[lttng-modules.git] / 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>

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0))

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(5,7,0)) */

/*
 * 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(5,7,0)) */

#else

#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0))

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

#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0)) */

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

#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0)) */

#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_all();
	}
	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>
6d2a620c	23
263b6c88 MD	24	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0))
	25
	26	static inline
	27	void wrapper_vmalloc_sync_mappings(void)
	28	{
	29	void (*vmalloc_sync_mappings_sym)(void);
	30
	31	vmalloc_sync_mappings_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_mappings");
	32	if (vmalloc_sync_mappings_sym) {
	33	vmalloc_sync_mappings_sym();
	34	} else {
	35	#ifdef CONFIG_X86
	36	/*
	37	* Only x86 needs vmalloc_sync_mappings to make sure LTTng does not
	38	* trigger recursive page faults.
	39	*/
	40	printk_once(KERN_WARNING "LTTng: vmalloc_sync_mappings symbol lookup failed.\n");
	41	printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
	42	#endif
	43	}
	44	}
	45
	46	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0)) */
	47
	48	/*
	49	* Map vmalloc_sync_mappings to vmalloc_sync_all() on kernels before 5.7.
	50	*/
6d2a620c	51	static inline
263b6c88	52	void wrapper_vmalloc_sync_mappings(void)
6d2a620c MD	53	{
	54	void (*vmalloc_sync_all_sym)(void);
	55
c539a324	56	vmalloc_sync_all_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
6d2a620c MD	57	if (vmalloc_sync_all_sym) {
	58	vmalloc_sync_all_sym();
	59	} else {
	60	#ifdef CONFIG_X86
	61	/*
	62	* Only x86 needs vmalloc_sync_all to make sure LTTng does not
	63	* trigger recursive page faults.
	64	*/
e36de50d MD	65	printk_once(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n");
e36de50d MD	66	printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n");
6d2a620c MD	67	#endif
	68	}
	69	}
263b6c88 MD	70
	71	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0)) */
	72
6d2a620c MD	73	#else
6d2a620c MD	74
263b6c88 MD	75	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0))
263b6c88 MD	76
6d2a620c	77	static inline
263b6c88 MD	78	void wrapper_vmalloc_sync_mappings(void)
	79	{
	80	return vmalloc_sync_mappings();
	81	}
	82
	83	#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0)) */
	84
	85	static inline
	86	void wrapper_vmalloc_sync_mappings(void)
6d2a620c MD	87	{
	88	return vmalloc_sync_all();
	89	}
263b6c88 MD	90
	91	#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,7,0)) */
	92
6d2a620c	93	#endif
b13f3ebe	94
48f5e0b5 MJ	95	#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
	96	static inline
	97	void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
	98	{
	99	void *ret;
	100
	101	ret = kvmalloc_node(size, flags, node);
	102	if (is_vmalloc_addr(ret)) {
	103	/*
	104	* Make sure we don't trigger recursive page faults in the
	105	* tracing fast path.
	106	*/
263b6c88	107	wrapper_vmalloc_sync_mappings();
48f5e0b5 MJ	108	}
	109	return ret;
	110	}
	111
	112	static inline
	113	void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
	114	{
	115	return lttng_kvmalloc_node(size, flags \| __GFP_ZERO, node);
	116	}
	117
	118	static inline
	119	void *lttng_kvmalloc(unsigned long size, gfp_t flags)
	120	{
	121	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
	122	}
	123
	124	static inline
	125	void *lttng_kvzalloc(unsigned long size, gfp_t flags)
	126	{
	127	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
	128	}
	129
	130	static inline
	131	void lttng_kvfree(const void *addr)
