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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 10011C433EF for ; Wed, 16 Mar 2022 05:18:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=j/lvAXrgvdfo0hW5vMc0VtI2JUwgfc6AMSACpIqLFns=; b=pGPODqHOxBq/Qi AEF+vYMejbyapQf4z9CDT7s9EAxmy1J7w/uBPhKu2VhZlM697erGK/7GFsI9sNMiGVurBpvH+pzWH SBafxJVUeSjs9MVX/ESw4taDxSij1Xkxf640uNIKx9bkfN3773bI8xZ0mcY5rcx4EAjqpTHObV/UL wVmNBIluqhsbp1EGqdI9SiX2gkdFizK3H34RfTwq6fdyK40L1kXIChrm9LJrOAGGDd1u6P+596Gkm SKQ56a+FGXatDQwoN9xtNQVOLBx2GTi+8tTspxCHWFRriSmgWEn3z3waVcBgKZbECyCkyjHKdvGgD /ecfFFErKp2sbG8uy+bQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUM2M-00BT66-09; Wed, 16 Mar 2022 05:17:30 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nUM2H-00BT55-L7 for linux-arm-kernel@lists.infradead.org; Wed, 16 Mar 2022 05:17:26 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647407844; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8lb7YiG6jmX9H862cki7378pfEtBHK+urmW4PjB20D0=; b=aMmjBAe4fH+8FZwAwAhbhrKdhYUeVw+l02oG4WoN4kZ1o5RzpGXxwvCLnFSeB1UYu0IwGH AS9ysjBa0j70Li+IA6yxin6AgN2X9MF8OwGpEB+xTug2oaXItjg0mswfFVJNoyHChKx2FP CQN17qmvtEMthbjuoFFldyYU8F0WQZM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-640-c6b1-FWcMZuXSH2DwAglVw-1; Wed, 16 Mar 2022 01:17:21 -0400 X-MC-Unique: c6b1-FWcMZuXSH2DwAglVw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6652A101AA52; Wed, 16 Mar 2022 05:17:20 +0000 (UTC) Received: from localhost (ovpn-13-134.pek2.redhat.com [10.72.13.134]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 608A0440EE1; Wed, 16 Mar 2022 05:17:19 +0000 (UTC) Date: Wed, 16 Mar 2022 13:17:16 +0800 From: Baoquan He To: "Leizhen (ThunderTown)" Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , linux-kernel@vger.kernel.org, Dave Young , Vivek Goyal , Eric Biederman , kexec@lists.infradead.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, Rob Herring , Frank Rowand , devicetree@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou , John Donnelly , Dave Kleikamp Subject: Re: [PATCH v21 1/5] kdump: return -ENOENT if required cmdline option does not exist Message-ID: References: <20220227030717.1464-1-thunder.leizhen@huawei.com> <20220227030717.1464-2-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.85 on 10.11.54.9 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220315_221725_774991_C9DFE0ED X-CRM114-Status: GOOD ( 27.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 03/15/22 at 09:32pm, Leizhen (ThunderTown) wrote: > > > On 2022/3/15 20:21, Baoquan He wrote: > > On 03/15/22 at 07:57pm, Baoquan He wrote: > >> On 02/27/22 at 11:07am, Zhen Lei wrote: > >>> The crashkernel=Y,low is an optional command-line option. When it doesn't > >>> exist, kernel will try to allocate minimum required memory below 4G > >>> automatically. Give it a unique error code to distinguish it from other > >>> error scenarios. > >>> > >>> Signed-off-by: Zhen Lei > >>> --- > >>> kernel/crash_core.c | 3 +-- > >>> 1 file changed, 1 insertion(+), 2 deletions(-) > >>> > >>> diff --git a/kernel/crash_core.c b/kernel/crash_core.c > >>> index 256cf6db573cd09..4d57c03714f4e13 100644 > >>> --- a/kernel/crash_core.c > >>> +++ b/kernel/crash_core.c > >>> @@ -243,9 +243,8 @@ static int __init __parse_crashkernel(char *cmdline, > >>> *crash_base = 0; > >>> > >>> ck_cmdline = get_last_crashkernel(cmdline, name, suffix); > >>> - > >>> if (!ck_cmdline) > >>> - return -EINVAL; > >>> + return -ENOENT; > >> > >> Firstly, I am not sure if '-ENOENT' is a right value to return. From the > >> code comment of ENOENT, it's used for file or dir? > >> #define ENOENT 2 /* No such file or directory */ > > This error code does not return to user mode, so there is no problem. > There are a lot of places in the kernel that are used this way. For example: > > int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) > { > if (!cpu_stop_queue_work(cpu, &work)) > return -ENOENT; OK, it's fine to me. Thanks for the investigation. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel