cregit-Linux how code gets into the kernel

Release 4.14 net/batman-adv/log.c

Directory: net/batman-adv
/* 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]; }

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Sven Eckelmann26100.00%1100.00%
Total26100.00%1100.00%


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; }

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Sven Eckelmann61100.00%1100.00%
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__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; }

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Sven Eckelmann115100.00%1100.00%
Total115100.00%1100.00%


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; }

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Sven Eckelmann71100.00%1100.00%
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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; }

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Sven Eckelmann46100.00%1100.00%
Total46100.00%1100.00%


static int batadv_log_release(struct inode *inode, struct file *file) { module_put(THIS_MODULE); return 0; }

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Sven Eckelmann24100.00%1100.00%
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static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log) { return !(debug_log->log_start - debug_log->log_end); }

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Sven Eckelmann23100.00%1100.00%
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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; }

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Sven Eckelmann236100.00%1100.00%
Total236100.00%1100.00%


static unsigned int 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; }

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Sven Eckelmann62100.00%1100.00%
Total62100.00%1100.00%

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; }

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Sven Eckelmann107100.00%2100.00%
Total107100.00%2100.00%


void batadv_debug_log_cleanup(struct batadv_priv *bat_priv) { kfree(bat_priv->debug_log); bat_priv->debug_log = NULL; }

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Sven Eckelmann23100.00%1100.00%
Total23100.00%1100.00%


Overall Contributors

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Sven Eckelmann906100.00%3100.00%
Total906100.00%3100.00%
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