From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751948AbbJ2IMk (ORCPT ); Thu, 29 Oct 2015 04:12:40 -0400 Received: from mail-wi0-f193.google.com ([209.85.212.193]:35406 "EHLO mail-wi0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750889AbbJ2IMg (ORCPT ); Thu, 29 Oct 2015 04:12:36 -0400 Date: Thu, 29 Oct 2015 09:05:44 +0100 From: LABBE Corentin To: linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, yamada.masahiro@socionext.com Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm: fix the return value of find_first{_zero}_bit Message-ID: <20151029080544.GB25880@Red> References: <1444892115-24784-1-git-send-email-clabbe.montjoie@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1444892115-24784-1-git-send-email-clabbe.montjoie@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 15, 2015 at 08:54:59AM +0200, LABBE Corentin wrote: > Building linux with W=1 on arm give me this warning; > In file included from ../include/linux/nodemask.h:92:0, > from ../include/linux/mmzone.h:16, > from ../include/linux/gfp.h:5, > from ../include/linux/kmod.h:22, > from ../include/linux/module.h:13, > from net/netfilter/xt_nat.mod.c:1: > ../include/linux/bitmap.h: In function 'bitmap_empty': > ../include/linux/bitmap.h:287:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] > return find_first_bit(src, nbits) == nbits; > > ../include/linux/bitmap.h: In function 'bitmap_full': > ../include/linux/bitmap.h:295:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] > return find_first_zero_bit(src, nbits) == nbits; > > The problem is that find_first{_zero}_bit() return type is unsigned long on > majority of arch. > > Since find_first{_zero}_bit cannot return negative value, unsigned long is > the best return type. > > After some read, it seems that find_next_bit_[lb]e/_find_next_zero_bit_[lb]e > are also incorectly set as return int. > > This patch fix the return type of all thoses functions. > > Signed-off-by: LABBE Corentin > --- > arch/arm/include/asm/bitops.h | 22 +++++++++++----------- > arch/arm/lib/findbit.S | 8 ++++---- > 2 files changed, 15 insertions(+), 15 deletions(-) > > diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h > index e943e6c..868414b 100644 > --- a/arch/arm/include/asm/bitops.h > +++ b/arch/arm/include/asm/bitops.h > @@ -159,18 +159,18 @@ extern int _test_and_change_bit(int nr, volatile unsigned long * p); > /* > * Little endian assembly bitops. nr = 0 -> byte 0 bit 0. > */ > -extern int _find_first_zero_bit_le(const void * p, unsigned size); > -extern int _find_next_zero_bit_le(const void * p, int size, int offset); > -extern int _find_first_bit_le(const unsigned long *p, unsigned size); > -extern int _find_next_bit_le(const unsigned long *p, int size, int offset); > +extern unsigned long _find_first_zero_bit_le(const void *p, unsigned size); > +extern unsigned long _find_next_zero_bit_le(const void *p, int size, int offset); > +extern unsigned long _find_first_bit_le(const unsigned long *p, unsigned size); > +extern unsigned long _find_next_bit_le(const unsigned long *p, int size, int offset); > > /* > * Big endian assembly bitops. nr = 0 -> byte 3 bit 0. > */ > -extern int _find_first_zero_bit_be(const void * p, unsigned size); > -extern int _find_next_zero_bit_be(const void * p, int size, int offset); > -extern int _find_first_bit_be(const unsigned long *p, unsigned size); > -extern int _find_next_bit_be(const unsigned long *p, int size, int offset); > +extern unsigned long _find_first_zero_bit_be(const void *p, unsigned size); > +extern unsigned long _find_next_zero_bit_be(const void *p, int size, int offset); > +extern unsigned long _find_first_bit_be(const unsigned long *p, unsigned size); > +extern unsigned long _find_next_bit_be(const unsigned long *p, int size, int offset); > > #ifndef CONFIG_SMP > /* > @@ -317,19 +317,19 @@ static inline unsigned long __ffs(unsigned long x) > > #ifdef __ARMEB__ > > -static inline int find_first_zero_bit_le(const void *p, unsigned size) > +static inline unsigned long find_first_zero_bit_le(const void *p, unsigned size) > { > return _find_first_zero_bit_le(p, size); > } > #define find_first_zero_bit_le find_first_zero_bit_le > > -static inline int find_next_zero_bit_le(const void *p, int size, int offset) > +static inline unsigned long find_next_zero_bit_le(const void *p, int size, int offset) > { > return _find_next_zero_bit_le(p, size, offset); > } > #define find_next_zero_bit_le find_next_zero_bit_le > > -static inline int find_next_bit_le(const void *p, int size, int offset) > +static inline unsigned long find_next_bit_le(const void *p, int size, int offset) > { > return _find_next_bit_le(p, size, offset); > } > diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S > index 7848780..b4f6aec 100644 > --- a/arch/arm/lib/findbit.S > +++ b/arch/arm/lib/findbit.S > @@ -19,7 +19,7 @@ > > /* > * Purpose : Find a 'zero' bit > - * Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit); > + * Prototype: unsigned long find_first_zero_bit(void *addr, unsigned int maxbit); > */ > ENTRY(_find_first_zero_bit_le) > teq r1, #0 > @@ -40,7 +40,7 @@ ENDPROC(_find_first_zero_bit_le) > > /* > * Purpose : Find next 'zero' bit > - * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) > + * Prototype: unsigned long find_next_zero_bit(void *addr, unsigned int maxbit, int offset) > */ > ENTRY(_find_next_zero_bit_le) > teq r1, #0 > @@ -60,7 +60,7 @@ ENDPROC(_find_next_zero_bit_le) > > /* > * Purpose : Find a 'one' bit > - * Prototype: int find_first_bit(const unsigned long *addr, unsigned int maxbit); > + * Prototype: unsigned long find_first_bit(const unsigned long *addr, unsigned int maxbit); > */ > ENTRY(_find_first_bit_le) > teq r1, #0 > @@ -81,7 +81,7 @@ ENDPROC(_find_first_bit_le) > > /* > * Purpose : Find next 'one' bit > - * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) > + * Prototype: unsigned long find_next_zero_bit(void *addr, unsigned int maxbit, int offset) > */ > ENTRY(_find_next_bit_le) > teq r1, #0 > -- > 2.4.9 > Hello Nobody actually made any comment on this. Best regards