From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752061AbeBYR0p (ORCPT ); Sun, 25 Feb 2018 12:26:45 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:50220 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751879AbeBYRXA (ORCPT ); Sun, 25 Feb 2018 12:23:00 -0500 X-Google-Smtp-Source: AG47ELtWRxBbX1gfcfULOsiBxoX2/WkKlgFs3mOQSd5+sIUgrpiXFOHR7D2Z8Y3JQs5OzEvkiv00kA== From: Mathieu Malaterre To: Michael Ellerman Cc: Benjamin Herrenschmidt , Paul Mackerras , Jiri Slaby , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Mathieu Malaterre Subject: [PATCH 06/21] powerpc: Avoid comparison of unsigned long >= 0 in __access_ok Date: Sun, 25 Feb 2018 18:22:21 +0100 Message-Id: <20180225172236.29650-7-malat@debian.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180225172236.29650-1-malat@debian.org> References: <20180225172236.29650-1-malat@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rewrite check size - 1 <= Y as size < Y since `size` is unsigned value. Fix warning (treated as error in W=1): CC arch/powerpc/kernel/signal_32.o In file included from ./include/linux/uaccess.h:14:0, from ./include/asm-generic/termios-base.h:8, from ./arch/powerpc/include/asm/termios.h:20, from ./include/uapi/linux/termios.h:6, from ./include/linux/tty.h:7, from arch/powerpc/kernel/signal_32.c:36: ./include/asm-generic/termios-base.h: In function ‘user_termio_to_kernel_termios’: ./arch/powerpc/include/asm/uaccess.h:52:35: error: comparison of unsigned expression >= 0 is always true [-Werror=type-limits] (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) ^ ./arch/powerpc/include/asm/uaccess.h:58:3: note: in expansion of macro ‘__access_ok’ __access_ok((__force unsigned long)(addr), (size), get_fs())) ^~~~~~~~~~~ ./arch/powerpc/include/asm/uaccess.h:262:6: note: in expansion of macro ‘access_ok’ if (access_ok(VERIFY_READ, __gu_addr, (size))) \ ^~~~~~~~~ ./arch/powerpc/include/asm/uaccess.h:80:2: note: in expansion of macro ‘__get_user_check’ __get_user_check((x), (ptr), sizeof(*(ptr))) ^~~~~~~~~~~~~~~~ ./include/asm-generic/termios-base.h:36:6: note: in expansion of macro ‘get_user’ if (get_user(termios->c_line, &termio->c_line) < 0) ^~~~~~~~ [...] cc1: all warnings being treated as errors Signed-off-by: Mathieu Malaterre --- arch/powerpc/include/asm/uaccess.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 51bfeb8777f0..fadc406bd39d 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -49,7 +49,7 @@ #define __access_ok(addr, size, segment) \ (((addr) <= (segment).seg) && \ - (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) + (((size) == 0) || ((size) < ((segment).seg - (addr))))) #endif -- 2.11.0