From d26ed650d9947a786bbda8de9cd914dbeebc1a68 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 23 Jun 2009 13:52:49 +0100 Subject: [PATCH] mm: don't rely on flags coincidence Indeed FOLL_WRITE matches FAULT_FLAG_WRITE, matches GUP_FLAGS_WRITE, and it's tempting to devise a set of Grand Unified Paging flags; but not today. So until then, let's rely upon the compiler to spot the coincidence, "rather than have that subtle dependency and a comment for it" - as you remarked in another context yesterday. Signed-off-by: Hugh Dickins Acked-by: Wu Fengguang Signed-off-by: Linus Torvalds --- mm/memory.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 98bcb90d5957..50da9511aa77 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1311,8 +1311,10 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, while (!(page = follow_page(vma, start, foll_flags))) { int ret; - /* FOLL_WRITE matches FAULT_FLAG_WRITE! */ - ret = handle_mm_fault(mm, vma, start, foll_flags & FOLL_WRITE); + ret = handle_mm_fault(mm, vma, start, + (foll_flags & FOLL_WRITE) ? + FAULT_FLAG_WRITE : 0); + if (ret & VM_FAULT_ERROR) { if (ret & VM_FAULT_OOM) return i ? i : -ENOMEM; -- 2.20.1