	132	{
	133	kvfree(addr);
	134	}
	135
	136	#else
	137
	138	#include <linux/slab.h>
48f5e0b5	139
20eb87c9 MD	140	static inline
	141	void print_vmalloc_node_range_warning(void)
	142	{
	143	printk_once(KERN_WARNING "LTTng: __vmalloc_node_range symbol lookup failed.\n");
	144	printk_once(KERN_WARNING "Tracer performance will be degraded on NUMA systems.\n");
	145	printk_once(KERN_WARNING "Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n");
	146	}
	147
48f5e0b5 MJ	148	/*
	149	* kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
	150	*/
	151	static inline
20eb87c9 MD	152	void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align,
	153	unsigned long start, unsigned long end, gfp_t gfp_mask,
	154	pgprot_t prot, unsigned long vm_flags, int node,
	155	const void *caller)
48f5e0b5	156	{
48f5e0b5 MJ	157	#ifdef CONFIG_KALLSYMS
48f5e0b5 MJ	158	/*
20eb87c9	159	* If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
48f5e0b5	160	*/
20eb87c9 MD	161	void (lttng__vmalloc_node_range)(unsigned long size, unsigned long align,
	162	unsigned long start, unsigned long end, gfp_t gfp_mask,
	163	pgprot_t prot, unsigned long vm_flags, int node,
	164	const void *caller);
	165
	166	lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
	167	if (lttng__vmalloc_node_range)
	168	return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot,
	169	vm_flags, node, caller);
48f5e0b5	170	#endif
20eb87c9 MD	171	if (node != NUMA_NO_NODE)
	172	print_vmalloc_node_range_warning();
	173	return __vmalloc(size, gfp_mask, prot);
48f5e0b5 MJ	174	}
	175
	176	/**
	177	* lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
	178	* failure, fall back to non-contiguous (vmalloc) allocation.
	179	* @size: size of the request.
	180	* @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
	181	*
	182	* Uses kmalloc to get the memory but if the allocation fails then falls back
	183	* to the vmalloc allocator. Use lttng_kvfree to free the memory.
	184	*
	185	* Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
	186	*/
	187	static inline
	188	void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
	189	{
	190	void *ret;
	191
	192	/*
	193	* vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables)
	194	* so the given set of flags has to be compatible.
	195	*/
	196	WARN_ON_ONCE((flags & GFP_KERNEL) != GFP_KERNEL);
	197
	198	/*
	199	* If the allocation fits in a single page, do not fallback.
	200	*/
	201	if (size <= PAGE_SIZE) {
	202	return kmalloc_node(size, flags, node);
	203	}
	204
	205	/*
	206	* Make sure that larger requests are not too disruptive - no OOM
	207	* killer and no allocation failure warnings as we have a fallback
	208	*/
	209	ret = kmalloc_node(size, flags \| __GFP_NOWARN \| __GFP_NORETRY, node);
	210	if (!ret) {
20eb87c9 MD	211	ret = __lttng_vmalloc_node_range(size, 1,
	212	VMALLOC_START, VMALLOC_END,
	213	flags \| __GFP_HIGHMEM, PAGE_KERNEL, 0,
	214	node, __builtin_return_address(0));
48f5e0b5 MJ	215	/*
	216	* Make sure we don't trigger recursive page faults in the
	217	* tracing fast path.
	218	*/
	219	wrapper_vmalloc_sync_all();
	220	}
	221	return ret;
	222	}
	223
	224	static inline
	225	void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
	226	{
	227	return lttng_kvmalloc_node(size, flags \| __GFP_ZERO, node);
	228	}
	229
	230	static inline
	231	void *lttng_kvmalloc(unsigned long size, gfp_t flags)
	232	{
	233	return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
	234	}
	235
	236	static inline
	237	void *lttng_kvzalloc(unsigned long size, gfp_t flags)
	238	{
	239	return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
	240	}
	241
	242	static inline
	243	void lttng_kvfree(const void *addr)
	244	{
	245	if (is_vmalloc_addr(addr)) {
	246	vfree(addr);
	247	} else {
	248	kfree(addr);
	249	}
	250	}
	251	#endif
	252
a90917c3	253	#endif /* _LTTNG_WRAPPER_VMALLOC_H */