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#ifndef _LINUX_MM_H
#define _LINUX_MM_H
#include <linux/sched.h>
#include <linux/errno.h>
#ifdef __KERNEL__
#include <linux/config.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/mmzone.h>
#include <linux/swap.h>
#include <linux/rbtree.h>
extern unsigned long max_mapnr;
extern unsigned long num_physpages;
extern void * high_memory;
extern int page_cluster;
/* The inactive_clean lists are per zone. */
extern struct list_head active_list;
extern struct list_head inactive_list;
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/atomic.h>
/*
* Linux kernel virtual memory manager primitives.
* The idea being to have a "virtual" mm in the same way
* we have a virtual fs - giving a cleaner interface to the
* mm details, and allowing different kinds of memory mappings
* (from shared memory to executable loading to arbitrary
* mmap() functions).
*/
/*
* This struct defines a memory VMM memory area. There is one of these
* per VM-area/task. A VM area is any part of the process virtual memory
* space that has a special rule for the page-fault handlers (ie a shared
* library, the executable area etc).
*/
struct vm_area_struct {
struct mm_struct * vm_mm; /* The address space we belong to. */
unsigned long vm_start; /* Our start address within vm_mm. */
unsigned long vm_end; /* The first byte after our end address
within vm_mm. */
/* linked list of VM areas per task, sorted by address */
struct vm_area_struct *vm_next;
pgprot_t vm_page_prot; /* Access permissions of this VMA. */
unsigned long vm_flags; /* Flags, listed below. */
rb_node_t vm_rb;
/*
* For areas with an address space and backing store,
* one of the address_space->i_mmap{,shared} lists,
* for shm areas, the list of attaches, otherwise unused.
*/
struct vm_area_struct *vm_next_share;
struct vm_area_struct **vm_pprev_share;
/* Function pointers to deal with this struct. */
struct vm_operations_struct * vm_ops;
/* Information about our backing store: */
unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
units, *not* PAGE_CACHE_SIZE */
struct file * vm_file; /* File we map to (can be NULL). */
unsigned long vm_raend; /* XXX: put full readahead info here. */
void * vm_private_data; /* was vm_pte (shared mem) */
};
/*
* vm_flags..
*/
#define VM_READ 0x00000001 /* currently active flags */
#define VM_WRITE 0x00000002
#define VM_EXEC 0x00000004
#define VM_SHARED 0x00000008
#define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */
#define VM_MAYWRITE 0x00000020
#define VM_MAYEXEC 0x00000040
#define VM_MAYSHARE 0x00000080
#define VM_GROWSDOWN 0x00000100 /* general info on the segment */
#define VM_GROWSUP 0x00000200
#define VM_SHM 0x00000400 /* shared memory area, don't swap out */
#define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */
#define VM_EXECUTABLE 0x00001000
#define VM_LOCKED 0x00002000
#define VM_IO 0x00004000 /* Memory mapped I/O or similar */
/* Used by sys_madvise() */
#define VM_SEQ_READ 0x00008000 /* App will access data sequentially */
#define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */
#define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
#define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
#define VM_RESERVED 0x00080000 /* Don't unmap it from swap_out */
#define VM_STACK_FLAGS 0x00000177
#define VM_READHINTMASK (VM_SEQ_READ | VM_RAND_READ)
#define VM_ClearReadHint(v) (v)->vm_flags &= ~VM_READHINTMASK
#define VM_NormalReadHint(v) (!((v)->vm_flags & VM_READHINTMASK))
#define VM_SequentialReadHint(v) ((v)->vm_flags & VM_SEQ_READ)
#define VM_RandomReadHint(v) ((v)->vm_flags & VM_RAND_READ)
/* read ahead limits */
extern int vm_min_readahead;
extern int vm_max_readahead;
/*
* mapping from the currently active vm_flags protection bits (the
* low four bits) to a page protection mask..
*/
extern pgprot_t protection_map[16];
/*
* These are the virtual MM functions - opening of an area, closing and
* unmapping it (needed to keep files on disk up-to-date etc), pointer
* to the functions called when a no-page or a wp-page exception occurs.
*/
struct vm_operations_struct {
void (*open)(struct vm_area_struct * area);
void (*close)(struct vm_area_struct * area);
struct page * (*nopage)(struct vm_area_struct * area, unsigned long address, int unused);
};
/*
* Each physical page in the system has a struct page associated with
* it to keep track of whatever it is we are using the page for at the
* moment. Note that we have no way to track which tasks are using
* a page.
