public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Wu Fengguang <fengguang.wu@intel.com>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: "mrubin@google.com" <mrubin@google.com>,
	"david@fromorbit.com" <david@fromorbit.com>,
	"axboe@kernel.dk" <axboe@kernel.dk>,
	"kosaki.motohiro@jp.fujitsu.com" <kosaki.motohiro@jp.fujitsu.com>,
	"nickpiggin@yahoo.com.au" <nickpiggin@yahoo.com.au>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [2.6.37-rc1] /proc/vmstat failure.
Date: Thu, 4 Nov 2010 10:20:52 +0800	[thread overview]
Message-ID: <20101104022052.GA7800@localhost> (raw)
In-Reply-To: <201011040654.GDB05271.SOFJFFtOMLHOQV@I-love.SAKURA.ne.jp>

On Thu, Nov 04, 2010 at 05:54:48AM +0800, Tetsuo Handa wrote:
> Wu Fengguang wrote:
> > On Wed, Nov 03, 2010 at 07:11:11PM +0800, Tetsuo Handa wrote:
> > > Hello.
> > > 
> > > "cat /proc/vmstat" triggered below failure.
> > > 
> > > BUG: unable to handle kernel paging request at 07c06d16
> > > IP: [<c050c336>] strnlen+0x6/0x20
> > 
> > It seems that m->private is of type (void *) while the original v is
> > (unsigned long *). Can be fixed by the following patch.
> 
> Fixed by this patch. Thank you.

Great, thanks!

> By the way, GCC treats "(void *) + offset" as "(char *) + offset"
> but it is GCC specific extention. Maybe we should avoid such usage
> in order to avoid build failure for other compilers.

"(void *) + offset" seems to be used quite often.

I tried enable this gcc option, only to see huge amount of warnings.

       -Wpointer-arith
           Warn about anything that depends on the "size of" a
           function type or of "void".  GNU C assigns these types a
           size of 1, for convenience in calculations with "void *"
           pointers and pointers to functions.

/cc/linux-next/scripts/mod/file2alias.c: In function ‘device_id_check’:
/cc/linux-next/scripts/mod/file2alias.c:88: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c:88: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c:88: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c:94: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c:94: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c:94: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c: In function ‘do_usb_table’:
/cc/linux-next/scripts/mod/file2alias.c:275: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c: In function ‘do_table’:
/cc/linux-next/scripts/mod/file2alias.c:870: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c: In function ‘handle_moddevtable’:
/cc/linux-next/scripts/mod/file2alias.c:897: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/file2alias.c:897: warning: pointer of type ‘void *’ used in arithmetic
  HOSTCC  scripts/mod/modpost.o
/cc/linux-next/scripts/mod/modpost.c: In function ‘parse_elf’:
/cc/linux-next/scripts/mod/modpost.c:412: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:456: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:472: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:489: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:491: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:491: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:494: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:501: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:503: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:503: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c: In function ‘sec_name’:
/cc/linux-next/scripts/mod/modpost.c:716: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:717: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c: In function ‘sech_name’:
/cc/linux-next/scripts/mod/modpost.c:723: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:724: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c: In function ‘reloc_location’:
/cc/linux-next/scripts/mod/modpost.c:1443: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:1444: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:1444: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c: In function ‘section_rela’:
/cc/linux-next/scripts/mod/modpost.c:1520: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:1521: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c: In function ‘section_rel’:
/cc/linux-next/scripts/mod/modpost.c:1564: warning: pointer of type ‘void *’ used in arithmetic
/cc/linux-next/scripts/mod/modpost.c:1565: warning: pointer of type ‘void *’ used in arithmetic

Thanks,
Fengguang

  reply	other threads:[~2010-11-04  2:20 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <201011010053.ADE86905.JMLFHVtSQOOFOF@I-love.SAKURA.ne.jp>
2010-11-03 11:11 ` [2.6.37-rc1] /proc/vmstat failure Tetsuo Handa
2010-11-03 17:43   ` Linus Torvalds
2010-11-03 17:46   ` Wu Fengguang
2010-11-03 17:55     ` Linus Torvalds
2010-11-03 21:54     ` Tetsuo Handa
2010-11-04  2:20       ` Wu Fengguang [this message]
2010-11-04  2:52         ` Américo Wang
2010-11-04  2:53           ` Wu Fengguang
2010-11-04  3:31             ` Américo Wang
2010-11-04  3:43               ` Wu Fengguang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20101104022052.GA7800@localhost \
    --to=fengguang.wu@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=axboe@kernel.dk \
    --cc=david@fromorbit.com \
    --cc=kosaki.motohiro@jp.fujitsu.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mrubin@google.com \
    --cc=nickpiggin@yahoo.com.au \
    --cc=penguin-kernel@I-love.SAKURA.ne.jp \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox