vmalloc.c 68.7 KB
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/*
 *  linux/mm/vmalloc.c
 *
 *  Copyright (C) 1993  Linus Torvalds
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
 *  Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
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 *  Numa awareness, Christoph Lameter, SGI, June 2005
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 */

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#include <linux/vmalloc.h>
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#include <linux/mm.h>
#include <linux/module.h>
#include <linux/highmem.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/debugobjects.h>
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#include <linux/kallsyms.h>
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#include <linux/list.h>
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#include <linux/notifier.h>
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#include <linux/rbtree.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
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#include <linux/pfn.h>
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#include <linux/kmemleak.h>
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#include <linux/atomic.h>
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#include <linux/compiler.h>
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#include <linux/llist.h>
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#include <linux/bitops.h>
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#include <asm/uaccess.h>
#include <asm/tlbflush.h>
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#include <asm/shmparam.h>
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#include "internal.h"

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struct vfree_deferred {
	struct llist_head list;
	struct work_struct wq;
};
static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);

static void __vunmap(const void *, int);

static void free_work(struct work_struct *w)
{
	struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
	struct llist_node *llnode = llist_del_all(&p->list);
	while (llnode) {
		void *p = llnode;
		llnode = llist_next(llnode);
		__vunmap(p, 1);
	}
}

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/*** Page table manipulation functions ***/
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static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
{
	pte_t *pte;

	pte = pte_offset_kernel(pmd, addr);
	do {
		pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
		WARN_ON(!pte_none(ptent) && !pte_present(ptent));
	} while (pte++, addr += PAGE_SIZE, addr != end);
}

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static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
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{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
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		if (pmd_clear_huge(pmd))
			continue;
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		if (pmd_none_or_clear_bad(pmd))
			continue;
		vunmap_pte_range(pmd, addr, next);
	} while (pmd++, addr = next, addr != end);
}

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static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
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{
	pud_t *pud;
	unsigned long next;

	pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
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		if (pud_clear_huge(pud))
			continue;
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		if (pud_none_or_clear_bad(pud))
			continue;
		vunmap_pmd_range(pud, addr, next);
	} while (pud++, addr = next, addr != end);
}

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static void vunmap_page_range(unsigned long addr, unsigned long end)
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{
	pgd_t *pgd;
	unsigned long next;

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd))
			continue;
		vunmap_pud_range(pgd, addr, next);
	} while (pgd++, addr = next, addr != end);
}

static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
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		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
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{
	pte_t *pte;

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	/*
	 * nr is a running index into the array which helps higher level
	 * callers keep track of where we're up to.
	 */

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	pte = pte_alloc_kernel(pmd, addr);
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	if (!pte)
		return -ENOMEM;
	do {
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		struct page *page = pages[*nr];

		if (WARN_ON(!pte_none(*pte)))
			return -EBUSY;
		if (WARN_ON(!page))
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			return -ENOMEM;
		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
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		(*nr)++;
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	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

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static int vmap_pmd_range(pud_t *pud, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
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{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_alloc(&init_mm, pud, addr);
	if (!pmd)
		return -ENOMEM;
	do {
		next = pmd_addr_end(addr, end);
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		if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
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			return -ENOMEM;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

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static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
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{
	pud_t *pud;
	unsigned long next;

	pud = pud_alloc(&init_mm, pgd, addr);
	if (!pud)
		return -ENOMEM;
	do {
		next = pud_addr_end(addr, end);
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		if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
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			return -ENOMEM;
	} while (pud++, addr = next, addr != end);
	return 0;
}

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/*
 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
 * will have pfns corresponding to the "pages" array.
 *
 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
 */
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static int vmap_page_range_noflush(unsigned long start, unsigned long end,
				   pgprot_t prot, struct page **pages)
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{
	pgd_t *pgd;
	unsigned long next;
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	unsigned long addr = start;
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	int err = 0;
	int nr = 0;
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	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
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		err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
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		if (err)
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			return err;
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	} while (pgd++, addr = next, addr != end);
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	return nr;
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}

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static int vmap_page_range(unsigned long start, unsigned long end,
			   pgprot_t prot, struct page **pages)
{
	int ret;

	ret = vmap_page_range_noflush(start, end, prot, pages);
	flush_cache_vmap(start, end);
	return ret;
}

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int is_vmalloc_or_module_addr(const void *x)
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{
	/*
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	 * ARM, x86-64 and sparc64 put modules in a special place,
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	 * and fall back on vmalloc() if that fails. Others
	 * just put it in the vmalloc space.
	 */
#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
	unsigned long addr = (unsigned long)x;
	if (addr >= MODULES_VADDR && addr < MODULES_END)
		return 1;
#endif
	return is_vmalloc_addr(x);
}

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/*
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 * Walk a vmap address to the struct page it maps.
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 */
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struct page *vmalloc_to_page(const void *vmalloc_addr)
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{
	unsigned long addr = (unsigned long) vmalloc_addr;
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	struct page *page = NULL;
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	pgd_t *pgd = pgd_offset_k(addr);

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	/*
	 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
	 * architectures that do not vmalloc module space
	 */
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	VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
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	if (!pgd_none(*pgd)) {
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		pud_t *pud = pud_offset(pgd, addr);
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		if (!pud_none(*pud)) {
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			pmd_t *pmd = pmd_offset(pud, addr);
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			if (!pmd_none(*pmd)) {
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				pte_t *ptep, pte;

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				ptep = pte_offset_map(pmd, addr);
				pte = *ptep;
				if (pte_present(pte))
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					page = pte_page(pte);
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				pte_unmap(ptep);
			}
		}
	}
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	return page;
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}
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EXPORT_SYMBOL(vmalloc_to_page);
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/*
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 * Map a vmalloc()-space virtual address to the physical page frame number.
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 */
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unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
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{
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	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
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}
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EXPORT_SYMBOL(vmalloc_to_pfn);
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/*** Global kva allocator ***/

#define VM_VM_AREA	0x04

static DEFINE_SPINLOCK(vmap_area_lock);
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/* Export for kexec only */
LIST_HEAD(vmap_area_list);
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static LLIST_HEAD(vmap_purge_list);
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static struct rb_root vmap_area_root = RB_ROOT;

/* The vmap cache globals are protected by vmap_area_lock */
static struct rb_node *free_vmap_cache;
static unsigned long cached_hole_size;
static unsigned long cached_vstart;
static unsigned long cached_align;

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static unsigned long vmap_area_pcpu_hole;
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static struct vmap_area *__find_vmap_area(unsigned long addr)
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{
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	struct rb_node *n = vmap_area_root.rb_node;

	while (n) {
		struct vmap_area *va;

		va = rb_entry(n, struct vmap_area, rb_node);
		if (addr < va->va_start)
			n = n->rb_left;
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		else if (addr >= va->va_end)
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			n = n->rb_right;
		else
			return va;
	}

	return NULL;
}

static void __insert_vmap_area(struct vmap_area *va)
{
	struct rb_node **p = &vmap_area_root.rb_node;
	struct rb_node *parent = NULL;
	struct rb_node *tmp;

	while (*p) {
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		struct vmap_area *tmp_va;
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		parent = *p;
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		tmp_va = rb_entry(parent, struct vmap_area, rb_node);
		if (va->va_start < tmp_va->va_end)
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			p = &(*p)->rb_left;
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		else if (va->va_end > tmp_va->va_start)
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			p = &(*p)->rb_right;
		else
			BUG();
	}

	rb_link_node(&va->rb_node, parent, p);
	rb_insert_color(&va->rb_node, &vmap_area_root);

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	/* address-sort this list */
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	tmp = rb_prev(&va->rb_node);
	if (tmp) {
		struct vmap_area *prev;
		prev = rb_entry(tmp, struct vmap_area, rb_node);
		list_add_rcu(&va->list, &prev->list);
	} else
		list_add_rcu(&va->list, &vmap_area_list);
}

static void purge_vmap_area_lazy(void);

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static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);

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/*
 * Allocate a region of KVA of the specified size and alignment, within the
 * vstart and vend.
 */
static struct vmap_area *alloc_vmap_area(unsigned long size,
				unsigned long align,
				unsigned long vstart, unsigned long vend,
				int node, gfp_t gfp_mask)
{
	struct vmap_area *va;
	struct rb_node *n;
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	unsigned long addr;
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	int purged = 0;
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	struct vmap_area *first;
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	BUG_ON(!size);
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	BUG_ON(offset_in_page(size));
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	BUG_ON(!is_power_of_2(align));
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	might_sleep_if(gfpflags_allow_blocking(gfp_mask));

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	va = kmalloc_node(sizeof(struct vmap_area),
			gfp_mask & GFP_RECLAIM_MASK, node);
	if (unlikely(!va))
		return ERR_PTR(-ENOMEM);

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	/*
	 * Only scan the relevant parts containing pointers to other objects
	 * to avoid false negatives.
	 */
	kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);

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retry:
	spin_lock(&vmap_area_lock);
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	/*
	 * Invalidate cache if we have more permissive parameters.
	 * cached_hole_size notes the largest hole noticed _below_
	 * the vmap_area cached in free_vmap_cache: if size fits
	 * into that hole, we want to scan from vstart to reuse
	 * the hole instead of allocating above free_vmap_cache.
	 * Note that __free_vmap_area may update free_vmap_cache
	 * without updating cached_hole_size or cached_align.
	 */
	if (!free_vmap_cache ||
			size < cached_hole_size ||
			vstart < cached_vstart ||
			align < cached_align) {
nocache:
		cached_hole_size = 0;
		free_vmap_cache = NULL;
	}
	/* record if we encounter less permissive parameters */
	cached_vstart = vstart;
	cached_align = align;

	/* find starting point for our search */
	if (free_vmap_cache) {
		first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
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		addr = ALIGN(first->va_end, align);
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		if (addr < vstart)
			goto nocache;
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		if (addr + size < addr)
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			goto overflow;

	} else {
		addr = ALIGN(vstart, align);
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		if (addr + size < addr)
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			goto overflow;

		n = vmap_area_root.rb_node;
		first = NULL;

		while (n) {
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			struct vmap_area *tmp;
			tmp = rb_entry(n, struct vmap_area, rb_node);
			if (tmp->va_end >= addr) {
				first = tmp;
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				if (tmp->va_start <= addr)
					break;
				n = n->rb_left;
			} else
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				n = n->rb_right;
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		}
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		if (!first)
			goto found;
	}
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	/* from the starting point, walk areas until a suitable hole is found */
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	while (addr + size > first->va_start && addr + size <= vend) {
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		if (addr + cached_hole_size < first->va_start)
			cached_hole_size = first->va_start - addr;
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		addr = ALIGN(first->va_end, align);
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		if (addr + size < addr)
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			goto overflow;

