From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Mon, 30 May 2016 07:05:47 +0000 Subject: Re: [PATCH] Revert "i2c: dev: switch from register_chrdev to cdev API" Message-Id: <20160530070547.GA18199@mwanda> List-Id: References: <1464426467-1824-1-git-send-email-wsa@the-dreams.de> <20160528091559.GR11011@mwanda> <20160528160458.GA1614@katana> In-Reply-To: <20160528160458.GA1614@katana> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Wolfram Sang Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Erico Nunes , kernel-janitors@vger.kernel.org, LKP On Sat, May 28, 2016 at 06:04:58PM +0200, Wolfram Sang wrote: > > > These kinds of use after frees don't always cause a runtime problem. I > > found it using static analysis, but I bet you could detect it if you > > enabled kasan. The other option is to enable PAGE_POISONING? > > Thanks, PAGE_POISONING did trigger the issue. So, I now picked up your > patch instead of the revert because I could verify the problem and the > proper solution. Thanks again. > > What I still wonder: Which analysis reported the problem to you? I > always run sparse, smatch, cppcheck, and coccicheck on the patches when > applying and no-one reported the issue. It's a Smatch warning but you have to build the cross function db to detect this. It takes a while (a few hours) but the command is simple enough. ./smatch_scripts/build_kernel_data.sh regards, dan carpenter