From patchwork Wed Oct 2 18:00:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 11171735 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4740676 for ; Wed, 2 Oct 2019 18:02:33 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2B5AF21848 for ; Wed, 2 Oct 2019 18:02:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B5AF21848 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iFivn-0005HJ-B6; Wed, 02 Oct 2019 18:00:55 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iFivm-0005H8-7h for xen-devel@lists.xenproject.org; Wed, 02 Oct 2019 18:00:54 +0000 X-Inumbo-ID: 934094e2-e53e-11e9-b588-bc764e2007e4 Received: from foss.arm.com (unknown [217.140.110.172]) by localhost (Halon) with ESMTP id 934094e2-e53e-11e9-b588-bc764e2007e4; Wed, 02 Oct 2019 18:00:53 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2BFC41597; Wed, 2 Oct 2019 11:00:53 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 41EEF3F706; Wed, 2 Oct 2019 11:00:52 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Wed, 2 Oct 2019 19:00:42 +0100 Message-Id: <20191002180047.17144-2-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20191002180047.17144-1-julien.grall@arm.com> References: <20191002180047.17144-1-julien.grall@arm.com> Subject: [Xen-devel] [PATCH for-4.13 1/6] xen/arm: fix get_cpu_info() when built with clang X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Artem_Mygaiev@epam.com, Volodymyr Babchuk , Julien Grall , Stefano Stabellini , Julien Grall MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Clang understands the GCCism in use here, but still complains that sp is unitialised. In such cases, resort to the older versions of this code, which directly read sp into the temporary variable. Note that GCCism is still kept in default because other compilers (e.g. clang) may also define __GNUC__, so AFAIK there are no proper way to detect properly GCC. This means that in the event Xen is ported to a new compiler, the code will need to be updated. But that likely not going to be the only place where Xen will need to be adapted... This is based on the x86 counterpart. Signed-off-by: Julien Grall Acked-by: Stefano Stabellini --- Changes in v2: - Update the commit message to explain the ordering in the code. - Add Stefano's acked-by --- xen/include/asm-arm/current.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/xen/include/asm-arm/current.h b/xen/include/asm-arm/current.h index 1653e89d30..80503578cf 100644 --- a/xen/include/asm-arm/current.h +++ b/xen/include/asm-arm/current.h @@ -28,8 +28,16 @@ struct cpu_info { static inline struct cpu_info *get_cpu_info(void) { +#ifdef __clang__ + unsigned long sp; + + asm ("mov %0, sp" : "=r" (sp)); +#else register unsigned long sp asm ("sp"); - return (struct cpu_info *)((sp & ~(STACK_SIZE - 1)) + STACK_SIZE - sizeof(struct cpu_info)); +#endif + + return (struct cpu_info *)((sp & ~(STACK_SIZE - 1)) + + STACK_SIZE - sizeof(struct cpu_info)); } #define guest_cpu_user_regs() (&get_cpu_info()->guest_cpu_user_regs)