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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/stat.h>
35#include <linux/stddef.h>
36#include <linux/types.h>
37#include <linux/uaccess.h>
38#include <linux/wait.h>
39#include <stdarg.h>
40
41#define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)
42
43static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;
44
45static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log,
46 size_t idx)
47{
48 return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
49}
50
51static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log,
52 char c)
53{
54 char *char_addr;
55
56 char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
57 *char_addr = c;
58 debug_log->log_end++;
59
60 if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
61 debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
62}
63
64__printf(2, 3)
65static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log,
66 const char *fmt, ...)
67{
68 va_list args;
69 static char debug_log_buf[256];
70 char *p;
71
72 if (!debug_log)
73 return 0;
74
75 spin_lock_bh(&debug_log->lock);
76 va_start(args, fmt);
77 vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
78 va_end(args);
79
80 for (p = debug_log_buf; *p != 0; p++)
81 batadv_emit_log_char(debug_log, *p);
82
83 spin_unlock_bh(&debug_log->lock);
84
85 wake_up(&debug_log->queue_wait);
86
87 return 0;
88}
89
90int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
91{
92 va_list args;
93 char tmp_log_buf[256];
94
95 va_start(args, fmt);
96 vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args);
97 batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s",
98 jiffies_to_msecs(jiffies), tmp_log_buf);
99 va_end(args);
100
101 return 0;
102}
103
104static int batadv_log_open(struct inode *inode, struct file *file)
105{
106 if (!try_module_get(THIS_MODULE))
107 return -EBUSY;
108
109 nonseekable_open(inode, file);
110 file->private_data = inode->i_private;
111 return 0;
112}
113
114static int batadv_log_release(struct inode *inode, struct file *file)
115{
116 module_put(THIS_MODULE);
117 return 0;
118}
119
120static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log)
121{
122 return !(debug_log->log_start - debug_log->log_end);
123}
124
125static ssize_t batadv_log_read(struct file *file, char __user *buf,
126 size_t count, loff_t *ppos)
127{
128 struct batadv_priv *bat_priv = file->private_data;
129 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
130 int error, i = 0;
131 char *char_addr;
132 char c;
133
134 if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
135 return -EAGAIN;
136
137 if (!buf)
138 return -EINVAL;
139
140 if (count == 0)
141 return 0;
142
143 if (!access_ok(VERIFY_WRITE, buf, count))
144 return -EFAULT;
145
146 error = wait_event_interruptible(debug_log->queue_wait,
147 (!batadv_log_empty(debug_log)));
148
149 if (error)
150 return error;
151
152 spin_lock_bh(&debug_log->lock);
153
154 while ((!error) && (i < count) &&
155 (debug_log->log_start != debug_log->log_end)) {
156 char_addr = batadv_log_char_addr(debug_log,
157 debug_log->log_start);
158 c = *char_addr;
159
160 debug_log->log_start++;
161
162 spin_unlock_bh(&debug_log->lock);
163
164 error = __put_user(c, buf);
165
166 spin_lock_bh(&debug_log->lock);
167
168 buf++;
169 i++;
170 }
171
172 spin_unlock_bh(&debug_log->lock);
173
174 if (!error)
175 return i;
176
177 return error;
178}
179
180static unsigned int batadv_log_poll(struct file *file, poll_table *wait)
181{
182 struct batadv_priv *bat_priv = file->private_data;
183 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
184
185 poll_wait(file, &debug_log->queue_wait, wait);
186
187 if (!batadv_log_empty(debug_log))
188 return POLLIN | POLLRDNORM;
189
190 return 0;
191}
192
193static const struct file_operations batadv_log_fops = {
194 .open = batadv_log_open,
195 .release = batadv_log_release,
196 .read = batadv_log_read,
197 .poll = batadv_log_poll,
198 .llseek = no_llseek,
199};
200
201int batadv_debug_log_setup(struct batadv_priv *bat_priv)
202{
203 struct dentry *d;
204
205 if (!bat_priv->debug_dir)
206 goto err;
207
208 bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
209 if (!bat_priv->debug_log)
210 goto err;
211
212 spin_lock_init(&bat_priv->debug_log->lock);
213 init_waitqueue_head(&bat_priv->debug_log->queue_wait);
214
215 d = debugfs_create_file("log", S_IFREG | S_IRUSR,
216 bat_priv->debug_dir, bat_priv,
217 &batadv_log_fops);
218 if (!d)
219 goto err;
220
221 return 0;
222
223err:
224 return -ENOMEM;
225}
226
227void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
228{
229 kfree(bat_priv->debug_log);
230 bat_priv->debug_log = NULL;
231}
232
