blob: 036536945dd9e06f53adf21c165f087a4700c3cc [file] [log] [blame]
/*
* 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
* Numa awareness, Christoph Lameter, SGI, June 2005
*/
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/debugobjects.h>
#include <linux/kallsyms.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include <asm/tlbflush.h>
/*** Page table manipulation functions ***/
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);
}
static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
{
pmd_t *pmd;
unsigned long next;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd))
continue;
vunmap_pte_range(pmd, addr, next);
} while (pmd++, addr = next, addr != end);
}
static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
{
pud_t *pud;
unsigned long next;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
vunmap_pmd_range(pud, addr, next);
} while (pud++, addr = next, addr != end);
}
static void vunmap_page_range(unsigned long addr, unsigned long end)
{
pgd_t *pgd;
unsigned long next;
BUG_ON(addr >= end);
pgd = pgd_offset_k(addr);
flush_cache_vunmap(addr, end);
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,
unsigned long end, pgprot_t prot, struct page **pages, int *nr)
{
pte_t *pte;
/*
* nr is a running index into the array which helps higher level
* callers keep track of where we're up to.
*/
pte = pte_alloc_kernel(pmd, addr);
if (!pte)
return -ENOMEM;
do {
struct page *page = pages[*nr];
if (WARN_ON(!pte_none(*pte)))
return -EBUSY;
if (WARN_ON(!page))
return -ENOMEM;
set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
(*nr)++;
} while (pte++, addr += PAGE_SIZE, addr != end);
return 0;
}
static int vmap_pmd_range(pud_t *pud, unsigned long addr,
unsigned long end, pgprot_t prot, struct page **pages, int *nr)
{
pmd_t *pmd;
unsigned long next;
pmd = pmd_alloc(&init_mm, pud, addr);
if (!pmd)
return -ENOMEM;
do {
next = pmd_addr_end(addr, end);
if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
return -ENOMEM;
} while (pmd++, addr = next, addr != end);
return 0;
}
static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
unsigned long end, pgprot_t prot, struct page **pages, int *nr)
{
pud_t *pud;
unsigned long next;
pud = pud_alloc(&init_mm, pgd, addr);
if (!pud)
return -ENOMEM;
do {
next = pud_addr_end(addr, end);
if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
return -ENOMEM;
} while (pud++, addr = next, addr != end);
return 0;
}
/*
* 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]
*/
static int vmap_page_range(unsigned long addr, unsigned long end,
pgprot_t prot, struct page **pages)
{
pgd_t *pgd;
unsigned long next;
int err = 0;
int nr = 0;
BUG_ON(addr >= end);
pgd = pgd_offset_k(addr);
do {
next = pgd_addr_end(addr, end);
err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
if (err)
break;
} while (pgd++, addr = next, addr != end);
flush_cache_vmap(addr, end);
if (unlikely(err))
return err;
return nr;
}
static inline int is_vmalloc_or_module_addr(const void *x)
{
/*
* x86-64 and sparc64 put modules in a special place,
* 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);
}
/*
* Walk a vmap address to the struct page it maps.
*/
struct page *vmalloc_to_page(const void *vmalloc_addr)
{
unsigned long addr = (unsigned long) vmalloc_addr;
struct page *page = NULL;
pgd_t *pgd = pgd_offset_k(addr);
/*
* XXX we might need to change this if we add VIRTUAL_BUG_ON for
* architectures that do not vmalloc module space
*/
VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
if (!pgd_none(*pgd)) {
pud_t *pud = pud_offset(pgd, addr);
if (!pud_none(*pud)) {
pmd_t *pmd = pmd_offset(pud, addr);
if (!pmd_none(*pmd)) {
pte_t *ptep, pte;
ptep = pte_offset_map(pmd, addr);
pte = *ptep;
if (pte_present(pte))
page = pte_page(pte);
pte_unmap(ptep);
}
}
}
return page;
}
EXPORT_SYMBOL(vmalloc_to_page);
/*
* Map a vmalloc()-space virtual address to the physical page frame number.