*
* Try to keep the most commonly accessed fields in single cache lines
* here (16 bytes or greater). This ordering should be particularly
* beneficial on 32-bit processors.
*
* The first line is data used in page cache lookup, the second line
* is used for linear searches (eg. clock algorithm scans).
*
* TODO: make this structure smaller, it could be as small as 32 bytes.
*/
typedef struct page {
struct list_head list; /* ->mapping has some page lists. */
struct address_space *mapping; /* The inode (or ...) we belong to. */
unsigned long index; /* Our offset within mapping. */
struct page *next_hash; /* Next page sharing our hash bucket in
the pagecache hash table. */
atomic_t count; /* Usage count, see below. */
unsigned long flags; /* atomic flags, some possibly
updated asynchronously */
struct list_head lru; /* Pageout list, eg. active_list;
protected by pagemap_lru_lock !! */
wait_queue_head_t wait; /* Page locked? Stand in line... */
struct page **pprev_hash; /* Complement to *next_hash. */
struct buffer_head * buffers; /* Buffer maps us to a disk block. */
void *virtual; /* Kernel virtual address (NULL if
not kmapped, ie. highmem) */
struct zone_struct *zone; /* Memory zone we are in. */
} mem_map_t;
/*
* Methods to modify the page usage count.
*
* What counts for a page usage:
* - cache mapping (page->mapping)
* - disk mapping (page->buffers)
* - page mapped in a task's page tables, each mapping
* is counted separately
*
* Also, many kernel routines increase the page count before a critical
* routine so they can be sure the page doesn't go away from under them.
*/
#define get_page(p) atomic_inc(&(p)->count)
#define put_page(p) __free_page(p)
#define put_page_testzero(p) atomic_dec_and_test(&(p)->count)
#define page_count(p) atomic_read(&(p)->count)
#define set_page_count(p,v) atomic_set(&(p)->count, v)
/*
* Various page->flags bits:
*
* PG_reserved is set for special pages, which can never be swapped
* out. Some of them might not even exist (eg empty_bad_page)...
*
* Multiple processes may "see" the same page. E.g. for untouched
* mappings of /dev/null, all processes see the same page full of
* zeroes, and text pages of executables and shared libraries have
* only one copy in memory, at most, normally.
*
* For the non-reserved pages, page->count denotes a reference count.
* page->count == 0 means the page is free.
* page->count == 1 means the page is used for exactly one purpose
* (e.g. a private data page of one process).
*
* A page may be used for kmalloc() or anyone else who does a
* __get_free_page(). In this case the page->count is at least 1, and
* all other fields are unused but should be 0 or NULL. The
* management of this page is the responsibility of the one who uses
* it.
*
* The other pages (we may call them "process pages") are completely
* managed by the Linux memory manager: I/O, buffers, swapping etc.
* The following discussion applies only to them.
*
* A page may belong to an inode's memory mapping. In this case,
* page->mapping is the pointer to the inode, and page->index is the
* file offset of the page, in units of PAGE_CACHE_SIZE.
*
* A page may have buffers allocated to it. In this case,
* page->buffers is a circular list of these buffer heads. Else,
* page->buffers == NULL.
*
* For pages belonging to inodes, the page->count is the number of
* attaches, plus 1 if buffers are allocated to the page, plus one
* for the page cache itself.
*
* All pages belonging to an inode are in these doubly linked lists:
* mapping->clean_pages, mapping->dirty_pages and mapping->locked_pages;
* using the page->list list_head. These fields are also used for
* freelist managemet (when page->count==0).
*
* There is also a hash table mapping (mapping,index) to the page
* in memory if present. The lists for this hash table use the fields
* page->next_hash and page->pprev_hash.
*
* All process pages can do I/O:
* - inode pages may need to be read from disk,
* - inode pages which have been modified and are MAP_SHARED may need
* to be written to disk,
* - private pages which have been modified may need to be swapped out
* to swap space and (later) to be read back into memory.
* During disk I/O, PG_locked is used. This bit is set before I/O
* and reset when I/O completes. page->wait is a wait queue of all
* tasks waiting for the I/O on this page to complete.
* PG_uptodate tells whether the page's contents is valid.
* When a read completes, the page becomes uptodate, unless a disk I/O
* error happened.
