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

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * wrapper/vmalloc.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_VMALLOC_H
#define _LTTNG_WRAPPER_VMALLOC_H

#include <linux/version.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>

#ifdef CONFIG_KALLSYMS

#include <linux/kallsyms.h>
#include <wrapper/kallsyms.h>
#include <lttng/kernel-version.h>

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0) \
  || LTTNG_KERNEL_RANGE(5,4,28, 5,5,0)            \
  || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0)            \
  || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0)         \
  || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0)         \
  || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0)          \
  || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0))	  \
  || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,16,0,0) \
  || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0)   \
  || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)

static inline
void wrapper_vmalloc_sync_mappings(void)
{
	void (*vmalloc_sync_mappings_sym)(void);

	vmalloc_sync_mappings_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_mappings");
	if (vmalloc_sync_mappings_sym) {
		vmalloc_sync_mappings_sym();
	} else {
#ifdef CONFIG_X86
		/*
		 * Only x86 needs vmalloc_sync_mappings to make sure LTTng does not
		 * trigger recursive page faults.
		 */
		printk_once(KERN_WARNING "LTTng: vmalloc_sync_mappings symbol lookup failed.\n");
		printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
#endif
	}
}

#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */

/*
 * Map vmalloc_sync_mappings to vmalloc_sync_all() on kernels before 5.7.
 */
static inline
void wrapper_vmalloc_sync_mappings(void)
{
	void (*vmalloc_sync_all_sym)(void);

	vmalloc_sync_all_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
	if (vmalloc_sync_all_sym) {
		vmalloc_sync_all_sym();
	} else {
#ifdef CONFIG_X86
		/*
		 * Only x86 needs vmalloc_sync_all to make sure LTTng does not
		 * trigger recursive page faults.
		 */
		printk_once(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
		printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
#endif
	}
}

#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */

#else

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0) \
  || LTTNG_KERNEL_RANGE(5,4,28, 5,5,0)            \
  || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0)            \
  || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0)         \
  || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0)         \
  || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0)          \
  || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0))	  \
  || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,18,0,0) \
  || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0)   \
  || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)

static inline
void wrapper_vmalloc_sync_mappings(void)
{
	return vmalloc_sync_mappings();
}

#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */

static inline
void wrapper_vmalloc_sync_mappings(void)
{
	return vmalloc_sync_all();
}

#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */

#endif

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
static inline
void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
{
	void *ret;

	ret = kvmalloc_node(size, flags, node);
	if (is_vmalloc_addr(ret)) {
		/*
		 * Make sure we don't trigger recursive page faults in the
		 * tracing fast path.
		 */
		wrapper_vmalloc_sync_mappings();
	}
	return ret;
}

static inline
void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
{
	return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node);
}

static inline
void *lttng_kvmalloc(unsigned long size, gfp_t flags)
{
	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
}

static inline
void *lttng_kvzalloc(unsigned long size, gfp_t flags)
{
	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
}

static inline
void lttng_kvfree(const void *addr)
{
	kvfree(addr);
}

#else

#include <linux/slab.h>

static inline
void print_vmalloc_node_range_warning(void)
{
	printk_once(KERN_WARNING "LTTng: __vmalloc_node_range symbol lookup failed.\n");
	printk_once(KERN_WARNING "Tracer performance will be degraded on NUMA systems.\n");
	printk_once(KERN_WARNING "Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n");
}

/*
 * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
 */
static inline
void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align,
			unsigned long start, unsigned long end, gfp_t gfp_mask,
			pgprot_t prot, unsigned long vm_flags, int node,
			const void *caller)
{
#ifdef CONFIG_KALLSYMS
	/*
	 * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
	 */
	void *(*lttng__vmalloc_node_range)(unsigned long size, unsigned long align,
			unsigned long start, unsigned long end, gfp_t gfp_mask,
			pgprot_t prot, unsigned long vm_flags, int node,
			const void *caller);

	lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
	if (lttng__vmalloc_node_range)
		return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot,
				vm_flags, node, caller);
#endif
	if (node != NUMA_NO_NODE)
		print_vmalloc_node_range_warning();
	return __vmalloc(size, gfp_mask, prot);
}