*/
unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
{
return page_to_pfn(vmalloc_to_page(vmalloc_addr));
}
EXPORT_SYMBOL(vmalloc_to_pfn);
/*** Global kva allocator ***/
#define VM_LAZY_FREE 0x01
#define VM_LAZY_FREEING 0x02
#define VM_VM_AREA 0x04
struct vmap_area {
unsigned long va_start;
unsigned long va_end;
unsigned long flags;
struct rb_node rb_node; /* address sorted rbtree */
struct list_head list; /* address sorted list */
struct list_head purge_list; /* "lazy purge" list */
void *private;
struct rcu_head rcu_head;
};
static DEFINE_SPINLOCK(vmap_area_lock);
static struct rb_root vmap_area_root = RB_ROOT;
static LIST_HEAD(vmap_area_list);
static struct vmap_area *__find_vmap_area(unsigned long addr)
{
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;
else if (addr > va->va_start)
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) {
struct vmap_area *tmp;
parent = *p;
tmp = rb_entry(parent, struct vmap_area, rb_node);
if (va->va_start < tmp->va_end)
p = &(*p)->rb_left;
else if (va->va_end > tmp->va_start)
p = &(*p)->rb_right;
else
BUG();
}
rb_link_node(&va->rb_node, parent, p);
rb_insert_color(&va->rb_node, &vmap_area_root);
/* address-sort this list so it is usable like the vmlist */
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);
/*
* 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;
unsigned long addr;
int purged = 0;
BUG_ON(size & ~PAGE_MASK);
addr = ALIGN(vstart, align);
va = kmalloc_node(sizeof(struct vmap_area),
gfp_mask & GFP_RECLAIM_MASK, node);
if (unlikely(!va))
return ERR_PTR(-ENOMEM);
retry:
spin_lock(&vmap_area_lock);
/* XXX: could have a last_hole cache */
n = vmap_area_root.rb_node;
if (n) {
struct vmap_area *first = NULL;
do {
struct vmap_area *tmp;
tmp = rb_entry(n, struct vmap_area, rb_node);
if (tmp->va_end >= addr) {
if (!first && tmp->va_start < addr + size)
first = tmp;
n = n->rb_left;
} else {
first = tmp;
n = n->rb_right;
}
} while (n);
if (!first)
goto found;
if (first->va_end < addr) {
n = rb_next(&first->rb_node);
if (n)
first = rb_entry(n, struct vmap_area, rb_node);
else
goto found;
}
while (addr + size >= first->va_start && addr + size <= vend) {
addr = ALIGN(first->va_end + PAGE_SIZE, align);
n = rb_next(&first->rb_node);
if (n)
first = rb_entry(n, struct vmap_area, rb_node);
else
goto found;
}
}
found:
if (addr + size > vend) {
spin_unlock(&vmap_area_lock);
if (!purged) {
purge_vmap_area_lazy();
purged = 1;
goto retry;
}
if (printk_ratelimit())
printk(KERN_WARNING "vmap allocation failed: "
"use vmalloc=<size> to increase size.\n");
return ERR_PTR(-EBUSY);
}
BUG_ON(addr & (align-1));
va->va_start = addr;
va->va_end = addr + size;
va->flags = 0;
__insert_vmap_area(va);
spin_unlock(&vmap_area_lock);
return va;
}
static void rcu_free_va(struct rcu_head *head)
{
struct vmap_area *va = container_of(head, struct vmap_area, rcu_head);
kfree(va);
}
static void __free_vmap_area(struct vmap_area *va)
{
BUG_ON(RB_EMPTY_NODE(&va->rb_node));
rb_erase(&va->rb_node, &vmap_area_root);
RB_CLEAR_NODE(&va->rb_node);
list_del_rcu(&va->list);
call_rcu(&va->rcu_head, rcu_free_va);
}
/*
* 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);
}
/*
* 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);
/*
* 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)
{
static DEFINE_SPINLOCK(purge_lock);
LIST_HEAD(valist);
struct vmap_area *va;
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) {
if (!spin_trylock(&purge_lock))
return;
} else
spin_lock(&purge_lock);
rcu_read_lock();
list_for_each_entry_rcu(va, &vmap_area_list, list) {
if (va->flags & VM_LAZY_FREE) {
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;
unmap_vmap_area(va);
list_add_tail(&va->purge_list, &valist);
va->flags |= VM_LAZY_FREEING;
va->flags &= ~VM_LAZY_FREE;
}
}
rcu_read_unlock();
if (nr) {
BUG_ON(nr > atomic_read(&vmap_lazy_nr));
atomic_sub(nr, &vmap_lazy_nr);
}
if (nr || force_flush)
flush_tlb_kernel_range(*start, *end);
if (nr) {
spin_lock(&vmap_area_lock);
list_for_each_entry(va, &valist, purge_list)
__free_vmap_area(va);
spin_unlock(&vmap_area_lock);
}
spin_unlock(&purge_lock);
}
/*
* Kick off a purge of the outstanding lazy areas.
