public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "Daniel K." <dk@uw.no>
To: Namhyung Kim <namhyung@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Roland McGrath <roland@redhat.com>,
	Oleg Nesterov <oleg@redhat.com>,
	linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>
Subject: Re: [PATCH RESEND v3 09/24] ptrace: cleanup arch_ptrace() on frv
Date: Sat, 02 Oct 2010 06:13:13 +0000	[thread overview]
Message-ID: <4CA6CD79.80804@uw.no> (raw)
In-Reply-To: <1285995551.1696.19.camel@leonhard>

Namhyung Kim wrote:
> 2010-10-02 (토), 12:57 +0900, Namhyung Kim:
>> 2010-10-02 (토), 03:18 +0000, Daniel K.:
>>> Namhyung Kim wrote:
>>>>       case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
>>>>             ret = -EIO;
>>> -             if ((addr & 3) || addr < 0)
>>> +             if (addr & 3)
>>>                     break;
>>>
>>>> -		ret = 0;
>>>> -		switch (addr >> 2) {
>>>> +		switch (regno) {
>>>>  		case 0 ... PT__END - 1:
>>>> -			ret = put_reg(child, addr >> 2, data);
>>>> -			break;
>>>> -
>>>> -		default:
>>>> -			ret = -EIO;
>>>> +			ret = put_reg(child, regno, data);
>>>>  			break;
>>>>  		}
>>>>  		break;
>>> With this, you remove the default case, and no longer return -EIO in the
>>> cases of PT__END + n, as in the PTRACE_PEEKUSR section above.
>>>
>>> This is a change of behaviour as far as I can tell, and not just a cleanup.
> 
> It would not be a change of behaviour. Because 'ret' was initialized
> with -EIO and only changed in the switch case. So assignment before
> switch can be removed and then will return -EIO in default case.

You are right, I was thrown by the piles of needless code here.

In fact, the whole switch can now be replaced with:

	if (regno < PT__END)
		ret = put_reg(child, regno, data);

but it is perhaps better to use the switch-style, for symmetry with
the PTRACE_PEEKUSR case directly above it?


Sorry to cause alarm.


Daniel K.

  reply	other threads:[~2010-10-02  6:15 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-30  9:27 [PATCH RESEND v3 00/24] ptrace cleanups Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 01/24] ptrace: change signature of sys_ptrace() and friends Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 02/24] ptrace: cleanup ptrace_request() Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 03/24] ptrace: change signature of arch_ptrace() Namhyung Kim
2010-09-30 18:58   ` David Miller
2010-10-04 19:21     ` Geert Uytterhoeven
2010-09-30  9:27 ` [PATCH RESEND v3 04/24] ptrace: cleanup arch_ptrace() on x86 Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 05/24] ptrace: cleanup arch_ptrace() on ARM Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 06/24] ptrace: cleanup arch_ptrace() on avr32 Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 07/24] ptrace: cleanup arch_ptrace() and friends on Blackfin Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 08/24] ptrace: cleanup arch_ptrace() on cris Namhyung Kim
2010-09-30 10:36   ` Mikael Starvik
2010-09-30  9:27 ` [PATCH RESEND v3 09/24] ptrace: cleanup arch_ptrace() on frv Namhyung Kim
2010-10-02  3:18   ` Daniel K.
2010-10-02  3:57     ` Namhyung Kim
2010-10-02  4:59       ` Namhyung Kim
2010-10-02  6:13         ` Daniel K. [this message]
2010-09-30  9:27 ` [PATCH RESEND v3 10/24] ptrace: cleanup arch_ptrace() on h8300 Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 11/24] ptrace: cleanup arch_ptrace() on m32r Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 12/24] ptrace: cleanup arch_ptrace() on m68k Namhyung Kim
2010-10-04 19:22   ` Geert Uytterhoeven
2010-09-30  9:27 ` [PATCH RESEND v3 13/24] ptrace: cleanup arch_ptrace() on m68knommu Namhyung Kim
2010-10-04 23:42   ` Andrew Morton
2010-10-05  3:49     ` [PATCH UPDATED] " Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 14/24] ptrace: cleanup arch_ptrace() on microblaze Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 15/24] ptrace: cleanup arch_ptrace() on MIPS Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 16/24] ptrace: cleanup arch_ptrace() on mn10300 Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 17/24] ptrace: cleanup arch_ptrace() on parisc Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 18/24] ptrace: cleanup arch_ptrace() on powerpc Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 19/24] ptrace: cleanup arch_ptrace() on score Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 20/24] ptrace: cleanup arch_ptrace() on sh Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 21/24] ptrace: cleanup arch_ptrace() on sparc Namhyung Kim
2010-09-30 19:00   ` David Miller
2010-09-30  9:27 ` [PATCH RESEND v3 22/24] ptrace: cleanup arch_ptrace() on tile Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 23/24] ptrace: cleanup arch_ptrace() on um Namhyung Kim
2010-09-30  9:27 ` [PATCH RESEND v3 24/24] ptrace: cleanup arch_ptrace() on xtensa Namhyung Kim

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=4CA6CD79.80804@uw.no \
    --to=dk@uw.no \
    --cc=akpm@linux-foundation.org \
    --cc=dhowells@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=namhyung@gmail.com \
    --cc=oleg@redhat.com \
    --cc=roland@redhat.com \
    /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