Received: by 2002:a25:ab43:0:0:0:0:0 with SMTP id u61csp1029793ybi; Thu, 30 May 2019 10:24:51 -0700 (PDT) X-Google-Smtp-Source: APXvYqyRQflctVWjGXXqRHkTEBl067Uuh5DCOxoQnj8ElXL8PO295mQ7VxZMwReywH/1FGCAuuCd X-Received: by 2002:a63:de53:: with SMTP id y19mr4675120pgi.166.1559237091745; Thu, 30 May 2019 10:24:51 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1559237091; cv=none; d=google.com; s=arc-20160816; b=IF8pgbyUwvlL2XFMrjrTUHF30Wy9qcj2+HwGXr6In2OrhTH52z99K42eUGMjFt93uh AHAH3CJD3KTY1aCip2Mc7X4HyO+TPhWhP7YRv1fA+fFOnpIJm+SVKvozZb1Wkv8vbEWU nqN1YRa/bokHQzvpZEQcgLhlj+7V/v+TmaVrzwFQZSHlHFpTv0sf34fiqd1JbFalmBvM wI9Tz8LBcZeMnh7LNIteReBVwtSFyBuoNw7vEfLx6Li8CsdK+Pia1Jaou6dd8F/fxlHi NOpNTBoa0vgiIgW5kqU60Tlp3een+5B1ajwPG950Phjl4uk7Ph6HJcJ5tRVstLS2wTO8 4DBA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:subject:mime-version:user-agent :message-id:in-reply-to:date:references:cc:to:from; bh=3NQrw1Rc25poFOtF3o67VfIz9e2YYCBPeZZk68bOS3k=; b=hW2XbDEEVPXaBgYPzoXF2g6n337jYL94lvhqqlWWCUkZAQCtaIuZwSGPPsY6+oo4MT iLtLpJ868xTewWG7JC1d7Le1EX5fkBvBaLifhB0FGB2SXhWZHhiR9LXFq8W1GlVLNGt2 7qKLapSgBE4nWMZPIzFU51rR/H2T/jIBSrhOVfd8kkUDSjDDIoqCEqv+Cw21sOwjhxkL u+AkAqMAEAj9DVXDGe+sdXOHW0XI2MmmWFIcpVMM53MUkyqo6P426pmuYwx6Gf7Sgcmo 1R7xEH0netxuGNsn/hMxwXItSZEiuPYupI37g7Q5Y4ijgmNrwZX1OeMM+VNmcpznJyBh kH1w== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=xmission.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h5si3522529pgs.486.2019.05.30.10.24.36; Thu, 30 May 2019 10:24:51 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=xmission.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726819AbfE3RVw (ORCPT + 99 others); Thu, 30 May 2019 13:21:52 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:53606 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725961AbfE3RVw (ORCPT ); Thu, 30 May 2019 13:21:52 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1hWOkN-0000K1-Ck; Thu, 30 May 2019 11:21:47 -0600 Received: from ip72-206-97-68.om.om.cox.net ([72.206.97.68] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1hWOkM-0005Yj-Id; Thu, 30 May 2019 11:21:47 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Oleg Nesterov Cc: Deepa Dinamani , Al Viro , Linus Torvalds , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, arnd@arndb.de, dbueso@suse.de, axboe@kernel.dk, dave@stgolabs.net, e@80x24.org, jbaron@akamai.com, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, omar.kilani@gmail.com, tglx@linutronix.de, stable@vger.kernel.org References: <20190522032144.10995-1-deepa.kernel@gmail.com> <20190529161157.GA27659@redhat.com> <87woi8rt96.fsf@xmission.com> <871s0grlzo.fsf@xmission.com> <20190530160823.GI22536@redhat.com> Date: Thu, 30 May 2019 12:20:52 -0500 In-Reply-To: <20190530160823.GI22536@redhat.com> (Oleg Nesterov's message of "Thu, 30 May 2019 18:08:24 +0200") Message-ID: <87lfynrh8r.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1hWOkM-0005Yj-Id;;;mid=<87lfynrh8r.fsf@xmission.com>;;;hst=in01.mta.xmission.com;;;ip=72.206.97.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1895Z1ierl2kaF3bw8R919nMbS+HF5Tt3c= X-SA-Exim-Connect-IP: 72.206.97.68 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on sa07.xmission.com X-Spam-Level: X-Spam-Status: No, score=-0.2 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG autolearn=disabled version=3.4.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.5000] * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa07 1397; Body=1 Fuz1=1 Fuz2=1] X-Spam-DCC: XMission; sa07 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Oleg Nesterov X-Spam-Relay-Country: X-Spam-Timing: total 325 ms - load_scoreonly_sql: 0.05 (0.0%), signal_user_changed: 4.1 (1.3%), b_tie_ro: 3.0 (0.9%), parse: 1.33 (0.4%), extract_message_metadata: 17 (5.2%), get_uri_detail_list: 1.50 (0.5%), tests_pri_-1000: 28 (8.5%), tests_pri_-950: 3.2 (1.0%), tests_pri_-900: 2.1 (0.7%), tests_pri_-90: 34 (10.5%), check_bayes: 31 (9.6%), b_tokenize: 14 (4.2%), b_tok_get_all: 8 (2.3%), b_comp_prob: 4.3 (1.3%), b_tok_touch_all: 2.5 (0.8%), b_finish: 0.95 (0.3%), tests_pri_0: 214 (65.7%), check_dkim_signature: 0.68 (0.2%), check_dkim_adsp: 2.7 (0.8%), poll_dns_idle: 0.43 (0.1%), tests_pri_10: 2.3 (0.7%), tests_pri_500: 11 (3.5%), rewrite_mail: 0.00 (0.0%) Subject: Re: pselect/etc semantics X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Oleg Nesterov writes: > On 05/30, Eric W. Biederman wrote: >> >> ebiederm@xmission.com (Eric W. Biederman) writes: >> >> > Which means I believe we have a semantically valid change in behavior >> > that is causing a regression. >> >> I haven't made a survey of all of the functions yet but >> fucntions return -ENORESTARTNOHAND will never return -EINTR and are >> immune from this problem. > > Hmm. handle_signal: > > case -ERESTARTNOHAND: > regs->ax = -EINTR; > break; > > but I am not sure I understand which problem do you mean.. Yes. My mistake. I looked at the transparent restart case for when a signal is not pending and failed to look at what happens when a signal is delivered. So yes. Everything changed does appear to have a behavioral difference where they can now succeed and not return -EINTR. Eric