[lttng-modules.git] / include / wrapper / blkdev.h

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * wrapper/blkdev.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>
 */

#ifndef _LTTNG_WRAPPER_BLKDEV_H
#define _LTTNG_WRAPPER_BLKDEV_H

#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0) \
	|| LTTNG_RHEL_KERNEL_RANGE(5,14,0,162,0,0, 5,15,0,0,0,0))
#include <linux/blkdev.h>
#else
#include <linux/genhd.h>
#endif

#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,17,0) \
	|| LTTNG_RHEL_KERNEL_RANGE(5,14,0,162,0,0, 5,15,0,0,0,0))
#define LTTNG_GENHD_FL_HIDDEN GENHD_FL_HIDDEN
#else
#define LTTNG_GENHD_FL_HIDDEN GENHD_FL_SUPPRESS_PARTITION_INFO
#endif

#ifdef CONFIG_KALLSYMS_ALL

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

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;
}

/*
 * Canary function to check for 'block_class' at compile time.
 *
 * From 'include/linux/blkdev.h':
 *
 *   extern struct class block_class;
 */
static inline
struct class *__canary__get_block_class(void)
{
	return &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;
}

/*
 * No canary for 'disk_type', it's only defined in 'block/genhd.c'.
 *
 * static inline
 * struct device_type *__canary__get_disk_type(void)
 * {
 * 	return &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_BLKDEV_H */
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
9f36eaed	2	*
82fbf9d3	3	* wrapper/blkdev.h
f0dbdefb HD	4	*
	5	* wrapper around block layer functions and data structures. Using
	6	* KALLSYMS to get its address when available, else we need to have a
	7	* kernel that exports this function to GPL modules.
	8	*
	9	* Copyright (C) 2011-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
f0dbdefb HD	10	*/
f0dbdefb HD	11
82fbf9d3 MJ	12	#ifndef _LTTNG_WRAPPER_BLKDEV_H
82fbf9d3 MJ	13	#define _LTTNG_WRAPPER_BLKDEV_H
9f36eaed	14
9f2d2694 MJ	15	#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0) \
9f2d2694 MJ	16	\|\| LTTNG_RHEL_KERNEL_RANGE(5,14,0,162,0,0, 5,15,0,0,0,0))
868e0b6d MJ	17	#include <linux/blkdev.h>
868e0b6d MJ	18	#else
f0dbdefb	19	#include <linux/genhd.h>
868e0b6d	20	#endif
f0dbdefb	21
9f2d2694 MJ	22	#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,17,0) \
9f2d2694 MJ	23	\|\| LTTNG_RHEL_KERNEL_RANGE(5,14,0,162,0,0, 5,15,0,0,0,0))
fe72ab45 MJ	24	#define LTTNG_GENHD_FL_HIDDEN GENHD_FL_HIDDEN
	25	#else
	26	#define LTTNG_GENHD_FL_HIDDEN GENHD_FL_SUPPRESS_PARTITION_INFO
	27	#endif
	28
ff04d185	29	#ifdef CONFIG_KALLSYMS_ALL
f0dbdefb HD	30
f0dbdefb HD	31	#include <linux/kallsyms.h>
5a2f5e92	32	#include <wrapper/kallsyms.h>
f0dbdefb	33
f0dbdefb HD	34	static inline
	35	struct class *wrapper_get_block_class(void)
	36	{
	37	struct class *ptr_block_class;
	38
	39	ptr_block_class = (struct class *) kallsyms_lookup_dataptr("block_class");
	40	if (!ptr_block_class) {
e36de50d	41	printk_once(KERN_WARNING "LTTng: block_class symbol lookup failed.\n");
f0dbdefb HD	42	return NULL;
	43	}
	44	return ptr_block_class;
	45	}
	46
3dfec228 MJ	47	/*
	48	* Canary function to check for 'block_class' at compile time.
	49	*
82fbf9d3	50	* From 'include/linux/blkdev.h':
3dfec228 MJ	51	*
	52	* extern struct class block_class;
	53	*/
	54	static inline
	55	struct class *__canary__get_block_class(void)
	56	{
	57	return &block_class;
	58	}
	59
f0dbdefb HD	60	static inline
	61	struct device_type *wrapper_get_disk_type(void)
	62	{
	63	struct device_type *ptr_disk_type;
	64
	65	ptr_disk_type = (struct device_type *) kallsyms_lookup_dataptr("disk_type");
	66	if (!ptr_disk_type) {
e36de50d	67	printk_once(KERN_WARNING "LTTng: disk_type symbol lookup failed.\n");
f0dbdefb HD	68	return NULL;
	69	}
	70	return ptr_disk_type;
	71	}
	72
3dfec228 MJ	73	/*
	74	* No canary for 'disk_type', it's only defined in 'block/genhd.c'.
	75	*
	76	* static inline
	77	* struct device_type *__canary__get_disk_type(void)
	78	* {
	79	* return &disk_type;
	80	* }
	81	*/
	82
f0dbdefb HD	83	#else
	84
	85	static inline
	86	struct class *wrapper_get_block_class(void)
	87	{
	88	/*
	89	* Symbol block_class is not exported.
	90	* TODO: return &block_class;
	91	*/
	92	/* Feature currently unavailable without KALLSYMS_ALL */
	93	return NULL;
	94	}
	95
	96	static inline
	97	struct device_type *wrapper_get_disk_type(void)
	98	{
	99	/*
	100	* Symbol disk_type is not exported.
	101	* TODO: return &disk_type;
	102	*/
	103	/* Feature currently unavailable without KALLSYMS_ALL */
	104	return NULL;
	105	}
	106
	107	#endif
	108
82fbf9d3	109	#endif /* _LTTNG_WRAPPER_BLKDEV_H */