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/* Copyright (C) 2010-2017 B.A.T.M.A.N. contributors:
*
* Marek Lindner
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "log.h"
#include "main.h"
#include <linux/compiler.h>
#include <linux/debugfs.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/fcntl.h>
#include <linux/fs.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/sched.h> /* for linux/wait.h */
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <stdarg.h>
#define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)
static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;
static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log,
size_t idx)
{
return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
}
static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log,
char c)
{
char *char_addr;
char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
*char_addr = c;
debug_log->log_end++;
if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
}
__printf(2, 3)
static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log,
const char *fmt, ...)
{
va_list args;
static char debug_log_buf[256];
char *p;
if (!debug_log)
return 0;
spin_lock_bh(&debug_log->lock);
va_start(args, fmt);
vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
va_end(args);
for (p = debug_log_buf; *p != 0; p++)
batadv_emit_log_char(debug_log, *p);
spin_unlock_bh(&debug_log->lock);
wake_up(&debug_log->queue_wait);
return 0;
}
int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
{
va_list args;
char tmp_log_buf[256];
va_start(args, fmt);
vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args);
batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s",
jiffies_to_msecs(jiffies), tmp_log_buf);
va_end(args);
return 0;
}
static int batadv_log_open(struct inode *inode, struct file *file)
{
if (!try_module_get(THIS_MODULE))
return -EBUSY;
nonseekable_open(inode, file);
file->private_data = inode->i_private;
return 0;
}
static int batadv_log_release(struct inode *inode, struct file *file)
{
module_put(THIS_MODULE);
return 0;
}
static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log)
{
return !(debug_log->log_start - debug_log->log_end);
}
static ssize_t batadv_log_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct batadv_priv *bat_priv = file->private_data;
struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
int error, i = 0;
char *char_addr;
char c;
if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
return -EAGAIN;
if (!buf)
return -EINVAL;
if (count == 0)
return 0;
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
error = wait_event_interruptible(debug_log->queue_wait,
(!batadv_log_empty(debug_log)));
if (error)
return error;
spin_lock_bh(&debug_log->lock);
while ((!error) && (i < count) &&
(debug_log->log_start != debug_log->log_end)) {
char_addr = batadv_log_char_addr(debug_log,
debug_log->log_start);
c = *char_addr;
debug_log->log_start++;
spin_unlock_bh(&debug_log->lock);
error = __put_user(c, buf);
spin_lock_bh(&debug_log->lock);
buf++;
i++;
}
spin_unlock_bh(&debug_log->lock);
if (!error)
return i;
return error;
}
static __poll_t batadv_log_poll(struct file *file, poll_table *wait)
{
struct batadv_priv *bat_priv = file->private_data;
struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
poll_wait(file, &debug_log->queue_wait, wait);
if (!batadv_log_empty(debug_log))
return POLLIN | POLLRDNORM;
return 0;
}
static const struct file_operations batadv_log_fops = {
.open = batadv_log_open,
.release = batadv_log_release,
.read = batadv_log_read,
.poll = batadv_log_poll,
.llseek = no_llseek,
};
int batadv_debug_log_setup(struct batadv_priv *bat_priv)
{
struct dentry *d;
if (!bat_priv->debug_dir)
goto err;
bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
if (!bat_priv->debug_log)
goto err;
spin_lock_init(&bat_priv->debug_log->lock);
init_waitqueue_head(&bat_priv->debug_log->queue_wait);
d = debugfs_create_file("log", 0400, bat_priv->debug_dir, bat_priv,
&batadv_log_fops);
if (!d)
goto err;
return 0;
err:
return -ENOMEM;
}
void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
{
kfree(bat_priv->debug_log);
bat_priv->debug_log = NULL;
}
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