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		if (list_is_last(&first->list, &vmap_area_list))
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			goto found;
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		first = list_next_entry(first, list);
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	}

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found:
	if (addr + size > vend)
		goto overflow;
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	va->va_start = addr;
	va->va_end = addr + size;
	va->flags = 0;
	__insert_vmap_area(va);
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	free_vmap_cache = &va->rb_node;
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	spin_unlock(&vmap_area_lock);

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	BUG_ON(!IS_ALIGNED(va->va_start, align));
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	BUG_ON(va->va_start < vstart);
	BUG_ON(va->va_end > vend);

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	return va;
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overflow:
	spin_unlock(&vmap_area_lock);
	if (!purged) {
		purge_vmap_area_lazy();
		purged = 1;
		goto retry;
	}
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	if (gfpflags_allow_blocking(gfp_mask)) {
		unsigned long freed = 0;
		blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
		if (freed > 0) {
			purged = 0;
			goto retry;
		}
	}

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	if (printk_ratelimit())
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		pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
			size);
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	kfree(va);
	return ERR_PTR(-EBUSY);
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}

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int register_vmap_purge_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&vmap_notify_list, nb);
}
EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);

int unregister_vmap_purge_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
}
EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);

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static void __free_vmap_area(struct vmap_area *va)
{
	BUG_ON(RB_EMPTY_NODE(&va->rb_node));
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	if (free_vmap_cache) {
		if (va->va_end < cached_vstart) {
			free_vmap_cache = NULL;
		} else {
			struct vmap_area *cache;
			cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
			if (va->va_start <= cache->va_start) {
				free_vmap_cache = rb_prev(&va->rb_node);
				/*
				 * We don't try to update cached_hole_size or
				 * cached_align, but it won't go very wrong.
				 */
			}
		}
	}
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	rb_erase(&va->rb_node, &vmap_area_root);
	RB_CLEAR_NODE(&va->rb_node);
	list_del_rcu(&va->list);

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	/*
	 * Track the highest possible candidate for pcpu area
	 * allocation.  Areas outside of vmalloc area can be returned
	 * here too, consider only end addresses which fall inside
	 * vmalloc area proper.
	 */
	if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
		vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);

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	kfree_rcu(va, rcu_head);
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}

/*
 * Free a region of KVA allocated by alloc_vmap_area
 */
static void free_vmap_area(struct vmap_area *va)
{
	spin_lock(&vmap_area_lock);
	__free_vmap_area(va);
	spin_unlock(&vmap_area_lock);
}

/*
 * Clear the pagetable entries of a given vmap_area
 */
static void unmap_vmap_area(struct vmap_area *va)
{
	vunmap_page_range(va->va_start, va->va_end);
}

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static void vmap_debug_free_range(unsigned long start, unsigned long end)
{
	/*
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	 * Unmap page tables and force a TLB flush immediately if pagealloc
	 * debugging is enabled.  This catches use after free bugs similarly to
	 * those in linear kernel virtual address space after a page has been
	 * freed.
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	 *
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	 * All the lazy freeing logic is still retained, in order to minimise
	 * intrusiveness of this debugging feature.
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	 *
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	 * This is going to be *slow* (linear kernel virtual address debugging
	 * doesn't do a broadcast TLB flush so it is a lot faster).
570
	 */
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	if (debug_pagealloc_enabled()) {
		vunmap_page_range(start, end);
		flush_tlb_kernel_range(start, end);
	}
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}

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/*
 * lazy_max_pages is the maximum amount of virtual address space we gather up
 * before attempting to purge with a TLB flush.
 *
 * There is a tradeoff here: a larger number will cover more kernel page tables
 * and take slightly longer to purge, but it will linearly reduce the number of
 * global TLB flushes that must be performed. It would seem natural to scale
 * this number up linearly with the number of CPUs (because vmapping activity
 * could also scale linearly with the number of CPUs), however it is likely
 * that in practice, workloads might be constrained in other ways that mean
 * vmap activity will not scale linearly with CPUs. Also, I want to be
 * conservative and not introduce a big latency on huge systems, so go with
 * a less aggressive log scale. It will still be an improvement over the old
 * code, and it will be simple to change the scale factor if we find that it
 * becomes a problem on bigger systems.
 */
static unsigned long lazy_max_pages(void)
{
	unsigned int log;

	log = fls(num_online_cpus());

	return log * (32UL * 1024 * 1024 / PAGE_SIZE);
}

static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);

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/* for per-CPU blocks */
static void purge_fragmented_blocks_allcpus(void);

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/*
 * called before a call to iounmap() if the caller wants vm_area_struct's
 * immediately freed.
 */
void set_iounmap_nonlazy(void)
{
	atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
}

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/*
 * Purges all lazily-freed vmap areas.
 *
 * If sync is 0 then don't purge if there is already a purge in progress.
 * If force_flush is 1, then flush kernel TLBs between *start and *end even
 * if we found no lazy vmap areas to unmap (callers can use this to optimise
 * their own TLB flushing).
 * Returns with *start = min(*start, lowest purged address)
 *              *end = max(*end, highest purged address)
 */
static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
					int sync, int force_flush)
{
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	static DEFINE_SPINLOCK(purge_lock);
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	struct llist_node *valist;
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	struct vmap_area *va;
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	struct vmap_area *n_va;
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	int nr = 0;

	/*
	 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
	 * should not expect such behaviour. This just simplifies locking for
	 * the case that isn't actually used at the moment anyway.
	 */
	if (!sync && !force_flush) {
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		if (!spin_trylock(&purge_lock))
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			return;
	} else
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		spin_lock(&purge_lock);
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	if (sync)
		purge_fragmented_blocks_allcpus();

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	valist = llist_del_all(&vmap_purge_list);
	llist_for_each_entry(va, valist, purge_list) {
		if (va->va_start < *start)
			*start = va->va_start;
		if (va->va_end > *end)
			*end = va->va_end;
		nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
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	}

658
	if (nr)
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		atomic_sub(nr, &vmap_lazy_nr);

	if (nr || force_flush)
		flush_tlb_kernel_range(*start, *end);

	if (nr) {
		spin_lock(&vmap_area_lock);
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		llist_for_each_entry_safe(va, n_va, valist, purge_list)
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			__free_vmap_area(va);
		spin_unlock(&vmap_area_lock);
	}
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	spin_unlock(&purge_lock);
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}

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/*
 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
 * is already purging.
 */
static void try_purge_vmap_area_lazy(void)
{
	unsigned long start = ULONG_MAX, end = 0;

	__purge_vmap_area_lazy(&start, &end, 0, 0);
}

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/*
 * Kick off a purge of the outstanding lazy areas.
 */
static void purge_vmap_area_lazy(void)
{
	unsigned long start = ULONG_MAX, end = 0;

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	__purge_vmap_area_lazy(&start, &end, 1, 0);
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}

/*
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 * Free a vmap area, caller ensuring that the area has been unmapped
 * and flush_cache_vunmap had been called for the correct range
 * previously.
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 */
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static void free_vmap_area_noflush(struct vmap_area *va)
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{
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	int nr_lazy;

	nr_lazy = atomic_add_return((va->va_end - va->va_start) >> PAGE_SHIFT,
				    &vmap_lazy_nr);

	/* After this point, we may free va at any time */
	llist_add(&va->purge_list, &vmap_purge_list);

	if (unlikely(nr_lazy > lazy_max_pages()))
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		try_purge_vmap_area_lazy();
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}

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/*
 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
 * called for the correct range previously.
 */
static void free_unmap_vmap_area_noflush(struct vmap_area *va)
{
	unmap_vmap_area(va);
	free_vmap_area_noflush(va);
}

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/*
 * Free and unmap a vmap area
 */
static void free_unmap_vmap_area(struct vmap_area *va)
{
	flush_cache_vunmap(va->va_start, va->va_end);
	free_unmap_vmap_area_noflush(va);
}

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static struct vmap_area *find_vmap_area(unsigned long addr)
{
	struct vmap_area *va;

	spin_lock(&vmap_area_lock);
	va = __find_vmap_area(addr);
	spin_unlock(&vmap_area_lock);

	return va;
}

static void free_unmap_vmap_area_addr(unsigned long addr)
{
	struct vmap_area *va;

	va = find_vmap_area(addr);
	BUG_ON(!va);
	free_unmap_vmap_area(va);
}


/*** Per cpu kva allocator ***/

/*
 * vmap space is limited especially on 32 bit architectures. Ensure there is
 * room for at least 16 percpu vmap blocks per CPU.
 */
/*
 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
 * to #define VMALLOC_SPACE		(VMALLOC_END-VMALLOC_START). Guess
 * instead (we just need a rough idea)
 */
#if BITS_PER_LONG == 32
#define VMALLOC_SPACE		(128UL*1024*1024)
#else
#define VMALLOC_SPACE		(128UL*1024*1024*1024)
#endif

#define VMALLOC_PAGES		(VMALLOC_SPACE / PAGE_SIZE)
#define VMAP_MAX_ALLOC		BITS_PER_LONG	/* 256K with 4K pages */
#define VMAP_BBMAP_BITS_MAX	1024	/* 4MB with 4K pages */
#define VMAP_BBMAP_BITS_MIN	(VMAP_MAX_ALLOC*2)
#define VMAP_MIN(x, y)		((x) < (y) ? (x) : (y)) /* can't use min() */
#define VMAP_MAX(x, y)		((x) > (y) ? (x) : (y)) /* can't use max() */
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#define VMAP_BBMAP_BITS		\
		VMAP_MIN(VMAP_BBMAP_BITS_MAX,	\
		VMAP_MAX(VMAP_BBMAP_BITS_MIN,	\
			VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
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#define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)

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static bool vmap_initialized __read_mostly = false;

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struct vmap_block_queue {
	spinlock_t lock;
	struct list_head free;
};

struct vmap_block {
	spinlock_t lock;
	struct vmap_area *va;
	unsigned long free, dirty;
794
	unsigned long dirty_min, dirty_max; /*< dirty range */
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	struct list_head free_list;
	struct rcu_head rcu_head;
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	struct list_head purge;
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};

/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);

/*
 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
 * in the free path. Could get rid of this if we change the API to return a
 * "cookie" from alloc, to be passed to free. But no big deal yet.
 */
static DEFINE_SPINLOCK(vmap_block_tree_lock);
static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);

