/*
 * Here's a sample kernel module showing the use of jprobes to dump
 * the arguments of _do_fork().
 *
 * For more information on theory of operation of jprobes, see
 * Documentation/kprobes.txt
 *
 * Build and insert the kernel module as done in the kprobe example.
 * You will see the trace data in /var/log/messages and on the
 * console whenever _do_fork() is invoked to create a new process.
 * (Some messages may be suppressed if syslogd is configured to
 * eliminate duplicate messages.)
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/kprobes.h>

/*
 * Jumper probe for _do_fork.
 * Mirror principle enables access to arguments of the probed routine
 * from the probe handler.
 */

/* Proxy routine having the same arguments as actual _do_fork() routine */
static long j_do_fork(unsigned long clone_flags, unsigned long stack_start,
	      unsigned long stack_size, int __user *parent_tidptr,
	      int __user *child_tidptr, unsigned long tls)
{
	pr_info("jprobe: clone_flags = 0x%lx, stack_start = 0x%lx "
		"stack_size = 0x%lx\n", clone_flags, stack_start, stack_size);

	/* Always end with a call to jprobe_return(). */
	jprobe_return();
	return 0;
}

static struct jprobe my_jprobe = {
	.entry			= j_do_fork,
	.kp = {
		.symbol_name	= "_do_fork",
	},
};

static int __init jprobe_init(void)
{
	int ret;

	ret = register_jprobe(&my_jprobe);
	if (ret < 0) {
		pr_err("register_jprobe failed, returned %d\n", ret);
		return -1;
	}
	pr_info("Planted jprobe at %p, handler addr %p\n",
	       my_jprobe.kp.addr, my_jprobe.entry);
	return 0;
}

static void __exit jprobe_exit(void)
{
	unregister_jprobe(&my_jprobe);
	pr_info("jprobe at %p unregistered\n", my_jprobe.kp.addr);
}

module_init(jprobe_init)
module_exit(jprobe_exit)
MODULE_LICENSE("GPL");
4b7c3dc8ae6bee8026'>tree</a><a href='/cgit.cgi/linux/net-next.git/commit/net/wireless/wext-proc.c?id=087fa712a00685dac4bcc64b7c3dc8ae6bee8026'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/net/wireless/wext-proc.c?id=087fa712a00685dac4bcc64b7c3dc8ae6bee8026'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/net/wireless/wext-proc.c'>
<input type='hidden' name='id' value='087fa712a00685dac4bcc64b7c3dc8ae6bee8026'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/log/?id=087fa712a00685dac4bcc64b7c3dc8ae6bee8026'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/net?id=087fa712a00685dac4bcc64b7c3dc8ae6bee8026'>net</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/wireless?id=087fa712a00685dac4bcc64b7c3dc8ae6bee8026'>wireless</a>/<a href='/cgit.cgi/linux/net-next.git/log/net/wireless/wext-proc.c?id=087fa712a00685dac4bcc64b7c3dc8ae6bee8026'>wext-proc.c</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/net/wireless/wext-proc.c?id=087fa712a00685dac4bcc64b7c3dc8ae6bee8026&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>