*/
static void purge_vmap_area_lazy(void)
{
unsigned long start = ULONG_MAX, end = 0;
__purge_vmap_area_lazy(&start, &end, 0, 0);
}
/*
* Free and unmap a vmap area
*/
static void free_unmap_vmap_area(struct vmap_area *va)
{
va->flags |= VM_LAZY_FREE;
atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
purge_vmap_area_lazy();
}
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() */
#define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
VMALLOC_PAGES / NR_CPUS / 16))
#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
struct vmap_block_queue {
spinlock_t lock;
struct list_head free;
struct list_head dirty;
unsigned int nr_dirty;
};
struct vmap_block {
spinlock_t lock;
struct vmap_area *va;
struct vmap_block_queue *vbq;
unsigned long free, dirty;
DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
union {
struct {
struct list_head free_list;
struct list_head dirty_list;
};
struct rcu_head rcu_head;
};
};
/* 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;
}
static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
{
struct vmap_block_queue *vbq;
struct vmap_block *vb;
struct vmap_area *va;
unsigned long vb_idx;
int node, err;
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);
if (unlikely(IS_ERR(va))) {
kfree(vb);
return ERR_PTR(PTR_ERR(va));
}
err = radix_tree_preload(gfp_mask);
if (unlikely(err)) {
kfree(vb);
free_vmap_area(va);
return ERR_PTR(err);
}
spin_lock_init(&vb->lock);
vb->va = va;
vb->free = VMAP_BBMAP_BITS;
vb->dirty = 0;
bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
INIT_LIST_HEAD(&vb->free_list);
INIT_LIST_HEAD(&vb->dirty_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);
vb->vbq = vbq;
spin_lock(&vbq->lock);
list_add(&vb->free_list, &vbq->free);
spin_unlock(&vbq->lock);
put_cpu_var(vmap_cpu_blocks);
return vb;
}
static void rcu_free_vb(struct rcu_head *head)
{
struct vmap_block *vb = container_of(head, struct vmap_block, rcu_head);
kfree(vb);
}
static void free_vmap_block(struct vmap_block *vb)
{
struct vmap_block *tmp;
unsigned long vb_idx;
spin_lock(&vb->vbq->lock);
if (!list_empty(&vb->free_list))
list_del(&vb->free_list);
if (!list_empty(&vb->dirty_list))
list_del(&vb->dirty_list);
spin_unlock(&vb->vbq->lock);
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);
free_unmap_vmap_area(vb->va);
call_rcu(&vb->rcu_head, rcu_free_vb);
}
static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
{
struct vmap_block_queue *vbq;
struct vmap_block *vb;
unsigned long addr = 0;
unsigned int order;
BUG_ON(size & ~PAGE_MASK);
BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
order = get_order(size);
again:
rcu_read_lock();
vbq = &get_cpu_var(vmap_block_queue);
list_for_each_entry_rcu(vb, &vbq->free, free_list) {
int i;
spin_lock(&vb->lock);
i = bitmap_find_free_region(vb->alloc_map,
VMAP_BBMAP_BITS, order);
if (i >= 0) {
addr = vb->va->va_start + (i << PAGE_SHIFT);
BUG_ON(addr_to_vb_idx(addr) !=
addr_to_vb_idx(vb->va->va_start));
vb->free -= 1UL << order;
if (vb->free == 0) {
spin_lock(&vbq->lock);
list_del_init(&vb->free_list);
spin_unlock(&vbq->lock);
}
spin_unlock(&vb->lock);
break;
}
spin_unlock(&vb->lock);
}
put_cpu_var(vmap_cpu_blocks);
rcu_read_unlock();
if (!addr) {
vb = new_vmap_block(gfp_mask);
if (IS_ERR(vb))
return vb;
goto again;
}
return (void *)addr;
}
static void vb_free(const void *addr, unsigned long size)
{
unsigned long offset;
unsigned long vb_idx;
unsigned int order;
struct vmap_block *vb;
BUG_ON(size & ~PAGE_MASK);
BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
order = get_order(size);
offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
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);
spin_lock(&vb->lock);
bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order);
if (!vb->dirty) {
spin_lock(&vb->vbq->lock);
list_add(&vb->dirty_list, &vb->vbq->dirty);
spin_unlock(&vb->vbq->lock);
}
vb->dirty += 1UL << order;
if (vb->dirty == VMAP_BBMAP_BITS) {
BUG_ON(vb->free || !list_empty(&vb->free_list));
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;
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) {
