From patchwork Fri May 1 13:24:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226601 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, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 6EA58C47253 for ; Fri, 1 May 2020 13:46:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DC982051A for ; Fri, 1 May 2020 13:46:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588340773; bh=XjxUPLmaZfpR/Y4FaTxgXOpZTIC1gf1eeU66oXHFRZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=f1ex5lp+4TmT/3PogZUJnQqL513hJnfTYiI+Z/HnKKjZJ7Fh4ZwnPY1JBtRL5NbUA ae6suc/MHEEYwpyGZzP9AjG58/YNjczfbCW1F/CPBDJuLJLqaDCrIc1xE2J0iSGUEg rx7ZIwj0ZVru1q/J1kQ2viG+B9I57NJ3oum08Wm4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731764AbgEANpB (ORCPT ); Fri, 1 May 2020 09:45:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:46362 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731802AbgEANo7 (ORCPT ); Fri, 1 May 2020 09:44:59 -0400 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 61F412051A; Fri, 1 May 2020 13:44:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588340698; bh=XjxUPLmaZfpR/Y4FaTxgXOpZTIC1gf1eeU66oXHFRZ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tBZgV9/mROBZvbKl3wIlRluwtJD10xmnR4kmZ0JwDWv37tfyK5bXSblpSA8syeOYd kl19/i/mYcL8elanNd4H2oN/35+6SauDmw8FTgencqW9gx7l01NEnYK18Npkr36iWW bWSlZZ0swLqneWtyPFa0+/0fEP/92185EM/BQNHc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ilie Halip , Fangrui Song , Mark Rutland , Catalin Marinas , Sasha Levin Subject: [PATCH 5.6 088/106] arm64: Delete the space separator in __emit_inst Date: Fri, 1 May 2020 15:24:01 +0200 Message-Id: <20200501131554.114385744@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131543.421333643@linuxfoundation.org> References: <20200501131543.421333643@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: Fangrui Song [ Upstream commit c9a4ef66450145a356a626c833d3d7b1668b3ded ] In assembly, many instances of __emit_inst(x) expand to a directive. In a few places __emit_inst(x) is used as an assembler macro argument. For example, in arch/arm64/kvm/hyp/entry.S ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN) expands to the following by the C preprocessor: alternative_insn nop, .inst (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 Both comma and space are separators, with an exception that content inside a pair of parentheses/quotes is not split, so the clang integrated assembler splits the arguments to: nop, .inst, (0xd500401f | ((0) << 16 | (4) << 5) | ((!!1) << 8)), 4, 1 GNU as preprocesses the input with do_scrub_chars(). Its arm64 backend (along with many other non-x86 backends) sees: alternative_insn nop,.inst(0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # .inst(...) is parsed as one argument while its x86 backend sees: alternative_insn nop,.inst (0xd500401f|((0)<<16|(4)<<5)|((!!1)<<8)),4,1 # The extra space before '(' makes the whole .inst (...) parsed as two arguments The non-x86 backend's behavior is considered unintentional (https://sourceware.org/bugzilla/show_bug.cgi?id=25750). So drop the space separator inside `.inst (...)` to make the clang integrated assembler work. Suggested-by: Ilie Halip Signed-off-by: Fangrui Song Reviewed-by: Mark Rutland Link: https://github.com/ClangBuiltLinux/linux/issues/939 Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin --- arch/arm64/include/asm/sysreg.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index b91570ff9db14..931037500e83c 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -49,7 +49,9 @@ #ifndef CONFIG_BROKEN_GAS_INST #ifdef __ASSEMBLY__ -#define __emit_inst(x) .inst (x) +// The space separator is omitted so that __emit_inst(x) can be parsed as +// either an assembler directive or an assembler macro argument. +#define __emit_inst(x) .inst(x) #else #define __emit_inst(x) ".inst " __stringify((x)) "\n\t" #endif