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=-1.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 2B801C433DF for ; Thu, 14 May 2020 04:31:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E434206C0 for ; Thu, 14 May 2020 04:31:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589430708; bh=zl3jEjDdHHsLyqPz83LYn1KOjUo1N49J7Zaj/EbrBrg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=1ulX1520X6VDnMiPgNHhIZ9w+QcZd/uW3MfnBcXyAkGfqVTXHiGeHqbFIN8LEt22z IDLgWgVbRynwaAao3ReQgSXHWuFsYel+WqBNfURGxIe3eL8xr8XoQsbW+Ufu96Cw4f CjLct/TZaD7vFfEv398FU/fu0bS52XLuLxN/Z384= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725954AbgENEbr (ORCPT ); Thu, 14 May 2020 00:31:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:55880 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725788AbgENEbq (ORCPT ); Thu, 14 May 2020 00:31:46 -0400 Received: from mail-wm1-f43.google.com (mail-wm1-f43.google.com [209.85.128.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DDE9120748 for ; Thu, 14 May 2020 04:31:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589430706; bh=zl3jEjDdHHsLyqPz83LYn1KOjUo1N49J7Zaj/EbrBrg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=cj7XNy68bRQOX0yKQ7mNNsvaoADyu+6qVLjA/ObAbTtbM0EqQVhz/Rwz9eS66x+ED RfY8wHCR8tJqFSDCDOZPyGqY5rJPAnUSwNe3/UJ8nvdxaaKoiPDvK5o/DCPSTqmrnr cIlYWsvDyyh0dbEZJn/bPcNAMvLfQUAGsXOJSowc= Received: by mail-wm1-f43.google.com with SMTP id y24so30888148wma.4 for ; Wed, 13 May 2020 21:31:45 -0700 (PDT) X-Gm-Message-State: AGi0PuYUwrjmgve5bskBFf4wJO8jOmY2KsMCmuxgi/1t72DNtcWWyZDI QZAZm7OXTw6dmeGQtUXhdNFoiIPpDKOdkmsCWBLxpQ== X-Google-Smtp-Source: APiQypKbysOY3c+gRinfdq+0VIiJqMYY2wb7uUD0pUgiMjMcdGzgM04OMfBPR6FZ4oc89Yhiyx5Vyk6UcvZbzQ03LIY= X-Received: by 2002:a05:600c:2299:: with SMTP id 25mr25570949wmf.138.1589430704269; Wed, 13 May 2020 21:31:44 -0700 (PDT) MIME-Version: 1.0 References: <20200505134354.774943181@linutronix.de> <20200505134904.166735365@linutronix.de> <835459920.20630.1589420674977.JavaMail.zimbra@efficios.com> In-Reply-To: <835459920.20630.1589420674977.JavaMail.zimbra@efficios.com> From: Andy Lutomirski Date: Wed, 13 May 2020 21:31:32 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch V4 part 3 09/29] x86/entry/32: Provide macro to emit IDT entry stubs To: Mathieu Desnoyers Cc: Thomas Gleixner , linux-kernel , x86 , paulmck , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , rostedt , "Joel Fernandes, Google" , Boris Ostrovsky , Juergen Gross , Brian Gerst , Josh Poimboeuf , Will Deacon 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 On Wed, May 13, 2020 at 6:44 PM Mathieu Desnoyers wrote: > > ----- On May 5, 2020, at 9:44 AM, Thomas Gleixner tglx@linutronix.de wrote: > > [...] > > > +.macro idtentry vector asmsym cfunc has_error_code:req sane=0 > > +SYM_CODE_START(\asmsym) > > + ASM_CLAC > > + cld > > Looking at the various interrupt and trap entry points for 32 and 64-bit > x86, I notice a lack of consistency in use of the following instruction > sequence at the asm entry point: > > - ASM_CLAC, > - cld (clear direction flag). > > Are they always needed, or only for interrupt handlers ? They're needed for all entries except SYSCALL, but they're hidden inside helpers in many cases.