/*
 * We should probably have a fallback mechanism to allocate virtual memory
 * out of partially filled vmap blocks. However vmap block sizing should be
 * fairly reasonable according to the vmalloc size, so it shouldn't be a
 * big problem.
 */

static unsigned long addr_to_vb_idx(unsigned long addr)
{
	addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
	addr /= VMAP_BLOCK_SIZE;
	return addr;
}

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static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
{
	unsigned long addr;

	addr = va_start + (pages_off << PAGE_SHIFT);
	BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
	return (void *)addr;
}

/**
 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
 *                  block. Of course pages number can't exceed VMAP_BBMAP_BITS
 * @order:    how many 2^order pages should be occupied in newly allocated block
 * @gfp_mask: flags for the page level allocator
 *
 * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
 */
static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
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{
	struct vmap_block_queue *vbq;
	struct vmap_block *vb;
	struct vmap_area *va;
	unsigned long vb_idx;
	int node, err;
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	void *vaddr;
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	node = numa_node_id();

	vb = kmalloc_node(sizeof(struct vmap_block),
			gfp_mask & GFP_RECLAIM_MASK, node);
	if (unlikely(!vb))
		return ERR_PTR(-ENOMEM);

	va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
					VMALLOC_START, VMALLOC_END,
					node, gfp_mask);
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	if (IS_ERR(va)) {
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		kfree(vb);
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		return ERR_CAST(va);
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	}

	err = radix_tree_preload(gfp_mask);
	if (unlikely(err)) {
		kfree(vb);
		free_vmap_area(va);
		return ERR_PTR(err);
	}

873
	vaddr = vmap_block_vaddr(va->va_start, 0);
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	spin_lock_init(&vb->lock);
	vb->va = va;
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	/* At least something should be left free */
	BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
	vb->free = VMAP_BBMAP_BITS - (1UL << order);
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	vb->dirty = 0;
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	vb->dirty_min = VMAP_BBMAP_BITS;
	vb->dirty_max = 0;
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	INIT_LIST_HEAD(&vb->free_list);

	vb_idx = addr_to_vb_idx(va->va_start);
	spin_lock(&vmap_block_tree_lock);
	err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
	spin_unlock(&vmap_block_tree_lock);
	BUG_ON(err);
	radix_tree_preload_end();

	vbq = &get_cpu_var(vmap_block_queue);
	spin_lock(&vbq->lock);
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	list_add_tail_rcu(&vb->free_list, &vbq->free);
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	spin_unlock(&vbq->lock);
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	put_cpu_var(vmap_block_queue);
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897
	return vaddr;
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}

static void free_vmap_block(struct vmap_block *vb)
{
	struct vmap_block *tmp;
	unsigned long vb_idx;

	vb_idx = addr_to_vb_idx(vb->va->va_start);
	spin_lock(&vmap_block_tree_lock);
	tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
	spin_unlock(&vmap_block_tree_lock);
	BUG_ON(tmp != vb);

911
	free_vmap_area_noflush(vb->va);
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	kfree_rcu(vb, rcu_head);
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}

915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931
static void purge_fragmented_blocks(int cpu)
{
	LIST_HEAD(purge);
	struct vmap_block *vb;
	struct vmap_block *n_vb;
	struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);

	rcu_read_lock();
	list_for_each_entry_rcu(vb, &vbq->free, free_list) {

		if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
			continue;

		spin_lock(&vb->lock);
		if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
			vb->free = 0; /* prevent further allocs after releasing lock */
			vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
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			vb->dirty_min = 0;
			vb->dirty_max = VMAP_BBMAP_BITS;
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			spin_lock(&vbq->lock);
			list_del_rcu(&vb->free_list);
			spin_unlock(&vbq->lock);
			spin_unlock(&vb->lock);
			list_add_tail(&vb->purge, &purge);
		} else
			spin_unlock(&vb->lock);
	}
	rcu_read_unlock();

	list_for_each_entry_safe(vb, n_vb, &purge, purge) {
		list_del(&vb->purge);
		free_vmap_block(vb);
	}
}

static void purge_fragmented_blocks_allcpus(void)
{
	int cpu;

	for_each_possible_cpu(cpu)
		purge_fragmented_blocks(cpu);
}

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static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
{
	struct vmap_block_queue *vbq;
	struct vmap_block *vb;
962
	void *vaddr = NULL;
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	unsigned int order;

965
	BUG_ON(offset_in_page(size));
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	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
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	if (WARN_ON(size == 0)) {
		/*
		 * Allocating 0 bytes isn't what caller wants since
		 * get_order(0) returns funny result. Just warn and terminate
		 * early.
		 */
		return NULL;
	}
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	order = get_order(size);

	rcu_read_lock();
	vbq = &get_cpu_var(vmap_block_queue);
	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
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		unsigned long pages_off;
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		spin_lock(&vb->lock);
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		if (vb->free < (1UL << order)) {
			spin_unlock(&vb->lock);
			continue;
		}
987

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		pages_off = VMAP_BBMAP_BITS - vb->free;
		vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
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		vb->free -= 1UL << order;
		if (vb->free == 0) {
			spin_lock(&vbq->lock);
			list_del_rcu(&vb->free_list);
			spin_unlock(&vbq->lock);
		}
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		spin_unlock(&vb->lock);
		break;
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	}
1000

1001
	put_cpu_var(vmap_block_queue);
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	rcu_read_unlock();

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	/* Allocate new block if nothing was found */
	if (!vaddr)
		vaddr = new_vmap_block(order, gfp_mask);
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	return vaddr;
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}

static void vb_free(const void *addr, unsigned long size)
{
	unsigned long offset;
	unsigned long vb_idx;
	unsigned int order;
	struct vmap_block *vb;

1018
	BUG_ON(offset_in_page(size));
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	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
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	flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);

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	order = get_order(size);

	offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
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	offset >>= PAGE_SHIFT;
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	vb_idx = addr_to_vb_idx((unsigned long)addr);
	rcu_read_lock();
	vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
	rcu_read_unlock();
	BUG_ON(!vb);

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	vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);

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	spin_lock(&vb->lock);
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	/* Expand dirty range */
	vb->dirty_min = min(vb->dirty_min, offset);
	vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
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	vb->dirty += 1UL << order;
	if (vb->dirty == VMAP_BBMAP_BITS) {
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		BUG_ON(vb->free);
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		spin_unlock(&vb->lock);
		free_vmap_block(vb);
	} else
		spin_unlock(&vb->lock);
}

/**
 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
 *
 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
 * to amortize TLB flushing overheads. What this means is that any page you
 * have now, may, in a former life, have been mapped into kernel virtual
 * address by the vmap layer and so there might be some CPUs with TLB entries
 * still referencing that page (additional to the regular 1:1 kernel mapping).
 *
 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
 * be sure that none of the pages we have control over will have any aliases
 * from the vmap layer.
 */
void vm_unmap_aliases(void)
{
	unsigned long start = ULONG_MAX, end = 0;
	int cpu;
	int flush = 0;

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	if (unlikely(!vmap_initialized))
		return;

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	for_each_possible_cpu(cpu) {
		struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
		struct vmap_block *vb;

		rcu_read_lock();
		list_for_each_entry_rcu(vb, &vbq->free, free_list) {
			spin_lock(&vb->lock);
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			if (vb->dirty) {
				unsigned long va_start = vb->va->va_start;
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				unsigned long s, e;
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				s = va_start + (vb->dirty_min << PAGE_SHIFT);
				e = va_start + (vb->dirty_max << PAGE_SHIFT);
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				start = min(s, start);
				end   = max(e, end);
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				flush = 1;
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			}
			spin_unlock(&vb->lock);
		}
		rcu_read_unlock();
	}

	__purge_vmap_area_lazy(&start, &end, 1, flush);
}
EXPORT_SYMBOL_GPL(vm_unmap_aliases);

/**
 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
 * @mem: the pointer returned by vm_map_ram
 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
 */
void vm_unmap_ram(const void *mem, unsigned int count)
{
1108
	unsigned long size = (unsigned long)count << PAGE_SHIFT;
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	unsigned long addr = (unsigned long)mem;

	BUG_ON(!addr);
	BUG_ON(addr < VMALLOC_START);
	BUG_ON(addr > VMALLOC_END);
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	BUG_ON(!PAGE_ALIGNED(addr));
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	debug_check_no_locks_freed(mem, size);
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	vmap_debug_free_range(addr, addr+size);
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	if (likely(count <= VMAP_MAX_ALLOC))
		vb_free(mem, size);
	else
		free_unmap_vmap_area_addr(addr);
}
EXPORT_SYMBOL(vm_unmap_ram);

/**
 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
 * @pages: an array of pointers to the pages to be mapped
 * @count: number of pages
 * @node: prefer to allocate data structures on this node
 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
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 *
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 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
 * faster than vmap so it's good.  But if you mix long-life and short-life
 * objects with vm_map_ram(), it could consume lots of address space through
 * fragmentation (especially on a 32bit machine).  You could see failures in
 * the end.  Please use this function for short-lived objects.
 *
1139
 * Returns: a pointer to the address that has been mapped, or %NULL on failure
N
Nick Piggin 已提交
1140 1141 1142
 */
void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
{
1143
	unsigned long size = (unsigned long)count << PAGE_SHIFT;
N
Nick Piggin 已提交
1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169
	unsigned long addr;
	void *mem;

	if (likely(count <= VMAP_MAX_ALLOC)) {
		mem = vb_alloc(size, GFP_KERNEL);
		if (IS_ERR(mem))
			return NULL;
		addr = (unsigned long)mem;
	} else {
		struct vmap_area *va;
		va = alloc_vmap_area(size, PAGE_SIZE,
				VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
		if (IS_ERR(va))
			return NULL;

		addr = va->va_start;
		mem = (void *)addr;
	}
	if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
		vm_unmap_ram(mem, count);
		return NULL;
	}
	return mem;
}
EXPORT_SYMBOL(vm_map_ram);

1170
static struct vm_struct *vmlist __initdata;
N
Nicolas Pitre 已提交
1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196
/**
 * vm_area_add_early - add vmap area early during boot
 * @vm: vm_struct to add
 *
 * This function is used to add fixed kernel vm area to vmlist before
 * vmalloc_init() is called.  @vm->addr, @vm->size, and @vm->flags
 * should contain proper values and the other fields should be zero.
 *
 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
 */
void __init vm_area_add_early(struct vm_struct *vm)
{
	struct vm_struct *tmp, **p;

	BUG_ON(vmap_initialized);
	for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
		if (tmp->addr >= vm->addr) {
			BUG_ON(tmp->addr < vm->addr + vm->size);
			break;
		} else
			BUG_ON(tmp->addr + tmp->size > vm->addr);
	}
	vm->next = *p;
	*p = vm;
}

