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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E940C3A5A9 for ; Wed, 4 Sep 2019 15:59:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 065F82339D for ; Wed, 4 Sep 2019 15:59:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567612763; bh=TGRMB95YGQkQ03FI3rbztcHl2l8WMOmLww0pLVy6bpI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uR0sWBAPVDMGMZD0lK9L01VcGBmMnL93nD0BTo28Pr+WHTp8Cf4bRs6fX3vUDNC2L YWMeeoscL+1U1Im/u7RASTiJVMvexBd8j6lZqgZd7VRU7kEjB86wrR8E7AJvbiCmYG u9OModkB+vvxAA8VzbKc3SusZ8UvMiD+pAAHqtQk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732363AbfIDP7W (ORCPT ); Wed, 4 Sep 2019 11:59:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:33778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731508AbfIDP7V (ORCPT ); Wed, 4 Sep 2019 11:59:21 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5736C20820; Wed, 4 Sep 2019 15:59:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567612760; bh=TGRMB95YGQkQ03FI3rbztcHl2l8WMOmLww0pLVy6bpI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IWshuuCr0L0GBvgTb/bA3iz7epxmfJbAbVGVOrgqsq7AGeBwMAIoFFcwHHdtxWCpn 7/ZulQpq5y+ZgdMm2yTmONOgxAJ8LcTdBARe93DOqpx947dZ7ik7lNvy+oCN4Y7Okx b0uWmNu7msMrQONLBrjEWK541cdbRHBKhraJHmWc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Anup Patel , Anup Patel , Alistair Francis , Christoph Hellwig , Paul Walmsley , Sasha Levin , linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 5.2 65/94] RISC-V: Fix FIXMAP area corruption on RV32 systems Date: Wed, 4 Sep 2019 11:57:10 -0400 Message-Id: <20190904155739.2816-65-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190904155739.2816-1-sashal@kernel.org> References: <20190904155739.2816-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anup Patel [ Upstream commit a256f2e329df0773022d28df2c3d206b9aaf1e61 ] Currently, various virtual memory areas of Linux RISC-V are organized in increasing order of their virtual addresses is as follows: 1. User space area (This is lowest area and starts at 0x0) 2. FIXMAP area 3. VMALLOC area 4. Kernel area (This is highest area and starts at PAGE_OFFSET) The maximum size of user space aread is represented by TASK_SIZE. On RV32 systems, TASK_SIZE is defined as VMALLOC_START which causes the user space area to overlap the FIXMAP area. This allows user space apps to potentially corrupt the FIXMAP area and kernel OF APIs will crash whenever they access corrupted FDT in the FIXMAP area. On RV64 systems, TASK_SIZE is set to fixed 256GB and no other areas happen to overlap so we don't see any FIXMAP area corruptions. This patch fixes FIXMAP area corruption on RV32 systems by setting TASK_SIZE to FIXADDR_START. We also move FIXADDR_TOP, FIXADDR_SIZE, and FIXADDR_START defines to asm/pgtable.h so that we can avoid cyclic header includes. Signed-off-by: Anup Patel Tested-by: Alistair Francis Reviewed-by: Christoph Hellwig Signed-off-by: Paul Walmsley Signed-off-by: Sasha Levin --- arch/riscv/include/asm/fixmap.h | 4 ---- arch/riscv/include/asm/pgtable.h | 12 ++++++++++-- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h index c207f6634b91c..15b3edaabc280 100644 --- a/arch/riscv/include/asm/fixmap.h +++ b/arch/riscv/include/asm/fixmap.h @@ -25,10 +25,6 @@ enum fixed_addresses { __end_of_fixed_addresses }; -#define FIXADDR_SIZE (__end_of_fixed_addresses * PAGE_SIZE) -#define FIXADDR_TOP (VMALLOC_START) -#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) - #define FIXMAP_PAGE_IO PAGE_KERNEL #define __early_set_fixmap __set_fixmap diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index f7c3f7de15f27..e6faa469c133b 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -408,14 +408,22 @@ static inline void pgtable_cache_init(void) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) +#define FIXADDR_TOP VMALLOC_START +#ifdef CONFIG_64BIT +#define FIXADDR_SIZE PMD_SIZE +#else +#define FIXADDR_SIZE PGDIR_SIZE +#endif +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + /* - * Task size is 0x40000000000 for RV64 or 0xb800000 for RV32. + * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32. * Note that PGDIR_SIZE must evenly divide TASK_SIZE. */ #ifdef CONFIG_64BIT #define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2) #else -#define TASK_SIZE VMALLOC_START +#define TASK_SIZE FIXADDR_START #endif #include -- 2.20.1