/*
 * kretprobe_example.c
 *
 * Here's a sample kernel module showing the use of return probes to
 * report the return value and total time taken for probed function
 * to run.
 *
 * usage: insmod kretprobe_example.ko func=<func_name>
 *
 * If no func_name is specified, _do_fork is instrumented
 *
 * For more information on theory of operation of kretprobes, 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 the probed function returns. (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>
#include <linux/ktime.h>
#include <linux/limits.h>
#include <linux/sched.h>

static char func_name[NAME_MAX] = "_do_fork";
module_param_string(func, func_name, NAME_MAX, S_IRUGO);
MODULE_PARM_DESC(func, "Function to kretprobe; this module will report the"
			" function's execution time");

/* per-instance private data */
struct my_data {
	ktime_t entry_stamp;
};

/* Here we use the entry_hanlder to timestamp function entry */
static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
{
	struct my_data *data;

	if (!current->mm)
		return 1;	/* Skip kernel threads */

	data = (struct my_data *)ri->data;
	data->entry_stamp = ktime_get();
	return 0;
}

/*
 * Return-probe handler: Log the return value and duration. Duration may turn
 * out to be zero consistently, depending upon the granularity of time
 * accounting on the platform.
 */
static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
{
	unsigned long retval = regs_return_value(regs);
	struct my_data *data = (struct my_data *)ri->data;
	s64 delta;
	ktime_t now;

	now = ktime_get();
	delta = ktime_to_ns(ktime_sub(now, data->entry_stamp));
	pr_info("%s returned %lu and took %lld ns to execute\n",
			func_name, retval, (long long)delta);
	return 0;
}

static struct kretprobe my_kretprobe = {
	.handler		= ret_handler,
	.entry_handler		= entry_handler,
	.data_size		= sizeof(struct my_data),
	/* Probe up to 20 instances concurrently. */
	.maxactive		= 20,
};

static int __init kretprobe_init(void)
{
	int ret;

	my_kretprobe.kp.symbol_name = func_name;
	ret = register_kretprobe(&my_kretprobe);
	if (ret < 0) {
		pr_err("register_kretprobe failed, returned %d\n", ret);
		return -1;
	}
	pr_info("Planted return probe at %s: %p\n",
			my_kretprobe.kp.symbol_name, my_kretprobe.kp.addr);
	return 0;
}

static void __exit kretprobe_exit(void)
{
	unregister_kretprobe(&my_kretprobe);
	pr_info("kretprobe at %p unregistered\n", my_kretprobe.kp.addr);

	/* nmissed > 0 suggests that maxactive was set too low. */
	pr_info("Missed probing %d instances of %s\n",
		my_kretprobe.nmissed, my_kretprobe.kp.symbol_name);
}

module_init(kretprobe_init)
module_exit(kretprobe_exit)
MODULE_LICENSE("GPL");
-next.git/log/include/dt-bindings?id=8d1fb01df8f64af14c833805dcbd05bf4582e028'>dt-bindings</a>/<a href='/cgit.cgi/linux/net-next.git/log/include/dt-bindings/clock?id=8d1fb01df8f64af14c833805dcbd05bf4582e028'>clock</a>/<a href='/cgit.cgi/linux/net-next.git/log/include/dt-bindings/clock/maxim,max77620.h?id=8d1fb01df8f64af14c833805dcbd05bf4582e028'>maxim,max77620.h</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/include/dt-bindings/clock/maxim,max77620.h?id=8d1fb01df8f64af14c833805dcbd05bf4582e028&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Kalle Valo &lt;kvalo@codeaurora.org&gt;</td><td class='right'>2017-01-27 14:19:25 +0200</td></tr>
<tr><th>committer</th><td>Kalle Valo &lt;kvalo@codeaurora.org&gt;</td><td class='right'>2017-01-28 09:15:50 +0200</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/arch/m32r?h=nds-private-remove&amp;id=2b1d530cb3157f828fcaadd259613f59db3c6d1c'>2b1d530cb3157f828fcaadd259613f59db3c6d1c</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/arch/m32r?id=2b1d530cb3157f828fcaadd259613f59db3c6d1c'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=2b1d530cb3157f828fcaadd259613f59db3c6d1c'>fb5dfe8f2e6956f54377c7275f330cd158ead259</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/arch/m32r?h=nds-private-remove&amp;id=2b1d530cb3157f828fcaadd259613f59db3c6d1c'>tools/arch/m32r</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/arch/m32r?h=nds-private-remove&amp;id=bd19b5ab1da654de456e102250822ec06311d6ad'>bd19b5ab1da654de456e102250822ec06311d6ad</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/arch/m32r?h=nds-private-remove&amp;id=2b1d530cb3157f828fcaadd259613f59db3c6d1c&amp;id2=bd19b5ab1da654de456e102250822ec06311d6ad'>diff</a>)</td></tr></table>
<div class='commit-subject'>MAINTAINERS: ath9k-devel is closed</div><div class='commit-msg'>ath9k-devel list is now closed, only linux-wireless should be used.

Reported-by: Michael Renzmann &lt;mrenzmann@madwifi-project.org&gt;
Signed-off-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=2b1d530cb3157f828fcaadd259613f59db3c6d1c'>Diffstat</a> (limited to 'tools/arch/m32r')</div><table summary='diffstat' class='diffstat'>