1197 1198 1199
/**
 * vm_area_register_early - register vmap area early during boot
 * @vm: vm_struct to register
1200
 * @align: requested alignment
1201 1202 1203 1204 1205 1206 1207 1208
 *
 * This function is used to register kernel vm area before
 * vmalloc_init() is called.  @vm->size and @vm->flags should contain
 * proper values on entry and other fields should be zero.  On return,
 * vm->addr contains the allocated address.
 *
 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
 */
1209
void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1210 1211
{
	static size_t vm_init_off __initdata;
1212 1213 1214 1215
	unsigned long addr;

	addr = ALIGN(VMALLOC_START + vm_init_off, align);
	vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1216

1217
	vm->addr = (void *)addr;
1218

N
Nicolas Pitre 已提交
1219
	vm_area_add_early(vm);
1220 1221
}

N
Nick Piggin 已提交
1222 1223
void __init vmalloc_init(void)
{
I
Ivan Kokshaysky 已提交
1224 1225
	struct vmap_area *va;
	struct vm_struct *tmp;
N
Nick Piggin 已提交
1226 1227 1228 1229
	int i;

	for_each_possible_cpu(i) {
		struct vmap_block_queue *vbq;
1230
		struct vfree_deferred *p;
N
Nick Piggin 已提交
1231 1232 1233 1234

		vbq = &per_cpu(vmap_block_queue, i);
		spin_lock_init(&vbq->lock);
		INIT_LIST_HEAD(&vbq->free);
1235 1236 1237
		p = &per_cpu(vfree_deferred, i);
		init_llist_head(&p->list);
		INIT_WORK(&p->wq, free_work);
N
Nick Piggin 已提交
1238
	}
1239

I
Ivan Kokshaysky 已提交
1240 1241
	/* Import existing vmlist entries. */
	for (tmp = vmlist; tmp; tmp = tmp->next) {
1242
		va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1243
		va->flags = VM_VM_AREA;
I
Ivan Kokshaysky 已提交
1244 1245
		va->va_start = (unsigned long)tmp->addr;
		va->va_end = va->va_start + tmp->size;
1246
		va->vm = tmp;
I
Ivan Kokshaysky 已提交
1247 1248
		__insert_vmap_area(va);
	}
1249 1250 1251

	vmap_area_pcpu_hole = VMALLOC_END;

1252
	vmap_initialized = true;
N
Nick Piggin 已提交
1253 1254
}

1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
/**
 * map_kernel_range_noflush - map kernel VM area with the specified pages
 * @addr: start of the VM area to map
 * @size: size of the VM area to map
 * @prot: page protection flags to use
 * @pages: pages to map
 *
 * Map PFN_UP(@size) pages at @addr.  The VM area @addr and @size
 * specify should have been allocated using get_vm_area() and its
 * friends.
 *
 * NOTE:
 * This function does NOT do any cache flushing.  The caller is
 * responsible for calling flush_cache_vmap() on to-be-mapped areas
 * before calling this function.
 *
 * RETURNS:
 * The number of pages mapped on success, -errno on failure.
 */
int map_kernel_range_noflush(unsigned long addr, unsigned long size,
			     pgprot_t prot, struct page **pages)
{
	return vmap_page_range_noflush(addr, addr + size, prot, pages);
}

/**
 * unmap_kernel_range_noflush - unmap kernel VM area
 * @addr: start of the VM area to unmap
 * @size: size of the VM area to unmap
 *
 * Unmap PFN_UP(@size) pages at @addr.  The VM area @addr and @size
 * specify should have been allocated using get_vm_area() and its
 * friends.
 *
 * NOTE:
 * This function does NOT do any cache flushing.  The caller is
 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
 * before calling this function and flush_tlb_kernel_range() after.
 */
void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
{
	vunmap_page_range(addr, addr + size);
}
1298
EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1299 1300 1301 1302 1303 1304 1305 1306 1307

/**
 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
 * @addr: start of the VM area to unmap
 * @size: size of the VM area to unmap
 *
 * Similar to unmap_kernel_range_noflush() but flushes vcache before
 * the unmapping and tlb after.
 */
N
Nick Piggin 已提交
1308 1309 1310
void unmap_kernel_range(unsigned long addr, unsigned long size)
{
	unsigned long end = addr + size;
1311 1312

	flush_cache_vunmap(addr, end);
N
Nick Piggin 已提交
1313 1314 1315
	vunmap_page_range(addr, end);
	flush_tlb_kernel_range(addr, end);
}
1316
EXPORT_SYMBOL_GPL(unmap_kernel_range);
N
Nick Piggin 已提交
1317

1318
int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
N
Nick Piggin 已提交
1319 1320
{
	unsigned long addr = (unsigned long)area->addr;
1321
	unsigned long end = addr + get_vm_area_size(area);
N
Nick Piggin 已提交
1322 1323
	int err;

1324
	err = vmap_page_range(addr, end, prot, pages);
N
Nick Piggin 已提交
1325

1326
	return err > 0 ? 0 : err;
N
Nick Piggin 已提交
1327 1328 1329
}
EXPORT_SYMBOL_GPL(map_vm_area);

1330
static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1331
			      unsigned long flags, const void *caller)
1332
{
1333
	spin_lock(&vmap_area_lock);
1334 1335 1336 1337
	vm->flags = flags;
	vm->addr = (void *)va->va_start;
	vm->size = va->va_end - va->va_start;
	vm->caller = caller;
1338
	va->vm = vm;
1339
	va->flags |= VM_VM_AREA;
1340
	spin_unlock(&vmap_area_lock);
1341
}
1342

1343
static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1344
{
1345
	/*
1346
	 * Before removing VM_UNINITIALIZED,
1347 1348 1349 1350
	 * we should make sure that vm has proper values.
	 * Pair with smp_rmb() in show_numa_info().
	 */
	smp_wmb();
1351
	vm->flags &= ~VM_UNINITIALIZED;
1352 1353
}

N
Nick Piggin 已提交
1354
static struct vm_struct *__get_vm_area_node(unsigned long size,
1355
		unsigned long align, unsigned long flags, unsigned long start,
1356
		unsigned long end, int node, gfp_t gfp_mask, const void *caller)
N
Nick Piggin 已提交
1357
{
1358
	struct vmap_area *va;
N
Nick Piggin 已提交
1359
	struct vm_struct *area;
L
Linus Torvalds 已提交
1360

1361
	BUG_ON(in_interrupt());
L
Linus Torvalds 已提交
1362
	size = PAGE_ALIGN(size);
1363 1364
	if (unlikely(!size))
		return NULL;
L
Linus Torvalds 已提交
1365

1366 1367 1368 1369
	if (flags & VM_IOREMAP)
		align = 1ul << clamp_t(int, get_count_order_long(size),
				       PAGE_SHIFT, IOREMAP_MAX_ORDER);

1370
	area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
L
Linus Torvalds 已提交
1371 1372 1373
	if (unlikely(!area))
		return NULL;

1374 1375
	if (!(flags & VM_NO_GUARD))
		size += PAGE_SIZE;
L
Linus Torvalds 已提交
1376

N
Nick Piggin 已提交
1377 1378 1379 1380
	va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
	if (IS_ERR(va)) {
		kfree(area);
		return NULL;
L
Linus Torvalds 已提交
1381 1382
	}

1383
	setup_vmalloc_vm(area, va, flags, caller);
1384

L
Linus Torvalds 已提交
1385 1386 1387
	return area;
}

C
Christoph Lameter 已提交
1388 1389 1390
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
				unsigned long start, unsigned long end)
{
D
David Rientjes 已提交
1391 1392
	return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
				  GFP_KERNEL, __builtin_return_address(0));
C
Christoph Lameter 已提交
1393
}
1394
EXPORT_SYMBOL_GPL(__get_vm_area);
C
Christoph Lameter 已提交
1395

1396 1397
struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
				       unsigned long start, unsigned long end,
1398
				       const void *caller)
1399
{
D
David Rientjes 已提交
1400 1401
	return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
				  GFP_KERNEL, caller);
1402 1403
}

L
Linus Torvalds 已提交
1404
/**
S
Simon Arlott 已提交
1405
 *	get_vm_area  -  reserve a contiguous kernel virtual area
L
Linus Torvalds 已提交
1406 1407 1408 1409 1410 1411 1412 1413 1414
 *	@size:		size of the area
 *	@flags:		%VM_IOREMAP for I/O mappings or VM_ALLOC
 *
 *	Search an area of @size in the kernel virtual mapping area,
 *	and reserved it for out purposes.  Returns the area descriptor
 *	on success or %NULL on failure.
 */
struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
{
1415
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
D
David Rientjes 已提交
1416 1417
				  NUMA_NO_NODE, GFP_KERNEL,
				  __builtin_return_address(0));
1418 1419 1420
}

struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1421
				const void *caller)
1422
{
1423
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
D
David Rientjes 已提交
1424
				  NUMA_NO_NODE, GFP_KERNEL, caller);
L
Linus Torvalds 已提交
1425 1426
}

1427 1428 1429 1430 1431 1432 1433 1434 1435
/**
 *	find_vm_area  -  find a continuous kernel virtual area
 *	@addr:		base address
 *
 *	Search for the kernel VM area starting at @addr, and return it.
 *	It is up to the caller to do all required locking to keep the returned
 *	pointer valid.
 */
struct vm_struct *find_vm_area(const void *addr)
1436
{
N
Nick Piggin 已提交
1437
	struct vmap_area *va;
1438

N
Nick Piggin 已提交
1439 1440
	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA)
1441
		return va->vm;
L
Linus Torvalds 已提交
1442 1443 1444 1445

	return NULL;
}

1446
/**
S
Simon Arlott 已提交
1447
 *	remove_vm_area  -  find and remove a continuous kernel virtual area
1448 1449 1450 1451 1452 1453
 *	@addr:		base address
 *
 *	Search for the kernel VM area starting at @addr, and remove it.
 *	This function returns the found VM area, but using it is NOT safe
 *	on SMP machines, except for its size or flags.
 */
1454
struct vm_struct *remove_vm_area(const void *addr)
1455
{
N
Nick Piggin 已提交
1456 1457 1458 1459
	struct vmap_area *va;

	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA) {
1460
		struct vm_struct *vm = va->vm;
1461

1462 1463 1464 1465 1466
		spin_lock(&vmap_area_lock);
		va->vm = NULL;
		va->flags &= ~VM_VM_AREA;
		spin_unlock(&vmap_area_lock);

