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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0A5DC43334 for ; Tue, 19 Jul 2022 23:49:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229585AbiGSXtY (ORCPT ); Tue, 19 Jul 2022 19:49:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229565AbiGSXtW (ORCPT ); Tue, 19 Jul 2022 19:49:22 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90A8B43E6D for ; Tue, 19 Jul 2022 16:49:21 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-31e60b8bb07so19857287b3.1 for ; Tue, 19 Jul 2022 16:49:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=Po9Y/gTzarxHrhYTITOFvy2JwCB88ahX2IAz9RZr3y8=; b=CBu2FxXInNBIGTHwxBQtN5BTaJRj7DzoWL4LiKBMXadUQbInajt5azKCCiPzvAQ2J9 CVjHorJd7GhmvuW+i3r5vx7Ts7ORtSrQRK5lkPKjyAWwsKDXXgzjUxUqd5Cm7QZRadoj I/5wl2Gdb2OS9eYMPLprZwp0dyEzNeIU818n4HNyVB/FvhgZtHUX0/B0HhZBFfcfl/2V GQFkwSL4KPAzxWPurFrezGFbWZNdNhXKzINPET3WMavcLTlDaaFAVqhlq6s8Eje3laRB iyxpICNm3o2cFMK0uXovPZy50k6nWEo+CRYAy+db/Q8jGblRWoqBy47K71sPfYSu/lMj 8z6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=Po9Y/gTzarxHrhYTITOFvy2JwCB88ahX2IAz9RZr3y8=; b=Fq/BSR32j2551rAfFrcKt7jRzUdNYgRTxoxRltXz4rvS8ZdY7Ni0abjJANDtTswyf8 /4kbvhPOuqDSw1y91uRLjxt7uW3L64d6cnN7x78I3fLEuepnhb0OF57Qs7Zij1Vjwi5t nROpADZKf+30mCu6EUDDfl8+4sPqCOcG9QzSUH4iKSjiPjdkGhkySNDuQl+H8eUBAa+v 2Lli+6DmymZwnpfvlrQEew50uSO1WY9uP9QjR6bij94gZo457sPkKfA/EOJ+hbi1wg9m 7KA11myoFk1B7+nRbTlIZYJIdcvIQzIycrMceMY7FX951DadpD7A089J5g8qWFZeqrFB ZlbA== X-Gm-Message-State: AJIora8g6pIQIWKPkA4L+8keJDEXh9HqRNC1/o83Rd7pinhbSm/CbIwm RXerGrFFc3+DkeHXi7RadHu4rzs= X-Google-Smtp-Source: AGRyM1uaSZq7mthNo3vJmYZMkFYqfacvzy6A82uZNxJZGnURkqGX0BU/D616Fm+/JRRyoh8h3aWTqE0= X-Received: from pcc-desktop.svl.corp.google.com ([2620:15c:2ce:200:966b:4dac:ab6b:a57a]) (user=pcc job=sendgmr) by 2002:a81:a102:0:b0:31e:6264:3c3c with SMTP id y2-20020a81a102000000b0031e62643c3cmr4235308ywg.476.1658274560855; Tue, 19 Jul 2022 16:49:20 -0700 (PDT) Date: Tue, 19 Jul 2022 16:49:09 -0700 Message-Id: <20220719234909.1398992-1-pcc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.37.0.170.g444d1eabd0-goog Subject: [PATCH] arm64: set UXN on swapper page tables From: Peter Collingbourne To: Will Deacon Cc: Peter Collingbourne , Marc Zyngier , linux-arm-kernel@lists.infradead.org, Catalin Marinas , stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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 --- This fix is no longer needed since commit c3cee924bd85 ("arm64: head: cover entire kernel image in initial ID map"), which moved __idmap_kpti_flag to .data, but that commit is currently only present in next. 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. -- 2.37.0.170.g444d1eabd0-goog