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mm: replace get_vaddr_frames() write/force parameters with gup_flags

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This removes the 'write' and 'force' from get_vaddr_frames() and
replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in
callers as use of this flag can result in surprising behaviour (and
hence bugs) within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Lorenzo Stoakes
2016-10-13 01:20:15 +01:00
committed by Linus Torvalds
parent 3b913179c3
commit 7f23b3504a
5 changed files with 11 additions and 15 deletions
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13
mm/frame_vector.c
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@@ -11,10 +11,7 @@
* get_vaddr_frames() - map virtual addresses to pfns
* @start: starting user address
* @nr_frames: number of pages / pfns from start to map
* @write: whether pages will be written to by the caller
* @force: whether to force write access even if user mapping is
* readonly. See description of the same argument of
get_user_pages().
* @gup_flags: flags modifying lookup behaviour
* @vec: structure which receives pages / pfns of the addresses mapped.
* It should have space for at least nr_frames entries.
*
@@ -34,23 +31,17 @@
* This function takes care of grabbing mmap_sem as necessary.
*/
int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
bool write, bool force, struct frame_vector *vec)
unsigned int gup_flags, struct frame_vector *vec)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
int ret = 0;
int err;
int locked;
unsigned int gup_flags = 0;
if (nr_frames == 0)
return 0;
if (write)
gup_flags |= FOLL_WRITE;
if (force)
gup_flags |= FOLL_FORCE;
if (WARN_ON_ONCE(nr_frames > vec->nr_allocated))
nr_frames = vec->nr_allocated;