[linux-2.6-block.git] / kernel / gcov / base.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  This code maintains a list of active profiling data structures.
 *
 *    Copyright IBM Corp. 2009
 *    Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
 *
 *    Uses gcc-internal data definitions.
 *    Based on the gcov-kernel patch by:
 *		 Hubertus Franke <frankeh@us.ibm.com>
 *		 Nigel Hinds <nhinds@us.ibm.com>
 *		 Rajan Ravindran <rajancr@us.ibm.com>
 *		 Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
 *		 Paul Larson
 */

#define pr_fmt(fmt)	"gcov: " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include "gcov.h"

int gcov_events_enabled;
DEFINE_MUTEX(gcov_lock);

/**
 * gcov_enable_events - enable event reporting through gcov_event()
 *
 * Turn on reporting of profiling data load/unload-events through the
 * gcov_event() callback. Also replay all previous events once. This function
 * is needed because some events are potentially generated too early for the
 * callback implementation to handle them initially.
 */
void gcov_enable_events(void)
{
	struct gcov_info *info = NULL;

	mutex_lock(&gcov_lock);
	gcov_events_enabled = 1;

	/* Perform event callback for previously registered entries. */
	while ((info = gcov_info_next(info))) {
		gcov_event(GCOV_ADD, info);
		cond_resched();
	}

	mutex_unlock(&gcov_lock);
}

#ifdef CONFIG_MODULES
/* Update list and generate events when modules are unloaded. */
static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
				void *data)
{
	struct module *mod = data;
	struct gcov_info *info = NULL;
	struct gcov_info *prev = NULL;

	if (event != MODULE_STATE_GOING)
		return NOTIFY_OK;
	mutex_lock(&gcov_lock);

	/* Remove entries located in module from linked list. */
	while ((info = gcov_info_next(info))) {
		if (within_module((unsigned long)info, mod)) {
			gcov_info_unlink(prev, info);
			if (gcov_events_enabled)
				gcov_event(GCOV_REMOVE, info);
		} else
			prev = info;
	}

	mutex_unlock(&gcov_lock);

	return NOTIFY_OK;
}

static struct notifier_block gcov_nb = {
	.notifier_call	= gcov_module_notifier,
};

static int __init gcov_init(void)
{
	return register_module_notifier(&gcov_nb);
}
device_initcall(gcov_init);
#endif /* CONFIG_MODULES */
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
2521f2c2 PO	2	/*
	3	* This code maintains a list of active profiling data structures.
	4	*
	5	* Copyright IBM Corp. 2009
	6	* Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
	7	*
	8	* Uses gcc-internal data definitions.
	9	* Based on the gcov-kernel patch by:
	10	* Hubertus Franke <frankeh@us.ibm.com>
	11	* Nigel Hinds <nhinds@us.ibm.com>
	12	* Rajan Ravindran <rajancr@us.ibm.com>
	13	* Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
	14	* Paul Larson
	15	*/
	16
	17	#define pr_fmt(fmt) "gcov: " fmt
	18
	19	#include <linux/init.h>
	20	#include <linux/module.h>
	21	#include <linux/mutex.h>
9d796e66	22	#include <linux/sched.h>
2521f2c2 PO	23	#include "gcov.h"
2521f2c2 PO	24
826eba0d GH	25	int gcov_events_enabled;
826eba0d GH	26	DEFINE_MUTEX(gcov_lock);
05384213	27
2521f2c2 PO	28	/**
	29	* gcov_enable_events - enable event reporting through gcov_event()
	30	*
	31	* Turn on reporting of profiling data load/unload-events through the
	32	* gcov_event() callback. Also replay all previous events once. This function
	33	* is needed because some events are potentially generated too early for the
	34	* callback implementation to handle them initially.
	35	*/
	36	void gcov_enable_events(void)
	37	{
8cbce376	38	struct gcov_info *info = NULL;
2521f2c2 PO	39
	40	mutex_lock(&gcov_lock);
	41	gcov_events_enabled = 1;
8cbce376	42
2521f2c2	43	/* Perform event callback for previously registered entries. */
9d796e66	44	while ((info = gcov_info_next(info))) {
2521f2c2	45	gcov_event(GCOV_ADD, info);
9d796e66 AR	46	cond_resched();
9d796e66 AR	47	}
8cbce376	48
2521f2c2 PO	49	mutex_unlock(&gcov_lock);
	50	}
	51
	52	#ifdef CONFIG_MODULES
2521f2c2 PO	53	/* Update list and generate events when modules are unloaded. */
	54	static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
	55	void *data)
	56	{
	57	struct module *mod = data;
8cbce376 FH	58	struct gcov_info *info = NULL;
8cbce376 FH	59	struct gcov_info *prev = NULL;
2521f2c2 PO	60
	61	if (event != MODULE_STATE_GOING)
	62	return NOTIFY_OK;
	63	mutex_lock(&gcov_lock);
8cbce376	64
2521f2c2	65	/* Remove entries located in module from linked list. */
8cbce376	66	while ((info = gcov_info_next(info))) {
c65abf35	67	if (within_module((unsigned long)info, mod)) {
8cbce376	68	gcov_info_unlink(prev, info);
2521f2c2 PO	69	if (gcov_events_enabled)
	70	gcov_event(GCOV_REMOVE, info);
	71	} else
	72	prev = info;
	73	}
8cbce376	74
2521f2c2 PO	75	mutex_unlock(&gcov_lock);
	76
	77	return NOTIFY_OK;
	78	}
	79
	80	static struct notifier_block gcov_nb = {
	81	.notifier_call = gcov_module_notifier,
	82	};
	83
	84	static int __init gcov_init(void)
	85	{
	86	return register_module_notifier(&gcov_nb);
	87	}
	88	device_initcall(gcov_init);
	89	#endif /* CONFIG_MODULES */