From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id 55E8B386100A for ; Fri, 30 Oct 2020 17:57:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 55E8B386100A Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-269-s5YjGCwqMEiuoalmS_cLeA-1; Fri, 30 Oct 2020 13:57:06 -0400 X-MC-Unique: s5YjGCwqMEiuoalmS_cLeA-1 Received: by mail-qk1-f199.google.com with SMTP id d5so4416837qkg.16 for ; Fri, 30 Oct 2020 10:57:06 -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:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=RkuGNLVWkV7ugw7S8pnzznEyeFjdJYrAVew0wk5qi+Q=; b=o13iWJ4NVH7FtoCjqGoWZVrFDLt5bFbDx8u262qnu37S3ltr3CZieImpXi3y22+weC NSzToL98FR2nB++K+k82raJozkVlHVydxCVdarycFEp00VxHnA5GJXxQyQS5EC1xWzZ2 ruT/vGLmQhyDHJoK6nR+do2z6sTB08u3P4TqiAFmMRk0hBZgFSLgYgZUWoD9jhpWcQNe qjIoL/cAKWEXX3eY+xUhroijYldciYcR82Hl5kiiKS5HYl9VKYcAJfv2IeQDtSwpEMhn ia6Z78wIO0V4zAjVq/9RdsIPG1xvvdo1MASrUtLPd1gBHVKOuYM0ZJw4jGZuIb76jCob seyw== X-Gm-Message-State: AOAM530o0o0poru49mMA/1XhVfLiumfDZGy+tczN8u750LKyu24+Bg5z 5nWcmAjWAllsClI50QewiST/Z4jPkdUOuaJivYt0IKjToowVob+8YGpJNOa95g8KP0AO3jYcc3U e3bLqXLr82FSpy/Mcchun X-Received: by 2002:a05:620a:1024:: with SMTP id a4mr3475597qkk.390.1604080626302; Fri, 30 Oct 2020 10:57:06 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwZa5sISgxr4ZOLlhy6SzwkIBss3GqS+/s02o4muBIZ9IX/WAKQVYeArk77gPD3lh4shViwng== X-Received: by 2002:a05:620a:1024:: with SMTP id a4mr3475582qkk.390.1604080626155; Fri, 30 Oct 2020 10:57:06 -0700 (PDT) Received: from [192.168.1.16] (198-84-214-74.cpe.teksavvy.com. [198.84.214.74]) by smtp.gmail.com with ESMTPSA id v65sm3083647qkb.88.2020.10.30.10.57.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 30 Oct 2020 10:57:05 -0700 (PDT) Subject: Re: [Y2038] Question about porting y2038-tests to glibc To: Joseph Myers Cc: Florian Weimer , libc-alpha@sourceware.org, Andreas Schwab , libc-help , Alistair Francis References: <20201028110156.747fb676@jawa> <20201029104404.6b1fc1d7@jawa> <20201030104440.3bd26e0e@jawa> <3e2beb53-b666-ead8-1876-fc085684d61d@redhat.com> From: Carlos O'Donell Organization: Red Hat Message-ID: Date: Fri, 30 Oct 2020 13:57:04 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, 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: Fri, 30 Oct 2020 17:57:10 -0000 On 10/30/20 1:29 PM, Joseph Myers wrote: > On Fri, 30 Oct 2020, Carlos O'Donell via Libc-alpha wrote: > >> I would accept QEMU usage in build-many-glibcs.py, and I also agree >> that such checks must have a clean baseline. > > Note that anything involving QEMU user emulation for these time tests > probably needs QEMU work to add an option to use a different time for the > emulated program, unless such an option already exists. (For that matter, > QEMU system emulation would also need such an option.) The option for '-rtc [base=utc|localtime|datetime][,clock=host|rt|vm][,driftfix=none|slew]' exists today. It could be tested to verify it works in user or system modes and as such represents a way forward. So '-rtc base=20380120,clock=rt' should put you past the y2038 transition, and '-rtc base=20380119,clock=rt' should put you before the y2038. -- Cheers, Carlos.