From db702a7af6c85d94ff32b6110b3646180f93f086 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 10 Jan 2012 09:33:47 -0200 Subject: [PATCH] [media] cx231xx: cx231xx_devused is racy cx231xx_devused is racy. Re-implement it in a proper way, to remove the risk of mangling it. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/cx231xx/cx231xx-cards.c | 36 ++++++++++++++--------------- 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/drivers/media/video/cx231xx/cx231xx-cards.c b/drivers/media/video/cx231xx/cx231xx-cards.c index bd82f017ccd..1f2fbbfebc7 100644 --- a/drivers/media/video/cx231xx/cx231xx-cards.c +++ b/drivers/media/video/cx231xx/cx231xx-cards.c @@ -854,7 +854,7 @@ void cx231xx_release_resources(struct cx231xx *dev) usb_put_dev(dev->udev); /* Mark device as unused */ - cx231xx_devused &= ~(1 << dev->devno); + clear_bit(dev->devno, &cx231xx_devused); kfree(dev->video_mode.alt_max_pkt_size); kfree(dev->vbi_mode.alt_max_pkt_size); @@ -1039,21 +1039,21 @@ static int cx231xx_usb_probe(struct usb_interface *interface, return -ENODEV; /* Check to see next free device and mark as used */ - nr = find_first_zero_bit(&cx231xx_devused, CX231XX_MAXBOARDS); - cx231xx_devused |= 1 << nr; - - if (nr >= CX231XX_MAXBOARDS) { - cx231xx_err(DRIVER_NAME - ": Supports only %i cx231xx boards.\n", CX231XX_MAXBOARDS); - cx231xx_devused &= ~(1 << nr); - return -ENOMEM; - } + do { + nr = find_first_zero_bit(&cx231xx_devused, CX231XX_MAXBOARDS); + if (nr >= CX231XX_MAXBOARDS) { + /* No free device slots */ + cx231xx_err(DRIVER_NAME ": Supports only %i devices.\n", + CX231XX_MAXBOARDS); + return -ENOMEM; + } + } while (test_and_set_bit(nr, &cx231xx_devused)); /* allocate memory for our device state and initialize it */ dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (dev == NULL) { cx231xx_err(DRIVER_NAME ": out of memory!\n"); - cx231xx_devused &= ~(1 << nr); + clear_bit(dev->devno, &cx231xx_devused); return -ENOMEM; } @@ -1129,7 +1129,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface, if (assoc_desc->bFirstInterface != ifnum) { cx231xx_err(DRIVER_NAME ": Not found " "matching IAD interface\n"); - cx231xx_devused &= ~(1 << nr); + clear_bit(dev->devno, &cx231xx_devused); kfree(dev); dev = NULL; return -ENODEV; @@ -1148,7 +1148,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface, retval = v4l2_device_register(&interface->dev, &dev->v4l2_dev); if (retval) { cx231xx_errdev("v4l2_device_register failed\n"); - cx231xx_devused &= ~(1 << nr); + clear_bit(dev->devno, &cx231xx_devused); kfree(dev); dev = NULL; return -EIO; @@ -1156,7 +1156,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface, /* allocate device struct */ retval = cx231xx_init_dev(&dev, udev, nr); if (retval) { - cx231xx_devused &= ~(1 << dev->devno); + clear_bit(dev->devno, &cx231xx_devused); v4l2_device_unregister(&dev->v4l2_dev); kfree(dev); dev = NULL; @@ -1181,7 +1181,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface, if (dev->video_mode.alt_max_pkt_size == NULL) { cx231xx_errdev("out of memory!\n"); - cx231xx_devused &= ~(1 << nr); + clear_bit(dev->devno, &cx231xx_devused); v4l2_device_unregister(&dev->v4l2_dev); kfree(dev); dev = NULL; @@ -1215,7 +1215,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface, if (dev->vbi_mode.alt_max_pkt_size == NULL) { cx231xx_errdev("out of memory!\n"); - cx231xx_devused &= ~(1 << nr); + clear_bit(dev->devno, &cx231xx_devused); v4l2_device_unregister(&dev->v4l2_dev); kfree(dev); dev = NULL; @@ -1250,7 +1250,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface, if (dev->sliced_cc_mode.alt_max_pkt_size == NULL) { cx231xx_errdev("out of memory!\n"); - cx231xx_devused &= ~(1 << nr); + clear_bit(dev->devno, &cx231xx_devused); v4l2_device_unregister(&dev->v4l2_dev); kfree(dev); dev = NULL; @@ -1286,7 +1286,7 @@ static int cx231xx_usb_probe(struct usb_interface *interface, if (dev->ts1_mode.alt_max_pkt_size == NULL) { cx231xx_errdev("out of memory!\n"); - cx231xx_devused &= ~(1 << nr); + clear_bit(dev->devno, &cx231xx_devused); v4l2_device_unregister(&dev->v4l2_dev); kfree(dev); dev = NULL; -- 2.11.4.GIT