Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934501AbbGVOwq (ORCPT ); Wed, 22 Jul 2015 10:52:46 -0400 Received: from mail2.asahi-net.or.jp ([202.224.39.198]:61993 "EHLO mail2.asahi-net.or.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932206AbbGVOwo (ORCPT ); Wed, 22 Jul 2015 10:52:44 -0400 From: Yoshinori Sato To: Arnd Bergmann Cc: Yoshinori Sato , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4] asm-generic: {get,put}_user ptr argument evaluate only 1 time Date: Wed, 22 Jul 2015 23:52:36 +0900 Message-Id: <1437576756-28388-1-git-send-email-ysato@users.sourceforge.jp> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1437023722-7432-1-git-send-email-ysato@users.sourceforge.jp> References: <1437023722-7432-1-git-send-email-ysato@users.sourceforge.jp> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1580 Lines: 53 Current implemantation ptr argument evaluate 2 times. It'll be an unexpected result. Changes v4: Temporary pointer type change to const void* Changes v3: Some build error fix. Changes v2: Argument x protect. Signed-off-by: Yoshinori Sato --- include/asm-generic/uaccess.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index 72d8803..f02e696 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -163,9 +163,10 @@ static inline __must_check long __copy_to_user(void __user *to, #define put_user(x, ptr) \ ({ \ + const void *__p = (ptr); \ might_fault(); \ - access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \ - __put_user(x, ptr) : \ + access_ok(VERIFY_WRITE, __p, sizeof(*ptr)) ? \ + __put_user((x), ((__typeof__(*(ptr)) *)__p)) : \ -EFAULT; \ }) @@ -225,9 +226,10 @@ extern int __put_user_bad(void) __attribute__((noreturn)); #define get_user(x, ptr) \ ({ \ + const void *__p = (ptr); \ might_fault(); \ - access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \ - __get_user(x, ptr) : \ + access_ok(VERIFY_READ, __p, sizeof(*ptr)) ? \ + __get_user((x), (__typeof__(*(ptr)) *)__p) : \ -EFAULT; \ }) -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/