From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Hans Verkuil <hverkuil@xs4all.nl>,
Keith Pyle <kpyle@austin.rr.com>,
Hans Verkuil <hverkuil-cisco@xs4all.nl>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
Sasha Levin <sashal@kernel.org>,
linux-media@vger.kernel.org
Subject: [PATCH AUTOSEL 5.2 155/249] media: hdpvr: fix locking and a missing msleep
Date: Mon, 15 Jul 2019 09:45:20 -0400 [thread overview]
Message-ID: <20190715134655.4076-155-sashal@kernel.org> (raw)
In-Reply-To: <20190715134655.4076-1-sashal@kernel.org>
From: Hans Verkuil <hverkuil@xs4all.nl>
[ Upstream commit 6bc5a4a1927556ff9adce1aa95ea408c95453225 ]
This driver has three locking issues:
- The wait_event_interruptible() condition calls hdpvr_get_next_buffer(dev)
which uses a mutex, which is not allowed. Rewrite with list_empty_careful()
that doesn't need locking.
- In hdpvr_read() the call to hdpvr_stop_streaming() didn't lock io_mutex,
but it should have since stop_streaming expects that.
- In hdpvr_device_release() io_mutex was locked when calling flush_work(),
but there it shouldn't take that mutex since the work done by flush_work()
also wants to lock that mutex.
There are also two other changes (suggested by Keith):
- msecs_to_jiffies(4000); (a NOP) should have been msleep(4000).
- Change v4l2_dbg to v4l2_info to always log if streaming had to be restarted.
Reported-by: Keith Pyle <kpyle@austin.rr.com>
Suggested-by: Keith Pyle <kpyle@austin.rr.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/usb/hdpvr/hdpvr-video.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/media/usb/hdpvr/hdpvr-video.c b/drivers/media/usb/hdpvr/hdpvr-video.c
index 7580fc5f2f12..6a6405b80797 100644
--- a/drivers/media/usb/hdpvr/hdpvr-video.c
+++ b/drivers/media/usb/hdpvr/hdpvr-video.c
@@ -435,7 +435,7 @@ static ssize_t hdpvr_read(struct file *file, char __user *buffer, size_t count,
/* wait for the first buffer */
if (!(file->f_flags & O_NONBLOCK)) {
if (wait_event_interruptible(dev->wait_data,
- hdpvr_get_next_buffer(dev)))
+ !list_empty_careful(&dev->rec_buff_list)))
return -ERESTARTSYS;
}
@@ -461,10 +461,17 @@ static ssize_t hdpvr_read(struct file *file, char __user *buffer, size_t count,
goto err;
}
if (!err) {
- v4l2_dbg(MSG_INFO, hdpvr_debug, &dev->v4l2_dev,
- "timeout: restart streaming\n");
+ v4l2_info(&dev->v4l2_dev,
+ "timeout: restart streaming\n");
+ mutex_lock(&dev->io_mutex);
hdpvr_stop_streaming(dev);
- msecs_to_jiffies(4000);
+ mutex_unlock(&dev->io_mutex);
+ /*
+ * The FW needs about 4 seconds after streaming
+ * stopped before it is ready to restart
+ * streaming.
+ */
+ msleep(4000);
err = hdpvr_start_streaming(dev);
if (err) {
ret = err;
@@ -1127,9 +1134,7 @@ static void hdpvr_device_release(struct video_device *vdev)
struct hdpvr_device *dev = video_get_drvdata(vdev);
hdpvr_delete(dev);
- mutex_lock(&dev->io_mutex);
flush_work(&dev->worker);
- mutex_unlock(&dev->io_mutex);
v4l2_device_unregister(&dev->v4l2_dev);
v4l2_ctrl_handler_free(&dev->hdl);
--
2.20.1
prev parent reply other threads:[~2019-07-15 15:10 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190715134655.4076-1-sashal@kernel.org>
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 019/249] media: dvb: usb: fix use after free in dvb_usb_device_exit Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 020/249] media: spi: IR LED: add missing of table registration Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 022/249] media: ov7740: avoid invalid framesize setting Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 023/249] media: marvell-ccic: fix DMA s/g desc number calculation Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 025/249] media: vpss: fix a potential NULL pointer dereference Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 026/249] media: media_device_enum_links32: clean a reserved field Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 028/249] media: venus: firmware: fix leaked of_node references Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 042/249] media: vim2m: fix two double-free issues Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 043/249] media: v4l2-core: fix use-after-free error Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 045/249] media: usb:zr364xx:Fix KASAN:null-ptr-deref Read in zr364xx_vidioc_querycap Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 050/249] media: mc-device.c: don't memset __user pointer contents Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 051/249] media: saa7164: fix remove_proc_entry warning Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 053/249] media: staging: media: davinci_vpfe: - Fix for memory leak if decoder initialization fails Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 058/249] tua6100: Avoid build warnings Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 062/249] media: platform: ao-cec-g12a: disable regmap fast_io for cec bus regmap Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 063/249] media: wl128x: Fix some error handling in fm_v4l2_init_video_device() Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 068/249] media: imx7-mipi-csis: Propagate the error if clock enabling fails Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 070/249] media: aspeed: change irq to threaded irq Sasha Levin
2019-07-15 13:43 ` [PATCH AUTOSEL 5.2 071/249] media: aspeed: fix a kernel warning on clk control Sasha Levin
2019-07-15 13:44 ` [PATCH AUTOSEL 5.2 087/249] media: uvcvideo: Fix access to uninitialized fields on probe error Sasha Levin
2019-07-15 13:44 ` [PATCH AUTOSEL 5.2 088/249] media: fdp1: Support M3N and E3 platforms Sasha Levin
2019-07-15 13:44 ` [PATCH AUTOSEL 5.2 094/249] media: davinci: vpif_capture: fix memory leak in vpif_probe() Sasha Levin
2019-07-15 13:44 ` [PATCH AUTOSEL 5.2 096/249] media: s5p-mfc: fix reading min scratch buffer size on MFC v6/v7 Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 142/249] media: staging: davinci: fix memory leaks and check for allocation failure Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 144/249] media: s5p-mfc: Make additional clocks optional Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 145/249] media: i2c: fix warning same module names Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 148/249] media: mt9m111: fix fw-node refactoring Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 151/249] media: coda: fix mpeg2 sequence number handling Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 152/249] media: coda: fix last buffer handling in V4L2_ENC_CMD_STOP Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 153/249] media: coda: increment sequence offset for the last returned frame Sasha Levin
2019-07-15 13:45 ` [PATCH AUTOSEL 5.2 154/249] media: vimc: cap: check v4l2_fill_pixfmt return value Sasha Levin
2019-07-15 13:45 ` Sasha Levin [this message]
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