[lttng-modules.git] / wrapper / ftrace.h

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 *
 * wrapper/ftrace.h
 *
 * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
 * available, else we need to have a kernel that exports this function to GPL
 * modules.
 *
 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#ifndef _LTTNG_WRAPPER_FTRACE_H
#define _LTTNG_WRAPPER_FTRACE_H

#include <linux/ftrace.h>
#include <linux/version.h>
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
#include <../kernel/trace/trace.h>
#endif

#ifdef CONFIG_KALLSYMS

#include <linux/kallsyms.h>
#include <wrapper/kallsyms.h>

static inline
int wrapper_register_ftrace_function_probe(char *glob,
		struct ftrace_probe_ops *ops, void *data)
{
	int (*register_ftrace_function_probe_sym)(char *glob,
			struct ftrace_probe_ops *ops, void *data);

	register_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("register_ftrace_function_probe");
	if (register_ftrace_function_probe_sym) {
		return register_ftrace_function_probe_sym(glob, ops, data);
	} else {
		printk_once(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
		return -EINVAL;
	}
}

static inline
void wrapper_unregister_ftrace_function_probe(char *glob,
		struct ftrace_probe_ops *ops, void *data)
{
	void (*unregister_ftrace_function_probe_sym)(char *glob,
			struct ftrace_probe_ops *ops, void *data);

	unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("unregister_ftrace_function_probe");
	if (unregister_ftrace_function_probe_sym) {
		unregister_ftrace_function_probe_sym(glob, ops, data);
	} else {
		printk_once(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
		WARN_ON(1);
	}
}

#else

static inline
int wrapper_register_ftrace_function_probe(char *glob,
		struct ftrace_probe_ops *ops, void *data)
{
	return register_ftrace_function_probe(glob, ops, data);
}

static inline
void wrapper_unregister_ftrace_function_probe(char *glob,
		struct ftrace_probe_ops *ops, void *data)
{
	return unregister_ftrace_function_probe(glob, ops, data);
}
#endif

#endif /* _LTTNG_WRAPPER_FTRACE_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
	2	*
	3	* wrapper/ftrace.h
	4	*
	5	* wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
	6	* available, else we need to have a kernel that exports this function to GPL
	7	* modules.
	8	*
	9	* Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*/
	11
	12	#ifndef _LTTNG_WRAPPER_FTRACE_H
	13	#define _LTTNG_WRAPPER_FTRACE_H
	14
	15	#include <linux/ftrace.h>
	16	#include <linux/version.h>
	17	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
	18	#include <../kernel/trace/trace.h>
	19	#endif
	20
	21	#ifdef CONFIG_KALLSYMS
	22
	23	#include <linux/kallsyms.h>
	24	#include <wrapper/kallsyms.h>
	25
	26	static inline
	27	int wrapper_register_ftrace_function_probe(char *glob,
	28	struct ftrace_probe_ops ops, void data)
	29	{
	30	int (register_ftrace_function_probe_sym)(char glob,
	31	struct ftrace_probe_ops ops, void data);
	32
	33	register_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("register_ftrace_function_probe");
	34	if (register_ftrace_function_probe_sym) {
	35	return register_ftrace_function_probe_sym(glob, ops, data);
	36	} else {
	37	printk_once(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
	38	return -EINVAL;
	39	}
	40	}
	41
	42	static inline
	43	void wrapper_unregister_ftrace_function_probe(char *glob,
	44	struct ftrace_probe_ops ops, void data)
	45	{
	46	void (unregister_ftrace_function_probe_sym)(char glob,
	47	struct ftrace_probe_ops ops, void data);
	48
	49	unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_funcptr("unregister_ftrace_function_probe");
	50	if (unregister_ftrace_function_probe_sym) {
	51	unregister_ftrace_function_probe_sym(glob, ops, data);
	52	} else {
	53	printk_once(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
	54	WARN_ON(1);
	55	}
	56	}
	57
	58	#else
	59
	60	static inline
	61	int wrapper_register_ftrace_function_probe(char *glob,
	62	struct ftrace_probe_ops ops, void data)
	63	{
	64	return register_ftrace_function_probe(glob, ops, data);
	65	}
	66
	67	static inline
	68	void wrapper_unregister_ftrace_function_probe(char *glob,
	69	struct ftrace_probe_ops ops, void data)
	70	{
	71	return unregister_ftrace_function_probe(glob, ops, data);
	72	}
	73	#endif
	74
	75	#endif /* _LTTNG_WRAPPER_FTRACE_H */