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,DKIMWL_WL_HIGH, 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 D987FC433ED for ; Fri, 9 Apr 2021 10:55:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 984E1610CF for ; Fri, 9 Apr 2021 10:55:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233615AbhDIKza (ORCPT ); Fri, 9 Apr 2021 06:55:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:49558 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232087AbhDIKz2 (ORCPT ); Fri, 9 Apr 2021 06:55:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617965715; 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=iRvExO2u4w6AmWe5Y0tb/mvT3i84fkN17wDJxZJ/hLs=; b=Ip3vCyi0qopT6pWKemIRJEmL3wLyYWEAPHo6rW0QZp1cOshj60vCAx765fdCow0SBjFyze Zbn+9G/4XV/xqwD44mnyjuX1r19IeXxy3EJ+8x/Rravhf7yvzfBFpf/d9orN3AsSjsocLJ XwV+E1AKMozSjOWtOpRt/WQQ5YuviYA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-320-NBpmevU0PbymDv5HEKTygA-1; Fri, 09 Apr 2021 06:55:12 -0400 X-MC-Unique: NBpmevU0PbymDv5HEKTygA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A2BBD9126D; Fri, 9 Apr 2021 10:55:11 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-112-70.ams2.redhat.com [10.36.112.70]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C1C5219C95; Fri, 9 Apr 2021 10:55:09 +0000 (UTC) From: Florian Weimer To: Ard Biesheuvel Cc: Peter Zijlstra , linux-toolchains@vger.kernel.org, Linux Kernel Mailing List , Josh Poimboeuf , Jason Baron , "Steven Rostedt (VMware)" Subject: Re: static_branch/jump_label vs branch merging References: Date: Fri, 09 Apr 2021 12:55:18 +0200 In-Reply-To: (Ard Biesheuvel's message of "Fri, 9 Apr 2021 11:57:22 +0200") Message-ID: <877dlbzq09.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ard Biesheuvel: > Wouldn't that require the compiler to interpret the contents of the > asm() block? Yes and no. It would require proper toolchain support, so in this case a new ELF relocation type, with compiler, assembler, and linker support to generate those relocations and process them. As far as I understand it, the kernel doesn't do things this way. Thanks, Florian