Loading...
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 * information 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 0x4000
37
38static void *erst_dbg_buf;
39static unsigned int erst_dbg_buf_len;
40
41/* Prevent erst_dbg_read/write from being invoked concurrently */
42static DEFINE_MUTEX(erst_dbg_mutex);
43
44static int erst_dbg_open(struct inode *inode, struct file *file)
45{
46 int rc, *pos;
47
48 if (erst_disable)
49 return -ENODEV;
50
51 pos = (int *)&file->private_data;
52
53 rc = erst_get_record_id_begin(pos);
54 if (rc)
55 return rc;
56
57 return nonseekable_open(inode, file);
58}
59
60static int erst_dbg_release(struct inode *inode, struct file *file)
61{
62 erst_get_record_id_end();
63
64 return 0;
65}
66
67static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
68{
69 int rc;
70 u64 record_id;
71 u32 record_count;
72
73 switch (cmd) {
74 case APEI_ERST_CLEAR_RECORD:
75 rc = copy_from_user(&record_id, (void __user *)arg,
76 sizeof(record_id));
77 if (rc)
78 return -EFAULT;
79 return erst_clear(record_id);
80 case APEI_ERST_GET_RECORD_COUNT:
81 rc = erst_get_record_count();
82 if (rc < 0)
83 return rc;
84 record_count = rc;
85 rc = put_user(record_count, (u32 __user *)arg);
86 if (rc)
87 return rc;
88 return 0;
89 default:
90 return -ENOTTY;
91 }
92}
93
94static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf,
95 size_t usize, loff_t *off)
96{
97 int rc, *pos;
98 ssize_t len = 0;
99 u64 id;
100
101 if (*off)
102 return -EINVAL;
103
104 if (mutex_lock_interruptible(&erst_dbg_mutex) != 0)
105 return -EINTR;
106
107 pos = (int *)&filp->private_data;
108
109retry_next:
110 rc = erst_get_record_id_next(pos, &id);
111 if (rc)
112 goto out;
113 /* no more record */
114 if (id == APEI_ERST_INVALID_RECORD_ID)
115 goto out;
116retry:
117 rc = len = erst_read(id, erst_dbg_buf, erst_dbg_buf_len);
118 /* The record may be cleared by others, try read next record */
119 if (rc == -ENOENT)
120 goto retry_next;
121 if (rc < 0)
122 goto out;
123 if (len > ERST_DBG_RECORD_LEN_MAX) {
124 pr_warning(ERST_DBG_PFX
125 "Record (ID: 0x%llx) length is too long: %zd\n",
126 id, len);
127 rc = -EIO;
128 goto out;
129 }
130 if (len > erst_dbg_buf_len) {
131 void *p;
132 rc = -ENOMEM;
133 p = kmalloc(len, GFP_KERNEL);
134 if (!p)
135 goto out;
136 kfree(erst_dbg_buf);
137 erst_dbg_buf = p;
138 erst_dbg_buf_len = len;
139 goto retry;
140 }
141
142 rc = -EINVAL;
143 if (len > usize)
144 goto out;
145
146 rc = -EFAULT;
147 if (copy_to_user(ubuf, erst_dbg_buf, len))
148 goto out;
149 rc = 0;
150out:
151 mutex_unlock(&erst_dbg_mutex);
152 return rc ? rc : len;
153}
154
155static ssize_t erst_dbg_write(struct file *filp, const char __user *ubuf,
156 size_t usize, loff_t *off)
157{
158 int rc;
159 struct cper_record_header *rcd;
160
161 if (!capable(CAP_SYS_ADMIN))
162 return -EPERM;
163
164 if (usize > ERST_DBG_RECORD_LEN_MAX) {
165 pr_err(ERST_DBG_PFX "Too long record to be written\n");
166 return -EINVAL;
167 }
168
169 if (mutex_lock_interruptible(&erst_dbg_mutex))
170 return -EINTR;
171 if (usize > erst_dbg_buf_len) {
172 void *p;
173 rc = -ENOMEM;
174 p = kmalloc(usize, GFP_KERNEL);
175 if (!p)
176 goto out;
177 kfree(erst_dbg_buf);
178 erst_dbg_buf = p;
179 erst_dbg_buf_len = usize;
180 }
181 rc = copy_from_user(erst_dbg_buf, ubuf, usize);
182 if (rc) {
183 rc = -EFAULT;
184 goto out;
185 }
186 rcd = erst_dbg_buf;
187 rc = -EINVAL;
188 if (rcd->record_length != usize)
189 goto out;
190
191 rc = erst_write(erst_dbg_buf);
192
193out:
