From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-13.7 required=5.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id D0D087D089 for ; Tue, 6 Nov 2018 17:32:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389815AbeKGC5U (ORCPT ); Tue, 6 Nov 2018 21:57:20 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:55370 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389759AbeKGC5S (ORCPT ); Tue, 6 Nov 2018 21:57:18 -0500 Received: by mail-wm1-f67.google.com with SMTP id s10-v6so11869339wmc.5 for ; Tue, 06 Nov 2018 09:31:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gQItUgY2gYwGKzTfMCUdpYoluo1ZEefUN3xekUmwX5I=; b=NCUfaakydyP1mEvjAcq8JqZWWvdcWMF4TaNfXTuOsryR1QLHPetRjJptGyLqia1LZ+ Ez1ekzw0lIFJ5zjJ3XMv0NGNc/pM04k26s037zRcMLaiQu2rwvOojgssKOv9bj3TUkKH j4LlZXbpr2MmixQik019u26VRZ068PYuvDqTRX00emE+RaLbDhlG9S3rqgy+rfR84VN8 vHzyWrq2sL6WmXv0GqN3HiTlTzotv9mWtuiirsp2rfxQyxAocP1ytm9By7vHNEzCp7pn UCA1eM2qOccn1KI00dbkHUrGtgR+uj1A6jGQc30kzEZb/2SowEoFdUPv7lcsBaxlqWRD 26Uw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gQItUgY2gYwGKzTfMCUdpYoluo1ZEefUN3xekUmwX5I=; b=dbWC67aSqK3Rb+/cTjHbbmbaKUSn8qa82zkyIHEFqw4vy8JOmGXLWCW5q/Dd0rPDdb UlyEX8UoPOgpAhh9hZz4bGGpoD+k5t5f/8cPbpS/zzZJJRZulkmR5jWblO0xmPoV38T/ HiSzi9UbzRRTGUXYBfkdo0nk7NQkoYYMRagLgPsJZM+SoG0Xp/AyJoXsOzxpSOlTFusj lQ/5A87gsPP2iRwZIB9VvtsRW7ByOgbGqtILwwKiQJFrUitZEbXf4iDGdzI/ZDOjdLTO zqcce6i0vzGhKYX2FwH/uKSAF+1Oq2bJyhQdo/uQU9yImjLBU1qxl1nCmdCCi5g2KeRS /uRg== X-Gm-Message-State: AGRZ1gJzaVYNak7VQas/a61nEqDUBRQbYZJE7RgR0dJrEwqzxRq0mcJl QWEhVAQnOFUaXoh+syAMeM/O5A== X-Google-Smtp-Source: AJdET5ewibFtIOBChjomp4ASbXPo7qin6bueX7L2jOoKAZ7ADOmOLeDKrR8tezhA6WYSL8tTi7qH3A== X-Received: by 2002:a1c:b8d:: with SMTP id 135-v6mr2659929wml.128.1541525461350; Tue, 06 Nov 2018 09:31:01 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id z17-v6sm16328416wrm.65.2018.11.06.09.31.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Nov 2018 09:31:00 -0800 (PST) From: Andrey Konovalov To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Will Deacon , Christoph Lameter , Andrew Morton , Mark Rutland , Nick Desaulniers , Marc Zyngier , Dave Martin , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sparse@vger.kernel.org, linux-mm@kvack.org, linux-kbuild@vger.kernel.org Cc: Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Jann Horn , Mark Brand , Chintan Pandya , Vishwath Mohan , Andrey Konovalov Subject: [PATCH v10 12/22] kasan, arm64: fix up fault handling logic Date: Tue, 6 Nov 2018 18:30:27 +0100 Message-Id: <4891a504adf61c0daf1e83642b6f7519328dfd5f.1541525354.git.andreyknvl@google.com> X-Mailer: git-send-email 2.19.1.930.g4563a0d9d0-goog In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org show_pte in arm64 fault handling relies on the fact that the top byte of a kernel pointer is 0xff, which isn't always the case with tag-based KASAN. This patch resets the top byte in show_pte. Reviewed-by: Andrey Ryabinin Reviewed-by: Dmitry Vyukov Signed-off-by: Andrey Konovalov --- arch/arm64/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 7d9571f4ae3d..d9a84d6f3343 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -141,6 +142,8 @@ void show_pte(unsigned long addr) pgd_t *pgdp; pgd_t pgd; + addr = (unsigned long)kasan_reset_tag((void *)addr); + if (addr < TASK_SIZE) { /* TTBR0 */ mm = current->active_mm; -- 2.19.1.930.g4563a0d9d0-goog