From patchwork Thu Feb 27 13:36:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 230507 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=-14.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 7449FC3F34A for ; Thu, 27 Feb 2020 13:49:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B444246A1 for ; Thu, 27 Feb 2020 13:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582811365; bh=PDMbmD8Sqlz13ShwSV+5MvJr2JPo+gqZP1cUKJNWXDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oaNTIZ0A4LfaZDvI8pQWJVIb+jkMTx6jdSEzv154HUYR0ANTIsH6mzEV6A42Cg3Ie muiXwiSQymKg+/0N/wfoNS/zCKjkcwy9CGC9YxwA7zRn3rWuYAtaE+k91S7S8BL2+b NBhp/75u2qau6ZqBtK5xjEsZ25CI/rzlpeyc0nlk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731035AbgB0NtX (ORCPT ); Thu, 27 Feb 2020 08:49:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:46712 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731031AbgB0NtW (ORCPT ); Thu, 27 Feb 2020 08:49:22 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AB12D20801; Thu, 27 Feb 2020 13:49:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582811362; bh=PDMbmD8Sqlz13ShwSV+5MvJr2JPo+gqZP1cUKJNWXDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YkgbL/xIpPqy0Kee3LzViMhDWfXZ623Kql7BAIluZo/9miTCOaxHtz7zBTW3Nsww3 QqYPmlFhFvMdEeoawoWNfBTHWxiL00DuU6cenS6SFk5tc+Zj1WkAb8vloPn9IM3jgw vVUGyrwsDfwjsBFwOny1vQl6TtIvnhp58ta7Xsk8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sami Tolvanen , Nick Desaulniers , Kees Cook , Will Deacon , Sasha Levin Subject: [PATCH 4.9 086/165] arm64: fix alternatives with LLVMs integrated assembler Date: Thu, 27 Feb 2020 14:36:00 +0100 Message-Id: <20200227132243.866507491@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132230.840899170@linuxfoundation.org> References: <20200227132230.840899170@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sami Tolvanen [ Upstream commit c54f90c2627cc316d365e3073614731e17dbc631 ] LLVM's integrated assembler fails with the following error when building KVM: :12:6: error: expected absolute expression .if kvm_update_va_mask == 0 ^ :21:6: error: expected absolute expression .if kvm_update_va_mask == 0 ^ :24:2: error: unrecognized instruction mnemonic NOT_AN_INSTRUCTION ^ LLVM ERROR: Error parsing inline asm These errors come from ALTERNATIVE_CB and __ALTERNATIVE_CFG, which test for the existence of the callback parameter in inline assembly using the following expression: " .if " __stringify(cb) " == 0\n" This works with GNU as, but isn't supported by LLVM. This change splits __ALTERNATIVE_CFG and ALTINSTR_ENTRY into separate macros to fix the LLVM build. Link: https://github.com/ClangBuiltLinux/linux/issues/472 Signed-off-by: Sami Tolvanen Tested-by: Nick Desaulniers Reviewed-by: Kees Cook Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/include/asm/alternative.h | 32 ++++++++++++++++++---------- 1 file changed, 21 insertions(+), 11 deletions(-) diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h index 7e842dcae4509..3626655175a2e 100644 --- a/arch/arm64/include/asm/alternative.h +++ b/arch/arm64/include/asm/alternative.h @@ -29,13 +29,16 @@ typedef void (*alternative_cb_t)(struct alt_instr *alt, void __init apply_alternatives_all(void); void apply_alternatives(void *start, size_t length); -#define ALTINSTR_ENTRY(feature,cb) \ +#define ALTINSTR_ENTRY(feature) \ " .word 661b - .\n" /* label */ \ - " .if " __stringify(cb) " == 0\n" \ " .word 663f - .\n" /* new instruction */ \ - " .else\n" \ + " .hword " __stringify(feature) "\n" /* feature bit */ \ + " .byte 662b-661b\n" /* source len */ \ + " .byte 664f-663f\n" /* replacement len */ + +#define ALTINSTR_ENTRY_CB(feature, cb) \ + " .word 661b - .\n" /* label */ \ " .word " __stringify(cb) "- .\n" /* callback */ \ - " .endif\n" \ " .hword " __stringify(feature) "\n" /* feature bit */ \ " .byte 662b-661b\n" /* source len */ \ " .byte 664f-663f\n" /* replacement len */ @@ -56,15 +59,14 @@ void apply_alternatives(void *start, size_t length); * * Alternatives with callbacks do not generate replacement instructions. */ -#define __ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg_enabled, cb) \ +#define __ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg_enabled) \ ".if "__stringify(cfg_enabled)" == 1\n" \ "661:\n\t" \ oldinstr "\n" \ "662:\n" \ ".pushsection .altinstructions,\"a\"\n" \ - ALTINSTR_ENTRY(feature,cb) \ + ALTINSTR_ENTRY(feature) \ ".popsection\n" \ - " .if " __stringify(cb) " == 0\n" \ ".pushsection .altinstr_replacement, \"a\"\n" \ "663:\n\t" \ newinstr "\n" \ @@ -72,17 +74,25 @@ void apply_alternatives(void *start, size_t length); ".popsection\n\t" \ ".org . - (664b-663b) + (662b-661b)\n\t" \ ".org . - (662b-661b) + (664b-663b)\n" \ - ".else\n\t" \ + ".endif\n" + +#define __ALTERNATIVE_CFG_CB(oldinstr, feature, cfg_enabled, cb) \ + ".if "__stringify(cfg_enabled)" == 1\n" \ + "661:\n\t" \ + oldinstr "\n" \ + "662:\n" \ + ".pushsection .altinstructions,\"a\"\n" \ + ALTINSTR_ENTRY_CB(feature, cb) \ + ".popsection\n" \ "663:\n\t" \ "664:\n\t" \ - ".endif\n" \ ".endif\n" #define _ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg, ...) \ - __ALTERNATIVE_CFG(oldinstr, newinstr, feature, IS_ENABLED(cfg), 0) + __ALTERNATIVE_CFG(oldinstr, newinstr, feature, IS_ENABLED(cfg)) #define ALTERNATIVE_CB(oldinstr, cb) \ - __ALTERNATIVE_CFG(oldinstr, "NOT_AN_INSTRUCTION", ARM64_CB_PATCH, 1, cb) + __ALTERNATIVE_CFG_CB(oldinstr, ARM64_CB_PATCH, 1, cb) #else #include