149 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			149 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			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 "gcov.h"
 | 
						|
 | 
						|
static struct gcov_info *gcov_info_head;
 | 
						|
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 = info->version;
 | 
						|
		/*
 | 
						|
		 * 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.
 | 
						|
	 */
 | 
						|
	info->next = gcov_info_head;
 | 
						|
	gcov_info_head = 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);
 | 
						|
 | 
						|
/**
 | 
						|
 * 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;
 | 
						|
 | 
						|
	mutex_lock(&gcov_lock);
 | 
						|
	gcov_events_enabled = 1;
 | 
						|
	/* Perform event callback for previously registered entries. */
 | 
						|
	for (info = gcov_info_head; info; info = info->next)
 | 
						|
		gcov_event(GCOV_ADD, info);
 | 
						|
	mutex_unlock(&gcov_lock);
 | 
						|
}
 | 
						|
 | 
						|
#ifdef CONFIG_MODULES
 | 
						|
static inline int within(void *addr, void *start, unsigned long size)
 | 
						|
{
 | 
						|
	return ((addr >= start) && (addr < start + size));
 | 
						|
}
 | 
						|
 | 
						|
/* 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;
 | 
						|
	struct gcov_info *prev;
 | 
						|
 | 
						|
	if (event != MODULE_STATE_GOING)
 | 
						|
		return NOTIFY_OK;
 | 
						|
	mutex_lock(&gcov_lock);
 | 
						|
	prev = NULL;
 | 
						|
	/* Remove entries located in module from linked list. */
 | 
						|
	for (info = gcov_info_head; info; info = info->next) {
 | 
						|
		if (within(info, mod->module_core, mod->core_size)) {
 | 
						|
			if (prev)
 | 
						|
				prev->next = info->next;
 | 
						|
			else
 | 
						|
				gcov_info_head = info->next;
 | 
						|
			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 */
 |