Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759014Ab1EMA3k (ORCPT ); Thu, 12 May 2011 20:29:40 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:45354 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758935Ab1EMA3j (ORCPT ); Thu, 12 May 2011 20:29:39 -0400 X-AuditID: b753bd60-a32c7ba000003bac-89-4dcc7b704b04 X-AuditID: b753bd60-a32c7ba000003bac-89-4dcc7b704b04 Message-ID: <4DCC7B6E.9000909@hitachi.com> Date: Fri, 13 May 2011 09:29:34 +0900 From: Masami Hiramatsu Organization: Systems Development Lab., Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2.17) Gecko/20110414 Thunderbird/3.1.10 MIME-Version: 1.0 To: Stephen Boyd Cc: linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli , Anil S Keshavamurthy , "David S. Miller" Subject: Re: [PATCH 5/9] kprobes: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning References: <1305244212-19183-1-git-send-email-sboyd@codeaurora.org> <1305244212-19183-6-git-send-email-sboyd@codeaurora.org> In-Reply-To: <1305244212-19183-6-git-send-email-sboyd@codeaurora.org> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1985 Lines: 59 (2011/05/13 8:50), Stephen Boyd wrote: > Enabling DEBUG_STRICT_USER_COPY_CHECKS causes the following > warning: > > In file included from arch/x86/include/asm/uaccess.h:573, > from kernel/kprobes.c:55: > In function 'copy_from_user', > inlined from 'write_enabled_file_bool' at > kernel/kprobes.c:2191: > arch/x86/include/asm/uaccess_64.h:65: > warning: call to 'copy_from_user_overflow' declared with > attribute warning: copy_from_user() buffer size is not provably > correct > > presumably due to buf_size being signed causing GCC to fail to > see that buf_size can't become negative. Good catch! At least, since the "count" is size_t, buf_size should be size_t too. Acked-by: Masami Hiramatsu Thank you! > > Cc: Ananth N Mavinakayanahalli > Cc: Anil S Keshavamurthy > Cc: David S. Miller > Cc: Masami Hiramatsu > Signed-off-by: Stephen Boyd > --- > kernel/kprobes.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 7798181..1938187 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -2185,7 +2185,7 @@ static ssize_t write_enabled_file_bool(struct file *file, > const char __user *user_buf, size_t count, loff_t *ppos) > { > char buf[32]; > - int buf_size; > + size_t buf_size; > > buf_size = min(count, (sizeof(buf)-1)); > if (copy_from_user(buf, user_buf, buf_size)) -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- 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/