int i;
spin_lock(&vb->lock);
i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
while (i < VMAP_BBMAP_BITS) {
unsigned long s, e;
int j;
j = find_next_zero_bit(vb->dirty_map,
VMAP_BBMAP_BITS, i);
s = vb->va->va_start + (i << PAGE_SHIFT);
e = vb->va->va_start + (j << PAGE_SHIFT);
vunmap_page_range(s, e);
flush = 1;
if (s < start)
start = s;
if (e > end)
end = e;
i = j;
i = find_next_bit(vb->dirty_map,
VMAP_BBMAP_BITS, i);
}
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)
{
unsigned long size = count << PAGE_SHIFT;
unsigned long addr = (unsigned long)mem;
BUG_ON(!addr);
BUG_ON(addr < VMALLOC_START);
BUG_ON(addr > VMALLOC_END);
BUG_ON(addr & (PAGE_SIZE-1));
debug_check_no_locks_freed(mem, size);
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
* @returns: a pointer to the address that has been mapped, or NULL on failure
*/
void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
{
unsigned long size = count << PAGE_SHIFT;
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);
void __init vmalloc_init(void)
{
int i;
for_each_possible_cpu(i) {
struct vmap_block_queue *vbq;
vbq = &per_cpu(vmap_block_queue, i);
spin_lock_init(&vbq->lock);
INIT_LIST_HEAD(&vbq->free);
INIT_LIST_HEAD(&vbq->dirty);
vbq->nr_dirty = 0;
}
}
void unmap_kernel_range(unsigned long addr, unsigned long size)
{
unsigned long end = addr + size;
vunmap_page_range(addr, end);
flush_tlb_kernel_range(addr, end);
}
int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
{
unsigned long addr = (unsigned long)area->addr;
unsigned long end = addr + area->size - PAGE_SIZE;
int err;
err = vmap_page_range(addr, end, prot, *pages);
if (err > 0) {
*pages += err;
err = 0;
}
return err;
}
EXPORT_SYMBOL_GPL(map_vm_area);
/*** Old vmalloc interfaces ***/
DEFINE_RWLOCK(vmlist_lock);
struct vm_struct *vmlist;
static struct vm_struct *__get_vm_area_node(unsigned long size,
unsigned long flags, unsigned long start, unsigned long end,
int node, gfp_t gfp_mask, void *caller)
{
static struct vmap_area *va;
struct vm_struct *area;
struct vm_struct *tmp, **p;
unsigned long align = 1;
BUG_ON(in_interrupt());
if (flags & VM_IOREMAP) {
int bit = fls(size);
if (bit > IOREMAP_MAX_ORDER)
bit = IOREMAP_MAX_ORDER;
else if (bit < PAGE_SHIFT)
bit = PAGE_SHIFT;
align = 1ul << bit;
}
size = PAGE_ALIGN(size);
if (unlikely(!size))
return NULL;
area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
if (unlikely(!area))
return NULL;
/*
* We always allocate a guard page.
*/
size += PAGE_SIZE;
va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
if (IS_ERR(va)) {
kfree(area);
return NULL;
}
area->flags = flags;
area->addr = (void *)va->va_start;
area->size = size;
area->pages = NULL;
area->nr_pages = 0;
area->phys_addr = 0;
area->caller = caller;
va->private = area;
va->flags |= VM_VM_AREA;
write_lock(&vmlist_lock);
for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
if (tmp->addr >= area->addr)
break;
}
area->next = *p;
*p = area;
write_unlock(&vmlist_lock);
return area;
}
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end)
{
return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL,
__builtin_return_address(0));
}
EXPORT_SYMBOL_GPL(__get_vm_area);
/**
* get_vm_area - reserve a contiguous kernel virtual area
* @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)
{
return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
-1, GFP_KERNEL, __builtin_return_address(0));
}
struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
void *caller)
{
return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END,
-1, GFP_KERNEL, caller);
}
struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,
int node, gfp_t gfp_mask)
{
return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,
gfp_mask, __builtin_return_address(0));
}
static struct vm_struct *find_vm_area(const void *addr)
{
struct vmap_area *va;
va = find_vmap_area((unsigned long)addr);
if (va && va->flags & VM_VM_AREA)
return va->private;
return NULL;
}
/**
* remove_vm_area - find and remove a continuous kernel virtual area
* @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.
