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=-1.1 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS 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 645C7C43381 for ; Tue, 26 Feb 2019 15:39:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 324482184D for ; Tue, 26 Feb 2019 15:39:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=talktalk.net header.i=@talktalk.net header.b="X9ggw+mS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727357AbfBZPjn (ORCPT ); Tue, 26 Feb 2019 10:39:43 -0500 Received: from smtp-out-5.talktalk.net ([62.24.135.69]:47250 "EHLO smtp-out-5.talktalk.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726478AbfBZPjn (ORCPT ); Tue, 26 Feb 2019 10:39:43 -0500 X-Greylist: delayed 487 seconds by postgrey-1.27 at vger.kernel.org; Tue, 26 Feb 2019 10:39:42 EST Received: from doppelsaurus.mobileactivedefense.com ([79.76.157.206]) by smtp.talktalk.net with SMTP id yehggDljfWIpcyehhglWss; Tue, 26 Feb 2019 15:31:33 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=talktalk.net; s=cmr1711; t=1551195093; bh=pJ/c7ZI9aYXDK7uU/xPUv+kNvJ4PLr3T262HTIpbvVU=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=X9ggw+mS6QZ7t5D/j4xLPTII2s7bKXsDlupSsbSkpEBLDKO48Sm0TKi06PGsVAeZo b3w/F0ihrVSuLHax2NazzDV1onrCzbtLclzX/1TC8v+P58SGPP/Om39ceOQNXMX5gX DiLF8oBZUVBn+zH/w6LDCMTck9m97sl3CfhFfkX8= X-Originating-IP: [79.76.157.206] X-Spam: 0 X-OAuthority: v=2.3 cv=W6NGqiek c=1 sm=1 tr=0 a=LmSXc42RNFFs0HDMf027+A==:117 a=LmSXc42RNFFs0HDMf027+A==:17 a=kj9zAlcOel0A:10 a=CFTnQlWoA9kA:10 a=drOt6m5kAAAA:8 a=Y-LMB9zJlimbqkLpmJIA:9 a=CjuIK1q_8ugA:10 a=RMMjzBEyIzXRtoq5n5K6:22 Received: from doppelsaurus.mobileactivedefense.com (localhost [127.0.0.1]) by doppelsaurus.mobileactivedefense.com (8.14.4/8.14.4/Debian-4+deb7u1) with ESMTP id x1QFVWtE004555; Tue, 26 Feb 2019 15:31:32 GMT Received: (from rw@localhost) by doppelsaurus.mobileactivedefense.com (8.14.4/8.14.3/Submit) id x1QFVWHJ004553; Tue, 26 Feb 2019 15:31:32 GMT X-Authentication-Warning: doppelsaurus.mobileactivedefense.com: rw set sender to rweikusat@talktalk.net using -f From: Rainer Weikusat To: Al Viro Cc: Jason Baron , netdev@vger.kernel.org Subject: Re: [RFC] nasty corner case in unix_dgram_sendmsg() In-Reply-To: <20190226063804.GI2217@ZenIV.linux.org.uk> (Al Viro's message of "Tue, 26 Feb 2019 06:38:04 +0000") References: <20190225035121.GH2217@ZenIV.linux.org.uk> <20190226062817.GA17962@ZenIV.linux.org.uk> <20190226063804.GI2217@ZenIV.linux.org.uk> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) Date: Tue, 26 Feb 2019 15:31:32 +0000 Message-ID: <878sy2k1m3.fsf@doppelsaurus.mobileactivedefense.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-CMAE-Envelope: MS4wfHaWD1mPxSXRR2QdxaLZQqnDNVYC3KIkv7fdOTLkBGJ4dKgUQqjF5jgvWD2lAQhy7hnPy838mnoLhSI1TTqGODdOpgubOwGnBV8NYhLKRSX8lKbTD/Q3 B7hnzegpGjTwE10JPo4WhK6ndDjALwQbPW/0adIy4axSxyMPSKqZQTLo4/bIarErgaxy6DbHrrVMiztkgw40BNBibrQrXWDtlGO3xRgzzQ41MbFzCizj5hCy oBfIXPsLOBnai53bZLx2mH2gqsHwXVYPcCVPYBsECj4= Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Al Viro writes: > On Tue, Feb 26, 2019 at 06:28:17AM +0000, Al Viro wrote: [...] >> * if after relocking we see that unix_peer(sk) now >> is equal to other, we arrange for wakeup forwarding from other's >> peer_wait *and* if that has (likely) succeeded we fail with -EAGAIN. >> Huh? This returns 1 if sending isn't possible at the moment, ie, if the process which tries to send has to wait.