linux-mips
[Top] [All Lists]

Re: [PATCH 5/6] fix warning on test_ti_thread_flag()

To: Akinobu Mita <mita@miraclelinux.com>
Subject: Re: [PATCH 5/6] fix warning on test_ti_thread_flag()
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Wed, 25 Jan 2006 13:28:51 +0100 (CET)
Cc: Linux Kernel Development <linux-kernel@vger.kernel.org>, Richard Henderson <rth@twiddle.net>, Ivan Kokshaysky <ink@jurassic.park.msu.ru>, Russell King <rmk@arm.linux.org.uk>, Ian Molton <spyro@f2s.com>, dev-etrax@axis.com, David Howells <dhowells@redhat.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Linus Torvalds <torvalds@osdl.org>, linux-ia64@vger.kernel.org, Hirokazu Takata <takata@linux-m32r.org>, linux-m68k@vger.kernel.org, Greg Ungerer <gerg@uclinux.org>, Linux/MIPS Development <linux-mips@linux-mips.org>, parisc-linux@parisc-linux.org, Linux/PPC Development <linuxppc-dev@ozlabs.org>, linux390@de.ibm.com, linuxsh-dev@lists.sourceforge.net, linuxsh-shmedia-dev@lists.sourceforge.net, sparclinux@vger.kernel.org, ultralinux@vger.kernel.org, Miles Bader <uclinux-v850@lsi.nec.co.jp>, Andi Kleen <ak@suse.de>, Chris Zankel <chris@zankel.net>
In-reply-to: <20060125113446.GF18584@miraclelinux.com>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <20060125112625.GA18584@miraclelinux.com> <20060125113446.GF18584@miraclelinux.com>
Sender: linux-mips-bounce@linux-mips.org
On Wed, 25 Jan 2006, Akinobu Mita wrote:
> If the arechitecture is
> - BITS_PER_LONG == 64
> - struct thread_info.flag 32 is bits
> - second argument of test_bit() was void *
> 
> Then compiler print error message on test_ti_thread_flags()
> in include/linux/thread_info.h
> 
> Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
> ---
>  thread_info.h |    2 +-
>  1 files changed, 1 insertion(+), 1 deletion(-)
> 
> Index: 2.6-git/include/linux/thread_info.h
> ===================================================================
> --- 2.6-git.orig/include/linux/thread_info.h  2006-01-25 19:07:12.000000000 
> +0900
> +++ 2.6-git/include/linux/thread_info.h       2006-01-25 19:14:26.000000000 
> +0900
> @@ -49,7 +49,7 @@
>  
>  static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
>  {
> -     return test_bit(flag,&ti->flags);
> +     return test_bit(flag, (void *)&ti->flags);
>  }

This is not safe. The bitops are defined to work on unsigned long only, so
flags should be changed to unsigned long instead, or you should use a
temporary.

Affected platforms:
  - alpha: flags is unsigned int
  - ia64, sh, x86_64: flags is __u32

The only affected 64-platforms are little endian, so it will silently work
after your change, though...

Gr{oetje,eeting}s,

                                                Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                                            -- Linus Torvalds

<Prev in Thread] Current Thread [Next in Thread>