1467
		vmap_debug_free_range(va->va_start, va->va_end);
1468
		kasan_free_shadow(vm);
1469 1470
		free_unmap_vmap_area(va);

N
Nick Piggin 已提交
1471 1472 1473
		return vm;
	}
	return NULL;
1474 1475
}

1476
static void __vunmap(const void *addr, int deallocate_pages)
L
Linus Torvalds 已提交
1477 1478 1479 1480 1481 1482
{
	struct vm_struct *area;

	if (!addr)
		return;

1483
	if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
D
Dan Carpenter 已提交
1484
			addr))
L
Linus Torvalds 已提交
1485 1486 1487 1488
		return;

	area = remove_vm_area(addr);
	if (unlikely(!area)) {
A
Arjan van de Ven 已提交
1489
		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
L
Linus Torvalds 已提交
1490 1491 1492 1493
				addr);
		return;
	}

1494 1495
	debug_check_no_locks_freed(addr, get_vm_area_size(area));
	debug_check_no_obj_freed(addr, get_vm_area_size(area));
1496

L
Linus Torvalds 已提交
1497 1498 1499 1500
	if (deallocate_pages) {
		int i;

		for (i = 0; i < area->nr_pages; i++) {
1501 1502 1503
			struct page *page = area->pages[i];

			BUG_ON(!page);
1504
			__free_pages(page, 0);
L
Linus Torvalds 已提交
1505 1506
		}

D
David Rientjes 已提交
1507
		kvfree(area->pages);
L
Linus Torvalds 已提交
1508 1509 1510 1511 1512
	}

	kfree(area);
	return;
}
1513
 
L
Linus Torvalds 已提交
1514 1515 1516 1517
/**
 *	vfree  -  release memory allocated by vmalloc()
 *	@addr:		memory base address
 *
S
Simon Arlott 已提交
1518
 *	Free the virtually continuous memory area starting at @addr, as
1519 1520
 *	obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
 *	NULL, no operation is performed.
L
Linus Torvalds 已提交
1521
 *
1522 1523 1524
 *	Must not be called in NMI context (strictly speaking, only if we don't
 *	have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
 *	conventions for vfree() arch-depenedent would be a really bad idea)
A
Andrew Morton 已提交
1525 1526
 *
 *	NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
L
Linus Torvalds 已提交
1527
 */
1528
void vfree(const void *addr)
L
Linus Torvalds 已提交
1529
{
1530
	BUG_ON(in_nmi());
1531 1532 1533

	kmemleak_free(addr);

1534 1535 1536
	if (!addr)
		return;
	if (unlikely(in_interrupt())) {
1537
		struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
1538 1539
		if (llist_add((struct llist_node *)addr, &p->list))
			schedule_work(&p->wq);
1540 1541
	} else
		__vunmap(addr, 1);
L
Linus Torvalds 已提交
1542 1543 1544 1545 1546 1547 1548 1549 1550 1551
}
EXPORT_SYMBOL(vfree);

/**
 *	vunmap  -  release virtual mapping obtained by vmap()
 *	@addr:		memory base address
 *
 *	Free the virtually contiguous memory area starting at @addr,
 *	which was created from the page array passed to vmap().
 *
1552
 *	Must not be called in interrupt context.
L
Linus Torvalds 已提交
1553
 */
1554
void vunmap(const void *addr)
L
Linus Torvalds 已提交
1555 1556
{
	BUG_ON(in_interrupt());
1557
	might_sleep();
1558 1559
	if (addr)
		__vunmap(addr, 0);
L
Linus Torvalds 已提交
1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576
}
EXPORT_SYMBOL(vunmap);

/**
 *	vmap  -  map an array of pages into virtually contiguous space
 *	@pages:		array of page pointers
 *	@count:		number of pages to map
 *	@flags:		vm_area->flags
 *	@prot:		page protection for the mapping
 *
 *	Maps @count pages from @pages into contiguous kernel virtual
 *	space.
 */
void *vmap(struct page **pages, unsigned int count,
		unsigned long flags, pgprot_t prot)
{
	struct vm_struct *area;
1577
	unsigned long size;		/* In bytes */
L
Linus Torvalds 已提交
1578

1579 1580
	might_sleep();

1581
	if (count > totalram_pages)
L
Linus Torvalds 已提交
1582 1583
		return NULL;

1584 1585
	size = (unsigned long)count << PAGE_SHIFT;
	area = get_vm_area_caller(size, flags, __builtin_return_address(0));
L
Linus Torvalds 已提交
1586 1587
	if (!area)
		return NULL;
1588

1589
	if (map_vm_area(area, prot, pages)) {
L
Linus Torvalds 已提交
1590 1591 1592 1593 1594 1595 1596 1597
		vunmap(area->addr);
		return NULL;
	}

	return area->addr;
}
EXPORT_SYMBOL(vmap);

1598 1599
static void *__vmalloc_node(unsigned long size, unsigned long align,
			    gfp_t gfp_mask, pgprot_t prot,
1600
			    int node, const void *caller);
A
Adrian Bunk 已提交
1601
static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1602
				 pgprot_t prot, int node)
L
Linus Torvalds 已提交
1603
{
1604
	const int order = 0;
L
Linus Torvalds 已提交
1605 1606
	struct page **pages;
	unsigned int nr_pages, array_size, i;
1607 1608
	const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
	const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
L
Linus Torvalds 已提交
1609

1610
	nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
L
Linus Torvalds 已提交
1611 1612 1613 1614
	array_size = (nr_pages * sizeof(struct page *));

	area->nr_pages = nr_pages;
	/* Please note that the recursion is strictly bounded. */
1615
	if (array_size > PAGE_SIZE) {
1616
		pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1617
				PAGE_KERNEL, node, area->caller);
1618
	} else {
1619
		pages = kmalloc_node(array_size, nested_gfp, node);
1620
	}
L
Linus Torvalds 已提交
1621 1622 1623 1624 1625 1626 1627 1628
	area->pages = pages;
	if (!area->pages) {
		remove_vm_area(area->addr);
		kfree(area);
		return NULL;
	}

	for (i = 0; i < area->nr_pages; i++) {
1629 1630
		struct page *page;

J
Jianguo Wu 已提交
1631
		if (node == NUMA_NO_NODE)
1632
			page = alloc_pages(alloc_mask, order);
C
Christoph Lameter 已提交
1633
		else
1634
			page = alloc_pages_node(node, alloc_mask, order);
1635 1636

		if (unlikely(!page)) {
L
Linus Torvalds 已提交
1637 1638 1639 1640
			/* Successfully allocated i pages, free them in __vunmap() */
			area->nr_pages = i;
			goto fail;
		}
1641
		area->pages[i] = page;
1642
		if (gfpflags_allow_blocking(gfp_mask))
1643
			cond_resched();
L
Linus Torvalds 已提交
1644 1645
	}

1646
	if (map_vm_area(area, prot, pages))
L
Linus Torvalds 已提交
1647 1648 1649 1650
		goto fail;
	return area->addr;

fail:
J
Joe Perches 已提交
1651 1652
	warn_alloc_failed(gfp_mask, order,
			  "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1653
			  (area->nr_pages*PAGE_SIZE), area->size);
L
Linus Torvalds 已提交
1654 1655 1656 1657 1658
	vfree(area->addr);
	return NULL;
}

/**
1659
 *	__vmalloc_node_range  -  allocate virtually contiguous memory
L
Linus Torvalds 已提交
1660
 *	@size:		allocation size
1661
 *	@align:		desired alignment
1662 1663
 *	@start:		vm area range start
 *	@end:		vm area range end
L
Linus Torvalds 已提交
1664 1665
 *	@gfp_mask:	flags for the page level allocator
 *	@prot:		protection mask for the allocated pages
1666
 *	@vm_flags:	additional vm area flags (e.g. %VM_NO_GUARD)
D
David Rientjes 已提交
1667
 *	@node:		node to use for allocation or NUMA_NO_NODE
1668
 *	@caller:	caller's return address
L
Linus Torvalds 已提交
1669 1670 1671 1672 1673
 *
 *	Allocate enough pages to cover @size from the page level
 *	allocator with @gfp_mask flags.  Map them into contiguous
 *	kernel virtual space, using a pagetable protection of @prot.
 */
1674 1675
void *__vmalloc_node_range(unsigned long size, unsigned long align,
			unsigned long start, unsigned long end, gfp_t gfp_mask,
1676 1677
			pgprot_t prot, unsigned long vm_flags, int node,
			const void *caller)
L
Linus Torvalds 已提交
1678 1679
{
	struct vm_struct *area;
1680 1681
	void *addr;
	unsigned long real_size = size;
L
Linus Torvalds 已提交
1682 1683

	size = PAGE_ALIGN(size);
1684
	if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1685
		goto fail;
L
Linus Torvalds 已提交
1686

1687 1688
	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
				vm_flags, start, end, node, gfp_mask, caller);
L
Linus Torvalds 已提交
1689
	if (!area)
1690
		goto fail;
L
Linus Torvalds 已提交
1691

1692
	addr = __vmalloc_area_node(area, gfp_mask, prot, node);
1693
	if (!addr)
1694
		return NULL;
1695

1696
	/*
1697 1698
	 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
	 * flag. It means that vm_struct is not fully initialized.
1699
	 * Now, it is fully initialized, so remove this flag here.
1700
	 */
1701
	clear_vm_uninitialized_flag(area);
1702

1703
	/*
1704 1705 1706
	 * A ref_count = 2 is needed because vm_struct allocated in
	 * __get_vm_area_node() contains a reference to the virtual address of
	 * the vmalloc'ed block.
1707
	 */
1708
	kmemleak_alloc(addr, real_size, 2, gfp_mask);
1709 1710

	return addr;
1711 1712 1713 1714 1715 1716

fail:
	warn_alloc_failed(gfp_mask, 0,
			  "vmalloc: allocation failure: %lu bytes\n",
			  real_size);
	return NULL;
L
Linus Torvalds 已提交
1717 1718
}

1719 1720 1721 1722 1723 1724
/**
 *	__vmalloc_node  -  allocate virtually contiguous memory
 *	@size:		allocation size
 *	@align:		desired alignment
 *	@gfp_mask:	flags for the page level allocator
 *	@prot:		protection mask for the allocated pages
D
David Rientjes 已提交
1725
 *	@node:		node to use for allocation or NUMA_NO_NODE
1726 1727 1728 1729 1730 1731 1732 1733
 *	@caller:	caller's return address
 *
 *	Allocate enough pages to cover @size from the page level
 *	allocator with @gfp_mask flags.  Map them into contiguous
 *	kernel virtual space, using a pagetable protection of @prot.
 */
static void *__vmalloc_node(unsigned long size, unsigned long align,
			    gfp_t gfp_mask, pgprot_t prot,
1734
			    int node, const void *caller)
1735 1736
{
	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1737
				gfp_mask, prot, 0, node, caller);
1738 1739
}