*
* For choosing which pages to swap out, inode pages carry a
* PG_referenced bit, which is set any time the system accesses
* that page through the (mapping,index) hash table. This referenced
* bit, together with the referenced bit in the page tables, is used
* to manipulate page->age and move the page across the active,
* inactive_dirty and inactive_clean lists.
*
* Note that the referenced bit, the page->lru list_head and the
* active, inactive_dirty and inactive_clean lists are protected by
* the pagemap_lru_lock, and *NOT* by the usual PG_locked bit!
*
* PG_skip is used on sparc/sparc64 architectures to "skip" certain
* parts of the address space.
*
* PG_error is set to indicate that an I/O error occurred on this page.
*
* PG_arch_1 is an architecture specific page state bit. The generic
* code guarantees that this bit is cleared for a page when it first
* is entered into the page cache.
*
* PG_highmem pages are not permanently mapped into the kernel virtual
* address space, they need to be kmapped separately for doing IO on
* the pages. The struct page (these bits with information) are always
* mapped into kernel address space...
*/
#define PG_locked 0 /* Page is locked. Don't touch. */
#define PG_error 1
#define PG_referenced 2
#define PG_uptodate 3
#define PG_dirty 4
#define PG_unused 5
#define PG_lru 6
#define PG_active 7
#define PG_slab 8
#define PG_skip 10
#define PG_highmem 11
#define PG_checked 12 /* kill me in 2.5.<early>. */
#define PG_arch_1 13
#define PG_reserved 14
#define PG_launder 15 /* written out by VM pressure.. */
/* Make it prettier to test the above... */
#define UnlockPage(page) unlock_page(page)
#define Page_Uptodate(page) test_bit(PG_uptodate, &(page)->flags)
#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags)
#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
#define PageDirty(page) test_bit(PG_dirty, &(page)->flags)
#define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags)
#define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags)
#define PageLocked(page) test_bit(PG_locked, &(page)->flags)
#define LockPage(page) set_bit(PG_locked, &(page)->flags)
#define TryLockPage(page) test_and_set_bit(PG_locked, &(page)->flags)
#define PageChecked(page) test_bit(PG_checked, &(page)->flags)
#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags)
#define PageLaunder(page) test_bit(PG_launder, &(page)->flags)
#define SetPageLaunder(page) set_bit(PG_launder, &(page)->flags)
#define DelallocPage(page) ((page)->buffers && test_bit(BH_Delay, &(page)->buffers->b_state))
extern void FASTCALL(set_page_dirty(struct page *));
/*
* The first mb is necessary to safely close the critical section opened by the
* TryLockPage(), the second mb is necessary to enforce ordering between
* the clear_bit and the read of the waitqueue (to avoid SMP races with a
* parallel wait_on_page).
*/
#define PageError(page) test_bit(PG_error, &(page)->flags)
#define SetPageError(page) set_bit(PG_error, &(page)->flags)
#define ClearPageError(page) clear_bit(PG_error, &(page)->flags)
#define PageReferenced(page) test_bit(PG_referenced, &(page)->flags)
#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags)
#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags)
#define PageTestandClearReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
#define PageSlab(page) test_bit(PG_slab, &(page)->flags)
#define PageSetSlab(page) set_bit(PG_slab, &(page)->flags)
#define PageClearSlab(page) clear_bit(PG_slab, &(page)->flags)
#define PageReserved(page) test_bit(PG_reserved, &(page)->flags)
#define PageActive(page) test_bit(PG_active, &(page)->flags)
#define SetPageActive(page) set_bit(PG_active, &(page)->flags)
#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags)
#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
#define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags)
#define TestClearPageLRU(page) test_and_clear_bit(PG_lru, &(page)->flags)
#ifdef CONFIG_HIGHMEM
#define PageHighMem(page) test_bit(PG_highmem, &(page)->flags)
#else
#define PageHighMem(page) 0 /* needed to optimize away at compile time */
#endif
#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags)
#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags)
/*
* Error return values for the *_nopage functions
*/
#define NOPAGE_SIGBUS (NULL)
#define NOPAGE_OOM ((struct page *) (-1))
/* The array of struct pages */
extern mem_map_t * mem_map;
/*
* There is only one page-allocator function, and two main namespaces to
* it. The alloc_page*() variants return 'struct page *' and as such
* can allocate highmem pages, the *get*page*() variants return
* virtual kernel addresses to the allocated page(s).
