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Commit 7f23b350 authored by Lorenzo Stoakes's avatar Lorenzo Stoakes Committed by Linus Torvalds
Browse files

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



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: default avatarLorenzo Stoakes <lstoakes@gmail.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3b913179

drivers/gpu/drm/exynos/exynos_drm_g2d.c

+2 −1
Original line number Diff line number Diff line
@@ -488,7 +488,8 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct drm_device *drm_dev, 
		goto err_free;

	}



	ret = get_vaddr_frames(start, npages, true, true, g2d_userptr->vec);

	ret = get_vaddr_frames(start, npages, FOLL_FORCE | FOLL_WRITE,

		g2d_userptr->vec);

	if (ret != npages) {

		DRM_ERROR("failed to get user pages from userptr.\n");

		if (ret < 0)

drivers/media/platform/omap/omap_vout.c

+1 −1
Original line number Diff line number Diff line
@@ -214,7 +214,7 @@ static int omap_vout_get_userptr(struct videobuf_buffer *vb, u32 virtp, 
	if (!vec)

		return -ENOMEM;



	ret = get_vaddr_frames(virtp, 1, true, false, vec);

	ret = get_vaddr_frames(virtp, 1, FOLL_WRITE, vec);

	if (ret != 1) {

		frame_vector_destroy(vec);

		return -EINVAL;

drivers/media/v4l2-core/videobuf2-memops.c

+5 −1
Original line number Diff line number Diff line
@@ -42,6 +42,10 @@ struct frame_vector *vb2_create_framevec(unsigned long start, 
	unsigned long first, last;

	unsigned long nr;

	struct frame_vector *vec;

	unsigned int flags = FOLL_FORCE;



	if (write)

		flags |= FOLL_WRITE;



	first = start >> PAGE_SHIFT;

	last = (start + length - 1) >> PAGE_SHIFT;
@@ -49,7 +53,7 @@ struct frame_vector *vb2_create_framevec(unsigned long start, 
	vec = frame_vector_create(nr);

	if (!vec)

		return ERR_PTR(-ENOMEM);

	ret = get_vaddr_frames(start & PAGE_MASK, nr, write, true, vec);

	ret = get_vaddr_frames(start & PAGE_MASK, nr, flags, vec);

	if (ret < 0)

		goto out_destroy;

	/* We accept only complete set of PFNs */

include/linux/mm.h

+1 −1
Original line number Diff line number Diff line
@@ -1305,7 +1305,7 @@ struct frame_vector { 
struct frame_vector *frame_vector_create(unsigned int nr_frames);

void frame_vector_destroy(struct frame_vector *vec);

int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,

		     bool write, bool force, struct frame_vector *vec);

		     unsigned int gup_flags, struct frame_vector *vec);

void put_vaddr_frames(struct frame_vector *vec);

int frame_vector_to_pages(struct frame_vector *vec);

void frame_vector_to_pfns(struct frame_vector *vec);

mm/frame_vector.c

+2 −11
Original line number Diff line number Diff line
@@ -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;