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-rw-r--r--mm/gup.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/mm/gup.c b/mm/gup.c
index d2ba0be71441..72c921da0f3b 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1469,32 +1469,48 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
return 1;
}
-static int __gup_device_huge_pmd(pmd_t pmd, unsigned long addr,
+static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
unsigned long fault_pfn;
+ int nr_start = *nr;
+
+ fault_pfn = pmd_pfn(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
+ if (!__gup_device_huge(fault_pfn, addr, end, pages, nr))
+ return 0;
- fault_pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
- return __gup_device_huge(fault_pfn, addr, end, pages, nr);
+ if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) {
+ undo_dev_pagemap(nr, nr_start, pages);
+ return 0;
+ }
+ return 1;
}
-static int __gup_device_huge_pud(pud_t pud, unsigned long addr,
+static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
unsigned long fault_pfn;
+ int nr_start = *nr;
+
+ fault_pfn = pud_pfn(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
+ if (!__gup_device_huge(fault_pfn, addr, end, pages, nr))
+ return 0;
- fault_pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
- return __gup_device_huge(fault_pfn, addr, end, pages, nr);
+ if (unlikely(pud_val(orig) != pud_val(*pudp))) {
+ undo_dev_pagemap(nr, nr_start, pages);
+ return 0;
+ }
+ return 1;
}
#else
-static int __gup_device_huge_pmd(pmd_t pmd, unsigned long addr,
+static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
BUILD_BUG();
return 0;
}
-static int __gup_device_huge_pud(pud_t pud, unsigned long addr,
+static int __gup_device_huge_pud(pud_t pud, pud_t *pudp, unsigned long addr,
unsigned long end, struct page **pages, int *nr)
{
BUILD_BUG();
@@ -1512,7 +1528,7 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
return 0;
if (pmd_devmap(orig))
- return __gup_device_huge_pmd(orig, addr, end, pages, nr);
+ return __gup_device_huge_pmd(orig, pmdp, addr, end, pages, nr);
refs = 0;
page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
@@ -1550,7 +1566,7 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
return 0;
if (pud_devmap(orig))
- return __gup_device_huge_pud(orig, addr, end, pages, nr);
+ return __gup_device_huge_pud(orig, pudp, addr, end, pages, nr);
refs = 0;
page = pud_page(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);