1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2010-2018 B.A.T.M.A.N. contributors:
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of version 2 of the GNU General Public
8 * License as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
22 #include <linux/compiler.h>
23 #include <linux/debugfs.h>
24 #include <linux/errno.h>
25 #include <linux/eventpoll.h>
26 #include <linux/export.h>
27 #include <linux/fcntl.h>
29 #include <linux/gfp.h>
30 #include <linux/jiffies.h>
31 #include <linux/kernel.h>
32 #include <linux/module.h>
33 #include <linux/poll.h>
34 #include <linux/sched.h> /* for linux/wait.h */
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <linux/stddef.h>
38 #include <linux/types.h>
39 #include <linux/uaccess.h>
40 #include <linux/wait.h>
43 #define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)
45 static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;
47 static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log,
50 return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
53 static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log,
58 char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
62 if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
63 debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
67 static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log,
71 static char debug_log_buf[256];
77 spin_lock_bh(&debug_log->lock);
79 vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
82 for (p = debug_log_buf; *p != 0; p++)
83 batadv_emit_log_char(debug_log, *p);
85 spin_unlock_bh(&debug_log->lock);
87 wake_up(&debug_log->queue_wait);
93 * batadv_debug_log() - Add debug log entry
94 * @bat_priv: the bat priv with all the soft interface information
97 * Return: 0 on success or negative error number in case of failure
99 int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
102 char tmp_log_buf[256];
105 vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args);
106 batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s",
107 jiffies_to_msecs(jiffies), tmp_log_buf);
113 static int batadv_log_open(struct inode *inode, struct file *file)
115 if (!try_module_get(THIS_MODULE))
118 nonseekable_open(inode, file);
119 file->private_data = inode->i_private;
123 static int batadv_log_release(struct inode *inode, struct file *file)
125 module_put(THIS_MODULE);
129 static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log)
131 return !(debug_log->log_start - debug_log->log_end);
134 static ssize_t batadv_log_read(struct file *file, char __user *buf,
135 size_t count, loff_t *ppos)
137 struct batadv_priv *bat_priv = file->private_data;
138 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
143 if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
152 if (!access_ok(VERIFY_WRITE, buf, count))
155 error = wait_event_interruptible(debug_log->queue_wait,
156 (!batadv_log_empty(debug_log)));
161 spin_lock_bh(&debug_log->lock);
163 while ((!error) && (i < count) &&
164 (debug_log->log_start != debug_log->log_end)) {
165 char_addr = batadv_log_char_addr(debug_log,
166 debug_log->log_start);
169 debug_log->log_start++;
171 spin_unlock_bh(&debug_log->lock);
173 error = __put_user(c, buf);
175 spin_lock_bh(&debug_log->lock);
181 spin_unlock_bh(&debug_log->lock);
189 static __poll_t batadv_log_poll(struct file *file, poll_table *wait)
191 struct batadv_priv *bat_priv = file->private_data;
192 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
194 poll_wait(file, &debug_log->queue_wait, wait);
196 if (!batadv_log_empty(debug_log))
197 return EPOLLIN | EPOLLRDNORM;
202 static const struct file_operations batadv_log_fops = {
203 .open = batadv_log_open,
204 .release = batadv_log_release,
205 .read = batadv_log_read,
206 .poll = batadv_log_poll,
211 * batadv_debug_log_setup() - Initialize debug log
212 * @bat_priv: the bat priv with all the soft interface information
214 * Return: 0 on success or negative error number in case of failure
216 int batadv_debug_log_setup(struct batadv_priv *bat_priv)
220 if (!bat_priv->debug_dir)
223 bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
224 if (!bat_priv->debug_log)
227 spin_lock_init(&bat_priv->debug_log->lock);
228 init_waitqueue_head(&bat_priv->debug_log->queue_wait);
230 d = debugfs_create_file("log", 0400, bat_priv->debug_dir, bat_priv,
242 * batadv_debug_log_cleanup() - Destroy debug log
243 * @bat_priv: the bat priv with all the soft interface information
245 void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
247 kfree(bat_priv->debug_log);
248 bat_priv->debug_log = NULL;