VM: add common helper function to create the page tables
This logic was duplicated four times, for no good reason.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/memory.c b/mm/memory.c
index 990e7dc6..74f95ae 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1146,6 +1146,18 @@
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.
*
@@ -1156,10 +1168,7 @@
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;
+ pte_t *pte;
spinlock_t *ptl;
retval = -EINVAL;
@@ -1167,14 +1176,7 @@
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;