From patchwork Mon Aug 8 12:53:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12938763 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 BA0BBC00140 for ; Mon, 8 Aug 2022 12:54:51 +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:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=DUQ2AIkEwwbfz95h9TxKwnIj7kEgEKEEsFWW9x9jM0Y=; b=tGtvZ+h7fRVZSK FYIrf0QNfD3L36rbUQLTQS8PwlEbIZsfJPBpPcQ2SvqSC3DPN9sQoGBq2MEiX3FabpvVWEdIHYtSj gGGrhYrwyOhj8VCVP83Aid8pif+2l+qfWBff+/BDNNh3giL86reUSnyWUYjoTq9jB7fVph/M1ci30 z2Ig/AJt9/ZvwRtz86ifK8M4qIyw493IYh5wIexaQ1S3oW37T4F0O7PxVDnlSxryiDh6S4KNTRo6w w9cEtr+KINJge1HZn+dXBMwBR3955mNikZbyiVaW/+Si15UsEJNSN3fJ6f4VP13ZtYHyoRn19uy1R YILofoBddHKiOQt+bMjA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oL2GK-00Dr4q-5N; Mon, 08 Aug 2022 12:53:40 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oL2GF-00Dr1a-Js for linux-arm-kernel@lists.infradead.org; Mon, 08 Aug 2022 12:53:37 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 1703EB80E84; Mon, 8 Aug 2022 12:53:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A0DBC433C1; Mon, 8 Aug 2022 12:53:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659963208; bh=BmIftkQ0BzMbYotXaR2i1XOZ3mRUNcoQMmDFYPC3egk=; h=From:To:Cc:Subject:Date:From; b=it47u2D7EoHexGB/oK8cSgI70d1TB6ZsbijH1HlcDoPkhIJDbi0ft6HozazrLV81w PAwjUsSiUuMqF/Fu2EPsUdMsFK4GmXI5j4sCJLUI4trb62OR1aBXgBX5LUlNDgEkB1 FDBbBETMuJBrldDoLXN+4tunfy3AM0TNyhf+Dw2pTpWjhrcW0fqVa6eMyNeu0yB7mr uTLM9VwEIX0weCL1hUyqJpdREBd7+AvuvN4sxoisIJm6mJ/f7TlYDDWa9fOXuQllLB WRx9XgVp2uPb/S1ho98dr1kGk+zna+Ign4CWeMco0eQ4jYOPLvztVdU90pTOM6Yloc dRzNXRM+Hjoug== From: Will Deacon To: gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Peter Collingbourne , stable@vger.kernel.org, Will Deacon , Ard Biesheuvel , Catalin Marinas Subject: [PATCH][for-stable] arm64: set UXN on swapper page tables Date: Mon, 8 Aug 2022 13:53:21 +0100 Message-Id: <20220808125321.32598-1-will@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220808_055335_828103_B1DC2EE9 X-CRM114-Status: GOOD ( 14.41 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Peter Collingbourne [ This issue was fixed upstream by accident in c3cee924bd85 ("arm64: head: cover entire kernel image in initial ID map") as part of a large refactoring of the arm64 boot flow. This simple fix is therefore preferred for -stable backporting ] On a system that implements FEAT_EPAN, read/write access to the idmap is denied because UXN is not set on the swapper PTEs. As a result, idmap_kpti_install_ng_mappings panics the kernel when accessing __idmap_kpti_flag. Fix it by setting UXN on these PTEs. Fixes: 18107f8a2df6 ("arm64: Support execute-only permissions with Enhanced PAN") Cc: # 5.15 Link: https://linux-review.googlesource.com/id/Ic452fa4b4f74753e54f71e61027e7222a0fae1b1 Signed-off-by: Peter Collingbourne Acked-by: Will Deacon Cc: Ard Biesheuvel Cc: Catalin Marinas Link: https://lore.kernel.org/r/20220719234909.1398992-1-pcc@google.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/kernel-pgtable.h | 4 ++-- arch/arm64/kernel/head.S | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h index 96dc0f7da258..a971d462f531 100644 --- a/arch/arm64/include/asm/kernel-pgtable.h +++ b/arch/arm64/include/asm/kernel-pgtable.h @@ -103,8 +103,8 @@ /* * Initial memory map attributes. */ -#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) -#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) +#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED | PTE_UXN) +#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S | PMD_SECT_UXN) #if ARM64_KERNEL_USES_PMD_MAPS #define SWAPPER_MM_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 6a98f1a38c29..8a93a0a7489b 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -285,7 +285,7 @@ SYM_FUNC_START_LOCAL(__create_page_tables) subs x1, x1, #64 b.ne 1b - mov x7, SWAPPER_MM_MMUFLAGS + mov_q x7, SWAPPER_MM_MMUFLAGS /* * Create the identity mapping.