// 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);} /** * store_gcov_u32 - store 32 bit number in gcov format to buffer * @buffer: target buffer or NULL * @off: offset into the buffer * @v: value to be stored * * Number format defined by gcc: numbers are recorded in the 32 bit * unsigned binary form of the endianness of the machine generating the * file. Returns the number of bytes stored. If @buffer is %NULL, doesn't * store anything. */size_t store_gcov_u32(void *buffer, size_t off, u32 v){	u32 *data; 	if (buffer) {		data = buffer + off;		*data = v;	} 	return sizeof(*data);} /** * store_gcov_u64 - store 64 bit number in gcov format to buffer * @buffer: target buffer or NULL * @off: offset into the buffer * @v: value to be stored * * Number format defined by gcc: numbers are recorded in the 32 bit * unsigned binary form of the endianness of the machine generating the * file. 64 bit numbers are stored as two 32 bit numbers, the low part * first. Returns the number of bytes stored. If @buffer is %NULL, doesn't store * anything. */size_t store_gcov_u64(void *buffer, size_t off, u64 v){	u32 *data; 	if (buffer) {		data = buffer + off; 		data[0] = (v & 0xffffffffUL);		data[1] = (v >> 32);	} 	return sizeof(*data) * 2;} #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 (gcov_info_within_module(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 */