C
Christoph Lameter 已提交
1740 1741
void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
{
D
David Rientjes 已提交
1742
	return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1743
				__builtin_return_address(0));
C
Christoph Lameter 已提交
1744
}
L
Linus Torvalds 已提交
1745 1746
EXPORT_SYMBOL(__vmalloc);

1747 1748 1749 1750 1751 1752 1753
static inline void *__vmalloc_node_flags(unsigned long size,
					int node, gfp_t flags)
{
	return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
					node, __builtin_return_address(0));
}

L
Linus Torvalds 已提交
1754 1755 1756 1757 1758 1759
/**
 *	vmalloc  -  allocate virtually contiguous memory
 *	@size:		allocation size
 *	Allocate enough pages to cover @size from the page level
 *	allocator and map them into contiguous kernel virtual space.
 *
1760
 *	For tight control over page level allocator and protection flags
L
Linus Torvalds 已提交
1761 1762 1763 1764
 *	use __vmalloc() instead.
 */
void *vmalloc(unsigned long size)
{
D
David Rientjes 已提交
1765 1766
	return __vmalloc_node_flags(size, NUMA_NO_NODE,
				    GFP_KERNEL | __GFP_HIGHMEM);
L
Linus Torvalds 已提交
1767 1768 1769
}
EXPORT_SYMBOL(vmalloc);

1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781
/**
 *	vzalloc - allocate virtually contiguous memory with zero fill
 *	@size:	allocation size
 *	Allocate enough pages to cover @size from the page level
 *	allocator and map them into contiguous kernel virtual space.
 *	The memory allocated is set to zero.
 *
 *	For tight control over page level allocator and protection flags
 *	use __vmalloc() instead.
 */
void *vzalloc(unsigned long size)
{
D
David Rientjes 已提交
1782
	return __vmalloc_node_flags(size, NUMA_NO_NODE,
1783 1784 1785 1786
				GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
}
EXPORT_SYMBOL(vzalloc);

1787
/**
1788 1789
 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
 * @size: allocation size
1790
 *
1791 1792
 * The resulting memory area is zeroed so it can be mapped to userspace
 * without leaking data.
1793 1794 1795 1796 1797 1798
 */
void *vmalloc_user(unsigned long size)
{
	struct vm_struct *area;
	void *ret;

1799 1800
	ret = __vmalloc_node(size, SHMLBA,
			     GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
D
David Rientjes 已提交
1801 1802
			     PAGE_KERNEL, NUMA_NO_NODE,
			     __builtin_return_address(0));
1803
	if (ret) {
N
Nick Piggin 已提交
1804
		area = find_vm_area(ret);
1805 1806
		area->flags |= VM_USERMAP;
	}
1807 1808 1809 1810
	return ret;
}
EXPORT_SYMBOL(vmalloc_user);

C
Christoph Lameter 已提交
1811 1812 1813
/**
 *	vmalloc_node  -  allocate memory on a specific node
 *	@size:		allocation size
1814
 *	@node:		numa node
C
Christoph Lameter 已提交
1815 1816 1817 1818
 *
 *	Allocate enough pages to cover @size from the page level
 *	allocator and map them into contiguous kernel virtual space.
 *
1819
 *	For tight control over page level allocator and protection flags
C
Christoph Lameter 已提交
1820 1821 1822 1823
 *	use __vmalloc() instead.
 */
void *vmalloc_node(unsigned long size, int node)
{
1824
	return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1825
					node, __builtin_return_address(0));
C
Christoph Lameter 已提交
1826 1827 1828
}
EXPORT_SYMBOL(vmalloc_node);

1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847
/**
 * vzalloc_node - allocate memory on a specific node with zero fill
 * @size:	allocation size
 * @node:	numa node
 *
 * Allocate enough pages to cover @size from the page level
 * allocator and map them into contiguous kernel virtual space.
 * The memory allocated is set to zero.
 *
 * For tight control over page level allocator and protection flags
 * use __vmalloc_node() instead.
 */
void *vzalloc_node(unsigned long size, int node)
{
	return __vmalloc_node_flags(size, node,
			 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
}
EXPORT_SYMBOL(vzalloc_node);

1848 1849 1850 1851
#ifndef PAGE_KERNEL_EXEC
# define PAGE_KERNEL_EXEC PAGE_KERNEL
#endif

L
Linus Torvalds 已提交
1852 1853 1854 1855 1856 1857 1858 1859
/**
 *	vmalloc_exec  -  allocate virtually contiguous, executable memory
 *	@size:		allocation size
 *
 *	Kernel-internal function to allocate enough pages to cover @size
 *	the page level allocator and map them into contiguous and
 *	executable kernel virtual space.
 *
1860
 *	For tight control over page level allocator and protection flags
L
Linus Torvalds 已提交
1861 1862 1863 1864 1865
 *	use __vmalloc() instead.
 */

void *vmalloc_exec(unsigned long size)
{
1866
	return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
D
David Rientjes 已提交
1867
			      NUMA_NO_NODE, __builtin_return_address(0));
L
Linus Torvalds 已提交
1868 1869
}

1870
#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1871
#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1872
#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1873
#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1874 1875 1876 1877
#else
#define GFP_VMALLOC32 GFP_KERNEL
#endif

L
Linus Torvalds 已提交
1878 1879 1880 1881 1882 1883 1884 1885 1886
/**
 *	vmalloc_32  -  allocate virtually contiguous memory (32bit addressable)
 *	@size:		allocation size
 *
 *	Allocate enough 32bit PA addressable pages to cover @size from the
 *	page level allocator and map them into contiguous kernel virtual space.
 */
void *vmalloc_32(unsigned long size)
{
1887
	return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
D
David Rientjes 已提交
1888
			      NUMA_NO_NODE, __builtin_return_address(0));
L
Linus Torvalds 已提交
1889 1890 1891
}
EXPORT_SYMBOL(vmalloc_32);

1892
/**
1893
 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1894
 *	@size:		allocation size
1895 1896 1897
 *
 * The resulting memory area is 32bit addressable and zeroed so it can be
 * mapped to userspace without leaking data.
1898 1899 1900 1901 1902 1903
 */
void *vmalloc_32_user(unsigned long size)
{
	struct vm_struct *area;
	void *ret;

1904
	ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
D
David Rientjes 已提交
1905
			     NUMA_NO_NODE, __builtin_return_address(0));
1906
	if (ret) {
N
Nick Piggin 已提交
1907
		area = find_vm_area(ret);
1908 1909
		area->flags |= VM_USERMAP;
	}
1910 1911 1912 1913
	return ret;
}
EXPORT_SYMBOL(vmalloc_32_user);

1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926
/*
 * small helper routine , copy contents to buf from addr.
 * If the page is not present, fill zero.
 */

static int aligned_vread(char *buf, char *addr, unsigned long count)
{
	struct page *p;
	int copied = 0;

	while (count) {
		unsigned long offset, length;

1927
		offset = offset_in_page(addr);
1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943
		length = PAGE_SIZE - offset;
		if (length > count)
			length = count;
		p = vmalloc_to_page(addr);
		/*
		 * To do safe access to this _mapped_ area, we need
		 * lock. But adding lock here means that we need to add
		 * overhead of vmalloc()/vfree() calles for this _debug_
		 * interface, rarely used. Instead of that, we'll use
		 * kmap() and get small overhead in this access function.
		 */
		if (p) {
			/*
			 * we can expect USER0 is not used (see vread/vwrite's
			 * function description)
			 */
1944
			void *map = kmap_atomic(p);
1945
			memcpy(buf, map + offset, length);
1946
			kunmap_atomic(map);
1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965
		} else
			memset(buf, 0, length);

		addr += length;
		buf += length;
		copied += length;
		count -= length;
	}
	return copied;
}

static int aligned_vwrite(char *buf, char *addr, unsigned long count)
{
	struct page *p;
	int copied = 0;

	while (count) {
		unsigned long offset, length;

1966
		offset = offset_in_page(addr);
1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982
		length = PAGE_SIZE - offset;
		if (length > count)
			length = count;
		p = vmalloc_to_page(addr);
		/*
		 * To do safe access to this _mapped_ area, we need
		 * lock. But adding lock here means that we need to add
		 * overhead of vmalloc()/vfree() calles for this _debug_
		 * interface, rarely used. Instead of that, we'll use
		 * kmap() and get small overhead in this access function.
		 */
		if (p) {
			/*
			 * we can expect USER0 is not used (see vread/vwrite's
			 * function description)
			 */
1983
			void *map = kmap_atomic(p);
1984
			memcpy(map + offset, buf, length);
1985
			kunmap_atomic(map);
1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
		}
		addr += length;
		buf += length;
		copied += length;
		count -= length;
	}
	return copied;
}

/**
 *	vread() -  read vmalloc area in a safe way.
 *	@buf:		buffer for reading data
 *	@addr:		vm address.
 *	@count:		number of bytes to be read.
 *
 *	Returns # of bytes which addr and buf should be increased.
 *	(same number to @count). Returns 0 if [addr...addr+count) doesn't
 *	includes any intersect with alive vmalloc area.
 *
 *	This function checks that addr is a valid vmalloc'ed area, and
 *	copy data from that area to a given buffer. If the given memory range
 *	of [addr...addr+count) includes some valid address, data is copied to
 *	proper area of @buf. If there are memory holes, they'll be zero-filled.
 *	IOREMAP area is treated as memory hole and no copy is done.
 *
 *	If [addr...addr+count) doesn't includes any intersects with alive
2012
 *	vm_struct area, returns 0. @buf should be kernel's buffer.
2013 2014 2015 2016 2017 2018 2019 2020
 *
 *	Note: In usual ops, vread() is never necessary because the caller
 *	should know vmalloc() area is valid and can use memcpy().
 *	This is for routines which have to access vmalloc area without
 *	any informaion, as /dev/kmem.
 *
 */

L
Linus Torvalds 已提交
2021 2022
long vread(char *buf, char *addr, unsigned long count)
{
2023 2024
	struct vmap_area *va;
	struct vm_struct *vm;
L
Linus Torvalds 已提交
2025
	char *vaddr, *buf_start = buf;
2026
	unsigned long buflen = count;
L
Linus Torvalds 已提交
2027 2028 2029 2030 2031 2032
	unsigned long n;

