From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 44631 invoked by alias); 17 Nov 2016 13:46:04 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 44553 invoked by uid 89); 17 Nov 2016 13:46:03 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,SPF_PASS autolearn=no version=3.3.2 spammy=Hx-languages-length:1145, cancel X-HELO: mail-qt0-f193.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=EH+StGLRmt0VTnZzyIgHw/0RVbFOA1u3SLcpuSNpNiM=; b=BMi+BPLKqNyZjooaUi5jEigToHy4rwn8MKlk8FbMjYHmscl9qm8DAwNICix9E8d2sD 8f2vBorojLcLslV8TaG+xR7L3ju8anbF4/pw8miIUZLJI2lqqP7bHDz13N6jhzHMCw4P hvtF89MWo8BIH/lw4ZTuTtqPgkVUn30A6RdEeLN7LZLvVQvlWDngUNEX21V4ZEySejvt ErS15igon2zZcaYiBlyuxoUrf1xJwKxjBDdShpxwq2nk9Ekd1+wjSeiKLIAr7vKQMa6G 0GSQGS7X6y91G9loTEDX/GjtGNFawKE1wvLqPOyVNxTl+UM6nokwNXPeqDiWjVeLLm8X u4Ug== X-Gm-Message-State: AKaTC01qEhT7xUCJHgfrKaWRXWEmK6o9sFKE7NMlpZQh+hwBDy5GI4/1fc0i1CXY/4SZTw== X-Received: by 10.237.61.176 with SMTP id i45mr1872227qtf.285.1479390360068; Thu, 17 Nov 2016 05:46:00 -0800 (PST) Subject: Re: [PATCH v7] getrandom system call wrapper [BZ #17252] To: Florian Weimer References: <3dd5d3b8-c196-98fb-1671-90cd90ab90c7@redhat.com> <244f578c-889a-a4cf-c686-bb2a5e49cca1@panix.com> <2d175242-1a82-9410-d01e-682ab4d9081e@panix.com> <0cca2fc9-14d2-9fa2-5a6e-fe00af31acd6@redhat.com> Cc: GNU C Library From: Zack Weinberg Message-ID: <4928b864-9691-021d-fcf9-b3ef9bd10f63@panix.com> Date: Thu, 17 Nov 2016 13:46:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.4.0 MIME-Version: 1.0 In-Reply-To: <0cca2fc9-14d2-9fa2-5a6e-fe00af31acd6@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2016-11/txt/msg00616.txt.bz2 On 11/17/2016 08:02 AM, Florian Weimer wrote: > On 11/16/2016 05:41 PM, Zack Weinberg wrote: >> On Wed, Nov 16, 2016 at 10:52 AM, Florian Weimer >> wrote: >>> On 11/16/2016 04:20 PM, Zack Weinberg wrote: >>>> I am seriously considering escalating my disagreement here to a >>>> formal objection. I would like to know why you think it is >>>> NECESSARY - not merely convenient or consistent with other stuff - >>>> for this function to be a cancellation point. >>> >>> It's necessary if you ever want to cancel a hanging getrandom in a >>> context where you cannot install a signal handler (so that you can >>> trigger EINTR when getrandom is stuck). >> >> That only pushes the question back a level. When would it ever be >> necessary to do that? Be as concrete as you possibly can. Actual >> code from a real program, if possible. > > It's not clear to me what you are asking here. > > Do you mean cancellation in general, or cancellation in conjunction with > getrandom specifically? Sorry. I meant cancellation specifically of a thread hanging in getrandom. zw