*/
struct vm_struct *remove_vm_area(const void *addr)
{
struct vmap_area *va;
va = find_vmap_area((unsigned long)addr);
if (va && va->flags & VM_VM_AREA) {
struct vm_struct *vm = va->private;
struct vm_struct *tmp, **p;
free_unmap_vmap_area(va);
vm->size -= PAGE_SIZE;
write_lock(&vmlist_lock);
for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
;
*p = tmp->next;
write_unlock(&vmlist_lock);
return vm;
}
return NULL;
}
static void __vunmap(const void *addr, int deallocate_pages)
{
struct vm_struct *area;
if (!addr)
return;
if ((PAGE_SIZE-1) & (unsigned long)addr) {
WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
return;
}
area = remove_vm_area(addr);
if (unlikely(!area)) {
WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
addr);
return;
}
debug_check_no_locks_freed(addr, area->size);
debug_check_no_obj_freed(addr, area->size);
if (deallocate_pages) {
int i;
for (i = 0; i < area->nr_pages; i++) {
struct page *page = area->pages[i];
BUG_ON(!page);
__free_page(page);
}
if (area->flags & VM_VPAGES)
vfree(area->pages);
else
kfree(area->pages);
}
kfree(area);
return;
}
/**
* vfree - release memory allocated by vmalloc()
* @addr: memory base address
*
* Free the virtually continuous memory area starting at @addr, as
* obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
* NULL, no operation is performed.
*
* Must not be called in interrupt context.
*/
void vfree(const void *addr)
{
BUG_ON(in_interrupt());
__vunmap(addr, 1);
}
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().
*
* Must not be called in interrupt context.
*/
void vunmap(const void *addr)
{
BUG_ON(in_interrupt());
__vunmap(addr, 0);
}
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;
if (count > num_physpages)
return NULL;
area = get_vm_area_caller((count << PAGE_SHIFT), flags,
__builtin_return_address(0));
if (!area)
return NULL;
if (map_vm_area(area, prot, &pages)) {
vunmap(area->addr);
return NULL;
}
return area->addr;
}
EXPORT_SYMBOL(vmap);
static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
int node, void *caller);
static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
pgprot_t prot, int node, void *caller)
{
struct page **pages;
unsigned int nr_pages, array_size, i;
nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
array_size = (nr_pages * sizeof(struct page *));
area->nr_pages = nr_pages;
/* Please note that the recursion is strictly bounded. */
if (array_size > PAGE_SIZE) {
pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,
PAGE_KERNEL, node, caller);
area->flags |= VM_VPAGES;
} else {
pages = kmalloc_node(array_size,
(gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO,
node);
}
area->pages = pages;
area->caller = caller;
if (!area->pages) {
remove_vm_area(area->addr);
kfree(area);
return NULL;
}
for (i = 0; i < area->nr_pages; i++) {
struct page *page;
if (node < 0)
page = alloc_page(gfp_mask);
else
page = alloc_pages_node(node, gfp_mask, 0);
if (unlikely(!page)) {
/* Successfully allocated i pages, free them in __vunmap() */
area->nr_pages = i;
goto fail;
}
area->pages[i] = page;
}
if (map_vm_area(area, prot, &pages))
goto fail;
return area->addr;
fail:
vfree(area->addr);
return NULL;
}
void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
{
return __vmalloc_area_node(area, gfp_mask, prot, -1,
__builtin_return_address(0));
}
/**
* __vmalloc_node - allocate virtually contiguous memory
* @size: allocation size
* @gfp_mask: flags for the page level allocator
* @prot: protection mask for the allocated pages
* @node: node to use for allocation or -1
* @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, gfp_t gfp_mask, pgprot_t prot,
int node, void *caller)
{
struct vm_struct *area;
size = PAGE_ALIGN(size);
if (!size || (size >> PAGE_SHIFT) > num_physpages)
return NULL;
area = __get_vm_area_node(size, VM_ALLOC, VMALLOC_START, VMALLOC_END,
node, gfp_mask, caller);
if (!area)
return NULL;
return __vmalloc_area_node(area, gfp_mask, prot, node, caller);
}
void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
{
return __vmalloc_node(size, gfp_mask, prot, -1,
__builtin_return_address(0));
}
EXPORT_SYMBOL(__vmalloc);
/**
* 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.
