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=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 682DFC46464 for ; Thu, 9 Aug 2018 17:15:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0FC4F21EFA for ; Thu, 9 Aug 2018 17:15:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="EfjUTFNx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0FC4F21EFA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732574AbeHITln (ORCPT ); Thu, 9 Aug 2018 15:41:43 -0400 Received: from mail-it0-f66.google.com ([209.85.214.66]:52900 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730634AbeHITln (ORCPT ); Thu, 9 Aug 2018 15:41:43 -0400 Received: by mail-it0-f66.google.com with SMTP id d9-v6so1259836itf.2 for ; Thu, 09 Aug 2018 10:15:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=la1oX93GBn15PIkbBPiUsj6AGZNnQ+90mcVLY2Zz2DE=; b=EfjUTFNxpT1mak+/0l69RIhVbzKFXd7jMtGwyeRBj1CoWGqNysML26Rhef9ZaPc/lc J7CP1ldJe54VzyRmPLcdcWiS7cwL20HMM+ohy34txFbhFASSOSxZWl0EszWE9EUcBwR1 YNWar9ehdEbE5c/kv/xCqfsCE0+fEHizc4+ho= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=la1oX93GBn15PIkbBPiUsj6AGZNnQ+90mcVLY2Zz2DE=; b=RtTTS52IG6dlkr2J+Kh7focdwRLJoLqlNA1PMdqCnV+XwHkaCu3JMoo2Ztqfj632+l putdcpT9BISRmezSweMFYwGC6Ku9/yTJFPb+pdmLhTbktnCmOLgB7Tlz0y6Qwi1IDVOc qESrCZxdoXoCQZa5+HmTPv/ZViy3iGub5y5uqyhHvU/1uNcwvAuEoinT/sUOJJbU6Psk HyiU3pc0EcnPSQN+1jVOsvLvpzyJR/4L9NVcYRZUwWPJKAXV5IsMFxmXMxgh6ykfIar0 DLPb4/tyan6Y0qLygssTpV2ecRr9S2STEtP6V1jcGFqlasHtj8f0CiXqI2GlgacVrBZB Vr3A== X-Gm-Message-State: AOUpUlGEGoTlqrI/0uze3tBXyGOP8XGZIe3XlM57ZqZ54UDo82jG5hHE U0DBbVsLZOScBiAOGwXPi7GL9IV77P3FK7vuPEGtZSYt X-Google-Smtp-Source: AA+uWPxddvnpBw6zUmhhrc5EIdnIfWCBFn8lqMDrFhH2HSq/u0oh64CZnLc9FBQFkBul+EkhrZtB5xglY4ruIRMX+Do= X-Received: by 2002:a24:b211:: with SMTP id u17-v6mr2636407ite.1.1533834954327; Thu, 09 Aug 2018 10:15:54 -0700 (PDT) MIME-Version: 1.0 References: <87wot0yqsx.fsf_-_@xmission.com> <20180809065605.32345-6-ebiederm@xmission.com> In-Reply-To: <20180809065605.32345-6-ebiederm@xmission.com> From: Linus Torvalds Date: Thu, 9 Aug 2018 10:15:43 -0700 Message-ID: Subject: Re: [PATCH v5 6/6] signal: Don't restart fork when signals come in. To: "Eric W. Biederman" Cc: Oleg Nesterov , Andrew Morton , Linux Kernel Mailing List , Wen Yang , majiang Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 8, 2018 at 11:57 PM Eric W. Biederman wrote: > > The code was being overly pesimistic. Pessimistic. > + if (type > PIDTYPE_TGID) { > + struct multiprocess_signals *delayed; > + hlist_for_each_entry(delayed, &t->signal->multiprocess, node) { > + sigset_t *signal = &delayed->signal; > + /* Can't queue both a stop and a continue signal */ > + if (sig == SIGCONT) { > + sigset_t flush; > + siginitset(&flush, SIG_KERNEL_STOP_MASK); > + sigandnsets(signal, signal, &flush); This looks odd and unnecessary. Why isn't this just a sigdelsetmask(signal, SIG_KERNEL_STOP_MASK); since all of the traditional stop bits should be in the low mask. I see that we apparently have this stupid pattern elsewhere too, and it looks like it's because we stupidly say "are the RT signals in the non-legacy set", when that definitely cannot be the case for the (very much legacy) tty flow control signals. Linus