[PATCH 05/10] mm: replace get_vaddr_frames() write/force parameters with gup_flags
From: Lorenzo Stoakes <hidden>
Date: 2016-10-13 00:20:15
Also in:
ceph-devel, dri-devel, intel-gfx, kvm, linux-alpha, linux-arm-kernel, linux-fbdev, linux-fsdevel, linux-media, linux-mips, linux-mm, linux-rdma, linux-s390, linux-samsung-soc, linux-scsi, linux-sh, linuxppc-dev, lkml, sparclinux
Subsystem:
drm drivers, drm drivers for exynos, media input infrastructure (v4l/dvb), memory management, memory management - core, the rest · Maintainers:
David Airlie, Simona Vetter, Inki Dae, Seung-Woo Kim, Kyungmin Park, Mauro Carvalho Chehab, Andrew Morton, David Hildenbrand, Linus Torvalds
This patch removes the write and force parameters from get_vaddr_frames() and replaces them with a gup_flags parameter 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 <redacted> --- drivers/gpu/drm/exynos/exynos_drm_g2d.c | 3 ++- drivers/media/platform/omap/omap_vout.c | 2 +- drivers/media/v4l2-core/videobuf2-memops.c | 6 +++++- include/linux/mm.h | 2 +- mm/frame_vector.c | 13 ++----------- 5 files changed, 11 insertions(+), 15 deletions(-)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
index aa92dec..fbd13fa 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c@@ -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)
diff --git a/drivers/media/platform/omap/omap_vout.c b/drivers/media/platform/omap/omap_vout.c
index e668dde..a31b95c 100644
--- a/drivers/media/platform/omap/omap_vout.c
+++ b/drivers/media/platform/omap/omap_vout.c@@ -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;
diff --git a/drivers/media/v4l2-core/videobuf2-memops.c b/drivers/media/v4l2-core/videobuf2-memops.c
index 3c3b517..1cd322e 100644
--- a/drivers/media/v4l2-core/videobuf2-memops.c
+++ b/drivers/media/v4l2-core/videobuf2-memops.c@@ -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 */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 27ab538..5ff084f6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -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);
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index 81b6749..db77dcb 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c@@ -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;
--
2.10.0
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>