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

#ifndef _LTTNG_WRAPPER_GENHD_H
#define _LTTNG_WRAPPER_GENHD_H

/*
 * wrapper/genhd.h
 *
 * wrapper around block layer functions and data structures. Using
 * KALLSYMS to get its address when available, else we need to have a
 * kernel that exports this function to GPL modules.
 *
 * Copyright (C) 2011-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <linux/genhd.h>

#ifdef CONFIG_KALLSYMS

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

static inline
char *wrapper_disk_name(struct gendisk *hd, int partno, char *buf)
{
	char *(*disk_name_sym)(struct gendisk *hd, int partno, char *buf);

	disk_name_sym = (void *) kallsyms_lookup_funcptr("disk_name");
	if (disk_name_sym) {
		return disk_name_sym(hd, partno, buf);
	} else {
		printk_once(KERN_WARNING "LTTng: disk_name symbol lookup failed.\n");
		return NULL;
	}
}

#else

static inline
char *wrapper_disk_name(struct gendisk *hd, int partno, char *buf)
{
	return disk_name(hd, partno, buf);
}

#endif

#ifdef CONFIG_KALLSYMS_ALL

static inline
struct class *wrapper_get_block_class(void)
{
	struct class *ptr_block_class;

	ptr_block_class = (struct class *) kallsyms_lookup_dataptr("block_class");
	if (!ptr_block_class) {
		printk_once(KERN_WARNING "LTTng: block_class symbol lookup failed.\n");
		return NULL;
	}
	return ptr_block_class;
}

static inline
struct device_type *wrapper_get_disk_type(void)
{
	struct device_type *ptr_disk_type;

	ptr_disk_type = (struct device_type *) kallsyms_lookup_dataptr("disk_type");
	if (!ptr_disk_type) {
		printk_once(KERN_WARNING "LTTng: disk_type symbol lookup failed.\n");
		return NULL;
	}
	return ptr_disk_type;
}

#else

static inline
struct class *wrapper_get_block_class(void)
{
	/*
	 * Symbol block_class is not exported.
	 * TODO: return &block_class;
	 */
	/* Feature currently unavailable without KALLSYMS_ALL */
	return NULL;
}

static inline
struct device_type *wrapper_get_disk_type(void)
{
	/*
	 * Symbol disk_type is not exported.
	 * TODO: return &disk_type;
	 */
	/* Feature currently unavailable without KALLSYMS_ALL */
	return NULL;
}

#endif

#endif /* _LTTNG_WRAPPER_GENHD_H */
Commit	Line	Data
f0dbdefb HD	1	#ifndef _LTTNG_WRAPPER_GENHD_H
	2	#define _LTTNG_WRAPPER_GENHD_H
	3
	4	/*
	5	* wrapper/genhd.h
	6	*
	7	* wrapper around block layer functions and data structures. Using
	8	* KALLSYMS to get its address when available, else we need to have a
	9	* kernel that exports this function to GPL modules.
	10	*
	11	* Copyright (C) 2011-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	12	*
	13	* This library is free software; you can redistribute it and/or
	14	* modify it under the terms of the GNU Lesser General Public
	15	* License as published by the Free Software Foundation; only
	16	* version 2.1 of the License.
	17	*
	18	* This library is distributed in the hope that it will be useful,
	19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	21	* Lesser General Public License for more details.
	22	*
	23	* You should have received a copy of the GNU Lesser General Public
	24	* License along with this library; if not, write to the Free Software
	25	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	26	*/
	27
	28	#include <linux/genhd.h>
	29
	30	#ifdef CONFIG_KALLSYMS
	31
	32	#include <linux/kallsyms.h>
5a2f5e92	33	#include <wrapper/kallsyms.h>
f0dbdefb HD	34
	35	static inline
	36	char wrapper_disk_name(struct gendisk hd, int partno, char *buf)
	37	{
	38	char (disk_name_sym)(struct gendisk hd, int partno, char buf);
	39
	40	disk_name_sym = (void *) kallsyms_lookup_funcptr("disk_name");
	41	if (disk_name_sym) {
	42	return disk_name_sym(hd, partno, buf);
	43	} else {
e36de50d	44	printk_once(KERN_WARNING "LTTng: disk_name symbol lookup failed.\n");
f0dbdefb HD	45	return NULL;
	46	}
	47	}
	48
	49	#else
	50
	51	static inline
	52	char wrapper_disk_name(struct gendisk hd, int partno, char *buf)
	53	{
	54	return disk_name(hd, partno, buf);
	55	}
	56
	57	#endif
	58
	59	#ifdef CONFIG_KALLSYMS_ALL
	60
	61	static inline
	62	struct class *wrapper_get_block_class(void)
	63	{
	64	struct class *ptr_block_class;
	65
	66	ptr_block_class = (struct class *) kallsyms_lookup_dataptr("block_class");
	67	if (!ptr_block_class) {
e36de50d	68	printk_once(KERN_WARNING "LTTng: block_class symbol lookup failed.\n");
f0dbdefb HD	69	return NULL;
	70	}
	71	return ptr_block_class;
	72	}
	73
	74	static inline
	75	struct device_type *wrapper_get_disk_type(void)
	76	{
	77	struct device_type *ptr_disk_type;
	78
	79	ptr_disk_type = (struct device_type *) kallsyms_lookup_dataptr("disk_type");
	80	if (!ptr_disk_type) {
e36de50d	81	printk_once(KERN_WARNING "LTTng: disk_type symbol lookup failed.\n");
f0dbdefb HD	82	return NULL;
	83	}
	84	return ptr_disk_type;
	85	}
	86
	87	#else
	88
	89	static inline
	90	struct class *wrapper_get_block_class(void)
	91	{
	92	/*
	93	* Symbol block_class is not exported.
	94	* TODO: return &block_class;
	95	*/
	96	/* Feature currently unavailable without KALLSYMS_ALL */
	97	return NULL;
	98	}
	99
	100	static inline
	101	struct device_type *wrapper_get_disk_type(void)
	102	{
	103	/*
	104	* Symbol disk_type is not exported.
	105	* TODO: return &disk_type;
	106	*/
	107	/* Feature currently unavailable without KALLSYMS_ALL */
	108	return NULL;
	109	}
	110
	111	#endif
	112
	113	#endif /* _LTTNG_WRAPPER_GENHD_H */