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>
46 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
48 #define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)
50 static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;
52 static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log,
55 return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
58 static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log,
63 char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
67 if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
68 debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
72 static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log,
76 static char debug_log_buf[256];
82 spin_lock_bh(&debug_log->lock);
84 vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
87 for (p = debug_log_buf; *p != 0; p++)
88 batadv_emit_log_char(debug_log, *p);
90 spin_unlock_bh(&debug_log->lock);
92 wake_up(&debug_log->queue_wait);
97 static int batadv_log_open(struct inode *inode, struct file *file)
99 if (!try_module_get(THIS_MODULE))
102 batadv_debugfs_deprecated(file,
103 "Use tracepoint batadv:batadv_dbg instead\n");
105 nonseekable_open(inode, file);
106 file->private_data = inode->i_private;
110 static int batadv_log_release(struct inode *inode, struct file *file)
112 module_put(THIS_MODULE);
116 static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log)
118 return !(debug_log->log_start - debug_log->log_end);
121 static ssize_t batadv_log_read(struct file *file, char __user *buf,
122 size_t count, loff_t *ppos)
124 struct batadv_priv *bat_priv = file->private_data;
125 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
130 if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
139 if (!access_ok(buf, count))
142 error = wait_event_interruptible(debug_log->queue_wait,
143 (!batadv_log_empty(debug_log)));
148 spin_lock_bh(&debug_log->lock);
150 while ((!error) && (i < count) &&
151 (debug_log->log_start != debug_log->log_end)) {
152 char_addr = batadv_log_char_addr(debug_log,
153 debug_log->log_start);
156 debug_log->log_start++;
158 spin_unlock_bh(&debug_log->lock);
160 error = __put_user(c, buf);
162 spin_lock_bh(&debug_log->lock);
168 spin_unlock_bh(&debug_log->lock);
176 static __poll_t batadv_log_poll(struct file *file, poll_table *wait)
178 struct batadv_priv *bat_priv = file->private_data;
179 struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
181 poll_wait(file, &debug_log->queue_wait, wait);
183 if (!batadv_log_empty(debug_log))
184 return EPOLLIN | EPOLLRDNORM;
189 static const struct file_operations batadv_log_fops = {
190 .open = batadv_log_open,
191 .release = batadv_log_release,
192 .read = batadv_log_read,
193 .poll = batadv_log_poll,
198 * batadv_debug_log_setup() - Initialize debug log
199 * @bat_priv: the bat priv with all the soft interface information
201 * Return: 0 on success or negative error number in case of failure
203 int batadv_debug_log_setup(struct batadv_priv *bat_priv)
207 if (!bat_priv->debug_dir)
210 bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
211 if (!bat_priv->debug_log)
214 spin_lock_init(&bat_priv->debug_log->lock);
215 init_waitqueue_head(&bat_priv->debug_log->queue_wait);
217 d = debugfs_create_file("log", 0400, bat_priv->debug_dir, bat_priv,
229 * batadv_debug_log_cleanup() - Destroy debug log
230 * @bat_priv: the bat priv with all the soft interface information
232 void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
234 kfree(bat_priv->debug_log);
235 bat_priv->debug_log = NULL;
238 #endif /* CONFIG_BATMAN_ADV_DEBUGFS */
241 * batadv_debug_log() - Add debug log entry
242 * @bat_priv: the bat priv with all the soft interface information
243 * @fmt: format string
245 * Return: 0 on success or negative error number in case of failure
247 int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
249 struct va_format vaf;
257 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
258 batadv_fdebug_log(bat_priv->debug_log, "[%10u] %pV",
259 jiffies_to_msecs(jiffies), &vaf);
262 trace_batadv_dbg(bat_priv, &vaf);