From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD6A4C54EBD for ; Sun, 8 Jan 2023 22:08:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233831AbjAHWIQ (ORCPT ); Sun, 8 Jan 2023 17:08:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235027AbjAHWIN (ORCPT ); Sun, 8 Jan 2023 17:08:13 -0500 Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [IPv6:2a00:1450:4864:20::132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59AD11054C for ; Sun, 8 Jan 2023 14:08:11 -0800 (PST) Received: by mail-lf1-x132.google.com with SMTP id b3so10298171lfv.2 for ; Sun, 08 Jan 2023 14:08:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:references:cc:to:from :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=f6ubnZnnnm86vU9G8oTF7iYXAATguR/oQ9JcuOI4Xb4=; b=E+xc4iTYp/PLYZ+e4TrolV7ng//esyyQjPKtR4jEnokZyBcEKoAi4zhZ9ruWeypdcl 7g2TtMyAcFsoPSX+Yvf4+c12wYd48f8B5l3P2tWT5A+AXV3pHriSyQtcSy8T3YNNfAma sNu04ApNLGnoAenyCgLrAD/EErt4sdwH8HZatJ3ygihxgbkzt6zikf9GT6KGvin4RzdR 9xDqgcDJheBp2i6j5rF5mqxOPfH+dUhEZpRsZpAAZtOU4NkH3m7Zj51MbXIcL32m0c9Y SvT63U5SHBwQ9/45cAU6bd8zdczxxoj5PwyUmru5Ft3yIZZmJNVybor8tN83+n44YgM5 9OWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:references:cc:to:from :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=f6ubnZnnnm86vU9G8oTF7iYXAATguR/oQ9JcuOI4Xb4=; b=iwNp0jw8IjhZoFFA3KsEwAY8KD4VTE7sOcV9K2aDKX7zedcHFnACo+xeF2bF/WB0HR BbNGYG4YoLKbmnbHloJbekhnlRxml9iUwmHVlqEZIpTfM00MCqZO5923DVu0LbtYem9+ +/WY3nmNQgYi8ZiFRAECKfM1qUALDGXjdJMvMq736TRx7M+2yu+p0nzM5wAfcDNdK9bB PGqYuN+AY1lHpRBjl2a+jFfu7as/mfxpJJ1JfSn8x9VllrvaQBTyKRSoELCOWDgcdDgY M/PUeKXuXm9nBiX2LOCIvGZcPt+FHGrojqI7QX8rBNq+cIWYw0G0+ijEacBbaaF9kJVq TXHA== X-Gm-Message-State: AFqh2ko87VvPPB8SoYqa37p4rn93LpDUfjBW507r4ZJd/9Xv+/v0hkR9 bc/x5zAzElZ2TQ4d+7anAJyCjQ== X-Google-Smtp-Source: AMrXdXsBReaMbutTRcZt/O0SaBsRbQ2XZpqlgv3sWb32zgktzJf0Rsigi+BnZVpThocB45KaI7TkPQ== X-Received: by 2002:a05:6512:308f:b0:4cb:1189:2862 with SMTP id z15-20020a056512308f00b004cb11892862mr13486061lfd.13.1673215689664; Sun, 08 Jan 2023 14:08:09 -0800 (PST) Received: from ?IPV6:2001:14ba:a085:4d00::8a5? (dzccz6yyyyyyyyyyybcwt-3.rev.dnainternet.fi. [2001:14ba:a085:4d00::8a5]) by smtp.gmail.com with ESMTPSA id s17-20020a056512215100b0049876c1bb24sm1264699lfr.225.2023.01.08.14.08.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 08 Jan 2023 14:08:09 -0800 (PST) Message-ID: <0b63ef49-7a59-0a72-503c-1de20a502c6a@linaro.org> Date: Mon, 9 Jan 2023 00:08:08 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH] drm/msm/dpu: Add check for cstate Content-Language: en-GB From: Dmitry Baryshkov To: Jiasheng Jiang , robdclark@gmail.com, quic_abhinavk@quicinc.com, sean@poorly.run, airlied@gmail.com, daniel@ffwll.ch, quic_jesszhan@quicinc.com, ville.syrjala@linux.intel.com, yang.lee@linux.alibaba.com Cc: linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20221206080517.43786-1-jiasheng@iscas.ac.cn> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/01/2023 23:56, Dmitry Baryshkov wrote: > On 06/12/2022 10:05, Jiasheng Jiang wrote: >> As kzalloc may fail and return NULL pointer, >> it should be better to check cstate >> in order to avoid the NULL pointer dereference >> in __drm_atomic_helper_crtc_reset. >> >> Fixes: 1cff7440a86e ("drm/msm: Convert to using >> __drm_atomic_helper_crtc_reset() for reset.") >> Signed-off-by: Jiasheng Jiang >> --- >>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 5 ++++- >>   1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c >> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c >> index 13ce321283ff..22c2787b7b38 100644 >> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c >> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c >> @@ -968,7 +968,10 @@ static void dpu_crtc_reset(struct drm_crtc *crtc) >>       if (crtc->state) >>           dpu_crtc_destroy_state(crtc, crtc->state); >> -    __drm_atomic_helper_crtc_reset(crtc, &cstate->base); >> +    if (cstate) >> +        __drm_atomic_helper_crtc_reset(crtc, &cstate->base); >> +    else >> +        __drm_atomic_helper_crtc_reset(crtc, NULL); > > NAK. > > The proper fix is to add the if() but to skip the else clause. We should > not reset the crtc's state if memory allocation failed. On the other hand... Some of the drivers do exactly this ops. With the message fixed: Reviewed-by: Dmitry Baryshkov -- With best wishes Dmitry