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18#include "log.h"
19#include "main.h"
20
21#include <linux/compiler.h>
22#include <linux/debugfs.h>
23#include <linux/errno.h>
24#include <linux/export.h>
25#include <linux/fcntl.h>
26#include <linux/fs.h>
27#include <linux/jiffies.h>
28#include <linux/kernel.h>
29#include <linux/module.h>
30#include <linux/poll.h>
31#include <linux/sched.h>
32#include <linux/slab.h>
33#include <linux/spinlock.h>
34#include <linux/stddef.h>
35#include <linux/types.h>
36#include <linux/uaccess.h>
37#include <linux/wait.h>
38#include <stdarg.h>
39
40#define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)
41
42static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;
43
44static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log,
45 size_t idx)
46{
47 return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
48}
49
50static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log,
51 char c)
52{
53 char *char_addr;
54
55 char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
56 *char_addr = c;
57 debug_log->log_end++;
58
59 if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
60 debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
61}
62
63__printf(2, 3)
64static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log,
65 const char *fmt, ...)
66{
67 va_list args;
68 static char debug_log_buf[256];
69 char *p;
70
71 if (!debug_log)
72 return 0;
73
74 spin_lock_bh(&debug_log->lock);
75 va_start(args, fmt);
76 vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
77 va_end(args);
78
79 for (p = debug_log_buf; *p != 0; p++)
80 batadv_emit_log_char(debug_log, *p);
81
82 spin_unlock_bh(&debug_log->lock);
83
84 wake_up(&debug_log->queue_wait);
85
86 return 0;
87}
88
89int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
90{
91 va_list args;
92 char tmp_log_buf[256];
93
94 va_start(args, fmt);
95 vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args);
96 batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s",
97 jiffies_to_msecs(jiffies), tmp_log_buf);
98 va_end(args);
99
100 return 0;
101}
102
103static int batadv_log_open(struct inode *inode, struct file *file)
104{
105 if (!try_module_get(THIS_MODULE))
106 return -EBUSY;
107
108 nonseekable_open(inode, file);
109 file->private_data = inode->i_private;
110 return 0;
111}
112
113static int batadv_log_release(struct inode *inode, struct file *file)
114{
115 module_put(THIS_MODULE);
116 return 0;
117}
118
119static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log)
120{
121 return !(debug_log->log_start - debug_log->log_end);
122}
123
124static ssize_t batadv_log_read(struct file *file, char __user *buf,
125 size_t count, loff_t *ppos)
126{
127 struct batadv_priv *bat_priv = file->private_data;
128 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
129 int error, i = 0;
130 char *char_addr;
131 char c;
132
133 if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
134 return -EAGAIN;
135
136 if (!buf)
137 return -EINVAL;
138
139 if (count == 0)
140 return 0;
141
142 if (!access_ok(VERIFY_WRITE, buf, count))
143 return -EFAULT;
144
145 error = wait_event_interruptible(debug_log->queue_wait,
146 (!batadv_log_empty(debug_log)));
147
148 if (error)
149 return error;
150
151 spin_lock_bh(&debug_log->lock);
152
153 while ((!error) && (i < count) &&
154 (debug_log->log_start != debug_log->log_end)) {
155 char_addr = batadv_log_char_addr(debug_log,
156 debug_log->log_start);
157 c = *char_addr;
158
159 debug_log->log_start++;
160
161 spin_unlock_bh(&debug_log->lock);
162
163 error = __put_user(c, buf);
164
165 spin_lock_bh(&debug_log->lock);
166
167 buf++;
168 i++;
169 }
170
171 spin_unlock_bh(&debug_log->lock);
172
173 if (!error)
174 return i;
175
176 return error;
177}
178
179static unsigned int batadv_log_poll(struct file *file, poll_table *wait)
180{
181 struct batadv_priv *bat_priv = file->private_data;
182 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
183
184 poll_wait(file, &debug_log->queue_wait, wait);
185
186 if (!batadv_log_empty(debug_log))
187 return POLLIN | POLLRDNORM;
188
189 return 0;
190}
191
192static const struct file_operations batadv_log_fops = {
193 .open = batadv_log_open,
194 .release = batadv_log_release,
195 .read = batadv_log_read,
196 .poll = batadv_log_poll,
197 .llseek = no_llseek,
198};
199
200int batadv_debug_log_setup(struct batadv_priv *bat_priv)
201{
202 struct dentry *d;
203
204 if (!bat_priv->debug_dir)
205 goto err;
206
207 bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
208 if (!bat_priv->debug_log)
209 goto err;
210
211 spin_lock_init(&bat_priv->debug_log->lock);
212 init_waitqueue_head(&bat_priv->debug_log->queue_wait);
213
214 d = debugfs_create_file("log", 0400, bat_priv->debug_dir, bat_priv,
215 &batadv_log_fops);
216 if (!d)
217 goto err;
218
219 return 0;
220
221err:
222 return -ENOMEM;
223}
224
225void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
226{
227 kfree(bat_priv->debug_log);
228 bat_priv->debug_log = NULL;
229}
230
