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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6D1D0C2BA19 for ; Tue, 14 Apr 2020 16:17:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4917120678 for ; Tue, 14 Apr 2020 16:17:02 +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="lWJKpyVs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391346AbgDNQQ5 (ORCPT ); Tue, 14 Apr 2020 12:16:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2390547AbgDNQQr (ORCPT ); Tue, 14 Apr 2020 12:16:47 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFD65C061A0C for ; Tue, 14 Apr 2020 09:16:47 -0700 (PDT) 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; bh=r8fDQKggXKxqP/PULk16XmyAUlc/RU4HQ2YTQKZ3Wuw=; b=lWJKpyVsLnE+APPi6xA1HuX0CI fteOch0wMZnrqVUoewWwfdpujygcw0fietYLplQN55DLyduy4e2MXF2swkeuhXKbZAwzqg3Z1WWEm SXAI96rSiBoXD/hWJmgsbnjyryUAGnFBz867ne/k+zQWKGwcysZRP1RbVeIFMKHgZTuRmRDhdNZBS 65IJLFhqaAthdcQTjuyTQsazgumm4poc4VI1OL9KpRpFe3rudyAWWp8mgbo/+sdItYfllVhfdKF2r g9kyfhO3TjjUaAlxJYiAs7MBA9gPZuiU2uY3msY1cYRZHtM5bkYuFFne+2mSAzIcyN2TxlnkZWGO9 3QwHmefA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOOEp-0000my-OM; Tue, 14 Apr 2020 16:16:39 +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 E534F304D58; Tue, 14 Apr 2020 18:16:36 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D47E72B22FBEF; Tue, 14 Apr 2020 18:16:36 +0200 (CEST) Date: Tue, 14 Apr 2020 18:16:36 +0200 From: Peter Zijlstra To: Alexandre Chartre Cc: x86@kernel.org, linux-kernel@vger.kernel.org, jpoimboe@redhat.com, jthierry@redhat.com, tglx@linutronix.de Subject: Re: [PATCH V3 5/9] objtool: Add return address unwind hints Message-ID: <20200414161636.GP20713@hirez.programming.kicks-ass.net> References: <20200414103618.12657-1-alexandre.chartre@oracle.com> <20200414103618.12657-6-alexandre.chartre@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200414103618.12657-6-alexandre.chartre@oracle.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 14, 2020 at 12:36:14PM +0200, Alexandre Chartre wrote: > Add the UNWIND_HINT_RADDR_DELETE and UNWIND_HINT_RADDR_ALTER unwind > hint macros to flag instructions which remove or modify return > addresses. I'm confused by this thing; why? AFAICT the rest of the patches are actually simpler without this one.