From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751615AbeCLXLH (ORCPT ); Mon, 12 Mar 2018 19:11:07 -0400 Received: from mail-cys01nam02on0075.outbound.protection.outlook.com ([104.47.37.75]:53152 "EHLO NAM02-CY1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751333AbeCLXLF (ORCPT ); Mon, 12 Mar 2018 19:11:05 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=Andrey.Grodzovsky@amd.com; Subject: Re: linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx To: "Li, Roman" , David Binderman , "Deucher, Alexander" , "Koenig, Christian" , "Zhou, David(ChunMing)" , "airlied@linux.ie" , "amd-gfx@lists.freedesktop.org" , "dri-devel@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" , "Wentland, Harry" References: <8b55ac58-ae20-7662-10bb-c446701cd67e@amd.com> From: Andrey Grodzovsky Message-ID: <2bf3f20c-cbbd-525b-5bd4-61e6d2d8a677@amd.com> Date: Mon, 12 Mar 2018 19:10:56 -0400 User-Agent: Mozilla/5.0 (X11; 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At least assert indeed should be there. Andrey On 03/12/2018 07:06 PM, Li, Roman wrote: > There is a check just before for-loop that should ensure pipe_ctx is not null: > > /* Only supports single display */ > if (context->stream_count != 1) > return false; > > To remove the subject warning - we can rather add an assert: > assert(pipe_ctx); > > Thanks, > Roman > > -----Original Message----- > From: Grodzovsky, Andrey > Sent: Monday, March 12, 2018 6:23 PM > To: David Binderman ; Deucher, Alexander ; Koenig, Christian ; Zhou, David(ChunMing) ; airlied@linux.ie; amd-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org; linux-kernel@vger.kernel.org; Wentland, Harry ; Li, Roman > Subject: Re: linux-4.16-rc5/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c:1723]: (warning) Possible null pointer dereference: pipe_ctx > > > > On 03/12/2018 06:22 AM, David Binderman wrote: >> hello there, >> >> Source code is >> >> >>     for (i = 0; i < dc->res_pool->pipe_count; i++) { >>         if (res_ctx->pipe_ctx[i].stream) { >>             pipe_ctx = &res_ctx->pipe_ctx[i]; >>             *pipe_idx = i; >>             break; >>         } >>     } > Indeed something like > > if (!pipe_ctx) >               return false; > > seems the right thing here. > > Harry, Roman , your opinion ? > > Andrey > >>     /* Only supports eDP */ >>     if (pipe_ctx->stream->sink->link->connector_signal != >> SIGNAL_TYPE_EDP) >>         return false; >> >> Suggest add some code to deal with the case that the for loop doesn't >> find what it is looking for and so pipe_ctx is NULL. >> >> Regards >> >> David Binderman >> >> _______________________________________________ >> amd-gfx mailing list >> amd-gfx@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx