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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 2B322C3A5A6 for ; Mon, 23 Sep 2019 08:47:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E03832087C for ; Mon, 23 Sep 2019 08:47:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="K1+zCvsa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731590AbfIWIr0 (ORCPT ); Mon, 23 Sep 2019 04:47:26 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:58446 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731460AbfIWIrZ (ORCPT ); Mon, 23 Sep 2019 04:47:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=/43GF0QWgIU5tkmUtQcTjX9yL5SM1r1TS8Ahy7IgToA=; b=K1+zCvsaewII+mHTy3eoOME7L 8jpgtr+xqiZNxhbLy48TCKcvo0sb5elmojLefPfZOSyoeetH4ZeIRnseyYu/uJxClwyioMtmgZ6+i x3MGNbjz5+DxGOpFMFc+8PGbORulTuI8DGmtoKngWbDpphyXH3sbw7cOz7YbhskSi6WlAevBmuRzF AlXWHcG9wL45968qfB2n0WLK7gVFWkAQJHqi1wgUvxA9iBn63t/6IVyE18WReWeLgDZnjVWMQq9J+ uFzIRF52TzH5ONzcbofMAcJ5VdGFE9GoYysFA9GlDN3QkT32YER24V80ZiAvgUIdcffUmhZiVIFo7 SpqZplQcg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCK09-0004sR-48; Mon, 23 Sep 2019 08:47:21 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id B8222303DFD; Mon, 23 Sep 2019 10:46:33 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C79032B1204C7; Mon, 23 Sep 2019 10:47:18 +0200 (CEST) Date: Mon, 23 Sep 2019 10:47:18 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: LKML , x86@kernel.org, Andy Lutomirski , Catalin Marinas , Will Deacon , Mark Rutland , Marc Zyngier , Paolo Bonzini , kvm@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [RFC patch 10/15] x86/entry: Move irq tracing to C code Message-ID: <20190923084718.GG2349@hirez.programming.kicks-ass.net> References: <20190919150314.054351477@linutronix.de> <20190919150809.446771597@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190919150809.446771597@linutronix.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 19, 2019 at 05:03:24PM +0200, Thomas Gleixner wrote: > To prepare for converting the exit to usermode code to the generic version, > move the irqflags tracing into C code. > > Signed-off-by: Thomas Gleixner > --- > arch/x86/entry/common.c | 10 ++++++++++ > arch/x86/entry/entry_32.S | 11 +---------- > arch/x86/entry/entry_64.S | 10 ++-------- > arch/x86/entry/entry_64_compat.S | 21 --------------------- > 4 files changed, 13 insertions(+), 39 deletions(-) > > --- a/arch/x86/entry/common.c > +++ b/arch/x86/entry/common.c > @@ -102,6 +102,8 @@ static void exit_to_usermode_loop(struct > struct thread_info *ti = current_thread_info(); > u32 cached_flags; > > + trace_hardirqs_off(); Bah.. so this gets called from: - C code, with IRQs disabled - entry_64.S:error_exit - entry_32.S:resume_userspace The first obviously doesn't need this annotation, but this patch doesn't remove the TRACE_IRQS_OFF from entry_64.S and only the 32bit case is changed. Is that entry_64.S case an oversight, or do we need an extensive comment on this one? > addr_limit_user_check(); > > lockdep_assert_irqs_disabled(); > @@ -137,6 +139,8 @@ static void exit_to_usermode_loop(struct > user_enter_irqoff(); > > mds_user_clear_cpu_buffers(); > + /* Return to userspace (IRET) will re-enable interrupts */ > + trace_hardirqs_on(); > }