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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 343CCC433E7 for ; Mon, 19 Oct 2020 13:49:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFCF9222D9 for ; Mon, 19 Oct 2020 13:49:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="bjmLHlUz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728557AbgJSNtr (ORCPT ); Mon, 19 Oct 2020 09:49:47 -0400 Received: from mx2.suse.de ([195.135.220.15]:47262 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728344AbgJSNtq (ORCPT ); Mon, 19 Oct 2020 09:49:46 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1603115385; 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=0WuEu1sVQYwypPrmeh7IRBZ4h6wCe1meEeUaExOedg4=; b=bjmLHlUzq4NO0ZPLwtRJ1+FOVEceZm8hIxvyXlWUP+fNXiERSRk+mo3ZpqKLhnA38DTkaf jzRUjxUVeC1zNT8Bdi75/VmjbctFveWyPyVU3v6SU7XUT/sbGP2Rg94/dMs6p+2Q1iPc8f WVuA6U70zeoMKukXSNeQYDZh+ifpn9I= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DDD1AB22E; Mon, 19 Oct 2020 13:49:44 +0000 (UTC) Date: Mon, 19 Oct 2020 15:49:44 +0200 From: Petr Mladek To: Matteo Croce Cc: linux-kernel@vger.kernel.org, Guenter Roeck , Arnd Bergmann , Mike Rapoport , Kees Cook , Pavel Tatashin , Robin Holt , Fabian Frederick , stable@vger.kernel.org Subject: Re: [PATCH 2/2] reboot: fix parsing of reboot cpu number Message-ID: <20201019134944.GC26718@alley> References: <20201016180907.171957-1-mcroce@linux.microsoft.com> <20201016180907.171957-3-mcroce@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201016180907.171957-3-mcroce@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri 2020-10-16 20:09:07, Matteo Croce wrote: > From: Matteo Croce > > The kernel cmdline reboot= argument allows to specify the CPU used > for rebooting, with the syntax `s####` among the other flags, e.g. > > reboot=soft,s4 > reboot=warm,s31,force > > In the early days the parsing was done with simple_strtoul(), later > deprecated in favor of the safer kstrtoint() which handles overflow. > > But kstrtoint() returns -EINVAL if there are non-digit characters > in a string, so if this flag is not the last given, it's silently > ignored as well as the subsequent ones. > > To fix it, revert the usage of simple_strtoul(), which is no longer > deprecated, and restore the old behaviour. > > While at it, merge two identical code blocks into one. > > Fixes: 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") > Signed-off-by: Matteo Croce > --- > diff --git a/kernel/reboot.c b/kernel/reboot.c > index c4e7965c39b9..475f790bbd75 100644 > --- a/kernel/reboot.c > +++ b/kernel/reboot.c > @@ -552,25 +552,19 @@ static int __init reboot_setup(char *str) > > case 's': > { > - int rc; > - > - if (isdigit(*(str+1))) { > - rc = kstrtoint(str+1, 0, &reboot_cpu); > - if (rc) > - return rc; > - if (reboot_cpu >= num_possible_cpus()) { > - reboot_cpu = 0; > - return -ERANGE; > - } > - } else if (str[1] == 'm' && str[2] == 'p' && > - isdigit(*(str+3))) { > - rc = kstrtoint(str+3, 0, &reboot_cpu); > - if (rc) > - return rc; > - if (reboot_cpu >= num_possible_cpus()) { > - reboot_cpu = 0; > + int cpu; > + > + /* > + * reboot_cpu is s[mp]#### with #### being the processor > + * to be used for rebooting. Skip 's' or 'smp' prefix. > + */ > + str += str[1] == 'm' && str[2] == 'p' ? 3 : 1; > + > + if (isdigit(str[0])) { > + cpu = simple_strtoul(str, NULL, 10); The original code did not force the base 10. And even the code before the commit 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") did not force the base 10. I am not sure if people use it. But sometimes it might be easier to define the CPU number in hexa format. With using simple_strtoul(str, NULL, 0): Reviewed-by: Petr Mladek Best Regards, Petr