194 mutex_unlock(&erst_dbg_mutex);
195 return rc < 0 ? rc : usize;
196}
197
198static const struct file_operations erst_dbg_ops = {
199 .owner = THIS_MODULE,
200 .open = erst_dbg_open,
201 .release = erst_dbg_release,
202 .read = erst_dbg_read,
203 .write = erst_dbg_write,
204 .unlocked_ioctl = erst_dbg_ioctl,
205 .llseek = no_llseek,
206};
207
208static struct miscdevice erst_dbg_dev = {
209 .minor = MISC_DYNAMIC_MINOR,
210 .name = "erst_dbg",
211 .fops = &erst_dbg_ops,
212};
213
214static __init int erst_dbg_init(void)
215{
216 if (erst_disable) {
217 pr_info(ERST_DBG_PFX "ERST support is disabled.\n");
218 return -ENODEV;
219 }
220 return misc_register(&erst_dbg_dev);
221}
222
223static __exit void erst_dbg_exit(void)
224{
225 misc_deregister(&erst_dbg_dev);
226 kfree(erst_dbg_buf);
227}
228
229module_init(erst_dbg_init);
230module_exit(erst_dbg_exit);
231
232MODULE_AUTHOR("Huang Ying");
233MODULE_DESCRIPTION("APEI Error Record Serialization Table debug support");
234MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * APEI Error Record Serialization Table debug support
4 *
5 * ERST is a way provided by APEI to save and retrieve hardware error
6 * information to and from a persistent store. This file provide the
7 * debugging/testing support for ERST kernel support and firmware
8 * implementation.
9 *
10 * Copyright 2010 Intel Corp.
11 * Author: Huang Ying <ying.huang@intel.com>
12 */
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/uaccess.h>
17#include <acpi/apei.h>
18#include <linux/miscdevice.h>
19
20#include "apei-internal.h"
21
22#define ERST_DBG_PFX "ERST DBG: "
23
24#define ERST_DBG_RECORD_LEN_MAX 0x4000
25
26static void *erst_dbg_buf;
27static unsigned int erst_dbg_buf_len;
28
29/* Prevent erst_dbg_read/write from being invoked concurrently */
30static DEFINE_MUTEX(erst_dbg_mutex);
31
32static int erst_dbg_open(struct inode *inode, struct file *file)
33{
34 int rc, *pos;
35
36 if (erst_disable)
37 return -ENODEV;
38
39 pos = (int *)&file->private_data;
40
41 rc = erst_get_record_id_begin(pos);
42 if (rc)
43 return rc;
44
45 return nonseekable_open(inode, file);
46}
47
48static int erst_dbg_release(struct inode *inode, struct file *file)
49{
50 erst_get_record_id_end();
51
52 return 0;
53}
54
55static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
56{
57 int rc;
58 u64 record_id;
59 u32 record_count;
60
61 switch (cmd) {
62 case APEI_ERST_CLEAR_RECORD:
63 rc = copy_from_user(&record_id, (void __user *)arg,
64 sizeof(record_id));
65 if (rc)
66 return -EFAULT;
67 return erst_clear(record_id);
68 case APEI_ERST_GET_RECORD_COUNT:
69 rc = erst_get_record_count();
70 if (rc < 0)
71 return rc;
72 record_count = rc;
73 rc = put_user(record_count, (u32 __user *)arg);
74 if (rc)
75 return rc;
76 return 0;
77 default:
78 return -ENOTTY;
79 }
80}
81
82static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf,
83 size_t usize, loff_t *off)
84{
85 int rc, *pos;
86 ssize_t len = 0;
87 u64 id;
88
89 if (*off)
90 return -EINVAL;
91
92 if (mutex_lock_interruptible(&erst_dbg_mutex) != 0)
93 return -EINTR;
94
95 pos = (int *)&filp->private_data;
96
97retry_next:
98 rc = erst_get_record_id_next(pos, &id);
99 if (rc)
100 goto out;
101 /* no more record */
102 if (id == APEI_ERST_INVALID_RECORD_ID) {
103 /*
104 * If the persistent store is empty initially, the function
105 * 'erst_read' below will return "-ENOENT" value. This causes
106 * 'retry_next' label is entered again. The returned value
107 * should be zero indicating the read operation is EOF.