*
* For tight control over page level allocator and protection flags
* use __vmalloc() instead.
*/
void *vmalloc(unsigned long size)
{
return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
-1, __builtin_return_address(0));
}
EXPORT_SYMBOL(vmalloc);
/**
* vmalloc_user - allocate zeroed virtually contiguous memory for userspace
* @size: allocation size
*
* The resulting memory area is zeroed so it can be mapped to userspace
* without leaking data.
*/
void *vmalloc_user(unsigned long size)
{
struct vm_struct *area;
void *ret;
ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
if (ret) {
area = find_vm_area(ret);
area->flags |= VM_USERMAP;
}
return ret;
}
EXPORT_SYMBOL(vmalloc_user);
/**
* vmalloc_node - allocate memory on a specific node
* @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.
*
* For tight control over page level allocator and protection flags
* use __vmalloc() instead.
*/
void *vmalloc_node(unsigned long size, int node)
{
return __vmalloc_node(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
node, __builtin_return_address(0));
}
EXPORT_SYMBOL(vmalloc_node);
#ifndef PAGE_KERNEL_EXEC
# define PAGE_KERNEL_EXEC PAGE_KERNEL
#endif
/**
* 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.
*
* For tight control over page level allocator and protection flags
* use __vmalloc() instead.
*/
void *vmalloc_exec(unsigned long size)
{
return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC);
}
#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
#else
#define GFP_VMALLOC32 GFP_KERNEL
#endif
/**
* 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)
{
return __vmalloc(size, GFP_VMALLOC32, PAGE_KERNEL);
}
EXPORT_SYMBOL(vmalloc_32);
/**
* vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
* @size: allocation size
*
* The resulting memory area is 32bit addressable and zeroed so it can be
* mapped to userspace without leaking data.
*/
void *vmalloc_32_user(unsigned long size)
{
struct vm_struct *area;
void *ret;
ret = __vmalloc(size, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL);
if (ret) {
area = find_vm_area(ret);
area->flags |= VM_USERMAP;
}
return ret;
}
EXPORT_SYMBOL(vmalloc_32_user);
long vread(char *buf, char *addr, unsigned long count)
{
struct vm_struct *tmp;
char *vaddr, *buf_start = buf;
unsigned long n;
/* Don't allow overflow */
if ((unsigned long) addr + count < count)
count = -(unsigned long) addr;
read_lock(&vmlist_lock);
for (tmp = vmlist; tmp; tmp = tmp->next) {
vaddr = (char *) tmp->addr;
if (addr >= vaddr + tmp->size - PAGE_SIZE)
continue;
while (addr < vaddr) {
if (count == 0)
goto finished;
*buf = '\0';
buf++;
addr++;
count--;
}
n = vaddr + tmp->size - PAGE_SIZE - addr;
do {
if (count == 0)
goto finished;
*buf = *addr;
buf++;
addr++;
count--;
} while (--n > 0);
}
finished:
read_unlock(&vmlist_lock);
return buf - buf_start;
}
long vwrite(char *buf, char *addr, unsigned long count)
{
struct vm_struct *tmp;
char *vaddr, *buf_start = buf;
unsigned long n;
/* Don't allow overflow */
if ((unsigned long) addr + count < count)
count = -(unsigned long) addr;
read_lock(&vmlist_lock);
for (tmp = vmlist; tmp; tmp = tmp->next) {
vaddr = (char *) tmp->addr;
if (addr >= vaddr + tmp->size - PAGE_SIZE)
continue;
while (addr < vaddr) {
if (count == 0)
goto finished;
buf++;
addr++;
count--;
}
n = vaddr + tmp->size - PAGE_SIZE - addr;
do {
if (count == 0)
goto finished;
*addr = *buf;
buf++;
addr++;
count--;
} while (--n > 0);
}
finished:
read_unlock(&vmlist_lock);
return buf - buf_start;
}
/**
* 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)
{
struct vm_struct *area;
unsigned long uaddr = vma->vm_start;
unsigned long usize = vma->vm_end - vma->vm_start;
if ((PAGE_SIZE-1) & (unsigned long)addr)
return -EINVAL;
area = find_vm_area(addr);
if (!area)
return -EINVAL;
if (!(area->flags & VM_USERMAP))
return -EINVAL;
if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
return -EINVAL;
addr += pgoff << PAGE_SHIFT;
do {
struct page *page = vmalloc_to_page(addr);
int ret;
ret = vm_insert_page(vma, uaddr, page);
if (ret)
return ret;
uaddr += PAGE_SIZE;
addr += PAGE_SIZE;
usize -= PAGE_SIZE;
} while (usize > 0);
/* Prevent "things" like memory migration? VM_flags need a cleanup... */
vma->vm_flags |= VM_RESERVED;
return 0;
}
EXPORT_SYMBOL(remap_vmalloc_range);
/*
* Implement a stub for vmalloc_sync_all() if the architecture chose not to
* have one.
*/
void __attribute__((weak)) vmalloc_sync_all(void)
{
}
static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
{
/* apply_to_page_range() does all the hard work. */
return 0;
}
/**
* alloc_vm_area - allocate a range of kernel address space
* @size: size of the area
*
* Returns: NULL on failure, vm_struct on success
*
* This function reserves a range of kernel address space, and
* allocates pagetables to map that range. No actual mappings
* are created. If the kernel address space is not shared
* between processes, it syncs the pagetable across all
* processes.
*/
struct vm_struct *alloc_vm_area(size_t size)
{
struct vm_struct *area;
area = get_vm_area_caller(size, VM_IOREMAP,
__builtin_return_address(0));
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,
area->size, f, NULL)) {
free_vm_area(area);
return NULL;
}
/* Make sure the pagetables are constructed in process kernel
mappings */
vmalloc_sync_all();
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);
#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)
{
loff_t n = *pos;
struct vm_struct *v;
read_lock(&vmlist_lock);
v = vmlist;
while (n > 0 && v) {
n--;
v = v->next;
}
if (!n)
return v;
return NULL;
}
static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
struct vm_struct *v = p;
++*pos;
return v->next;
}
static void s_stop(struct seq_file *m, void *p)
{
read_unlock(&vmlist_lock);
}
static void show_numa_info(struct seq_file *m, struct vm_struct *v)
{
if (NUMA_BUILD) {
unsigned int nr, *counters = m->private;
if (!counters)
return;
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]);
}
}
static int s_show(struct seq_file *m, void *p)
{
struct vm_struct *v = p;
seq_printf(m, "0x%p-0x%p %7ld",
v->addr, v->addr + v->size, v->size);
if (v->caller) {
char buff[2 * KSYM_NAME_LEN];
seq_putc(m, ' ');
sprint_symbol(buff, (unsigned long)v->caller);
seq_puts(m, buff);
}
if (v->nr_pages)
seq_printf(m, " pages=%d", v->nr_pages);
if (v->phys_addr)
seq_printf(m, " phys=%lx", v->phys_addr);
if (v->flags & VM_IOREMAP)
seq_printf(m, " ioremap");
if (v->flags & VM_ALLOC)
seq_printf(m, " vmalloc");
if (v->flags & VM_MAP)
seq_printf(m, " vmap");
if (v->flags & VM_USERMAP)
seq_printf(m, " user");
if (v->flags & VM_VPAGES)
seq_printf(m, " vpages");
show_numa_info(m, v);
seq_putc(m, '\n');
return 0;
}
static const struct seq_operations vmalloc_op = {
.start = s_start,
.next = s_next,
.stop = s_stop,
.show = s_show,
};
static int vmalloc_open(struct inode *inode, struct file *file)
{
unsigned int *ptr = NULL;
int ret;
if (NUMA_BUILD)
ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
ret = seq_open(file, &vmalloc_op);
if (!ret) {
struct seq_file *m = file->private_data;
m->private = ptr;
} else
kfree(ptr);
return ret;
}
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);
#endif