[deliverable/linux.git] / kernel / gcov / base.c

/*
 *  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"

static int gcov_events_enabled;
static DEFINE_MUTEX(gcov_lock);

/*
 * __gcov_init is called by gcc-generated constructor code for each object
 * file compiled with -fprofile-arcs.
 */
void __gcov_init(struct gcov_info *info)
{
	static unsigned int gcov_version;

	mutex_lock(&gcov_lock);
	if (gcov_version == 0) {
		gcov_version = gcov_info_version(info);
		/*
		 * Printing gcc's version magic may prove useful for debugging
		 * incompatibility reports.
		 */
		pr_info("version magic: 0x%x\n", gcov_version);
	}
	/*
	 * Add new profiling data structure to list and inform event
	 * listener.
	 */
	gcov_info_link(info);
	if (gcov_events_enabled)
		gcov_event(GCOV_ADD, info);
	mutex_unlock(&gcov_lock);
}
EXPORT_SYMBOL(__gcov_init);

/*
 * These functions may be referenced by gcc-generated profiling code but serve
 * no function for kernel profiling.
 */
void __gcov_flush(void)
{
	/* Unused. */
}
EXPORT_SYMBOL(__gcov_flush);

void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
{
	/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_add);

void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
{
	/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_single);

void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
{
	/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_delta);

void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
{
	/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_ior);

void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
{
	/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_time_profile);

void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
{
	/* Unused. */
}
EXPORT_SYMBOL(__gcov_merge_icall_topn);

/**
 * 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
2521f2c2 PO	1	/*
	2	* This code maintains a list of active profiling data structures.
	3	*
	4	* Copyright IBM Corp. 2009
	5	* Author(s): Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
	6	*
	7	* Uses gcc-internal data definitions.
	8	* Based on the gcov-kernel patch by:
	9	* Hubertus Franke <frankeh@us.ibm.com>
	10	* Nigel Hinds <nhinds@us.ibm.com>
	11	* Rajan Ravindran <rajancr@us.ibm.com>
	12	* Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
	13	* Paul Larson
	14	*/
	15
	16	#define pr_fmt(fmt) "gcov: " fmt
	17
	18	#include <linux/init.h>
	19	#include <linux/module.h>
	20	#include <linux/mutex.h>
9d796e66	21	#include <linux/sched.h>
2521f2c2 PO	22	#include "gcov.h"
2521f2c2 PO	23
2521f2c2 PO	24	static int gcov_events_enabled;
	25	static DEFINE_MUTEX(gcov_lock);
	26
	27	/*
	28	* __gcov_init is called by gcc-generated constructor code for each object
	29	* file compiled with -fprofile-arcs.
	30	*/
	31	void __gcov_init(struct gcov_info *info)
	32	{
	33	static unsigned int gcov_version;
	34
	35	mutex_lock(&gcov_lock);
	36	if (gcov_version == 0) {
8cbce376	37	gcov_version = gcov_info_version(info);
2521f2c2 PO	38	/*
	39	* Printing gcc's version magic may prove useful for debugging
	40	* incompatibility reports.
	41	*/
	42	pr_info("version magic: 0x%x\n", gcov_version);
	43	}
	44	/*
	45	* Add new profiling data structure to list and inform event
	46	* listener.
	47	*/
8cbce376	48	gcov_info_link(info);
2521f2c2 PO	49	if (gcov_events_enabled)
	50	gcov_event(GCOV_ADD, info);
	51	mutex_unlock(&gcov_lock);
	52	}
	53	EXPORT_SYMBOL(__gcov_init);
	54
	55	/*
	56	* These functions may be referenced by gcc-generated profiling code but serve
	57	* no function for kernel profiling.
	58	*/
	59	void __gcov_flush(void)
	60	{
	61	/* Unused. */
	62	}
	63	EXPORT_SYMBOL(__gcov_flush);
	64
	65	void __gcov_merge_add(gcov_type *counters, unsigned int n_counters)
	66	{
	67	/* Unused. */
	68	}
	69	EXPORT_SYMBOL(__gcov_merge_add);
	70
	71	void __gcov_merge_single(gcov_type *counters, unsigned int n_counters)
	72	{
	73	/* Unused. */
	74	}
	75	EXPORT_SYMBOL(__gcov_merge_single);
	76
	77	void __gcov_merge_delta(gcov_type *counters, unsigned int n_counters)
	78	{
	79	/* Unused. */
	80	}
	81	EXPORT_SYMBOL(__gcov_merge_delta);
	82
5f41ea03 FH	83	void __gcov_merge_ior(gcov_type *counters, unsigned int n_counters)
	84	{
	85	/* Unused. */
	86	}
	87	EXPORT_SYMBOL(__gcov_merge_ior);
	88
a992bf83 YP	89	void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
	90	{
	91	/* Unused. */
	92	}
	93	EXPORT_SYMBOL(__gcov_merge_time_profile);
	94
3e44c471 LS	95	void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
	96	{
	97	/* Unused. */
	98	}
	99	EXPORT_SYMBOL(__gcov_merge_icall_topn);
	100
2521f2c2 PO	101	/**
	102	* gcov_enable_events - enable event reporting through gcov_event()
	103	*
	104	* Turn on reporting of profiling data load/unload-events through the
	105	* gcov_event() callback. Also replay all previous events once. This function
	106	* is needed because some events are potentially generated too early for the
	107	* callback implementation to handle them initially.
	108	*/
	109	void gcov_enable_events(void)
	110	{
8cbce376	111	struct gcov_info *info = NULL;
2521f2c2 PO	112
	113	mutex_lock(&gcov_lock);
	114	gcov_events_enabled = 1;
8cbce376	115
2521f2c2	116	/* Perform event callback for previously registered entries. */
9d796e66	117	while ((info = gcov_info_next(info))) {
2521f2c2	118	gcov_event(GCOV_ADD, info);
9d796e66 AR	119	cond_resched();
9d796e66 AR	120	}
8cbce376	121
2521f2c2 PO	122	mutex_unlock(&gcov_lock);
	123	}
	124
	125	#ifdef CONFIG_MODULES
2521f2c2 PO	126	/* Update list and generate events when modules are unloaded. */
	127	static int gcov_module_notifier(struct notifier_block *nb, unsigned long event,
	128	void *data)
	129	{
	130	struct module *mod = data;
8cbce376 FH	131	struct gcov_info *info = NULL;
8cbce376 FH	132	struct gcov_info *prev = NULL;
2521f2c2 PO	133
	134	if (event != MODULE_STATE_GOING)
	135	return NOTIFY_OK;
	136	mutex_lock(&gcov_lock);
8cbce376	137
2521f2c2	138	/* Remove entries located in module from linked list. */
8cbce376	139	while ((info = gcov_info_next(info))) {
c65abf35	140	if (within_module((unsigned long)info, mod)) {
8cbce376	141	gcov_info_unlink(prev, info);
2521f2c2 PO	142	if (gcov_events_enabled)
	143	gcov_event(GCOV_REMOVE, info);
	144	} else
	145	prev = info;
	146	}
8cbce376	147
2521f2c2 PO	148	mutex_unlock(&gcov_lock);
	149
	150	return NOTIFY_OK;
	151	}
	152
	153	static struct notifier_block gcov_nb = {
	154	.notifier_call = gcov_module_notifier,
	155	};
	156
	157	static int __init gcov_init(void)
	158	{
	159	return register_module_notifier(&gcov_nb);
	160	}
	161	device_initcall(gcov_init);
	162	#endif /* CONFIG_MODULES */