ||
52 | static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg) | |
53 | { | |
54 | int rc; | |
55 | u64 record_id; | |
56 | u32 record_count; | |
57 | ||
58 | switch (cmd) { | |
59 | case APEI_ERST_CLEAR_RECORD: | |
60 | rc = copy_from_user(&record_id, (void __user *)arg, | |
61 | sizeof(record_id)); | |
62 | if (rc) | |
63 | return -EFAULT; | |
64 | return erst_clear(record_id); | |
65 | case APEI_ERST_GET_RECORD_COUNT: | |
66 | rc = erst_get_record_count(); | |
67 | if (rc < 0) | |
68 | return rc; | |
69 | record_count = rc; | |
70 | rc = put_user(record_count, (u32 __user *)arg); | |
71 | if (rc) | |
72 | return rc; | |
73 | return 0; | |
74 | default: | |
75 | return -ENOTTY; | |
76 | } | |
77 | } | |
78 | ||
79 | static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf, | |
80 | size_t usize, loff_t *off) | |
81 | { | |
82 | int rc; | |
83 | ssize_t len = 0; | |
84 | u64 id; | |
85 | ||
86 | if (*off != 0) | |
87 | return -EINVAL; | |
88 | ||
89 | if (mutex_lock_interruptible(&erst_dbg_mutex) != 0) | |
90 | return -EINTR; | |
91 | ||
92 | retry_next: | |
93 | rc = erst_get_next_record_id(&id); | |
94 | if (rc) | |
95 | goto out; | |
96 | /* no more record */ | |
97 | if (id == APEI_ERST_INVALID_RECORD_ID) | |
98 | goto out; | |
99 | retry: | |
100 | rc = len = erst_read(id, erst_dbg_buf, erst_dbg_buf_len); | |
101 | /* The record may be cleared by others, try read next record */ | |
102 | if (rc == -ENOENT) | |
103 | goto retry_next; | |
104 | if (rc < 0) | |
105 | goto out; | |
106 | if (len > ERST_DBG_RECORD_LEN_MAX) { | |
107 | pr_warning(ERST_DBG_PFX | |
108 | "Record (ID: 0x%llx) length is too long: %zd\n", | |
109 | id, len); | |
110 | rc = -EIO; | |
111 | goto out; | |
112 | } | |
113 | if (len > erst_dbg_buf_len) { | |
114 | kfree(erst_dbg_buf); | |
115 | rc = -ENOMEM; | |
116 | erst_dbg_buf = kmalloc(len, GFP_KERNEL); | |
117 | if (!erst_dbg_buf) | |
118 | goto out; | |
119 | erst_dbg_buf_len = len; | |
120 | goto retry; | |
121 | } | |
122 | ||
123 | rc = -EINVAL; | |
124 | if (len > usize) | |
125 | goto out; | |
126 | ||
127 | rc = -EFAULT; | |
128 | if (copy_to_user(ubuf, erst_dbg_buf, len)) | |
129 | goto out; | |
130 | rc = 0; | |
131 | out: | |
132 | mutex_unlock(&erst_dbg_mutex); | |
133 | return rc ? rc : len; | |
134 | } | |
135 | ||
136 | static ssize_t erst_dbg_write(struct file *filp, const char __user *ubuf, | |
137 | size_t usize, loff_t *off) | |
138 | { | |
139 | int rc; | |
140 | struct cper_record_header *rcd; | |
141 | ||
142 | if (!capable(CAP_SYS_ADMIN)) | |
143 | return -EPERM; | |
144 | ||
145 | if (usize > ERST_DBG_RECORD_LEN_MAX) { | |
146 | pr_err(ERST_DBG_PFX "Too long record to be written\n"); | |
147 | return -EINVAL; | |
148 | } | |
149 | ||
150 | if (mutex_lock_interruptible(&erst_dbg_mutex)) | |
151 | return -EINTR; | |
152 | if (usize > erst_dbg_buf_len) { | |
153 | kfree(erst_dbg_buf); | |
154 | rc = -ENOMEM; | |
155 | erst_dbg_buf = kmalloc(usize, GFP_KERNEL); | |
156 | if (!erst_dbg_buf) | |
157 | goto out; | |
158 | erst_dbg_buf_len = usize; | |
159 | } | |
160 | rc = copy_from_user(erst_dbg_buf, ubuf, usize); | |
161 | if (rc) { | |
162 | rc = -EFAULT; | |
163 | goto out; | |
164 | } | |
165 | rcd = erst_dbg_buf; | |
166 | rc = -EINVAL; | |
167 | if (rcd->record_length != usize) | |
168 | goto out; | |
169 | ||
170 | rc = erst_write(erst_dbg_buf); | |
171 | ||
172 | out: | |
173 | mutex_unlock(&erst_dbg_mutex); | |
174 | return rc < 0 ? rc : usize; | |
175 | } | |
176 | ||
177 | static const struct file_operations erst_dbg_ops = { | |
178 | .owner = THIS_MODULE, | |
179 | .open = erst_dbg_open, | |
180 | .read = erst_dbg_read, | |
181 | .write = erst_dbg_write, | |
182 | .unlocked_ioctl = erst_dbg_ioctl, | |
183 | }; | |
184 | ||
185 | static struct miscdevice erst_dbg_dev = { | |
186 | .minor = MISC_DYNAMIC_MINOR, | |
187 | .name = "erst_dbg", | |
188 | .fops = &erst_dbg_ops, | |
189 | }; | |
190 | ||
191 | static __init int erst_dbg_init(void) | |
192 | { | |
193 | return misc_register(&erst_dbg_dev); | |
194 | } | |
195 | ||
196 | static __exit void erst_dbg_exit(void) | |
197 | { | |
198 | misc_deregister(&erst_dbg_dev); | |
199 | kfree(erst_dbg_buf); | |
200 | } | |
201 | ||
202 | module_init(erst_dbg_init); | |
203 | module_exit(erst_dbg_exit); | |
204 | ||
205 | MODULE_AUTHOR("Huang Ying"); | |
206 | MODULE_DESCRIPTION("APEI Error Record Serialization Table debug support"); | |
207 | MODULE_LICENSE("GPL"); |