[PATCH] hugetlb: handle write-protection faults in follow_hugetlb_page
The follow_hugetlb_page() fix I posted (merged as git commit
5b23dbe8173c212d6a326e35347b038705603d39) missed one case. If the pte is
present, but not writable and write access is requested by the caller to
get_user_pages(), the code will do the wrong thing. Rather than calling
hugetlb_fault to make the pte writable, it notes the presence of the pte
and continues.
This simple one-liner makes sure we also fault on the pte for this case.
Please apply.
Signed-off-by: Adam Litke <[EMAIL PROTECTED]>
Acked-by: Dave Kleikamp <[EMAIL PROTECTED]>
---
mm/hugetlb.c |2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6121b57..6f97821 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -907,7 +907,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct
vm_area_struct *vma,
*/
pte = huge_pte_offset(mm, vaddr & HPAGE_MASK);
- if (!pte || pte_none(*pte)) {
+ if (!pte || pte_none(*pte) || (write && !pte_write(*pte))) {
int ret;
spin_unlock(>page_table_lock);
--
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[PATCH] hugetlb: handle write-protection faults in follow_hugetlb_page
The follow_hugetlb_page() fix I posted (merged as git commit
5b23dbe8173c212d6a326e35347b038705603d39) missed one case. If the pte is
present, but not writable and write access is requested by the caller to
get_user_pages(), the code will do the wrong thing. Rather than calling
hugetlb_fault to make the pte writable, it notes the presence of the pte
and continues.
This simple one-liner makes sure we also fault on the pte for this case.
Please apply.
Signed-off-by: Adam Litke [EMAIL PROTECTED]
Acked-by: Dave Kleikamp [EMAIL PROTECTED]
---
mm/hugetlb.c |2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6121b57..6f97821 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -907,7 +907,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct
vm_area_struct *vma,
*/
pte = huge_pte_offset(mm, vaddr HPAGE_MASK);
- if (!pte || pte_none(*pte)) {
+ if (!pte || pte_none(*pte) || (write !pte_write(*pte))) {
int ret;
spin_unlock(mm-page_table_lock);
--
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Please read the FAQ at http://www.tux.org/lkml/