108 */
109 len = 0;
110
111 goto out;
112 }
113retry:
114 rc = len = erst_read_record(id, erst_dbg_buf, erst_dbg_buf_len,
115 erst_dbg_buf_len, NULL);
116 /* The record may be cleared by others, try read next record */
117 if (rc == -ENOENT)
118 goto retry_next;
119 if (rc < 0)
120 goto out;
121 if (len > ERST_DBG_RECORD_LEN_MAX) {
122 pr_warn(ERST_DBG_PFX
123 "Record (ID: 0x%llx) length is too long: %zd\n", id, len);
124 rc = -EIO;
125 goto out;
126 }
127 if (len > erst_dbg_buf_len) {
128 void *p;
129 rc = -ENOMEM;
130 p = kmalloc(len, GFP_KERNEL);
131 if (!p)
132 goto out;
133 kfree(erst_dbg_buf);
134 erst_dbg_buf = p;
135 erst_dbg_buf_len = len;
136 goto retry;
137 }
138
139 rc = -EINVAL;
140 if (len > usize)
141 goto out;
142
143 rc = -EFAULT;
144 if (copy_to_user(ubuf, erst_dbg_buf, len))
145 goto out;
146 rc = 0;
147out:
148 mutex_unlock(&erst_dbg_mutex);
149 return rc ? rc : len;
150}
151
152static ssize_t erst_dbg_write(struct file *filp, const char __user *ubuf,
153 size_t usize, loff_t *off)
154{
155 int rc;
156 struct cper_record_header *rcd;
157
158 if (!capable(CAP_SYS_ADMIN))
159 return -EPERM;
160
161 if (usize > ERST_DBG_RECORD_LEN_MAX) {
162 pr_err(ERST_DBG_PFX "Too long record to be written\n");
163 return -EINVAL;
164 }
165
166 if (mutex_lock_interruptible(&erst_dbg_mutex))
167 return -EINTR;
168 if (usize > erst_dbg_buf_len) {
169 void *p;
170 rc = -ENOMEM;
171 p = kmalloc(usize, GFP_KERNEL);
172 if (!p)
173 goto out;
174 kfree(erst_dbg_buf);
175 erst_dbg_buf = p;
176 erst_dbg_buf_len = usize;
177 }
178 rc = copy_from_user(erst_dbg_buf, ubuf, usize);
179 if (rc) {
180 rc = -EFAULT;
181 goto out;
182 }
183 rcd = erst_dbg_buf;
184 rc = -EINVAL;
185 if (rcd->record_length != usize)
186 goto out;
187
188 rc = erst_write(erst_dbg_buf);
189
190out:
191 mutex_unlock(&erst_dbg_mutex);
192 return rc < 0 ? rc : usize;
193}
194
195static const struct file_operations erst_dbg_ops = {
196 .owner = THIS_MODULE,
197 .open = erst_dbg_open,
198 .release = erst_dbg_release,
199 .read = erst_dbg_read,
200 .write = erst_dbg_write,
201 .unlocked_ioctl = erst_dbg_ioctl,
202 .llseek = no_llseek,
203};
204
205static struct miscdevice erst_dbg_dev = {
206 .minor = MISC_DYNAMIC_MINOR,
207 .name = "erst_dbg",
208 .fops = &erst_dbg_ops,
209};
210
211static __init int erst_dbg_init(void)
212{
213 if (erst_disable) {
214 pr_info(ERST_DBG_PFX "ERST support is disabled.\n");
215 return -ENODEV;
216 }
217 return misc_register(&erst_dbg_dev);
218}
219
220static __exit void erst_dbg_exit(void)
221{
222 misc_deregister(&erst_dbg_dev);
223 kfree(erst_dbg_buf);
224}
225
226module_init(erst_dbg_init);
227module_exit(erst_dbg_exit);
228
229MODULE_AUTHOR("Huang Ying");
230MODULE_DESCRIPTION("APEI Error Record Serialization Table debug support");
231MODULE_LICENSE("GPL");