*/
extern struct page * FASTCALL(_alloc_pages(unsigned int gfp_mask, unsigned int order));
extern struct page * FASTCALL(__alloc_pages(unsigned int gfp_mask, unsigned int order, zonelist_t *zonelist));
extern struct page * alloc_pages_node(int nid, unsigned int gfp_mask, unsigned int order);
static inline struct page * alloc_pages(unsigned int gfp_mask, unsigned int order)
{
/*
* Gets optimized away by the compiler.
*/
if (order >= MAX_ORDER)
return NULL;
return _alloc_pages(gfp_mask, order);
}
#define alloc_page(gfp_mask) alloc_pages(gfp_mask, 0)
extern unsigned long FASTCALL(__get_free_pages(unsigned int gfp_mask, unsigned int order));
extern unsigned long FASTCALL(get_zeroed_page(unsigned int gfp_mask));
#define __get_free_page(gfp_mask) \
__get_free_pages((gfp_mask),0)
#define __get_dma_pages(gfp_mask, order) \
__get_free_pages((gfp_mask) | GFP_DMA,(order))
/*
* The old interface name will be removed in 2.5:
*/
#define get_free_page get_zeroed_page
/*
* There is only one 'core' page-freeing function.
*/
extern void FASTCALL(__free_pages(struct page *page, unsigned int order));
extern void FASTCALL(free_pages(unsigned long addr, unsigned int order));
#define __free_page(page) __free_pages((page), 0)
#define free_page(addr) free_pages((addr),0)
extern int start_aggressive_readahead(int);
extern void show_free_areas(void);
extern void show_free_areas_node(pg_data_t *pgdat);
extern void clear_page_tables(struct mm_struct *, unsigned long, int);
extern int fail_writepage(struct page *);
struct page * shmem_nopage(struct vm_area_struct * vma, unsigned long address, int unused);
struct file *shmem_file_setup(char * name, loff_t size);
extern void shmem_lock(struct file * file, int lock);
extern int shmem_zero_setup(struct vm_area_struct *);
extern void zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size);
extern int copy_page_range(struct mm_struct *dst, struct mm_struct *src, struct vm_area_struct *vma);
extern int remap_page_range(unsigned long from, unsigned long to, unsigned long size, pgprot_t prot);
extern int zeromap_page_range(unsigned long from, unsigned long size, pgprot_t prot);
extern int vmtruncate(struct inode * inode, loff_t offset);
extern pmd_t *FASTCALL(__pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address));
extern pte_t *FASTCALL(pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address));
extern int handle_mm_fault(struct mm_struct *mm,struct vm_area_struct *vma, unsigned long address, int write_access);
extern int make_pages_present(unsigned long addr, unsigned long end);
extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char *dst, int len);
extern int ptrace_writedata(struct task_struct *tsk, char * src, unsigned long dst, int len);
extern int ptrace_attach(struct task_struct *tsk);
extern int ptrace_detach(struct task_struct *, unsigned int);
extern void ptrace_disable(struct task_struct *);
extern int ptrace_check_attach(struct task_struct *task, int kill);
int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start,
int len, int write, int force, struct page **pages, struct vm_area_struct **vmas);
/*
* On a two-level page table, this ends up being trivial. Thus the
* inlining and the symmetry break with pte_alloc() that does all
* of this out-of-line.
