4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> [ Upstream commit 6cff72f6bcee89228a662435b7c47e21a391c8d0 ] Use an API that resembles more the actual use of num_channels. Found by cocci: drivers/media/usb/s2255/s2255drv.c:2362:5-24: WARNING: atomic_dec_and_test variation before object free at line 2363. drivers/media/usb/s2255/s2255drv.c:1557:5-24: WARNING: atomic_dec_and_test variation before object free at line 1558. Link: https://lore.kernel.org/linux-media/20240429-fix-cocci-v3-11-3c4865f5a4b0@xxxxxxxxxxxx Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/media/usb/s2255/s2255drv.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c index 3e3ecf214762a..9f9f2e231de61 100644 --- a/drivers/media/usb/s2255/s2255drv.c +++ b/drivers/media/usb/s2255/s2255drv.c @@ -256,7 +256,7 @@ struct s2255_vc { struct s2255_dev { struct s2255_vc vc[MAX_CHANNELS]; struct v4l2_device v4l2_dev; - atomic_t num_channels; + refcount_t num_channels; int frames; struct mutex lock; /* channels[].vdev.lock */ struct mutex cmdlock; /* protects cmdbuf */ @@ -1574,11 +1574,11 @@ static void s2255_video_device_release(struct video_device *vdev) container_of(vdev, struct s2255_vc, vdev); dprintk(dev, 4, "%s, chnls: %d\n", __func__, - atomic_read(&dev->num_channels)); + refcount_read(&dev->num_channels)); v4l2_ctrl_handler_free(&vc->hdl); - if (atomic_dec_and_test(&dev->num_channels)) + if (refcount_dec_and_test(&dev->num_channels)) s2255_destroy(dev); return; } @@ -1681,7 +1681,7 @@ static int s2255_probe_v4l(struct s2255_dev *dev) "failed to register video device!\n"); break; } - atomic_inc(&dev->num_channels); + refcount_inc(&dev->num_channels); v4l2_info(&dev->v4l2_dev, "V4L2 device registered as %s\n", video_device_node_name(&vc->vdev)); @@ -1689,11 +1689,11 @@ static int s2255_probe_v4l(struct s2255_dev *dev) pr_info("Sensoray 2255 V4L driver Revision: %s\n", S2255_VERSION); /* if no channels registered, return error and probe will fail*/ - if (atomic_read(&dev->num_channels) == 0) { + if (refcount_read(&dev->num_channels) == 0) { v4l2_device_unregister(&dev->v4l2_dev); return ret; } - if (atomic_read(&dev->num_channels) != MAX_CHANNELS) + if (refcount_read(&dev->num_channels) != MAX_CHANNELS) pr_warn("s2255: Not all channels available.\n"); return 0; } @@ -2242,7 +2242,7 @@ static int s2255_probe(struct usb_interface *interface, goto errorFWDATA1; } - atomic_set(&dev->num_channels, 0); + refcount_set(&dev->num_channels, 0); dev->pid = id->idProduct; dev->fw_data = kzalloc(sizeof(struct s2255_fw), GFP_KERNEL); if (!dev->fw_data) @@ -2362,12 +2362,12 @@ static void s2255_disconnect(struct usb_interface *interface) { struct s2255_dev *dev = to_s2255_dev(usb_get_intfdata(interface)); int i; - int channels = atomic_read(&dev->num_channels); + int channels = refcount_read(&dev->num_channels); mutex_lock(&dev->lock); v4l2_device_disconnect(&dev->v4l2_dev); mutex_unlock(&dev->lock); /*see comments in the uvc_driver.c usb disconnect function */ - atomic_inc(&dev->num_channels); + refcount_inc(&dev->num_channels); /* unregister each video device. */ for (i = 0; i < channels; i++) video_unregister_device(&dev->vc[i].vdev); @@ -2380,7 +2380,7 @@ static void s2255_disconnect(struct usb_interface *interface) dev->vc[i].vidstatus_ready = 1; wake_up(&dev->vc[i].wait_vidstatus); } - if (atomic_dec_and_test(&dev->num_channels)) + if (refcount_dec_and_test(&dev->num_channels)) s2255_destroy(dev); dev_info(&interface->dev, "%s\n", __func__); } -- 2.43.0
