| Message ID | 1457032369-10503-1-git-send-email-ricardo.ribalda@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello, On 2016-03-03 20:12, Ricardo Ribalda Delgado wrote: > On page unaligned frames, create_framevec forces get_vaddr_frames to > allocate an extra page at the end of the buffer. Under some > circumstances, this leads to -EINVAL on VIDIOC_QBUF. > > E.g: > We have vm_a that vm_area that goes from 0x1000 to 0x3000. And a > frame that goes from 0x1800 to 0x2800, i.e. 2 pages. > > frame_vector_create will be called with the following params: > > get_vaddr_frames(0x1800 , 2, write, 1, vec); > > get_vaddr will allocate the first page after checking that the memory > 0x1800-0x27ff is valid, but it will not allocate the second page because > the range 0x2800-0x37ff is out of the vm_a range. This results in > create_framevec returning -EFAULT > > Error Trace: > [ 9083.793015] video0: VIDIOC_QBUF: 00:00:00.00000000 index=1, > type=vid-cap, flags=0x00002002, field=any, sequence=0, > memory=userptr, bytesused=0, offset/userptr=0x7ff2b023ca80, length=5765760 > [ 9083.793028] timecode=00:00:00 type=0, flags=0x00000000, > frames=0, userbits=0x00000000 > [ 9083.793117] video0: VIDIOC_QBUF: error -22: 00:00:00.00000000 > index=2, type=vid-cap, flags=0x00000000, field=any, sequence=0, > memory=userptr, bytesused=0, offset/userptr=0x7ff2b07bc500, length=5765760 > > Fixes: 21fb0cb7ec65 ("[media] vb2: Provide helpers for mapping virtual addresses") > Reported-by: Albert Antony <albert@newtec.dk> > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > > Maybe we should cc stable. > > This error has not pop-out yet because userptr is usually called with memory > on the heap and malloc usually overallocate. This error has been a pain to trace :). > > Regards! > > > > drivers/media/v4l2-core/videobuf2-memops.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-memops.c b/drivers/media/v4l2-core/videobuf2-memops.c > index dbec5923fcf0..e4e4976c6849 100644 > --- a/drivers/media/v4l2-core/videobuf2-memops.c > +++ b/drivers/media/v4l2-core/videobuf2-memops.c > @@ -49,7 +49,7 @@ 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, nr, write, 1, vec); > + ret = get_vaddr_frames(start & PAGE_MASK, nr, write, 1, vec); > if (ret < 0) > goto out_destroy; > /* We accept only complete set of PFNs */ Best regards
On Thu 03-03-16 20:12:48, Ricardo Ribalda Delgado wrote: > On page unaligned frames, create_framevec forces get_vaddr_frames to > allocate an extra page at the end of the buffer. Under some > circumstances, this leads to -EINVAL on VIDIOC_QBUF. > > E.g: > We have vm_a that vm_area that goes from 0x1000 to 0x3000. And a > frame that goes from 0x1800 to 0x2800, i.e. 2 pages. > > frame_vector_create will be called with the following params: > > get_vaddr_frames(0x1800 , 2, write, 1, vec); > > get_vaddr will allocate the first page after checking that the memory > 0x1800-0x27ff is valid, but it will not allocate the second page because > the range 0x2800-0x37ff is out of the vm_a range. This results in > create_framevec returning -EFAULT > > Error Trace: > [ 9083.793015] video0: VIDIOC_QBUF: 00:00:00.00000000 index=1, > type=vid-cap, flags=0x00002002, field=any, sequence=0, > memory=userptr, bytesused=0, offset/userptr=0x7ff2b023ca80, length=5765760 > [ 9083.793028] timecode=00:00:00 type=0, flags=0x00000000, > frames=0, userbits=0x00000000 > [ 9083.793117] video0: VIDIOC_QBUF: error -22: 00:00:00.00000000 > index=2, type=vid-cap, flags=0x00000000, field=any, sequence=0, > memory=userptr, bytesused=0, offset/userptr=0x7ff2b07bc500, length=5765760 > > Fixes: 21fb0cb7ec65 ("[media] vb2: Provide helpers for mapping virtual addresses") > Reported-by: Albert Antony <albert@newtec.dk> > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> The patch looks good. Thanks for fixing this! You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > > Maybe we should cc stable. > > This error has not pop-out yet because userptr is usually called with memory > on the heap and malloc usually overallocate. This error has been a pain to trace :). > > Regards! > > > > drivers/media/v4l2-core/videobuf2-memops.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-memops.c b/drivers/media/v4l2-core/videobuf2-memops.c > index dbec5923fcf0..e4e4976c6849 100644 > --- a/drivers/media/v4l2-core/videobuf2-memops.c > +++ b/drivers/media/v4l2-core/videobuf2-memops.c > @@ -49,7 +49,7 @@ 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, nr, write, 1, vec); > + ret = get_vaddr_frames(start & PAGE_MASK, nr, write, 1, vec); > if (ret < 0) > goto out_destroy; > /* We accept only complete set of PFNs */ > -- > 2.7.0 >
diff --git a/drivers/media/v4l2-core/videobuf2-memops.c b/drivers/media/v4l2-core/videobuf2-memops.c index dbec5923fcf0..e4e4976c6849 100644 --- a/drivers/media/v4l2-core/videobuf2-memops.c +++ b/drivers/media/v4l2-core/videobuf2-memops.c @@ -49,7 +49,7 @@ 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, nr, write, 1, vec); + ret = get_vaddr_frames(start & PAGE_MASK, nr, write, 1, vec); if (ret < 0) goto out_destroy; /* We accept only complete set of PFNs */
On page unaligned frames, create_framevec forces get_vaddr_frames to allocate an extra page at the end of the buffer. Under some circumstances, this leads to -EINVAL on VIDIOC_QBUF. E.g: We have vm_a that vm_area that goes from 0x1000 to 0x3000. And a frame that goes from 0x1800 to 0x2800, i.e. 2 pages. frame_vector_create will be called with the following params: get_vaddr_frames(0x1800 , 2, write, 1, vec); get_vaddr will allocate the first page after checking that the memory 0x1800-0x27ff is valid, but it will not allocate the second page because the range 0x2800-0x37ff is out of the vm_a range. This results in create_framevec returning -EFAULT Error Trace: [ 9083.793015] video0: VIDIOC_QBUF: 00:00:00.00000000 index=1, type=vid-cap, flags=0x00002002, field=any, sequence=0, memory=userptr, bytesused=0, offset/userptr=0x7ff2b023ca80, length=5765760 [ 9083.793028] timecode=00:00:00 type=0, flags=0x00000000, frames=0, userbits=0x00000000 [ 9083.793117] video0: VIDIOC_QBUF: error -22: 00:00:00.00000000 index=2, type=vid-cap, flags=0x00000000, field=any, sequence=0, memory=userptr, bytesused=0, offset/userptr=0x7ff2b07bc500, length=5765760 Fixes: 21fb0cb7ec65 ("[media] vb2: Provide helpers for mapping virtual addresses") Reported-by: Albert Antony <albert@newtec.dk> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> --- Maybe we should cc stable. This error has not pop-out yet because userptr is usually called with memory on the heap and malloc usually overallocate. This error has been a pain to trace :). Regards! drivers/media/v4l2-core/videobuf2-memops.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)