*/
static inline pmd_t *pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
{
if (pgd_none(*pgd))
return __pmd_alloc(mm, pgd, address);
return pmd_offset(pgd, address);
}
extern int pgt_cache_water[2];
extern int check_pgt_cache(void);
extern void free_area_init(unsigned long * zones_size);
extern void free_area_init_node(int nid, pg_data_t *pgdat, struct page *pmap,
unsigned long * zones_size, unsigned long zone_start_paddr,
unsigned long *zholes_size);
extern void mem_init(void);
extern void show_mem(void);
extern void si_meminfo(struct sysinfo * val);
extern void swapin_readahead(swp_entry_t);
extern struct address_space swapper_space;
#define PageSwapCache(page) ((page)->mapping == &swapper_space)
static inline int is_page_cache_freeable(struct page * page)
{
return page_count(page) - !!page->buffers == 1;
}
extern int can_share_swap_page(struct page *);
extern int remove_exclusive_swap_page(struct page *);
extern void __free_pte(pte_t);
/* mmap.c */
extern void lock_vma_mappings(struct vm_area_struct *);
extern void unlock_vma_mappings(struct vm_area_struct *);
extern void insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
extern void __insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
extern void build_mmap_rb(struct mm_struct *);
extern void exit_mmap(struct mm_struct *);
extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long pgoff);
static inline unsigned long do_mmap(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long offset)
{
unsigned long ret = -EINVAL;
if ((offset + PAGE_ALIGN(len)) < offset)
goto out;
if (!(offset & ~PAGE_MASK))
ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
out:
return ret;
}
extern int do_munmap(struct mm_struct *, unsigned long, size_t);
extern unsigned long do_brk(unsigned long, unsigned long);
static inline void __vma_unlink(struct mm_struct * mm, struct vm_area_struct * vma, struct vm_area_struct * prev)
{
prev->vm_next = vma->vm_next;
rb_erase(&vma->vm_rb, &mm->mm_rb);
if (mm->mmap_cache == vma)
mm->mmap_cache = prev;
}
static inline int can_vma_merge(struct vm_area_struct * vma, unsigned long vm_flags)
{
if (!vma->vm_file && vma->vm_flags == vm_flags)
return 1;
else
return 0;
}
struct zone_t;
/* filemap.c */
extern void remove_inode_page(struct page *);
extern unsigned long page_unuse(struct page *);
extern void truncate_inode_pages(struct address_space *, loff_t);
/* generic vm_area_ops exported for stackable file systems */
extern int filemap_sync(struct vm_area_struct *, unsigned long, size_t, unsigned int);
extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int);
/*
* GFP bitmasks..
*/
/* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low four bits) */
#define __GFP_DMA 0x01
#define __GFP_HIGHMEM 0x02
/* Action modifiers - doesn't change the zoning */
#define __GFP_WAIT 0x10 /* Can wait and reschedule? */
#define __GFP_HIGH 0x20 /* Should access emergency pools? */
#define __GFP_IO 0x40 /* Can start low memory physical IO? */
#define __GFP_HIGHIO 0x80 /* Can start high mem physical IO? */
#define __GFP_FS 0x100 /* Can call down to low-level FS? */
#define GFP_NOHIGHIO (__GFP_HIGH | __GFP_WAIT | __GFP_IO)
#define GFP_NOIO (__GFP_HIGH | __GFP_WAIT)
#define GFP_NOFS (__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO)
#define GFP_ATOMIC (__GFP_HIGH)
#define GFP_USER ( __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)
#define GFP_HIGHUSER ( __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS | __GFP_HIGHMEM)
#define GFP_KERNEL (__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)
#define GFP_NFS (__GFP_HIGH | __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)
#define GFP_KSWAPD ( __GFP_WAIT | __GFP_IO | __GFP_HIGHIO | __GFP_FS)
/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
platforms, used as appropriate on others */
#define GFP_DMA __GFP_DMA
static inline unsigned int pf_gfp_mask(unsigned int gfp_mask)
{
/* avoid all memory balancing I/O methods if this task cannot block on I/O */
if (current->flags & PF_NOIO)
gfp_mask &= ~(__GFP_IO | __GFP_HIGHIO | __GFP_FS);
return gfp_mask;
}
/* vma is the first one with address < vma->vm_end,
* and even address < vma->vm_start. Have to extend vma. */
static inline int expand_stack(struct vm_area_struct * vma, unsigned long address)
{
unsigned long grow;
/*
* vma->vm_start/vm_end cannot change under us because the caller is required
* to hold the mmap_sem in write mode. We need to get the spinlock only
* before relocating the vma range ourself.
*/
address &= PAGE_MASK;
spin_lock(&vma->vm_mm->page_table_lock);
grow = (vma->vm_start - address) >> PAGE_SHIFT;
if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->rlim[RLIMIT_AS].rlim_cur) {
spin_unlock(&vma->vm_mm->page_table_lock);
return -ENOMEM;
}
vma->vm_start = address;
vma->vm_pgoff -= grow;
vma->vm_mm->total_vm += grow;
if (vma->vm_flags & VM_LOCKED)
vma->vm_mm->locked_vm += grow;
spin_unlock(&vma->vm_mm->page_table_lock);
return 0;
}
/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
struct vm_area_struct **pprev);
/* Look up the first VMA which intersects the interval start_addr..end_addr-1,
NULL if none. Assume start_addr < end_addr. */
static inline struct vm_area_struct * find_vma_intersection(struct mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
{
struct vm_area_struct * vma = find_vma(mm,start_addr);
if (vma && end_addr <= vma->vm_start)
vma = NULL;
return vma;
}
extern struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr);
#endif /* __KERNEL__ */
#endif
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