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 C8851C4332F for ; Mon, 26 Dec 2022 06:41:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231628AbiLZGlU (ORCPT ); Mon, 26 Dec 2022 01:41:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229619AbiLZGlP (ORCPT ); Mon, 26 Dec 2022 01:41:15 -0500 Received: from mail-ua1-x92c.google.com (mail-ua1-x92c.google.com [IPv6:2607:f8b0:4864:20::92c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1499261E for ; Sun, 25 Dec 2022 22:41:14 -0800 (PST) Received: by mail-ua1-x92c.google.com with SMTP id k23so2207858ual.8 for ; Sun, 25 Dec 2022 22:41:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=pIFJvpkO7mmQ+cyz+DICxCYAUcnhXk54K2D6tr7hNmA=; b=BYmghKmwaLqWgV1R5z53x4FUhMOzvIgRO9ihAgSXUmHX4vbdh5vTQOTkDCYMeEW/BJ 9uXmqxp7uPywqNtiAFPIAI3Q7cFo4sYuumlx7IqSQV9U4Kgn8n3ppLZVzusgwlHoxsT0 uRNyYw6PVm2Nl9gh+ZtQcQtAWpOaEhe3Rtg28= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=pIFJvpkO7mmQ+cyz+DICxCYAUcnhXk54K2D6tr7hNmA=; b=N5rs5Oqn/si9TzlRg23SX9biygPVzpGqk5m3xkFX9kC/EKFqUwuFqo82M9r21RzcLm bETMHwrgJ/IEfcUZfqieFFB8aXEoFN7Xg32wksFm0J6UGKAhiHk1w39ElaFQXLGmESzq ctMICoH/lvLbfoz/VrwzqnqA1gJzQT5Pxyq5h7YrMasRVSrq46OE6x5TXeT0G0ArGj7Z WMPUZQPvZ4l+8aVcEFq3s3wvEdX7MjLe+WlOreYQlvO3lzNGVfHXqFds+QmaVrESZcl/ Z1Sq+S/wiERx+CtbeI0I1tplJiXM/g9hc7h+Zo3SIZVn7mhHpYbh/VN6SVrXmaJvFmfn 8P9g== X-Gm-Message-State: AFqh2krrFL3zOdePo3VPS4efZz/hMkyvWv4WQDO5w+1W5VlS2hBrVvsg 2AQMZhM6kXlwPQbFUVG+48uoQbPkcMea8fmxfyNUCZ+LEL0B5A== X-Google-Smtp-Source: AMrXdXtocbgpBPb70sNQS0nN5Qje72F2peRA9iLUAtVoyaKwtwgnm3WCoQ4AVmRPpjMRkUISpECBKKr1mzk1nSgdIqw= X-Received: by 2002:ab0:7411:0:b0:418:b849:8187 with SMTP id r17-20020ab07411000000b00418b8498187mr1580687uap.43.1672036796827; Sun, 25 Dec 2022 22:39:56 -0800 (PST) MIME-Version: 1.0 References: <20221226061711.3988-1-chuanjian@nfschina.com> In-Reply-To: <20221226061711.3988-1-chuanjian@nfschina.com> From: Chen-Yu Tsai Date: Mon, 26 Dec 2022 14:39:45 +0800 Message-ID: Subject: Re: [PATCH] drivers/media/v4l2-core/v4l2-h264.c : add detection of null pointers To: Dong Chuanjian Cc: mchehab@kernel.org, hverkuil-cisco@xs4all.nl, nicolas.dufresne@collabora.com, sebastian.fricke@collabora.com, ezequiel@vanguardiasur.com.ar, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 26, 2022 at 2:17 PM Dong Chuanjian wrote: > > Continue the program when the pointer assignment is successful. > > Signed-off-by: Dong Chuanjian > > diff --git a/drivers/media/v4l2-core/v4l2-h264.c b/drivers/media/v4l2-core/v4l2-h264.c > index 72bd64f65198..1163cd48ff33 100644 > --- a/drivers/media/v4l2-core/v4l2-h264.c > +++ b/drivers/media/v4l2-core/v4l2-h264.c > @@ -343,18 +343,19 @@ static const char *format_ref_list_b(const struct v4l2_h264_reflist_builder *bui > int n = 0, i; > > *out_str = kmalloc(tmp_str_size, GFP_KERNEL); > - > - n += snprintf(*out_str + n, tmp_str_size - n, "|"); > - > - for (i = 0; i < builder->num_valid; i++) { > - int frame_num = builder->refs[reflist[i].index].frame_num; > - u32 poc = v4l2_h264_get_poc(builder, reflist + i); > - bool longterm = builder->refs[reflist[i].index].longterm; > - > - n += scnprintf(*out_str + n, tmp_str_size - n, "%i%c%c|", > - longterm ? frame_num : poc, > - longterm ? 'l' : 's', > - ref_type_to_char(reflist[i].fields)); > + if (*out_str != NULL) { I would suggest returning early if it's NULL. The change would be cleaner as you wouldn't need to reindent the whole code block. ChenYu > + n += snprintf(*out_str + n, tmp_str_size - n, "|"); > + > + for (i = 0; i < builder->num_valid; i++) { > + int frame_num = builder->refs[reflist[i].index].frame_num; > + u32 poc = v4l2_h264_get_poc(builder, reflist + i); > + bool longterm = builder->refs[reflist[i].index].longterm; > + > + n += scnprintf(*out_str + n, tmp_str_size - n, "%i%c%c|", > + longterm ? frame_num : poc, > + longterm ? 'l' : 's', > + ref_type_to_char(reflist[i].fields)); > + } > } > > return *out_str; > -- > 2.18.2 >