/**
 * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
 * failure, fall back to non-contiguous (vmalloc) allocation.
 * @size: size of the request.
 * @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
 *
 * Uses kmalloc to get the memory but if the allocation fails then falls back
 * to the vmalloc allocator. Use lttng_kvfree to free the memory.
 *
 * Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
 */
static inline
void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
{
	void *ret;

	/*
	 * vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables)
	 * so the given set of flags has to be compatible.
	 */
	WARN_ON_ONCE((flags & GFP_KERNEL) != GFP_KERNEL);

	/*
	 * If the allocation fits in a single page, do not fallback.
	 */
	if (size <= PAGE_SIZE) {
		return kmalloc_node(size, flags, node);
	}

	/*
	 * Make sure that larger requests are not too disruptive - no OOM
	 * killer and no allocation failure warnings as we have a fallback
	 */
	ret = kmalloc_node(size, flags | __GFP_NOWARN | __GFP_NORETRY, node);
	if (!ret) {
		ret = __lttng_vmalloc_node_range(size, 1,
				VMALLOC_START, VMALLOC_END,
				flags | __GFP_HIGHMEM, PAGE_KERNEL, 0,
				node, __builtin_return_address(0));
		/*
		 * Make sure we don't trigger recursive page faults in the
		 * tracing fast path.
		 */
		wrapper_vmalloc_sync_mappings();
	}
	return ret;
}

static inline
void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
{
	return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node);
}

static inline
void *lttng_kvmalloc(unsigned long size, gfp_t flags)
{
	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
}

static inline
void *lttng_kvzalloc(unsigned long size, gfp_t flags)
{
	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
}

static inline
void lttng_kvfree(const void *addr)
{
	if (is_vmalloc_addr(addr)) {
		vfree(addr);
	} else {
		kfree(addr);
	}
}
#endif

#endif /* _LTTNG_WRAPPER_VMALLOC_H */
Commit	Line	Data
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
9f36eaed	2	*
886d51a3	3	* wrapper/vmalloc.h
6d2a620c MD	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	*
886d51a3	9	* Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6d2a620c MD	10	*/
6d2a620c MD	11
9f36eaed MJ	12	#ifndef _LTTNG_WRAPPER_VMALLOC_H
	13	#define _LTTNG_WRAPPER_VMALLOC_H
	14
48f5e0b5 MJ	15	#include <linux/version.h>
48f5e0b5 MJ	16	#include <linux/vmalloc.h>
01ab5113	17	#include <linux/mm.h>
48f5e0b5	18
6d2a620c MD	19	#ifdef CONFIG_KALLSYMS
	20
	21	#include <linux/kallsyms.h>
5a2f5e92	22	#include <wrapper/kallsyms.h>
2b3dbafc	23	#include <lttng/kernel-version.h>
6d2a620c	24
2b3dbafc OP	25	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0) \
	26	\|\| LTTNG_KERNEL_RANGE(5,4,28, 5,5,0) \
	27	\|\| LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
	28	\|\| LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
	29	\|\| LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
	30	\|\| LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
2e4c781e SB	31	\|\| LTTNG_KERNEL_RANGE(4,4,218, 4,5,0)) \
	32	\|\| LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,16,0,0) \
	33	\|\| LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
	34	\|\| LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)
263b6c88 MD	35
	36	static inline
	37	void wrapper_vmalloc_sync_mappings(void)
	38	{
	39	void (*vmalloc_sync_mappings_sym)(void);
	40
	41	vmalloc_sync_mappings_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_mappings");
	42	if (vmalloc_sync_mappings_sym) {
	43	vmalloc_sync_mappings_sym();
	44	} else {
	45	#ifdef CONFIG_X86
	46	/*
	47	* Only x86 needs vmalloc_sync_mappings to make sure LTTng does not
	48	* trigger recursive page faults.
	49	*/
	50	printk_once(KERN_WARNING "LTTng: vmalloc_sync_mappings symbol lookup failed.\n");
	51	printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
	52	#endif
	53	}
	54	}
	55
1d618748	56	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
263b6c88 MD	57
	58	/*
	59	* Map vmalloc_sync_mappings to vmalloc_sync_all() on kernels before 5.7.
	60	*/
6d2a620c	61	static inline
263b6c88	62	void wrapper_vmalloc_sync_mappings(void)
6d2a620c MD	63	{
	64	void (*vmalloc_sync_all_sym)(void);
	65
c539a324	66	vmalloc_sync_all_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
6d2a620c MD	67	if (vmalloc_sync_all_sym) {
	68	vmalloc_sync_all_sym();
	69	} else {
	70	#ifdef CONFIG_X86
	71	/*
	72	* Only x86 needs vmalloc_sync_all to make sure LTTng does not
	73	* trigger recursive page faults.
	74	*/
e36de50d MD	75	printk_once(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
e36de50d MD	76	printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
6d2a620c MD	77	#endif
	78	}
	79	}
263b6c88	80
1d618748	81	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
263b6c88	82
6d2a620c MD	83	#else
6d2a620c MD	84
2b3dbafc OP	85	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0) \
	86	\|\| LTTNG_KERNEL_RANGE(5,4,28, 5,5,0) \
	87	\|\| LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
	88	\|\| LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
	89	\|\| LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
	90	\|\| LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
2e4c781e SB	91	\|\| LTTNG_KERNEL_RANGE(4,4,218, 4,5,0)) \
	92	\|\| LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,18,0,0) \
	93	\|\| LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
	94	\|\| LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)
263b6c88	95
6d2a620c	96	static inline
263b6c88 MD	97	void wrapper_vmalloc_sync_mappings(void)
	98	{
	99	return vmalloc_sync_mappings();
	100	}
	101
1d618748	102	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
263b6c88 MD	103
	104	static inline
	105	void wrapper_vmalloc_sync_mappings(void)
6d2a620c MD	106	{
	107	return vmalloc_sync_all();
	108	}
263b6c88	109
1d618748	110	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
263b6c88	111
6d2a620c	112	#endif
b13f3ebe	113
48f5e0b5 MJ	114	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
	115	static inline
	116	void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
	117	{
	118	void *ret;
	119
	120	ret = kvmalloc_node(size, flags, node);
	121	if (is_vmalloc_addr(ret)) {
	122	/*
	123	* Make sure we don't trigger recursive page faults in the
	124	* tracing fast path.
	125	*/
263b6c88	126	wrapper_vmalloc_sync_mappings();
