From bedf0883cbe3015d21aec5ed47ddffb429f6cca7 Mon Sep 17 00:00:00 2001 From: Julien Brunel Date: Mon, 1 Sep 2008 10:57:27 +0200 Subject: [PATCH] USB: drivers/usb/misc: Use an IS_ERR test rather than a NULL test In case of error, the function backlight_device_register returns an ERR pointer, but never returns a NULL pointer. So a NULL test that may come after a call to this function should be strengthened by an IS_ERR test. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @match_bad_null_test@ expression x, E; statement S1,S2; @@ x = backlight_device_register(...) ... when != x = E * if (x != NULL) S1 else S2 // Signed-off-by: Julien Brunel Signed-off-by: Julia Lawall Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/appledisplay.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c index a076c24a312..71d672ea122 100644 --- a/drivers/usb/misc/appledisplay.c +++ b/drivers/usb/misc/appledisplay.c @@ -314,7 +314,7 @@ error: pdata->urbdata, pdata->urb->transfer_dma); usb_free_urb(pdata->urb); } - if (pdata->bd) + if (pdata->bd && !IS_ERR(pdata->bd)) backlight_device_unregister(pdata->bd); kfree(pdata->msgdata); } -- 2.20.1