From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jesper Juhl Subject: [PATCH] add NULL short circuit to fb_dealloc_cmap() Date: Sun, 17 Jul 2005 20:43:41 +0200 Message-ID: <200507172043.41473.jesper.juhl@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: Resource freeing functions should generally be safe to call with NULL pointers. Why? - there is some precedence in the kernel for this for deallocation functions. - removes the need for callers to check pointers for NULL. - space is saved overall by less code to test pointers for NULL all over the place. - removes possible NULL pointer dereferences when a caller forgot to check. This patch makes fb_dealloc_cmap() safe to call with a NULL pointer argument. Signed-off-by: Jesper Juhl --- drivers/video/fbcmap.c | 3 +++ 1 files changed, 3 insertions(+) --- linux-2.6.13-rc3-orig/drivers/video/fbcmap.c 2005-06-17 21:48:29.000000000 +0200 +++ linux-2.6.13-rc3/drivers/video/fbcmap.c 2005-07-17 20:33:43.000000000 +0200 @@ -130,6 +130,9 @@ fail: void fb_dealloc_cmap(struct fb_cmap *cmap) { + if (unlikely(!cmap)) + return; + kfree(cmap->red); kfree(cmap->green); kfree(cmap->blue);