48f5e0b5 MJ	127	}
	128	return ret;
	129	}
	130
	131	static inline
	132	void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
	133	{
	134	return lttng_kvmalloc_node(size, flags \| __GFP_ZERO, node);
	135	}
	136
	137	static inline
	138	void *lttng_kvmalloc(unsigned long size, gfp_t flags)
	139	{
	140	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
	141	}
	142
	143	static inline
	144	void *lttng_kvzalloc(unsigned long size, gfp_t flags)
	145	{
	146	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
	147	}
	148
	149	static inline
	150	void lttng_kvfree(const void *addr)
	151	{
	152	kvfree(addr);
	153	}
	154
	155	#else
	156
	157	#include <linux/slab.h>
48f5e0b5	158
20eb87c9 MD	159	static inline
	160	void print_vmalloc_node_range_warning(void)
	161	{
	162	printk_once(KERN_WARNING "LTTng: __vmalloc_node_range symbol lookup failed.\n");
	163	printk_once(KERN_WARNING "Tracer performance will be degraded on NUMA systems.\n");
	164	printk_once(KERN_WARNING "Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n");
	165	}
	166
48f5e0b5 MJ	167	/*
	168	* kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
	169	*/
	170	static inline
20eb87c9 MD	171	void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align,
	172	unsigned long start, unsigned long end, gfp_t gfp_mask,
	173	pgprot_t prot, unsigned long vm_flags, int node,
	174	const void *caller)
48f5e0b5	175	{
48f5e0b5 MJ	176	#ifdef CONFIG_KALLSYMS
48f5e0b5 MJ	177	/*
20eb87c9	178	* If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
48f5e0b5	179	*/
20eb87c9 MD	180	void (lttng__vmalloc_node_range)(unsigned long size, unsigned long align,
	181	unsigned long start, unsigned long end, gfp_t gfp_mask,
	182	pgprot_t prot, unsigned long vm_flags, int node,
	183	const void *caller);
	184
	185	lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
	186	if (lttng__vmalloc_node_range)
	187	return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot,
	188	vm_flags, node, caller);
48f5e0b5	189	#endif
20eb87c9 MD	190	if (node != NUMA_NO_NODE)
	191	print_vmalloc_node_range_warning();
	192	return __vmalloc(size, gfp_mask, prot);
48f5e0b5 MJ	193	}
	194
	195	/**
	196	* lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
	197	* failure, fall back to non-contiguous (vmalloc) allocation.
	198	* @size: size of the request.
	199	* @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
	200	*
	201	* Uses kmalloc to get the memory but if the allocation fails then falls back
	202	* to the vmalloc allocator. Use lttng_kvfree to free the memory.
	203	*
	204	* Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
	205	*/
	206	static inline
	207	void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
	208	{
	209	void *ret;
	210
	211	/*
	212	* vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables)
	213	* so the given set of flags has to be compatible.
	214	*/
	215	WARN_ON_ONCE((flags & GFP_KERNEL) != GFP_KERNEL);
	216
	217	/*
	218	* If the allocation fits in a single page, do not fallback.
	219	*/
	220	if (size <= PAGE_SIZE) {
	221	return kmalloc_node(size, flags, node);
	222	}
	223
	224	/*
	225	* Make sure that larger requests are not too disruptive - no OOM
	226	* killer and no allocation failure warnings as we have a fallback
	227	*/
	228	ret = kmalloc_node(size, flags \| __GFP_NOWARN \| __GFP_NORETRY, node);
	229	if (!ret) {
20eb87c9 MD	230	ret = __lttng_vmalloc_node_range(size, 1,
	231	VMALLOC_START, VMALLOC_END,
	232	flags \| __GFP_HIGHMEM, PAGE_KERNEL, 0,
	233	node, __builtin_return_address(0));
48f5e0b5 MJ	234	/*
	235	* Make sure we don't trigger recursive page faults in the
	236	* tracing fast path.
	237	*/
f3e4ba5d	238	wrapper_vmalloc_sync_mappings();
48f5e0b5 MJ	239	}
	240	return ret;
	241	}
	242
	243	static inline
	244	void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
	245	{
	246	return lttng_kvmalloc_node(size, flags \| __GFP_ZERO, node);
	247	}
	248
	249	static inline
	250	void *lttng_kvmalloc(unsigned long size, gfp_t flags)
	251	{
	252	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
	253	}
	254
	255	static inline
	256	void *lttng_kvzalloc(unsigned long size, gfp_t flags)
	257	{
	258	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
	259	}
	260
	261	static inline
	262	void lttng_kvfree(const void *addr)
	263	{
	264	if (is_vmalloc_addr(addr)) {
	265	vfree(addr);
	266	} else {
	267	kfree(addr);
	268	}
	269	}
	270	#endif
	271
a90917c3	272	#endif /* _LTTNG_WRAPPER_VMALLOC_H */