kernel-ark/samples/markers/marker-example.c
Denis V. Lunev 16e70f64a9 samples: use non-racy method for /proc/marker-example creation
Use proc_create() to make sure that ->proc_fops be setup before gluing PDE to
main tree.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:21 -07:00

54 lines
1.1 KiB
C

/* marker-example.c
*
* Executes a marker when /proc/marker-example is opened.
*
* (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
*
* This file is released under the GPLv2.
* See the file COPYING for more details.
*/
#include <linux/module.h>
#include <linux/marker.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
struct proc_dir_entry *pentry_example;
static int my_open(struct inode *inode, struct file *file)
{
int i;
trace_mark(subsystem_event, "integer %d string %s", 123,
"example string");
for (i = 0; i < 10; i++)
trace_mark(subsystem_eventb, MARK_NOARGS);
return -EPERM;
}
static struct file_operations mark_ops = {
.open = my_open,
};
static int example_init(void)
{
printk(KERN_ALERT "example init\n");
pentry_example = proc_create("marker-example", 0444, NULL, &mark_ops);
if (!pentry_example)
return -EPERM;
return 0;
}
static void example_exit(void)
{
printk(KERN_ALERT "example exit\n");
remove_proc_entry("marker-example", NULL);
}
module_init(example_init)
module_exit(example_exit)
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mathieu Desnoyers");
MODULE_DESCRIPTION("Marker example");