From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yoshinori Sato Subject: [PATCH v2] asm-generic: {get,put}_user ptr argument evaluate only 1 time Date: Thu, 16 Jul 2015 23:16:39 +0900 Message-ID: <1437056199-2326-1-git-send-email-ysato@users.sourceforge.jp> References: <1437023722-7432-1-git-send-email-ysato@users.sourceforge.jp> Return-path: Received: from mail2.asahi-net.or.jp ([202.224.39.198]:45589 "EHLO mail2.asahi-net.or.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932180AbbGPOQv (ORCPT ); Thu, 16 Jul 2015 10:16:51 -0400 In-Reply-To: <1437023722-7432-1-git-send-email-ysato@users.sourceforge.jp> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Arnd Bergmann Cc: Yoshinori Sato , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Current implemantation ptr argument evaluate 2 times. It'll be an unexpected result. Changes v2: Add parenthesis to argument "x". 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..ba6ab80 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) \ ({ \ + __typeof__((ptr)) __p = (ptr); \ might_fault(); \ - access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \ - __put_user(x, ptr) : \ + access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \ + __put_user((x), __p) : \ -EFAULT; \ }) @@ -225,9 +226,10 @@ extern int __put_user_bad(void) __attribute__((noreturn)); #define get_user(x, ptr) \ ({ \ + __typeof__((ptr)) __p = (ptr); \ might_fault(); \ - access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \ - __get_user(x, ptr) : \ + access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \ + __get_user((x), __p) : \ -EFAULT; \ }) -- 2.1.4