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 <hugh.dickins@tiscali.co.uk>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory.c b/mm/memory.c
index 98bcb90..50da951 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1311,8 +1311,10 @@
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;