kernel/include/media/videobuf2-memops.h, branch linux-6.12.y

media: videobuf2: revert "get_userptr: buffers are always writable"

2022-12-06T07:14:31Z

Commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always writable") caused problems in a corner case (passing read-only shmem memory as a userptr). So revert this patch. The original problem for which that commit was originally made is something that I could not reproduce after reverting it. So just go back to the way it was for many years, and if problems arise in the future, then another approach should be taken to resolve it. This patch is based on a patch from Hirokazu. Fixes: 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always writable") Signed-off-by: Hirokazu Honda Signed-off-by: Hans Verkuil Acked-by: Tomasz Figa Signed-off-by: Mauro Carvalho Chehab

media: videobuf2-vmalloc: get_userptr: buffers are always writable

2019-05-29T12:05:58Z

In vb2_vmalloc_get_userptr() the framevector is created with the 'write' argument set to false when vb2_create_framevec() is called for OUTPUT buffers. So the pages are marked as read-only. However, userspace will write to these buffers since it will fill in the data to output. Since get_userptr is only called if the userptr of the queued buffer has changed since the last time that same buffer was queued, this will fail when the buffer contents is updated and the buffer is queued again. E.g., userspace fills buffer 1 with the output video and queues it. The first time get_userptr is called and the pages are grabbed and pinned in memory and marked read-only. The second time buffer 1 is filled with different video data and queued again. Since the userptr hasn't changed the get_userptr() callback isn't called again. Since the pages were marked as read-only the new contents isn't updated. Just always call vb2_create_framevec() with FOLL_WRITE to always allow writing to the buffers. Using USERPTR streaming with OUTPUT devices is almost never done. And when it is done it is via v4l2-compliance and a driver like vim2m. But since v4l2-compliance doesn't actually inspect the capture buffer and compare it to the original output buffer, this issue was never noticed. But the vicodec driver actually needs to parse the bitstream in the OUTPUT buffers and any errors there will be immediately noticed. So this time v4l2-compliance failed the USERPTR streaming test. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab

media: vb2: add cross references at memops and v4l2 kernel-doc markups

2017-12-18T17:27:41Z

Add cross-references where needed and add periods at the end of each kernel-doc paragraph, in order to make it coherent with other VB2 descriptions. Acked-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab

[media] vb2: convert vb2_vmarea_handler refcount from atomic_t to refcount_t

2017-04-05T18:31:57Z

Use refcount_t to manage the refcount to the memory type specific buffer videobuf2 buffer implementations. refcount_t is better suitable for the purpose than atomic_t. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab

[media] media: videobuf2: Replace videobuf2-core with videobuf2-v4l2

2015-10-01T11:48:18Z

Make videobuf2-v4l2 as a wrapper of videobuf2-core for v4l2-use. And replace videobuf2-core.h with videobuf2-v4l2.h. This renaming change should be accompanied by the modifications of all device drivers that include videobuf2-core.h. It can be done with just running this shell script. replace() { str1=$1 str2=$2 dir=$3 for file in $(find $dir -name *.h -o -name *.c -o -name Makefile) do echo $file sed "s/$str1/$str2/g" $file > $file.out mv $file.out $file done } replace "videobuf2-core" "videobuf2-v4l2" "include/media/" replace "videobuf2-core" "videobuf2-v4l2" "drivers/media/" replace "videobuf2-core" "videobuf2-v4l2" "drivers/usb/gadget/" replace "videobuf2-core" "videobuf2-v4l2" "drivers/staging/media/" Signed-off-by: Junghak Sung Signed-off-by: Geunyoung Kim Acked-by: Seung-Woo Kim Acked-by: Inki Dae Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab

Merge tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

2015-09-11T23:42:39Z

Pull media updates from Mauro Carvalho Chehab: "A series of patches that move part of the code used to allocate memory from the media subsystem to the mm subsystem" [ The mm parts have been acked by VM people, and the series was apparently in -mm for a while - Linus ] * tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: [media] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames() [media] media: vb2: Remove unused functions [media] media: vb2: Convert vb2_dc_get_userptr() to use frame vector [media] media: vb2: Convert vb2_vmalloc_get_userptr() to use frame vector [media] media: vb2: Convert vb2_dma_sg_get_userptr() to use frame vector [media] vb2: Provide helpers for mapping virtual addresses [media] media: omap_vout: Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns() [media] mm: Provide new get_vaddr_frames() helper [media] vb2: Push mmap_sem down to memops

[media] videobuf2-memops.h: add to device-drivers DocBook

2015-08-22T12:05:54Z

The comment metadata was wrong: Warning(.//include/media/videobuf2-memops.h:25): cannot understand function prototype: 'struct vb2_vmarea_handler ' Warning(.//include/media/videobuf2-memops.h): no structured comments found Fix and add to DocBook. Signed-off-by: Mauro Carvalho Chehab Acked-by: Jonathan Corbet

[media] media: vb2: Remove unused functions

2015-08-16T16:15:21Z

Conversion to the use of pinned pfns made some functions unused. Remove them. Also there's no need to lock mmap_sem in __buf_prepare() anymore. Tested-by: Marek Szyprowski Signed-off-by: Jan Kara Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab

[media] vb2: Provide helpers for mapping virtual addresses

2015-08-16T16:10:42Z

Provide simple helper functions to map virtual address range into an array of pfns / pages. Tested-by: Marek Szyprowski Signed-off-by: Jan Kara Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab

[media] v4l: vb2-dma-contig: let mmap method to use dma_mmap_coherent call

2012-11-25T19:20:25Z

Let mmap method to use dma_mmap_coherent call. Moreover, this patch removes vb2_mmap_pfn_range from videobuf2 helpers as it was suggested by Laurent Pinchart. The function is no longer used in vb2 code. Signed-off-by: Marek Szyprowski Signed-off-by: Tomasz Stanislawski Acked-by: Laurent Pinchart Acked-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab