From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mundt Date: Wed, 13 Jul 2011 08:13:19 +0000 Subject: Re: [PATCH 5/5] drivers/video/msm/mdp.c: adjust error handling code Message-Id: <20110713081318.GB13701@linux-sh.org> List-Id: References: <1309788705-22278-5-git-send-email-julia@diku.dk> In-Reply-To: <1309788705-22278-5-git-send-email-julia@diku.dk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Julia Lawall Cc: David Brown , kernel-janitors@vger.kernel.org, Daniel Walker , Bryan Huntsman , linux-arm-msm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, Jul 04, 2011 at 04:11:45PM +0200, Julia Lawall wrote: > From: Julia Lawall > > Use the error handling code at the end of the function, rather than > returning directly. > > The semantic match that finds this problem is as follows: > (http://coccinelle.lip6.fr/) > > // > @r@ > identifier x; > @@ > > kfree(x) > > @@ > identifier r.x; > expression E1!=0,E2,E3,E4; > statement S; > @@ > > ( > if (<+...x...+>) S > | > if (...) { ... when != kfree(x) > when != if (...) { ... kfree(x); ... } > when != x = E3 > * return E1; > } > ... when != x = E2 > if (...) { ... when != x = E4 > kfree(x); ... return ...; } > ) > // > > Signed-off-by: Julia Lawall > Applied, thanks. > I wonder if the error handling code at the end of the function should be > calling clk_put as well? In that case, having a separate label for this > case would be useful. Otherwise, one of error_request_irq and error_get_clk > can be deleted > The MSM implementation for it is simply a nop, so it's not going to really matter one way or the other. In terms of general consistency it might be worth implementing. I expect that there are probably quite a few drivers that don't balance out their clk_get()'s with clk_put()'s however, perhaps this is another semantic patch candidate? At the very least it would be interesting to see the statistics.