	/* Don't allow overflow */
	if ((unsigned long) addr + count < count)
		count = -(unsigned long) addr;

2033 2034 2035 2036 2037 2038 2039 2040 2041 2042
	spin_lock(&vmap_area_lock);
	list_for_each_entry(va, &vmap_area_list, list) {
		if (!count)
			break;

		if (!(va->flags & VM_VM_AREA))
			continue;

		vm = va->vm;
		vaddr = (char *) vm->addr;
2043
		if (addr >= vaddr + get_vm_area_size(vm))
L
Linus Torvalds 已提交
2044 2045 2046 2047 2048 2049 2050 2051 2052
			continue;
		while (addr < vaddr) {
			if (count == 0)
				goto finished;
			*buf = '\0';
			buf++;
			addr++;
			count--;
		}
2053
		n = vaddr + get_vm_area_size(vm) - addr;
2054 2055
		if (n > count)
			n = count;
2056
		if (!(vm->flags & VM_IOREMAP))
2057 2058 2059 2060 2061 2062
			aligned_vread(buf, addr, n);
		else /* IOREMAP area is treated as memory hole */
			memset(buf, 0, n);
		buf += n;
		addr += n;
		count -= n;
L
Linus Torvalds 已提交
2063 2064
	}
finished:
2065
	spin_unlock(&vmap_area_lock);
2066 2067 2068 2069 2070 2071 2072 2073

	if (buf == buf_start)
		return 0;
	/* zero-fill memory holes */
	if (buf != buf_start + buflen)
		memset(buf, 0, buflen - (buf - buf_start));

	return buflen;
L
Linus Torvalds 已提交
2074 2075
}

2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093
/**
 *	vwrite() -  write vmalloc area in a safe way.
 *	@buf:		buffer for source data
 *	@addr:		vm address.
 *	@count:		number of bytes to be read.
 *
 *	Returns # of bytes which addr and buf should be incresed.
 *	(same number to @count).
 *	If [addr...addr+count) doesn't includes any intersect with valid
 *	vmalloc area, returns 0.
 *
 *	This function checks that addr is a valid vmalloc'ed area, and
 *	copy data from a buffer to the given addr. If specified range of
 *	[addr...addr+count) includes some valid address, data is copied from
 *	proper area of @buf. If there are memory holes, no copy to hole.
 *	IOREMAP area is treated as memory hole and no copy is done.
 *
 *	If [addr...addr+count) doesn't includes any intersects with alive
2094
 *	vm_struct area, returns 0. @buf should be kernel's buffer.
2095 2096 2097 2098 2099 2100 2101
 *
 *	Note: In usual ops, vwrite() is never necessary because the caller
 *	should know vmalloc() area is valid and can use memcpy().
 *	This is for routines which have to access vmalloc area without
 *	any informaion, as /dev/kmem.
 */

L
Linus Torvalds 已提交
2102 2103
long vwrite(char *buf, char *addr, unsigned long count)
{
2104 2105
	struct vmap_area *va;
	struct vm_struct *vm;
2106 2107 2108
	char *vaddr;
	unsigned long n, buflen;
	int copied = 0;
L
Linus Torvalds 已提交
2109 2110 2111 2112

	/* Don't allow overflow */
	if ((unsigned long) addr + count < count)
		count = -(unsigned long) addr;
2113
	buflen = count;
L
Linus Torvalds 已提交
2114

2115 2116 2117 2118 2119 2120 2121 2122 2123 2124
	spin_lock(&vmap_area_lock);
	list_for_each_entry(va, &vmap_area_list, list) {
		if (!count)
			break;

		if (!(va->flags & VM_VM_AREA))
			continue;

		vm = va->vm;
		vaddr = (char *) vm->addr;
2125
		if (addr >= vaddr + get_vm_area_size(vm))
L
Linus Torvalds 已提交
2126 2127 2128 2129 2130 2131 2132 2133
			continue;
		while (addr < vaddr) {
			if (count == 0)
				goto finished;
			buf++;
			addr++;
			count--;
		}
2134
		n = vaddr + get_vm_area_size(vm) - addr;
2135 2136
		if (n > count)
			n = count;
2137
		if (!(vm->flags & VM_IOREMAP)) {
2138 2139 2140 2141 2142 2143
			aligned_vwrite(buf, addr, n);
			copied++;
		}
		buf += n;
		addr += n;
		count -= n;
L
Linus Torvalds 已提交
2144 2145
	}
finished:
2146
	spin_unlock(&vmap_area_lock);
2147 2148 2149
	if (!copied)
		return 0;
	return buflen;
L
Linus Torvalds 已提交
2150
}
2151 2152

/**
2153 2154 2155 2156 2157
 *	remap_vmalloc_range_partial  -  map vmalloc pages to userspace
 *	@vma:		vma to cover
 *	@uaddr:		target user address to start at
 *	@kaddr:		virtual address of vmalloc kernel memory
 *	@size:		size of map area
2158 2159
 *
 *	Returns:	0 for success, -Exxx on failure
2160
 *
2161 2162 2163 2164
 *	This function checks that @kaddr is a valid vmalloc'ed area,
 *	and that it is big enough to cover the range starting at
 *	@uaddr in @vma. Will return failure if that criteria isn't
 *	met.
2165
 *
2166
 *	Similar to remap_pfn_range() (see mm/memory.c)
2167
 */
2168 2169
int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
				void *kaddr, unsigned long size)
2170 2171 2172
{
	struct vm_struct *area;

2173 2174 2175
	size = PAGE_ALIGN(size);

	if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2176 2177
		return -EINVAL;

2178
	area = find_vm_area(kaddr);
2179
	if (!area)
N
Nick Piggin 已提交
2180
		return -EINVAL;
2181 2182

	if (!(area->flags & VM_USERMAP))
N
Nick Piggin 已提交
2183
		return -EINVAL;
2184

2185
	if (kaddr + size > area->addr + area->size)
N
Nick Piggin 已提交
2186
		return -EINVAL;
2187 2188

	do {
2189
		struct page *page = vmalloc_to_page(kaddr);
N
Nick Piggin 已提交
2190 2191
		int ret;

2192 2193 2194 2195 2196
		ret = vm_insert_page(vma, uaddr, page);
		if (ret)
			return ret;

		uaddr += PAGE_SIZE;
2197 2198 2199
		kaddr += PAGE_SIZE;
		size -= PAGE_SIZE;
	} while (size > 0);
2200

2201
	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2202

N
Nick Piggin 已提交
2203
	return 0;
2204
}
2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227
EXPORT_SYMBOL(remap_vmalloc_range_partial);

/**
 *	remap_vmalloc_range  -  map vmalloc pages to userspace
 *	@vma:		vma to cover (map full range of vma)
 *	@addr:		vmalloc memory
 *	@pgoff:		number of pages into addr before first page to map
 *
 *	Returns:	0 for success, -Exxx on failure
 *
 *	This function checks that addr is a valid vmalloc'ed area, and
 *	that it is big enough to cover the vma. Will return failure if
 *	that criteria isn't met.
 *
 *	Similar to remap_pfn_range() (see mm/memory.c)
 */
int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
						unsigned long pgoff)
{
	return remap_vmalloc_range_partial(vma, vma->vm_start,
					   addr + (pgoff << PAGE_SHIFT),
					   vma->vm_end - vma->vm_start);
}
2228 2229
EXPORT_SYMBOL(remap_vmalloc_range);

2230 2231 2232 2233
/*
 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
 * have one.
 */
2234
void __weak vmalloc_sync_all(void)
2235 2236
{
}
2237 2238


2239
static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2240
{
2241 2242 2243 2244 2245 2246
	pte_t ***p = data;

	if (p) {
		*(*p) = pte;
		(*p)++;
	}
2247 2248 2249 2250 2251 2252
	return 0;
}

/**
 *	alloc_vm_area - allocate a range of kernel address space
 *	@size:		size of the area
2253
 *	@ptes:		returns the PTEs for the address space
2254 2255
 *
 *	Returns:	NULL on failure, vm_struct on success
2256 2257 2258
 *
 *	This function reserves a range of kernel address space, and
 *	allocates pagetables to map that range.  No actual mappings
2259 2260 2261 2262
 *	are created.
 *
 *	If @ptes is non-NULL, pointers to the PTEs (in init_mm)
 *	allocated for the VM area are returned.
2263
 */
2264
struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2265 2266 2267
{
	struct vm_struct *area;

2268 2269
	area = get_vm_area_caller(size, VM_IOREMAP,
				__builtin_return_address(0));
2270 2271 2272 2273 2274 2275 2276 2277
	if (area == NULL)
		return NULL;

	/*
	 * This ensures that page tables are constructed for this region
	 * of kernel virtual address space and mapped into init_mm.
	 */
	if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2278
				size, f, ptes ? &ptes : NULL)) {
2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294
		free_vm_area(area);
		return NULL;
	}

	return area;
}
EXPORT_SYMBOL_GPL(alloc_vm_area);

void free_vm_area(struct vm_struct *area)
{
	struct vm_struct *ret;
	ret = remove_vm_area(area->addr);
	BUG_ON(ret != area);
	kfree(area);
}
EXPORT_SYMBOL_GPL(free_vm_area);
2295

2296
#ifdef CONFIG_SMP
2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391
static struct vmap_area *node_to_va(struct rb_node *n)
{
	return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
}

/**
 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
 * @end: target address
 * @pnext: out arg for the next vmap_area
 * @pprev: out arg for the previous vmap_area
 *
 * Returns: %true if either or both of next and prev are found,
 *	    %false if no vmap_area exists
 *
 * Find vmap_areas end addresses of which enclose @end.  ie. if not
 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
 */
static bool pvm_find_next_prev(unsigned long end,
			       struct vmap_area **pnext,
			       struct vmap_area **pprev)
{
	struct rb_node *n = vmap_area_root.rb_node;
	struct vmap_area *va = NULL;

	while (n) {
		va = rb_entry(n, struct vmap_area, rb_node);
		if (end < va->va_end)
			n = n->rb_left;
		else if (end > va->va_end)
			n = n->rb_right;
		else
			break;
	}

	if (!va)
		return false;

	if (va->va_end > end) {
		*pnext = va;
		*pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
	} else {
		*pprev = va;
		*pnext = node_to_va(rb_next(&(*pprev)->rb_node));
	}
	return true;
}

