[lttng-modules.git] / wrapper / page_alloc.c

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 * wrapper/page_alloc.c
 *
 * wrapper around get_pfnblock_flags_mask and Ubuntu
 * get_pageblock_flags_mask. Using KALLSYMS to get their address when
 * available, else we need to have a kernel that exports this function
 * to GPL modules.
 *
 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#include <lttng-kernel-version.h>

#if (defined(CONFIG_KALLSYMS) \
	&& (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,19,2)	\
		|| LTTNG_KERNEL_RANGE(3,14,36, 3,15,0)		\
		|| LTTNG_KERNEL_RANGE(3,18,10, 3,19,0)		\
		|| LTTNG_DEBIAN_KERNEL_RANGE(3,16,7,9,0,0, 3,17,0,0,0,0) \
		|| LTTNG_UBUNTU_KERNEL_RANGE(3,16,7,34, 3,17,0,0)))

#include <linux/kallsyms.h>
#include <linux/mm_types.h>
#include <linux/module.h>
#include <wrapper/kallsyms.h>
#include <wrapper/page_alloc.h>

static
unsigned long (*get_pfnblock_flags_mask_sym)(struct page *page,
		unsigned long pfn,
		unsigned long end_bitidx,
		unsigned long mask);

unsigned long wrapper_get_pfnblock_flags_mask(struct page *page,
		unsigned long pfn,
		unsigned long end_bitidx,
		unsigned long mask)
{
	WARN_ON_ONCE(!get_pfnblock_flags_mask_sym);
	if (get_pfnblock_flags_mask_sym) {
		return get_pfnblock_flags_mask_sym(page, pfn, end_bitidx, mask);
	} else {
		return -ENOSYS;
	}
}
EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask);

int wrapper_get_pfnblock_flags_mask_init(void)
{
	get_pfnblock_flags_mask_sym =
		(void *) kallsyms_lookup_funcptr("get_pfnblock_flags_mask");
	if (!get_pfnblock_flags_mask_sym)
		return -1;
	return 0;
}
EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);

/*
 * Canary function to check for 'get_pfnblock_flags_mask()' at compile time.
 *
 * From 'include/linux/pageblock-flags.h':
 *
 *   unsigned long get_pfnblock_flags_mask(struct page *page,
 *                                         unsigned long pfn,
 *                                         unsigned long end_bitidx,
 *                                         unsigned long mask);
 */
__attribute__((unused)) static
unsigned long __canary__get_pfnblock_flags_mask(struct page *page,
						unsigned long pfn,
						unsigned long end_bitidx,
						unsigned long mask)
{
	return get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
}

#else

#include <linux/pageblock-flags.h>

#endif

#if (defined(CONFIG_KALLSYMS) \
	&& LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,50, 3,14,0,0))

#include <linux/kallsyms.h>
#include <linux/mm_types.h>
#include <linux/module.h>
#include <wrapper/kallsyms.h>
#include <wrapper/page_alloc.h>

static
unsigned long (*get_pageblock_flags_mask_sym)(struct page *page,
		unsigned long end_bitidx,
		unsigned long mask);

unsigned long wrapper_get_pageblock_flags_mask(struct page *page,
		unsigned long end_bitidx,
		unsigned long mask)
{
	WARN_ON_ONCE(!get_pageblock_flags_mask_sym);
	if (get_pageblock_flags_mask_sym) {
		return get_pageblock_flags_mask_sym(page, end_bitidx, mask);
	} else {
		return -ENOSYS;
	}
}
EXPORT_SYMBOL_GPL(wrapper_get_pageblock_flags_mask);

int wrapper_get_pageblock_flags_mask_init(void)
{
	get_pageblock_flags_mask_sym =
		(void *) kallsyms_lookup_funcptr("get_pageblock_flags_mask");
	if (!get_pageblock_flags_mask_sym)
		return -1;
	return 0;
}
EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);

