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=-1.1 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 0253AC38A24 for ; Thu, 7 May 2020 18:04:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C73D12145D for ; Thu, 7 May 2020 18:04:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588874688; bh=T9rkg8uqlS5E7KWzJgD3COhvBHTW96g2v1NcZviUg6k=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=bGA4ZD8go161vBSBgxIaSTnf0+fK+0gGAfB5HUKN978WsYkrlF3WI/J40bWD0mkjG NSHPFba3RuuF5umlmoksrvbEhDDiMwotX0OiqArE8AD9naiit/OxrwOq8nA+/Qjv55 /1a2T9/Z7EveGOTDG9n1zwDZmCQgsPG2f2dOHfec= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728366AbgEGSEs (ORCPT ); Thu, 7 May 2020 14:04:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:58144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728324AbgEGSEr (ORCPT ); Thu, 7 May 2020 14:04:47 -0400 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (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 BDA492145D for ; Thu, 7 May 2020 18:04:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588874687; bh=T9rkg8uqlS5E7KWzJgD3COhvBHTW96g2v1NcZviUg6k=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=wim1l6W3chef9YaxPnPte9jBg7O7X2C0S+yMJ2W/MJsIXE2vKjs2z1x+SpYyDOQUX +I0qKKYVJQ7yqw9eSVUcCpfj8wbSrL3ndjSfZzGmJIvzA0JrIXsIYahOt/bWGMhW6P TaXLHSVd0UWntiK+0d3keJ/c17psVGGCSZk0DgMc= Received: by mail-wm1-f54.google.com with SMTP id 188so7551637wmc.2 for ; Thu, 07 May 2020 11:04:46 -0700 (PDT) X-Gm-Message-State: AGi0PuYasp6CSCZ/O49KZ+nRHt9WUpC+Zaw38OSy9MwjFGsbg87K+7ab quzR9BEPOiPW3sbzZ/yEGZlWKCjygaSYBrD8FuZXaw== X-Google-Smtp-Source: APiQypIc/fzuVPEMb5iaQFfb3GsJ/KtVABEVlHy/7XBj1SRGVAjFihWffkPiWu63VKj0SJuTwDFUfnhMUoClw4MWgN0= X-Received: by 2002:a7b:c5d3:: with SMTP id n19mr4587126wmk.21.1588874685305; Thu, 07 May 2020 11:04:45 -0700 (PDT) MIME-Version: 1.0 References: <20200505131602.633487962@linutronix.de> <20200505134101.525508608@linutronix.de> In-Reply-To: <20200505134101.525508608@linutronix.de> From: Andy Lutomirski Date: Thu, 7 May 2020 11:04:34 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch V4 part 1 35/36] x86: Replace ist_enter() with nmi_enter() To: Thomas Gleixner Cc: LKML , X86 ML , "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , "Peter Zijlstra (Intel)" 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 Tue, May 5, 2020 at 7:14 AM Thomas Gleixner wrote: > > From: Peter Zijlstra > > A few exceptions (like #DB and #BP) can happen at any location in the code, > this then means that tracers should treat events from these exceptions as > NMI-like. The interrupted context could be holding locks with interrupts > disabled for instance. > > Similarly, #MC is an actual NMI-like exception. Is it permissible to send a signal from inside nmi_enter()? I imagine so, but I just want to make sure. --Andy