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=-1.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 3484AC43441 for ; Thu, 29 Nov 2018 19:28:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F2C16213A2 for ; Thu, 29 Nov 2018 19:28:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=amacapital-net.20150623.gappssmtp.com header.i=@amacapital-net.20150623.gappssmtp.com header.b="IhoFbv8d" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F2C16213A2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=amacapital.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726606AbeK3Geu (ORCPT ); Fri, 30 Nov 2018 01:34:50 -0500 Received: from mail-wr1-f66.google.com ([209.85.221.66]:41515 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726192AbeK3Geu (ORCPT ); Fri, 30 Nov 2018 01:34:50 -0500 Received: by mail-wr1-f66.google.com with SMTP id x10so3046569wrs.8 for ; Thu, 29 Nov 2018 11:28:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amacapital-net.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=j/8CjLTyHaB/rJBC5SbC/hOj/Hn7tnCT9tHhW9/lDn4=; b=IhoFbv8d9DaU0u6k37uJWvRE8hTtJj/Zrfz++PFeXSIojr5ByMZXyQbszdvXAIAikB Ev7/4jelSAaMb3rX3j/lZOeRqfKexceCMxoxvfcJ00FvEarxSfNl2Mt8UthTmV5nxTbd S1PKiTQ3XNVUxD7D+IgcYJeD1M5ALN52w9s2lki+8hj6ovjl1w6zy72ak+BTaAdA8GVf GXp6j6lETkcyJ/sklYL37mQEGRdqo7kwfoNy2DDHCaND/Na5/C2pRKktHBrv8iiH/ZlU ZZMpCaIJSHAUk9jMtLsdf0Yktx9Z0jn+uhIYY5kjugvrRYZq/yATn2PQs01Fq+ELLFf7 43LA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=j/8CjLTyHaB/rJBC5SbC/hOj/Hn7tnCT9tHhW9/lDn4=; b=c6n5sLXIk5DjBS3hxo0XsV1Spf9s6BqMzo+MRyU/TR9Xf+wbU1xgy5Xqn7jBSr4J0B Et9G4iYdwd2BG8kg0BmjWT0bsrfVmRs0V9ib4Pc9zpqlwt4fASdyhdP2SbNqmn2RYnGn Ohbqn5iyBTNavMMCY2CX59/FlbbssJEIR87VEa6hCGMbwjyaSKKd18xNrOWNiRnW5JqG cNHLy8YDGcBTa47QKEW1QZU9f67QOs7hlTdQ37q5zX7l1KxL4/ebuva4nkiKRnqgLELi VarW3HeJgE96e5rLftqDYePr/CQU3+wvXq/QrEnURaXGoh6l5YFdcUK80KL38jrLjams SdoQ== X-Gm-Message-State: AA+aEWZfxvJ5MoAYf/BhRJaXvFPsjIDBGobdaw+GRwqiVitQSmVXx5A5 m1E0ZvfPKiPi7jVoXb30t/OBWLO7F1dTFzWDrG0frQ== X-Google-Smtp-Source: AFSGD/VRmOn6pbaZX88jp3CU+n2VA0t44NpYJnbD2FLAXGjEXkiHpPVaQySj8jmV+D1lsEkgHs3O2sJgAkcldRnYvsg= X-Received: by 2002:a5d:5502:: with SMTP id b2mr2601876wrv.330.1543519699206; Thu, 29 Nov 2018 11:28:19 -0800 (PST) MIME-Version: 1.0 References: <20181126160217.GR2113@hirez.programming.kicks-ass.net> <20181129094210.GC2131@hirez.programming.kicks-ass.net> <20181129143853.GO2131@hirez.programming.kicks-ass.net> <20181129163342.tp5wlfcyiazwwyoh@treble> <0A629D30-ADCF-4159-9443-E5727146F65F@amacapital.net> <20181129121307.12393c57@gandalf.local.home> <20181129124404.2fe55dd0@gandalf.local.home> <20181129125857.75c55b96@gandalf.local.home> <20181129134725.6d86ade6@gandalf.local.home> <20181129141648.6ef944a9@gandalf.local.home> In-Reply-To: From: Andy Lutomirski Date: Thu, 29 Nov 2018 11:28:07 -0800 Message-ID: Subject: Re: [PATCH v2 4/4] x86/static_call: Add inline static call implementation for x86-64 To: Linus Torvalds Cc: Steven Rostedt , Josh Poimboeuf , Peter Zijlstra , Andrew Lutomirski , X86 ML , LKML , Ard Biesheuvel , Ingo Molnar , Thomas Gleixner , Masami Hiramatsu , Jason Baron , Jiri Kosina , David Laight , Borislav Petkov , julia@ni.com, jeyu@kernel.org, "H. Peter Anvin" 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 Thu, Nov 29, 2018 at 11:25 AM Linus Torvalds wrote: > > On Thu, Nov 29, 2018 at 11:16 AM Steven Rostedt wrote: > > > > But then we need to implement all numbers of parameters. > > Oh, I agree, it's nasty. > > But it's actually a nastiness that we've solved before. In particular, > with the system call mappings, which have pretty much the exact same > issue of "map unknown number of arguments to registers". > > Yes, it's different - there you map the unknown number of arguments to > a structure access instead. And yes, the macros are unbelievably ugly. > See > > arch/x86/include/asm/syscall_wrapper.h > > and the __MAP() macro from > > include/linux/syscalls.h > > so it's not pretty. But it would solve all the problems. > Until someone does: struct foo foo; static_call(thingy, foo); For syscalls, we know better than to do that. For static calls, I'm less confident.