From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56076 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754782AbeDFNaP (ORCPT ); Fri, 6 Apr 2018 09:30:15 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Yury Norov , Matthias Kaehlcke , Nick Desaulniers , Will Deacon , Nathan Chancellor Subject: [PATCH 4.4 28/72] arm64: avoid overflow in VA_START and PAGE_OFFSET Date: Fri, 6 Apr 2018 15:23:29 +0200 Message-Id: <20180406084307.528007339@linuxfoundation.org> In-Reply-To: <20180406084305.210085169@linuxfoundation.org> References: <20180406084305.210085169@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nick Desaulniers commit 82cd588052815eb4146f9f7c5347ca5e32c56360 upstream. The bitmask used to define these values produces overflow, as seen by this compiler warning: arch/arm64/kernel/head.S:47:8: warning: integer overflow in preprocessor expression #elif (PAGE_OFFSET & 0x1fffff) != 0 ^~~~~~~~~~~ arch/arm64/include/asm/memory.h:52:46: note: expanded from macro 'PAGE_OFFSET' #define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1)) ~~~~~~~~~~~~~~~~~~ ^ It would be preferrable to use GENMASK_ULL() instead, but it's not set up to be used from assembly (the UL() macro token pastes UL suffixes when not included in assembly sources). Suggested-by: Ard Biesheuvel Suggested-by: Yury Norov Suggested-by: Matthias Kaehlcke Signed-off-by: Nick Desaulniers Signed-off-by: Will Deacon [natechancellor: KIMAGE_VADDR doesn't exist] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/memory.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -49,8 +49,10 @@ * and PAGE_OFFSET - it must be within 128MB of the kernel text. */ #define VA_BITS (CONFIG_ARM64_VA_BITS) -#define VA_START (UL(0xffffffffffffffff) << VA_BITS) -#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1)) +#define VA_START (UL(0xffffffffffffffff) - \ + (UL(1) << VA_BITS) + 1) +#define PAGE_OFFSET (UL(0xffffffffffffffff) - \ + (UL(1) << (VA_BITS - 1)) + 1) #define MODULES_END (PAGE_OFFSET) #define MODULES_VADDR (MODULES_END - SZ_64M) #define PCI_IO_END (MODULES_VADDR - SZ_2M)