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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D391CC77B73 for ; Tue, 30 May 2023 19:55:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vuFk8ttGUswRhIqAUg1wXyW+SqCmZ12B6KJd7hsKinc=; b=gC5E8XJ8yGuyEz ldBEpTghBrkqOr/AtEWS6qTraGOhANqOAwfqqJ0IX4WYkBARP0WgOkmEIJiEaW7g5ZlBq7P6SkSfO LRAyINNN3arwdl12Jdn2ZkC+nlozVvih4gb0IGfkg26fHfsT9UsC8oHhLxjtK8fdaBFFrNmo8/gZP T6fPsuPl18OdB3N4HB5r5Wg0BwJYPJrcLGXl4nZX8RvMjQYrsDsVpfU/txn5LqybiYziJR7gmcJp8 QIdY/lMoF74xFx2JuPt7YZXb7dV60XnYaBMOfJuAv3EUFoBfdb6gUdsuuU3bQzjljETqZ+iKvqu9e O6eK3yrHK4tKsBZX0A+g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q45Qr-00F2O2-31; Tue, 30 May 2023 19:55:01 +0000 Received: from out-15.mta0.migadu.com ([91.218.175.15]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1q45Qo-00F2Mr-2H for linux-arm-kernel@lists.infradead.org; Tue, 30 May 2023 19:55:00 +0000 Date: Tue, 30 May 2023 19:54:51 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1685476495; 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=htwngbgIM6ZN3m6ZvTP5t2aYi4SJcXt18PpdVgVHy80=; b=Nwl2017bgJ899tFHJGB9HffKOzY3lgGKfnWiGeFSxr5rZCDIHtgQL/uvnQ9zbnW80mmi7w 4Ls9VxkU7VgpAQ3DwWx8PgiwSRxnWknxVEk4+ZOg13JRGX94IrtSeYqxTTtdJN3FMqThqX q4QsyL705SyPIvgUeorNLzAnkXgbXBo= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Marc Zyngier Cc: kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, James Morse , Suzuki K Poulose , Zenghui Yu , Quentin Perret , Will Deacon , Fuad Tabba Subject: Re: [PATCH v2 02/17] arm64: Prevent the use of is_kernel_in_hyp_mode() in hypervisor code Message-ID: References: <20230526143348.4072074-1-maz@kernel.org> <20230526143348.4072074-3-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230526143348.4072074-3-maz@kernel.org> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230530_125459_152596_EC7F893F X-CRM114-Status: GOOD ( 17.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Marc, On Fri, May 26, 2023 at 03:33:33PM +0100, Marc Zyngier wrote: > Using is_kernel_in_hyp_mode() in hypervisor code is a pretty bad > mistake. This helper only checks for CurrentEL being EL2, which > is always true. > > Make the link fail if using the helper in hypervisor context > by referencing a non-existent function. Whilst we're at it, > flag the helper as __always_inline, which it really should be. > > Signed-off-by: Marc Zyngier > --- > arch/arm64/include/asm/virt.h | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h > index 4eb601e7de50..91029709d133 100644 > --- a/arch/arm64/include/asm/virt.h > +++ b/arch/arm64/include/asm/virt.h > @@ -110,8 +110,13 @@ static inline bool is_hyp_mode_mismatched(void) > return __boot_cpu_mode[0] != __boot_cpu_mode[1]; > } > > -static inline bool is_kernel_in_hyp_mode(void) > +extern void gotcha_is_kernel_in_hyp_mode(void); > + > +static __always_inline bool is_kernel_in_hyp_mode(void) > { > +#if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__) > + gotcha_is_kernel_in_hyp_mode(); > +#endif > return read_sysreg(CurrentEL) == CurrentEL_EL2; > } Would BUILD_BUG() work in this context, or have I missed something? -- Thanks, Oliver _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel