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 X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6AC0C433E0 for ; Wed, 27 Jan 2021 06:38:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73D9320707 for ; Wed, 27 Jan 2021 06:38:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232490AbhA0Gh1 (ORCPT ); Wed, 27 Jan 2021 01:37:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234134AbhA0DNt (ORCPT ); Tue, 26 Jan 2021 22:13:49 -0500 Received: from mail-il1-x12f.google.com (mail-il1-x12f.google.com [IPv6:2607:f8b0:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A21F6C061788 for ; Tue, 26 Jan 2021 19:13:09 -0800 (PST) Received: by mail-il1-x12f.google.com with SMTP id f18so444837ilj.8 for ; Tue, 26 Jan 2021 19:13:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3M1zQf19J5vQNnJvY7qqgq7o0AemNbv+khJIT1wB/QE=; b=IgAeFMvxPVf6VitI98plqk0WfuJtV2d7hnCerwwb9NTSW7TjlcGfJoi+7kATjlMXQl GtoigKULokzQBIvZBGTcPjX/bIZC7AkpLnyjaGBc1quidSPpmtXH5cjSlW3Fh1FWSDxl sXLEokobSfTLANbhRyTnH3/OwWXZXlmHXQBKj97pBZOqq0rEh33VOJlz2Fomr4enZL39 D6aMyxc6zPVBeVhxiHX/zTdiUyEF4ypPUZvs8yKOhlqqHmDbL8BIKRTWUIRuMzDXiCRY bx27XGhIQJAviHmks2tKoMZ2reM9J3dDPA+j3ptzqDxGJT7cltYTAB8dI9riTFPYYZz4 k+Tg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3M1zQf19J5vQNnJvY7qqgq7o0AemNbv+khJIT1wB/QE=; b=tCUnWfZQUVvbdVCnET4HR0CI8qKXWp+t5undf4ucUEgry4Xyh3Z+VGvsBc/Ot0Af4A 3+7qw2ljN0Ij2SHAMnMySUPtORTlkXxFMUsoVTxuLv+jmwsgxHZQguXrLs6hzdy0S+Yh wDYHK1N36rP6eaANjttHXlrn7vJ/ulrPCmQjD9GUQVPXUd6I9scqzJvYiodr+Zl3QPMC ABIQRz40LMp+2dHM3ex/p9M3qiV7Qd9m7+0FN5bz2Zo1ySPiIJdUFNdXtWe+pptFlkyK 2rVgzRE8/uOKgW2yZUN3UtGZhEx8y+SoiXpX8j9Ci6yueuP8qQTQ/qfoH/JeYRHCakDr 9lSw== X-Gm-Message-State: AOAM532AFtg6pYq6ONyZVQ2S5eP6Dyns9ibRmr4xMENIlLegElVfHUjT X/aaheJEb+HlXArZZCe0tf8wcEiZl37Z5wys+G8= X-Google-Smtp-Source: ABdhPJx/vjoLbEAK5NmSmJJQvszKdv7pvcwgLTkU9XL7NNH/BMn4NGlskm6C0sKQ8XTL8zT2OBAlj4E6aBm8/ozN30Y= X-Received: by 2002:a05:6e02:cb:: with SMTP id r11mr7289042ilq.116.1611717189005; Tue, 26 Jan 2021 19:13:09 -0800 (PST) MIME-Version: 1.0 References: <20210126171141.122639-1-paul.gortmaker@windriver.com> <20210126171141.122639-5-paul.gortmaker@windriver.com> In-Reply-To: <20210126171141.122639-5-paul.gortmaker@windriver.com> From: Yury Norov Date: Tue, 26 Jan 2021 19:12:58 -0800 Message-ID: Subject: Re: [PATCH 4/8] lib: bitmap: move ERANGE check from set_region to check_region To: Paul Gortmaker Cc: Linux Kernel Mailing List , lizefan@huawei.com, Ingo Molnar , Thomas Gleixner , josh@joshtriplett.org, Peter Zijlstra , "Paul E. McKenney" , fweisbec@gmail.com, Rasmus Villemoes , Andy Shevchenko Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 26, 2021 at 9:12 AM Paul Gortmaker wrote: > > It makes sense to do all the checks in check_region() and not 1/2 > in check_region and 1/2 in set_region. > > Since set_region is called immediately after check_region, the net > effect on runtime is zero, but it gets rid of an if (...) return... > > Cc: Yury Norov > Cc: Rasmus Villemoes > Cc: Andy Shevchenko > Signed-off-by: Paul Gortmaker > --- > lib/bitmap.c | 14 +++++--------- > 1 file changed, 5 insertions(+), 9 deletions(-) > > diff --git a/lib/bitmap.c b/lib/bitmap.c > index 162e2850c622..833f152a2c43 100644 > --- a/lib/bitmap.c > +++ b/lib/bitmap.c > @@ -500,17 +500,12 @@ struct region { > unsigned int nbits; > }; > > -static int bitmap_set_region(const struct region *r, unsigned long *bitmap) > +static void bitmap_set_region(const struct region *r, unsigned long *bitmap) > { > unsigned int start; > > - if (r->end >= r->nbits) > - return -ERANGE; > - > for (start = r->start; start <= r->end; start += r->group_len) > bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); > - > - return 0; > } > > static int bitmap_check_region(const struct region *r) > @@ -518,6 +513,9 @@ static int bitmap_check_region(const struct region *r) > if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) > return -EINVAL; > > + if (r->end >= r->nbits) > + return -ERANGE; > + > return 0; > } > > @@ -656,9 +654,7 @@ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) > if (ret) > return ret; > > - ret = bitmap_set_region(&r, maskp); > - if (ret) > - return ret; > + bitmap_set_region(&r, maskp); > } > > return 0; > -- > 2.17.1 Acked-by: Yury Norov