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=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 7F477C433DF for ; Thu, 15 Oct 2020 14:37:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DE19212CC for ; Thu, 15 Oct 2020 14:37:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JsLODh9Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728888AbgJOOhL (ORCPT ); Thu, 15 Oct 2020 10:37:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:41874 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726925AbgJOOhL (ORCPT ); Thu, 15 Oct 2020 10:37:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602772630; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8D+jKZOPdRlEHQps569knoTqeoIFuK+hHSLLdva6RMw=; b=JsLODh9ZyPnxVVUYV4wGaTqgxpEp/8jLyUb4AsN16LvrF1KYxAjeusk5T1RWJLWyJYmzuR R3X44V1ftSZAsHB5zNs7zAkeizKVmId2uzZNjGTAzyscImLFjWeK4reiUd0sm1IOpY3D3a UsCXhDgWlyPb/d2MOrlo99C7cYl6vAs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-318-DySHVaUXNh6v_r4_2D9xRA-1; Thu, 15 Oct 2020 10:37:05 -0400 X-MC-Unique: DySHVaUXNh6v_r4_2D9xRA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E800D88C783; Thu, 15 Oct 2020 14:36:19 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.193.8]) by smtp.corp.redhat.com (Postfix) with SMTP id 77F9A6EF52; Thu, 15 Oct 2020 14:36:18 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 15 Oct 2020 16:36:19 +0200 (CEST) Date: Thu, 15 Oct 2020 16:36:17 +0200 From: Oleg Nesterov To: Jens Axboe Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, peterz@infradead.org Subject: Re: [PATCH 4/5] x86: wire up TIF_NOTIFY_SIGNAL Message-ID: <20201015143616.GD24156@redhat.com> References: <20201015131701.511523-1-axboe@kernel.dk> <20201015131701.511523-5-axboe@kernel.dk> <87o8l3a8af.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 10/15, Jens Axboe wrote: > > static void handle_signal_work(ti_work, regs) > { > if (ti_work & _TIF_NOTIFY_SIGNAL) > tracehook_notify_signal(); > > if (ti_work & _TIF_SIGPENDING) > arch_do_signal(regs); > } > > and then we can skip modifying arch_do_signal() all together, as it'll > only be called if _TIF_SIGPENDING is set. No, this can't work. We need to restart the syscall if TIF_NOTIFY_SIGNAL. Oleg.