/**
 * pvm_determine_end - find the highest aligned address between two vmap_areas
 * @pnext: in/out arg for the next vmap_area
 * @pprev: in/out arg for the previous vmap_area
 * @align: alignment
 *
 * Returns: determined end address
 *
 * Find the highest aligned address between *@pnext and *@pprev below
 * VMALLOC_END.  *@pnext and *@pprev are adjusted so that the aligned
 * down address is between the end addresses of the two vmap_areas.
 *
 * Please note that the address returned by this function may fall
 * inside *@pnext vmap_area.  The caller is responsible for checking
 * that.
 */
static unsigned long pvm_determine_end(struct vmap_area **pnext,
				       struct vmap_area **pprev,
				       unsigned long align)
{
	const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
	unsigned long addr;

	if (*pnext)
		addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
	else
		addr = vmalloc_end;

	while (*pprev && (*pprev)->va_end > addr) {
		*pnext = *pprev;
		*pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
	}

	return addr;
}

/**
 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
 * @offsets: array containing offset of each area
 * @sizes: array containing size of each area
 * @nr_vms: the number of areas to allocate
 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
 *
 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
 *	    vm_structs on success, %NULL on failure
 *
 * Percpu allocator wants to use congruent vm areas so that it can
 * maintain the offsets among percpu areas.  This function allocates
2392 2393 2394 2395
 * congruent vmalloc areas for it with GFP_KERNEL.  These areas tend to
 * be scattered pretty far, distance between two areas easily going up
 * to gigabytes.  To avoid interacting with regular vmallocs, these
 * areas are allocated from top.
2396 2397 2398 2399 2400 2401 2402 2403 2404 2405
 *
 * Despite its complicated look, this allocator is rather simple.  It
 * does everything top-down and scans areas from the end looking for
 * matching slot.  While scanning, if any of the areas overlaps with
 * existing vmap_area, the base address is pulled down to fit the
 * area.  Scanning is repeated till all the areas fit and then all
 * necessary data structres are inserted and the result is returned.
 */
struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
				     const size_t *sizes, int nr_vms,
2406
				     size_t align)
2407 2408 2409 2410 2411 2412 2413 2414 2415 2416
{
	const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
	const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
	struct vmap_area **vas, *prev, *next;
	struct vm_struct **vms;
	int area, area2, last_area, term_area;
	unsigned long base, start, end, last_end;
	bool purged = false;

	/* verify parameters and allocate data structures */
2417
	BUG_ON(offset_in_page(align) || !is_power_of_2(align));
2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447
	for (last_area = 0, area = 0; area < nr_vms; area++) {
		start = offsets[area];
		end = start + sizes[area];

		/* is everything aligned properly? */
		BUG_ON(!IS_ALIGNED(offsets[area], align));
		BUG_ON(!IS_ALIGNED(sizes[area], align));

		/* detect the area with the highest address */
		if (start > offsets[last_area])
			last_area = area;

		for (area2 = 0; area2 < nr_vms; area2++) {
			unsigned long start2 = offsets[area2];
			unsigned long end2 = start2 + sizes[area2];

			if (area2 == area)
				continue;

			BUG_ON(start2 >= start && start2 < end);
			BUG_ON(end2 <= end && end2 > start);
		}
	}
	last_end = offsets[last_area] + sizes[last_area];

	if (vmalloc_end - vmalloc_start < last_end) {
		WARN_ON(true);
		return NULL;
	}

2448 2449
	vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
	vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2450
	if (!vas || !vms)
2451
		goto err_free2;
2452 2453

	for (area = 0; area < nr_vms; area++) {
2454 2455
		vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
		vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540
		if (!vas[area] || !vms[area])
			goto err_free;
	}
retry:
	spin_lock(&vmap_area_lock);

	/* start scanning - we scan from the top, begin with the last area */
	area = term_area = last_area;
	start = offsets[area];
	end = start + sizes[area];

	if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
		base = vmalloc_end - last_end;
		goto found;
	}
	base = pvm_determine_end(&next, &prev, align) - end;

	while (true) {
		BUG_ON(next && next->va_end <= base + end);
		BUG_ON(prev && prev->va_end > base + end);

		/*
		 * base might have underflowed, add last_end before
		 * comparing.
		 */
		if (base + last_end < vmalloc_start + last_end) {
			spin_unlock(&vmap_area_lock);
			if (!purged) {
				purge_vmap_area_lazy();
				purged = true;
				goto retry;
			}
			goto err_free;
		}

		/*
		 * If next overlaps, move base downwards so that it's
		 * right below next and then recheck.
		 */
		if (next && next->va_start < base + end) {
			base = pvm_determine_end(&next, &prev, align) - end;
			term_area = area;
			continue;
		}

		/*
		 * If prev overlaps, shift down next and prev and move
		 * base so that it's right below new next and then
		 * recheck.
		 */
		if (prev && prev->va_end > base + start)  {
			next = prev;
			prev = node_to_va(rb_prev(&next->rb_node));
			base = pvm_determine_end(&next, &prev, align) - end;
			term_area = area;
			continue;
		}

		/*
		 * This area fits, move on to the previous one.  If
		 * the previous one is the terminal one, we're done.
		 */
		area = (area + nr_vms - 1) % nr_vms;
		if (area == term_area)
			break;
		start = offsets[area];
		end = start + sizes[area];
		pvm_find_next_prev(base + end, &next, &prev);
	}
found:
	/* we've found a fitting base, insert all va's */
	for (area = 0; area < nr_vms; area++) {
		struct vmap_area *va = vas[area];

		va->va_start = base + offsets[area];
		va->va_end = va->va_start + sizes[area];
		__insert_vmap_area(va);
	}

	vmap_area_pcpu_hole = base + offsets[last_area];

	spin_unlock(&vmap_area_lock);

	/* insert all vm's */
	for (area = 0; area < nr_vms; area++)
2541 2542
		setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
				 pcpu_get_vm_areas);
2543 2544 2545 2546 2547 2548

	kfree(vas);
	return vms;

err_free:
	for (area = 0; area < nr_vms; area++) {
2549 2550
		kfree(vas[area]);
		kfree(vms[area]);
2551
	}
2552
err_free2:
2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572
	kfree(vas);
	kfree(vms);
	return NULL;
}

/**
 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
 * @nr_vms: the number of allocated areas
 *
 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
 */
void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
{
	int i;

	for (i = 0; i < nr_vms; i++)
		free_vm_area(vms[i]);
	kfree(vms);
}
2573
#endif	/* CONFIG_SMP */
2574 2575 2576

#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)
2577
	__acquires(&vmap_area_lock)
2578 2579
{
	loff_t n = *pos;
2580
	struct vmap_area *va;
2581

2582
	spin_lock(&vmap_area_lock);
2583
	va = list_first_entry(&vmap_area_list, typeof(*va), list);
2584
	while (n > 0 && &va->list != &vmap_area_list) {
2585
		n--;
2586
		va = list_next_entry(va, list);
2587
	}
2588 2589
	if (!n && &va->list != &vmap_area_list)
		return va;
2590 2591 2592 2593 2594 2595 2596

	return NULL;

}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
2597
	struct vmap_area *va = p, *next;
2598 2599

	++*pos;
2600
	next = list_next_entry(va, list);
2601 2602 2603 2604
	if (&next->list != &vmap_area_list)
		return next;

	return NULL;
2605 2606 2607
}

static void s_stop(struct seq_file *m, void *p)
2608
	__releases(&vmap_area_lock)
2609
{
2610
	spin_unlock(&vmap_area_lock);
2611 2612
}

E
Eric Dumazet 已提交
2613 2614
static void show_numa_info(struct seq_file *m, struct vm_struct *v)
{
2615
	if (IS_ENABLED(CONFIG_NUMA)) {
E
Eric Dumazet 已提交
2616 2617 2618 2619 2620
		unsigned int nr, *counters = m->private;

		if (!counters)
			return;

2621 2622
		if (v->flags & VM_UNINITIALIZED)
			return;
2623 2624
		/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
		smp_rmb();
2625

E
Eric Dumazet 已提交
2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636
		memset(counters, 0, nr_node_ids * sizeof(unsigned int));

		for (nr = 0; nr < v->nr_pages; nr++)
			counters[page_to_nid(v->pages[nr])]++;

		for_each_node_state(nr, N_HIGH_MEMORY)
			if (counters[nr])
				seq_printf(m, " N%u=%u", nr, counters[nr]);
	}
}

2637 2638
static int s_show(struct seq_file *m, void *p)
{
2639 2640 2641
	struct vmap_area *va = p;
	struct vm_struct *v;

2642 2643 2644 2645 2646
	/*
	 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
	 * behalf of vmap area is being tear down or vm_map_ram allocation.
	 */
	if (!(va->flags & VM_VM_AREA))
2647 2648 2649
		return 0;

	v = va->vm;
2650

K
Kees Cook 已提交
2651
	seq_printf(m, "0x%pK-0x%pK %7ld",
2652 2653
		v->addr, v->addr + v->size, v->size);

J
Joe Perches 已提交
2654 2655
	if (v->caller)
		seq_printf(m, " %pS", v->caller);
2656

2657 2658 2659 2660
	if (v->nr_pages)
		seq_printf(m, " pages=%d", v->nr_pages);

	if (v->phys_addr)
2661
		seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2662 2663

	if (v->flags & VM_IOREMAP)
2664
		seq_puts(m, " ioremap");
2665 2666

	if (v->flags & VM_ALLOC)
2667
		seq_puts(m, " vmalloc");
2668 2669

	if (v->flags & VM_MAP)
2670
		seq_puts(m, " vmap");
2671 2672

	if (v->flags & VM_USERMAP)
2673
		seq_puts(m, " user");
2674

D
David Rientjes 已提交
2675
	if (is_vmalloc_addr(v->pages))
2676
		seq_puts(m, " vpages");
2677

E
Eric Dumazet 已提交
2678
	show_numa_info(m, v);
2679 2680 2681 2682
	seq_putc(m, '\n');
	return 0;
}

2683
static const struct seq_operations vmalloc_op = {
2684 2685 2686 2687 2688
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
};
2689 2690 2691

static int vmalloc_open(struct inode *inode, struct file *file)
{
2692 2693 2694 2695 2696
	if (IS_ENABLED(CONFIG_NUMA))
		return seq_open_private(file, &vmalloc_op,
					nr_node_ids * sizeof(unsigned int));
	else
		return seq_open(file, &vmalloc_op);
2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
}

static const struct file_operations proc_vmalloc_operations = {
	.open		= vmalloc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release_private,
};

static int __init proc_vmalloc_init(void)
{
	proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
	return 0;
}
module_init(proc_vmalloc_init);
2712

2713 2714
#endif