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path: root/drivers/media/v4l2-core/v4l2-event.c
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2018-11-27media: v4l: event: Add subscription to list before calling "add" operationSakari Ailus1-19/+24
commit 92539d3eda2c090b382699bbb896d4b54e9bdece upstream. Patch ad608fbcf166 changed how events were subscribed to address an issue elsewhere. As a side effect of that change, the "add" callback was called before the event subscription was added to the list of subscribed events, causing the first event queued by the add callback (and possibly other events arriving soon afterwards) to be lost. Fix this by adding the subscription to the list before calling the "add" callback, and clean up afterwards if that fails. Fixes: ad608fbcf166 ("media: v4l: event: Prevent freeing event subscriptions while accessed") Reported-by: Dave Stevenson <dave.stevenson@raspberrypi.org> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Tested-by: Dave Stevenson <dave.stevenson@raspberrypi.org> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Tested-by: Hans Verkuil <hans.verkuil@cisco.com> Cc: stable@vger.kernel.org (for 4.14 and up) Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-04media: v4l: event: Prevent freeing event subscriptions while accessedSakari Ailus1-18/+20
commit ad608fbcf166fec809e402d548761768f602702c upstream. The event subscriptions are added to the subscribed event list while holding a spinlock, but that lock is subsequently released while still accessing the subscription object. This makes it possible to unsubscribe the event --- and freeing the subscription object's memory --- while the subscription object is simultaneously accessed. Prevent this by adding a mutex to serialise the event subscription and unsubscription. This also gives a guarantee to the callback ops that the add op has returned before the del op is called. This change also results in making the elems field less special: subscriptions are only added to the event list once they are fully initialised. Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: stable@vger.kernel.org # for 4.14 and up Fixes: c3b5b0241f62 ("V4L/DVB: V4L: Events: Add backend") Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-20[media] v4l2-core: Use kvmalloc() for potentially big allocationsTomasz Figa1-3/+5
There are multiple places where arrays or otherwise variable sized buffer are allocated through V4L2 core code, including things like controls, memory pages, staging buffers for ioctls and so on. Such allocations can potentially require an order > 0 allocation from the page allocator, which is not guaranteed to be fulfilled and is likely to fail on a system with severe memory fragmentation (e.g. a system with very long uptime). Since the memory being allocated is intended to be used by the CPU exclusively, we can consider using vmalloc() as a fallback and this is exactly what the recently merged kvmalloc() helpers do. A kmalloc() call is still attempted, even for order > 0 allocations, but it is done with __GFP_NORETRY and __GFP_NOWARN, with expectation of failing if requested memory is not available instantly. Only then the vmalloc() fallback is used. This should give us fast and more reliable allocations even on systems with higher memory pressure and/or more fragmentation, while still retaining the same performance level on systems not suffering from such conditions. While at it, replace explicit array size calculations on changed allocations with kvmalloc_array(). Purposedly not touching videobuf1, as it is deprecated, has only few users remaining and would rather be seen removed instead. Signed-off-by: Tomasz Figa <tfiga@chromium.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-01-27[media] media: Drop FSF's postal address from the source code filesSakari Ailus1-5/+0
Drop the FSF's postal address from the source code files that typically contain mostly the license text. Of the 628 removed instances, 578 are outdated. The patch has been created with the following command without manual edits: git grep -l "675 Mass Ave\|59 Temple Place\|51 Franklin St" -- \ drivers/media/ include/media|while read i; do i=$i perl -e ' open(F,"< $ENV{i}"); $a=join("", <F>); $a =~ s/[ \t]*\*\n.*You should.*\n.*along with.*\n.*(\n.*USA.*$)?\n//m && $a =~ s/(^.*)Or, (point your browser to) /$1To obtain the license, $2\n$1/m; close(F); open(F, "> $ENV{i}"); print F $a; close(F);'; done Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2015-07-17[media] v4l2-event: v4l2_event_queue: do nothing if vdev == NULLHans Verkuil1-0/+3
If the vdev pointer == NULL, then just return. This makes it easier for subdev drivers to use this function without having to check if the sd->devnode pointer is NULL or not. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2014-05-24[media] v4l: Add source change eventArun Kumar K1-0/+36
This event indicates that the video device has encountered a source parameter change during runtime. This can typically be a resolution change detected by a video decoder OR a format change detected by an input connector. This needs to be nofified to the userspace and the application may be expected to reallocate buffers before proceeding. The application can subscribe to events on a specific pad or input port which it is interested in. Signed-off-by: Arun Kumar K <arun.kk@samsung.com> Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-02-05[media] V4L: Add v4l2_event_subdev_unsubscribe() helper functionSylwester Nawrocki1-0/+7
Add a v4l2 core helper function that can be used as the subdev .unsubscribe_event handler. This allows to eliminate some boilerplate from drivers that are only handling the control events. Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-11-21[media] v4l, smiapp, smiapp-pll, adp1653: Update contact informationSakari Ailus1-1/+1
Update contact information to correspond my e-mail address changes. Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-09-26[media] v4l2: make vidioc_(un)subscribe_event constHans Verkuil1-2/+2
Write-only ioctls should have a const argument in the ioctl op. Do this conversion for vidioc_(un)subscribe_event. Adding const for write-only ioctls was decided during the 2012 Media Workshop. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-08-14[media] v4l: move v4l2 core into a separate directoryMauro Carvalho Chehab1-0/+313
Currently, the v4l2 core is mixed together with other non-core drivers. Move them into a separate directory. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>