From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gregory CLEMENT Subject: Re: [PATCH] spi: Fix NULL pointer when setting SPI_CS_HIGH for GPIO CS Date: Fri, 25 Oct 2019 09:50:50 +0200 Message-ID: <87woctp8kl.fsf@FE-laptop> References: <20191024141309.22434-1-gregory.clement@bootlin.com> <20191024193225.GM46373@sirena.co.uk> Mime-Version: 1.0 Content-Type: text/plain Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Ferre , Alexandre Belloni , Ludovic Desroches , linux-arm-kernel@lists.infradead.org, Thomas Petazzoni , "kernelci.org bot" , stable@vger.kernel.org To: Mark Brown Return-path: In-Reply-To: <20191024193225.GM46373@sirena.co.uk> Sender: stable-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org Hi Mark, > On Thu, Oct 24, 2019 at 04:13:09PM +0200, Gregory CLEMENT wrote: >> Even if the flag use_gpio_descriptors is set, it is possible that >> cs_gpiods was not allocated, which leads to a kernel crash: >> >> Unable to handle kernel NULL pointer dereference at virtual address 00000000 >> pgd = (ptrval) >> [00000000] *pgd=00000000 >> Internal error: Oops: 5 [#1] ARM >> Modules linked in: >> CPU: 0 PID: 1 Comm: swapper Tainted: G W 5.4.0-rc3 #1 >> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) >> PC is at of_register_spi_device+0x20c/0x38c >> LR is at __of_find_property+0x3c/0x60 >> pc : [] lr : [] psr: 20000013 > > Please think hard before including complete backtraces in upstream > reports, they are very large and contain almost no useful information > relative to their size so often obscure the relevant content in your > message. If part of the backtrace is usefully illustrative then it's > usually better to pull out the relevant sections. You can remove it while applying it, or I can send a v2. Actually I thought you would squash it with the initial patch to avoid the bisectability break. Gregory -- Gregory Clement, Bootlin Embedded Linux and Kernel engineering http://bootlin.com