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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 71503C433DB for ; Tue, 9 Feb 2021 15:13:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D93464EB8 for ; Tue, 9 Feb 2021 15:13:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232395AbhBIPNW (ORCPT ); Tue, 9 Feb 2021 10:13:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232069AbhBIPNR (ORCPT ); Tue, 9 Feb 2021 10:13:17 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 466BDC061786 for ; Tue, 9 Feb 2021 07:12:37 -0800 (PST) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1612883555; 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=jWkC5nvDedOQcOGLRZAcnUf5BoS6QiBKxlVWMLT7CHM=; b=QGqKYYWnMA3mU43y2z7xvEqbZJbKvxBwkXGsBXae4OM90NZ3eGQqXWDM+E0OMOpsEBCzlh VJl5V67Wv3K8g73t9MZCDH8biIf1lXbgq3O6g6VrhR4Jr0P4kFiYOu3szJuxSb3kf9YToK nz6m5DusbGscbbWu5LyFha9CC4yH1AkTfqjBW+RdGUXF0Rd6wyWQZhZ5wSAja9MokHNo5C yuxYSGToLrJdbfSNLhjxEioTUe4sJsKFONt8x52y9KatkS4o37xnzSjfOKDwWrxMCOsB8I i9rrkxldIw4aEl+WUtFAaHl/Bly9+OBhVLWIABEh2Kj3oEhRWH2qyJYLpbG4Kg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1612883555; 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=jWkC5nvDedOQcOGLRZAcnUf5BoS6QiBKxlVWMLT7CHM=; b=Cpkjvk2fNjX4Xz21a2VIDvEz8oMpKWvUynhgIyef9vNg4bOneDvTt78kMOq+YLuwL1ZwLJ on4hL77BsZcwcgBQ== To: Josh Poimboeuf Cc: LKML , x86@kernel.org, Kees Cook Subject: Re: [patch 05/12] x86/irq: Provide macro for inlining irq stack switching In-Reply-To: <20210208204209.yccd76j7sp2zbv37@treble> References: <20210204204903.350275743@linutronix.de> <20210204211154.618389756@linutronix.de> <20210208204209.yccd76j7sp2zbv37@treble> Date: Tue, 09 Feb 2021 16:12:33 +0100 Message-ID: <87zh0db7ha.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 08 2021 at 14:42, Josh Poimboeuf wrote: > On Thu, Feb 04, 2021 at 09:49:08PM +0100, Thomas Gleixner wrote: >> #ifdef CONFIG_X86_64 >> + >> +#ifdef CONFIG_UNWINDER_FRAME_POINTER >> +# define IRQSTACK_CALL_CONSTRAINT , ASM_CALL_CONSTRAINT >> +#else >> +# define IRQSTACK_CALL_CONSTRAINT >> +#endif > > Is this really needed? i.e. does ASM_CALL_CONSTRAINT actually affect > code generation with !FRAME_POINTER? The problem is that if the asm inline is the first operation in a function some compilers insert the asm inline before setting up the frame pointer. That's actualy irrelevant here as the compiler cannot reorder against the C code leading to the asm inline. So we can probably replace it with a big fat comment. Thanks, tglx