From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-x333.google.com (mail-ot1-x333.google.com [IPv6:2607:f8b0:4864:20::333]) by sourceware.org (Postfix) with ESMTPS id 3046B3858410 for ; Mon, 24 Jan 2022 12:23:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3046B3858410 Received: by mail-ot1-x333.google.com with SMTP id x52-20020a05683040b400b0059ea92202daso6069329ott.7 for ; Mon, 24 Jan 2022 04:23:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=YYlLOJg2/I3bMaAMULA6XCU/fRTTrNAHP6ctQ8cwUw4=; b=n1dz/p/UxO5G3B06AFkKW0eZ52621Td9BJPOBc9bDWwFW+pvHgyEZYOnJKoFZ2+C/b X2gfDrzT+Av6kafUuGcEvZUG0gMj+Rzk6+kYHC3QKOX5GAOwc4KGdlfW+5EhRPzLpVGW zbCfZX+SHWor8woxvWuiPPGFi8f2Z8g9ychy/u8E3NRZ5zAnDkJmlgRzQ+js4qoOKryT E3IDpal4vctv5o38RO+hGQIZBYdMXluNAdCVs0lyo8hpgxLYKNpDB/pd4jVcMDpza6gh toFNuZsQEBAw5jln9cY0s+f2ohhzZCRyrBUlm3Ka/hjck2ez98x2HkTFmFlVvrHrU1mM I9yw== X-Gm-Message-State: AOAM532qz5qdr+9Xv4GGGLSbq4ii5yF5/7b5qMhBt9OL3LS8oCiqE0Yx g12btEU6Ki4ka+ctb6qhZCZC5L7yo4sXxQ== X-Google-Smtp-Source: ABdhPJwTMyNVUMB3pGZ3hdZa515jeKOiVFtlDAYEhTlwOGGP/OCaZ+bdjBc7wO32szOCaGeXUmiTVA== X-Received: by 2002:a05:6830:2a8c:: with SMTP id s12mr2705237otu.290.1643026986221; Mon, 24 Jan 2022 04:23:06 -0800 (PST) Received: from ?IPV6:2804:431:c7cb:27f8:c505:63c0:de61:b716? ([2804:431:c7cb:27f8:c505:63c0:de61:b716]) by smtp.gmail.com with ESMTPSA id c4sm4971252otp.34.2022.01.24.04.23.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 24 Jan 2022 04:23:06 -0800 (PST) Message-ID: <9263a5c2-48c4-a5d1-c159-2f0ee4e26c52@linaro.org> Date: Mon, 24 Jan 2022 09:23:04 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v4] linux: Fix ancillary 64-bit time timestamp conversion (BZ #28349, BZ #28350) Content-Language: en-US To: Florian Weimer Cc: Adhemerval Zanella via Libc-alpha References: <20211222185239.1088511-1-adhemerval.zanella@linaro.org> <8735lh6vqo.fsf@oldenburg.str.redhat.com> <372ae1ee-0163-7bf4-be1c-cc1f13b1a940@linaro.org> <87bl0149i2.fsf@oldenburg.str.redhat.com> From: Adhemerval Zanella In-Reply-To: <87bl0149i2.fsf@oldenburg.str.redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.8 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=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: Mon, 24 Jan 2022 12:23:09 -0000 On 24/01/2022 09:13, Florian Weimer wrote: > * Adhemerval Zanella: > >>> typo: MSG_[C]TRUNC >>> >>> (I think this MSG_CTRUNC result is a remaining bug we need to fix >>> separately for time32 mode.) >> >> Do you mean not returning the MSG_CTRUNC? > > No, if the caller uses CMSG_SPACE to allocate space for the expected > ancillary data, we should not produce MSG_CTRUNC by stuffing in > ancillary data that has not been requested. Maybe we can do this for > time32 code only. Again it seems that userspace emulation is rather > questionable here. But this would be only an issue for applications using _TIME_BITS=64 running on older kernels (so 32 bit timestamps would be visible to the caller). Since 64 bit is a opt-in feature, I think users will see way more potential issues running _TIME_BITS=64 on older kernels.