From patchwork Mon May 18 17:36:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 225841 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 29012C433E0 for ; Mon, 18 May 2020 17:46:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0217220835 for ; Mon, 18 May 2020 17:46:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589824010; bh=1IxgM8qSTOEdrK1L9TS8wCO2BnquIDeqgkd91GqoSFY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=AqVNjC0aaAk/VoQ/g0MZY/LiEJYq/WW8BfhXLshHuaCK0DieWWCw73CPc80SWrryn G9RnwA0eWWyBxDKL/jHez+VtGbImAQfYUvySZFCtlCpgGjCjOaHWnSdscO2d/ichU1 kDV/ZaYNum29qy/ms+6DwZ+atB0wyf821NNMxc3Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730135AbgERRqs (ORCPT ); Mon, 18 May 2020 13:46:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:46632 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730123AbgERRqo (ORCPT ); Mon, 18 May 2020 13:46:44 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8A1A120715; Mon, 18 May 2020 17:46:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589824004; bh=1IxgM8qSTOEdrK1L9TS8wCO2BnquIDeqgkd91GqoSFY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xm6TcISxypH8/w75zPTNGTZEohsVw4/gKJz5i58314tmVyCh0ZeYu0bwh5MqYV8qO xA67rFr07nO3uJyyBvrb7KNCI2CTsmnwuzO0UqqLg9cY2KfhWnD1BlZ7l+qywithdn hjHVsKYcFiuzSlcqv5cw0s8HiGRbcGn1GhiT9rVg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miroslav Benes , Josh Poimboeuf , Ingo Molnar , Andy Lutomirski , Dave Jones , Jann Horn , Peter Zijlstra , Thomas Gleixner , Vince Weaver Subject: [PATCH 4.14 031/114] x86/unwind/orc: Dont skip the first frame for inactive tasks Date: Mon, 18 May 2020 19:36:03 +0200 Message-Id: <20200518173509.357209406@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173503.033975649@linuxfoundation.org> References: <20200518173503.033975649@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Miroslav Benes commit f1d9a2abff66aa8156fbc1493abed468db63ea48 upstream. When unwinding an inactive task, the ORC unwinder skips the first frame by default. If both the 'regs' and 'first_frame' parameters of unwind_start() are NULL, 'state->sp' and 'first_frame' are later initialized to the same value for an inactive task. Given there is a "less than or equal to" comparison used at the end of __unwind_start() for skipping stack frames, the first frame is skipped. Drop the equal part of the comparison and make the behavior equivalent to the frame pointer unwinder. Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder") Reviewed-by: Miroslav Benes Signed-off-by: Miroslav Benes Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Andy Lutomirski Cc: Dave Jones Cc: Jann Horn Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vince Weaver Link: https://lore.kernel.org/r/7f08db872ab59e807016910acdbe82f744de7065.1587808742.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/unwind_orc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -574,7 +574,7 @@ void __unwind_start(struct unwind_state /* Otherwise, skip ahead to the user-specified starting frame: */ while (!unwind_done(state) && (!on_stack(&state->stack_info, first_frame, sizeof(long)) || - state->sp <= (unsigned long)first_frame)) + state->sp < (unsigned long)first_frame)) unwind_next_frame(state); return;