From 72fad7139b6829f71d7f41f39eb30da5760d90a8 Mon Sep 17 00:00:00 2001 From: Adam Litke Date: Mon, 10 Dec 2007 15:49:28 -0800 Subject: [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 Acked-by: Dave Kleikamp Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 6121b57bbe9..6f978218c2c 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); -- 2.20.1