#else

#include <linux/pageblock-flags.h>

#endif
Commit	Line	Data
	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
	2	* wrapper/page_alloc.c
	3	*
	4	* wrapper around get_pfnblock_flags_mask and Ubuntu
	5	* get_pageblock_flags_mask. Using KALLSYMS to get their address when
	6	* available, else we need to have a kernel that exports this function
	7	* to GPL modules.
	8	*
	9	* Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	10	*/
	11
	12	#include <lttng-kernel-version.h>
	13
	14	#if (defined(CONFIG_KALLSYMS) \
	15	&& (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,19,2) \
	16	\|\| LTTNG_KERNEL_RANGE(3,14,36, 3,15,0) \
	17	\|\| LTTNG_KERNEL_RANGE(3,18,10, 3,19,0) \
	18	\|\| LTTNG_DEBIAN_KERNEL_RANGE(3,16,7,9,0,0, 3,17,0,0,0,0) \
	19	\|\| LTTNG_UBUNTU_KERNEL_RANGE(3,16,7,34, 3,17,0,0)))
	20
	21	#include <linux/kallsyms.h>
	22	#include <linux/mm_types.h>
	23	#include <linux/module.h>
	24	#include <wrapper/kallsyms.h>
	25	#include <wrapper/page_alloc.h>
	26
	27	static
	28	unsigned long (get_pfnblock_flags_mask_sym)(struct page page,
	29	unsigned long pfn,
	30	unsigned long end_bitidx,
	31	unsigned long mask);
	32
	33	unsigned long wrapper_get_pfnblock_flags_mask(struct page *page,
	34	unsigned long pfn,
	35	unsigned long end_bitidx,
	36	unsigned long mask)
	37	{
	38	WARN_ON_ONCE(!get_pfnblock_flags_mask_sym);
	39	if (get_pfnblock_flags_mask_sym) {
	40	return get_pfnblock_flags_mask_sym(page, pfn, end_bitidx, mask);
	41	} else {
	42	return -ENOSYS;
	43	}
	44	}
	45	EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask);
	46
	47	int wrapper_get_pfnblock_flags_mask_init(void)
	48	{
	49	get_pfnblock_flags_mask_sym =
	50	(void *) kallsyms_lookup_funcptr("get_pfnblock_flags_mask");
	51	if (!get_pfnblock_flags_mask_sym)
	52	return -1;
	53	return 0;
	54	}
	55	EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);
	56
	57	/*
	58	* Canary function to check for 'get_pfnblock_flags_mask()' at compile time.
	59	*
	60	* From 'include/linux/pageblock-flags.h':
	61	*
	62	* unsigned long get_pfnblock_flags_mask(struct page *page,
	63	* unsigned long pfn,
	64	* unsigned long end_bitidx,
	65	* unsigned long mask);
	66	*/
	67	__attribute__((unused)) static
	68	unsigned long __canary__get_pfnblock_flags_mask(struct page *page,
	69	unsigned long pfn,
	70	unsigned long end_bitidx,
	71	unsigned long mask)
	72	{
	73	return get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
	74	}
	75
	76	#else
	77
	78	#include <linux/pageblock-flags.h>
	79
	80	#endif
	81
	82	#if (defined(CONFIG_KALLSYMS) \
	83	&& LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,50, 3,14,0,0))
	84
	85	#include <linux/kallsyms.h>
	86	#include <linux/mm_types.h>
	87	#include <linux/module.h>
	88	#include <wrapper/kallsyms.h>
	89	#include <wrapper/page_alloc.h>
	90
	91	static
	92	unsigned long (get_pageblock_flags_mask_sym)(struct page page,
	93	unsigned long end_bitidx,
	94	unsigned long mask);
	95
	96	unsigned long wrapper_get_pageblock_flags_mask(struct page *page,
	97	unsigned long end_bitidx,
	98	unsigned long mask)
	99	{
	100	WARN_ON_ONCE(!get_pageblock_flags_mask_sym);
	101	if (get_pageblock_flags_mask_sym) {
	102	return get_pageblock_flags_mask_sym(page, end_bitidx, mask);
	103	} else {
	104	return -ENOSYS;
	105	}
	106	}
	107	EXPORT_SYMBOL_GPL(wrapper_get_pageblock_flags_mask);
	108
	109	int wrapper_get_pageblock_flags_mask_init(void)
	110	{
	111	get_pageblock_flags_mask_sym =
	112	(void *) kallsyms_lookup_funcptr("get_pageblock_flags_mask");
	113	if (!get_pageblock_flags_mask_sym)
	114	return -1;
	115	return 0;
	116	}
	117	EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);
	118
	119	#else
	120
	121	#include <linux/pageblock-flags.h>
	122
	123	#endif