From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf35.google.com (mail-qv1-xf35.google.com [IPv6:2607:f8b0:4864:20::f35]) by sourceware.org (Postfix) with ESMTPS id 30EA5385781F for ; Wed, 7 Apr 2021 19:34:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 30EA5385781F Received: by mail-qv1-xf35.google.com with SMTP id e19so3227906qvu.3 for ; Wed, 07 Apr 2021 12:34:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=XcgZjtkS0R1fmp//WkYqY6gzvfdW7MYwgwkFCtugq0Q=; b=H1UnwEyGigNJW9YpQx+t/uU2Nduokl9EHyP+J3ITm/pvitshMSzhv3NAmfhT4H3PL3 CS29bS5ha3bbVBy0y6aRFsEWCKPgydinPU6TgDxDePTaoTQO4BdrKnfItEx0yRQ9JmRM P4KUXbVQHJsT8T4BDD1aFPKr5MZHrO4owUlHAqN3EcbXQsLfN2K5XpPXzFL8IL8wQ1Bo wq9uC9wyBxJJC36jFs0gB/BPh0EppVXMJGJwp2H3qvurSfpWOon5N1hmie6wQzXLXuLr NvwTM6mNlN/EnaGQfHHyOlIsgq2AYvD9EJrv+ynRRu9Lw0x9O1q2dzDL/IGtdA1gqSPs F5hQ== X-Gm-Message-State: AOAM532Q9/2ydliIpfx4X0sxS/8/pDacLWTnmwis+T/1iNFdJ4yLW6aE eCZYfygAZ7gP1EsBS4/tTXwc+A== X-Google-Smtp-Source: ABdhPJz9d7y5JN+QoU3NGTieI7DWFvNuFHRttQaxw/g0PSNxS+75Jen7oM1MHVvTO7SrAeA3yKGXWA== X-Received: by 2002:a0c:df0a:: with SMTP id g10mr5170929qvl.57.1617824066780; Wed, 07 Apr 2021 12:34:26 -0700 (PDT) Received: from [192.168.1.132] ([177.194.41.149]) by smtp.gmail.com with ESMTPSA id u21sm17523065qtq.11.2021.04.07.12.34.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 07 Apr 2021 12:34:26 -0700 (PDT) Subject: Re: [PATCH] linux: sysconf: limit _SC_MAX_ARG to 6 MiB [BZ #25305] To: Florian Weimer Cc: Michal Nazarewicz , libc-alpha@sourceware.org, carlos@systemhalted.org References: <20210407151058.1176364-1-mina86@mina86.com> <6c926d3b-3094-f220-7777-91dacf975275@linaro.org> <878s5u7x9g.fsf@oldenburg.str.redhat.com> <5e390f1e-3c31-c4e9-aae0-168f0b4725c7@linaro.org> <87pmz57w7w.fsf@oldenburg.str.redhat.com> From: Adhemerval Zanella Message-ID: <5fbf7775-7a3c-6b89-81d6-8596d371e27c@linaro.org> Date: Wed, 7 Apr 2021 16:34:24 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <87pmz57w7w.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-6.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 07 Apr 2021 19:34:30 -0000 On 07/04/2021 16:04, Florian Weimer wrote: > * Adhemerval Zanella: > >> IMHO being conservative and use the lower bound of all supported kernels. >> I really don't think trying to be smart here with dynamic probing >> will add much, specially since this upper limit is what kernel will >> support from now on. > > Ah, if the conservative choice does not penalize newer kernels, then I > guess that's okay as well. My understanding is newer kernel are more restrictive since they limit maximum argument plus environment size to up to 6MB, different than older kernels that have a higher bar to up 1/4 of maximum stack size. So I take you don't oppose to the patch. > > Then the argument goes like this: If you want us to make the limit > dynamic, add something to the auxiliary vector. 8-) I am not sure if kernel will be willing to make this dynamic, at least it seems not be an issue.