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=-6.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 91E18C433DF for ; Thu, 20 Aug 2020 10:54:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D10920724 for ; Thu, 20 Aug 2020 10:54:59 +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="LvYeFHf1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731459AbgHTKyz (ORCPT ); Thu, 20 Aug 2020 06:54:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730973AbgHTKw5 (ORCPT ); Thu, 20 Aug 2020 06:52:57 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FB8FC061385 for ; Thu, 20 Aug 2020 03:52:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=6a4fzHlDI/vqrQCkj8cPYEMr+0pCffBvrRSzShfRcXY=; b=LvYeFHf1xucbRhvIaADEKdr4tv g+BtOIXxOolgvKvGtfXED0g2gCuSkuQFxx6idfLpF6XoIwjaNXVSsr1vctQmRtN5WpcSFJCjfAlM0 BenmvqQWvLmXgQi09rlOaw6pDj3RZNOu+GRhA5ZFZTxmpeuXopEmo518MKa+HkE8mmN6UVoE6i6Pb Cu6pU3/8SRZ0DEp7HtQe49rSaGH5Lqb75Nd0z+efamWznZ02EmbD0DzjLxtJIJnWoD5ItIHegEcs2 v5xf6w24RaZSc/kOaZ1PSDpJj8sGrdcpc4arqiQtF5j0bVieS2LDMTJetj3iqFgP4P8HfTK0klXKd uGJpxHtg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k8iBS-0008Ft-Gm; Thu, 20 Aug 2020 10:52:38 +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 58E92305815; Thu, 20 Aug 2020 12:52:36 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 4073E2C38827B; Thu, 20 Aug 2020 12:52:36 +0200 (CEST) Message-ID: <20200820104905.178074795@infradead.org> User-Agent: quilt/0.66 Date: Thu, 20 Aug 2020 12:38:34 +0200 From: Peter Zijlstra To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Kyle Huey , Alexandre Chartre , Robert O'Callahan , "Paul E. McKenney" , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Andy Lutomirski , Josh Poimboeuf , Peter Zijlstra Subject: [RFC][PATCH 2/7] x86/debug: Sync BTF earlier References: <20200820103832.486877479@infradead.org> MIME-Version: 1.0 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 Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/kernel/traps.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -749,6 +749,13 @@ static __always_inline unsigned long deb /* Filter out all the reserved bits which are preset to 1 */ dr6 &= ~DR6_RESERVED; + /* + * The SDM says "The processor clears the BTF flag when it + * generates a debug exception." Clear TIF_BLOCKSTEP to keep + * TIF_BLOCKSTEP in sync with the hardware BTF flag. + */ + clear_thread_flag(TIF_BLOCKSTEP); + return dr6; } @@ -783,13 +790,6 @@ static void handle_debug(struct pt_regs int si_code; /* - * The SDM says "The processor clears the BTF flag when it - * generates a debug exception." Clear TIF_BLOCKSTEP to keep - * TIF_BLOCKSTEP in sync with the hardware BTF flag. - */ - clear_thread_flag(TIF_BLOCKSTEP); - - /* * If DR6 is zero, no point in trying to handle it. The kernel is * not using INT1. */