Hans Verkuil a0d6e64b34 media: cec: fix a deadlock situation ... commit a9e6107616 upstream. The cec_devnode struct has a lock meant to serialize access to the fields of this struct. This lock is taken during device node (un)registration and when opening or releasing a filehandle to the device node. When the last open filehandle is closed the cec adapter might be disabled by calling the adap_enable driver callback with the devnode.lock held. However, if during that callback a message or event arrives then the driver will call one of the cec_queue_event() variants in cec-adap.c, and those will take the same devnode.lock to walk the open filehandle list. This obviously causes a deadlock. This is quite easy to reproduce with the cec-gpio driver since that uses the cec-pin framework which generated lots of events and uses a kernel thread for the processing, so when adap_enable is called the thread is still running and can generate events. But I suspect that it might also happen with other drivers if an interrupt arrives signaling e.g. a received message before adap_enable had a chance to disable the interrupts. This patch adds a new mutex to serialize access to the fhs list. When adap_enable() is called the devnode.lock mutex is held, but not devnode.lock_fhs. The event functions in cec-adap.c will now use devnode.lock_fhs instead of devnode.lock, ensuring that it is safe to call those functions from the adap_enable callback. This specific issue only happens if the last open filehandle is closed and the physical address is invalid. This is not something that happens during normal operation, but it does happen when monitoring CEC traffic (e.g. cec-ctl --monitor) with an unconfigured CEC adapter. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Cc: <stable@vger.kernel.org> # for v5.13 and up Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-01-27 11:02:53 +01:00
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davinci	media: vpbe_osd.h/uvcvideo.h includes: fix trivial kernel-doc warnings	2021-03-22 10:24:07 +01:00
drv-intf
i2c	media: media/i2c: fix kerneldoc issues for media i2c headers	2021-03-22 10:23:43 +01:00
tpg
cec-notifier.h
cec-pin.h
cec.h	media: cec: fix a deadlock situation	2022-01-27 11:02:53 +01:00
demux.h
dmxdev.h
dvb-usb-ids.h	media: dvbsky: add support for MyGica T230C2_LITE and T230A	2021-07-12 09:16:29 +02:00
dvb_ca_en50221.h
dvb_demux.h
dvb_frontend.h
dvb_math.h
dvb_net.h
dvb_ringbuffer.h
dvb_vb2.h
dvbdev.h	media: dvbdev: Switch to new kerneldoc syntax for named variable macro argument	2021-03-11 11:59:45 +01:00
frame_vector.h
hevc-ctrls.h	media: hevc: Add segment address field	2021-07-12 09:16:32 +02:00
imx.h
media-dev-allocator.h	media: Fix Media Controller API config checks	2021-06-24 14:26:00 +02:00
media-device.h
media-devnode.h
media-entity.h	media: entity: Add lockdep check to media graph walk	2021-04-06 14:35:14 +02:00
media-request.h
rc-core.h	media: rc: rename s_learning_mode() to s_wideband_receiver()	2021-07-22 08:21:53 +02:00
rc-map.h	media: rc: add keymap for Toshiba CT-90405 remote	2021-06-08 15:56:58 +02:00
rcar-fcp.h
tuner-types.h
tuner.h
tveeprom.h
v4l2-async.h	media: Documentation: media: Fix v4l2-async kerneldoc syntax	2021-08-04 14:43:50 +02:00
v4l2-common.h
v4l2-ctrls.h	media: uapi: move MPEG-2 stateless controls out of staging	2021-05-23 19:21:31 +02:00
v4l2-dev.h
v4l2-device.h
v4l2-dv-timings.h
v4l2-event.h
v4l2-fh.h
v4l2-flash-led-class.h
v4l2-fwnode.h	media: v4l: fwnode: Rename and make static V4L2 async notifier helper	2021-04-06 14:35:59 +02:00
v4l2-h264.h	media: core headers: fix kernel-doc warnings	2021-03-22 10:22:22 +01:00
v4l2-image-sizes.h
v4l2-ioctl.h
v4l2-jpeg.h	media: Add parsing for APP14 data segment in jpeg helpers	2021-03-22 10:35:36 +01:00
v4l2-mc.h	media: v4l2-mc: Add link flags to v4l2_create_fwnode_links_to_pad()	2021-03-11 11:59:52 +01:00
v4l2-mediabus.h
v4l2-mem2mem.h
v4l2-rect.h
v4l2-subdev.h	media: v4l: subdev: Add pre_streamon and post_streamoff callbacks	2021-08-04 14:43:51 +02:00
videobuf-core.h
videobuf-dma-contig.h
videobuf-dma-sg.h
videobuf-vmalloc.h
videobuf2-core.h	media: videobuf2: rework vb2_mem_ops API	2021-11-18 19:16:13 +01:00
videobuf2-dma-contig.h
videobuf2-dma-sg.h
videobuf2-dvb.h
videobuf2-memops.h
videobuf2-v4l2.h	media: videobuf2-v4l2.c: add vb2_queue_change_type() helper	2021-06-08 12:04:08 +02:00
videobuf2-vmalloc.h
vsp1.h