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Commit c9cfcddf authored by Linus Torvalds's avatar Linus Torvalds
Browse files

VM: add common helper function to create the page tables 



This logic was duplicated four times, for no good reason.

Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 4168f7a3

fs/exec.c

+1 −11
Original line number Diff line number Diff line
@@ -306,9 +306,6 @@ void install_arg_page(struct vm_area_struct *vma, 
			struct page *page, unsigned long address)

{

	struct mm_struct *mm = vma->vm_mm;

	pgd_t * pgd;

	pud_t * pud;

	pmd_t * pmd;

	pte_t * pte;

	spinlock_t *ptl;
@@ -316,14 +313,7 @@ void install_arg_page(struct vm_area_struct *vma, 
		goto out;



	flush_dcache_page(page);

	pgd = pgd_offset(mm, address);

	pud = pud_alloc(mm, pgd, address);

	if (!pud)

		goto out;

	pmd = pmd_alloc(mm, pud, address);

	if (!pmd)

		goto out;

	pte = pte_alloc_map_lock(mm, pmd, address, &ptl);

	pte = get_locked_pte(mm, address, &ptl);

	if (!pte)

		goto out;

	if (!pte_none(*pte)) {

include/linux/mm.h

+2 −0
Original line number Diff line number Diff line
@@ -742,6 +742,8 @@ struct shrinker; 
extern struct shrinker *set_shrinker(int, shrinker_t);

extern void remove_shrinker(struct shrinker *shrinker);



extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));



int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);

int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);

int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);

mm/fremap.c

+2 −22
Original line number Diff line number Diff line
@@ -55,20 +55,10 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, 
	pgoff_t size;

	int err = -ENOMEM;

	pte_t *pte;

	pmd_t *pmd;

	pud_t *pud;

	pgd_t *pgd;

	pte_t pte_val;

	spinlock_t *ptl;



	pgd = pgd_offset(mm, addr);

	pud = pud_alloc(mm, pgd, addr);

	if (!pud)

		goto out;

	pmd = pmd_alloc(mm, pud, addr);

	if (!pmd)

		goto out;

	pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);

	pte = get_locked_pte(mm, addr, &ptl);

	if (!pte)

		goto out;
@@ -110,20 +100,10 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, 
{

	int err = -ENOMEM;

	pte_t *pte;

	pmd_t *pmd;

	pud_t *pud;

	pgd_t *pgd;

	pte_t pte_val;

	spinlock_t *ptl;



	pgd = pgd_offset(mm, addr);

	pud = pud_alloc(mm, pgd, addr);

	if (!pud)

		goto out;

	pmd = pmd_alloc(mm, pud, addr);

	if (!pmd)

		goto out;

	pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);

	pte = get_locked_pte(mm, addr, &ptl);

	if (!pte)

		goto out;

mm/memory.c

+14 −12
Original line number Diff line number Diff line
@@ -1146,6 +1146,18 @@ int zeromap_page_range(struct vm_area_struct *vma, 
	return err;

}



pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl)

{

	pgd_t * pgd = pgd_offset(mm, addr);

	pud_t * pud = pud_alloc(mm, pgd, addr);

	if (pud) {

		pmd_t * pmd = pmd_alloc(mm, pgd, addr);

		if (pmd)

			return pte_alloc_map_lock(mm, pmd, addr, ptl);

	}

	return NULL;

}



/*

 * This is the old fallback for page remapping.

 *
@@ -1156,9 +1168,6 @@ int zeromap_page_range(struct vm_area_struct *vma, 
static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)

{

	int retval;

	pgd_t * pgd;

	pud_t * pud;

	pmd_t * pmd;  

	pte_t *pte;

	spinlock_t *ptl;
@@ -1167,14 +1176,7 @@ static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *pa 
		goto out;

	retval = -ENOMEM;

	flush_dcache_page(page);

	pgd = pgd_offset(mm, addr);

	pud = pud_alloc(mm, pgd, addr);

	if (!pud)

		goto out;

	pmd = pmd_alloc(mm, pud, addr);

	if (!pmd)

		goto out;

	pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);

	pte = get_locked_pte(mm, addr, &ptl);

	if (!pte)

		goto out;

	retval = -EBUSY;