Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751245AbaLNFU3 (ORCPT ); Sun, 14 Dec 2014 00:20:29 -0500 Received: from mail-qg0-f47.google.com ([209.85.192.47]:35737 "EHLO mail-qg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750731AbaLNFU1 convert rfc822-to-8bit (ORCPT ); Sun, 14 Dec 2014 00:20:27 -0500 MIME-Version: 1.0 In-Reply-To: References: <1415653764-22162-1-git-send-email-cernekee@gmail.com> From: Steve French Date: Sat, 13 Dec 2014 23:20:06 -0600 Message-ID: Subject: Re: [PATCH 1/2] [CIFS] Fix signed/unsigned pointer warning To: Kevin Cernekee Cc: Steve French , "linux-cifs@vger.kernel.org" , "linux-kernel@vger.kernel.org" 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 Probably harmless patch - but I didn't notice the warning on x86 kernel build (building on Fedora 21, gcc 4.9.2) On Fri, Dec 12, 2014 at 11:19 AM, Kevin Cernekee wrote: > On Mon, Nov 10, 2014 at 1:09 PM, Kevin Cernekee wrote: >> Commit 2ae83bf93882d1 ("[CIFS] Fix setting time before epoch (negative >> time values)") changed "u64 t" to "s64 t", which makes do_div() complain >> about a pointer signedness mismatch: >> >> CC fs/cifs/netmisc.o >> In file included from ./arch/mips/include/asm/div64.h:12:0, >> from include/linux/kernel.h:124, >> from include/linux/list.h:8, >> from include/linux/wait.h:6, >> from include/linux/net.h:23, >> from fs/cifs/netmisc.c:25: >> fs/cifs/netmisc.c: In function ‘cifs_NTtimeToUnix’: >> include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast [enabled by default] >> (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ >> ^ >> fs/cifs/netmisc.c:941:22: note: in expansion of macro ‘do_div’ >> ts.tv_nsec = (long)do_div(t, 10000000) * 100; >> >> Introduce a temporary "u64 abs_t" variable to fix this. >> >> Signed-off-by: Kevin Cernekee >> --- >> fs/cifs/netmisc.c | 12 +++++++----- >> 1 file changed, 7 insertions(+), 5 deletions(-) >> >> >> Note: this is compile-tested only (on a 32-bit build). >> >> >> diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c >> index b333ff6..abae6dd 100644 >> --- a/fs/cifs/netmisc.c >> +++ b/fs/cifs/netmisc.c >> @@ -926,6 +926,7 @@ cifs_NTtimeToUnix(__le64 ntutc) >> >> /* Subtract the NTFS time offset, then convert to 1s intervals. */ >> s64 t = le64_to_cpu(ntutc) - NTFS_TIME_OFFSET; >> + u64 abs_t; >> >> /* >> * Unfortunately can not use normal 64 bit division on 32 bit arch, but >> @@ -933,13 +934,14 @@ cifs_NTtimeToUnix(__le64 ntutc) >> * to special case them >> */ >> if (t < 0) { >> - t = -t; >> - ts.tv_nsec = (long)(do_div(t, 10000000) * 100); >> + abs_t = -t; >> + ts.tv_nsec = (long)(do_div(abs_t, 10000000) * 100); >> ts.tv_nsec = -ts.tv_nsec; >> - ts.tv_sec = -t; >> + ts.tv_sec = -abs_t; >> } else { >> - ts.tv_nsec = (long)do_div(t, 10000000) * 100; >> - ts.tv_sec = t; >> + abs_t = t; >> + ts.tv_nsec = (long)do_div(abs_t, 10000000) * 100; >> + ts.tv_sec = abs_t; >> } >> >> return ts; >> -- >> 2.1.1 >> > > Hi guys, > > I am still seeing this warning on Linus' head of tree. Do you think > this is something we can pull in for 3.19? > > Thanks! -- Thanks, Steve -- 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/