From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758089Ab1EaSPk (ORCPT ); Tue, 31 May 2011 14:15:40 -0400 Received: from wolverine02.qualcomm.com ([199.106.114.251]:34308 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757974Ab1EaSOg (ORCPT ); Tue, 31 May 2011 14:14:36 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6362"; a="94496922" From: Stephen Boyd To: Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: [PATCH 3/4] x86: Implement strict user copy checks for x86_64 Date: Tue, 31 May 2011 11:14:32 -0700 Message-Id: <1306865673-20560-4-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.7.5.3.367.ga9930 In-Reply-To: <1306865673-20560-1-git-send-email-sboyd@codeaurora.org> References: <1306865673-20560-1-git-send-email-sboyd@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Strict user copy checks are only really supported on x86_32 even though the config option is selectable on x86_64. Add the necessary support to the 64 bit code to trigger copy_from_user() warnings at compile time. Signed-off-by: Stephen Boyd Acked-by: Ingo Molnar Acked-by: H. Peter Anvin --- arch/x86/include/asm/uaccess_64.h | 12 +++++++++--- arch/x86/lib/usercopy_64.c | 6 ++++++ 2 files changed, 15 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 1c66d30..6ca53e5 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -43,6 +43,14 @@ _copy_from_user(void *to, const void __user *from, unsigned len); __must_check unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len); +extern void copy_from_user_overflow(void) +#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS + __compiletime_error("copy_from_user() buffer size is not provably correct") +#else + __compiletime_warning("copy_from_user() buffer size is not provably correct") +#endif +; + static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n) @@ -52,10 +60,8 @@ static inline unsigned long __must_check copy_from_user(void *to, might_fault(); if (likely(sz == -1 || sz >= n)) n = _copy_from_user(to, from, n); -#ifdef CONFIG_DEBUG_VM else - WARN(1, "Buffer overflow detected!\n"); -#endif + copy_from_user_overflow(); return n; } diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index b7c2849..d7a5d9a 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -181,3 +181,9 @@ copy_user_handle_tail(char *to, char *from, unsigned len, unsigned zerorest) break; return len; } + +void copy_from_user_overflow(void) +{ + WARN(1, "Buffer overflow detected!\n"); +} +EXPORT_SYMBOL(copy_from_user_overflow); -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.