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From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-kernel@vger.kernel.org,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [PATCH 3/9] s390: Replace weird use of PTR_RET.
Date: Mon, 17 Jun 2013 07:03:10 +0200	[thread overview]
Message-ID: <20130617050310.GA4560@osiris> (raw)
In-Reply-To: <1371357768-4968-3-git-send-email-rusty@rustcorp.com.au>

On Sun, Jun 16, 2013 at 02:12:42PM +0930, Rusty Russell wrote:
> Saves repeating "(void __force *)__uptr" but it's less clear.  Using
> the output of PTR_RET() to determine the error rather than just
> testing IS_ERR() is odd.

Ok, if it's confusing I won't mind if it gets changed. I intended to
keep the code as short as possible, but.. ;)

> For example, I *assume* __gptr_to_uptr() never returns NULL?  Because
> the __ret would be 0 for the old code.  The new version is clearer, IMHO:
> it would try to get_user() on that address.

__gptr_to_uptr() could return 0 and it's not an error case. In that case
it should indeed try a to get_user() on that address.

> If you hate this variant, I can just s/PTR_RET/PTR_ERR_OR_ZERO/ instead.

Your patch is fine.

> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> ---
>  arch/s390/kvm/gaccess.h | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>


  reply	other threads:[~2013-06-17  5:03 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-01  9:56 [PATCH] virtio-mmio: Cocci spatch "ptr_ret.spatch" Thomas Meyer
2013-06-03  2:29 ` [RFC] PTR_ERR: return 0 if ptr isn't an error value Rusty Russell
2013-06-03  7:15   ` Uwe Kleine-König
2013-06-08 21:07     ` Julia Lawall
2013-06-13  4:37       ` Rusty Russell
2013-06-13  7:30         ` Michael S. Tsirkin
2013-06-13  7:56           ` Julia Lawall
2013-06-16  2:44             ` Rusty Russell
2013-06-16  4:42               ` [PATCH 1/9] PTR_RET is now PTR_ERR_OR_ZERO Rusty Russell
2013-06-16  4:42                 ` [PATCH 2/9] PTR_RET is now PTR_ERR_OR_ZERO(): Replace most Rusty Russell
2013-06-20  6:05                   ` David Miller
2013-06-25  7:47                   ` Benjamin Herrenschmidt
2013-06-16  4:42                 ` [PATCH 3/9] s390: Replace weird use of PTR_RET Rusty Russell
2013-06-17  5:03                   ` Heiko Carstens [this message]
2013-06-16  4:42                 ` [PATCH 4/9] acpi: " Rusty Russell
2013-06-16 11:55                   ` Rafael J. Wysocki
2013-06-16  4:42                 ` [PATCH 5/9] pinctrl: don't use PTR_RET() Rusty Russell
2013-06-16  4:42                 ` [PATCH 6/9] remoteproc: " Rusty Russell
2013-06-17  3:15                   ` Ohad Ben-Cohen
2013-06-17  3:49                     ` Rusty Russell
2013-06-16  4:42                 ` [PATCH 7/9] staging/zcache: " Rusty Russell
2013-06-16  4:42                 ` [PATCH 8/9] x86: remove weird PTR_ERR() in do_debug Rusty Russell
2013-06-19 18:43                   ` [tip:x86/debug] x86: Remove " tip-bot for Rusty Russell
2013-06-16  4:42                 ` [PATCH 9/9] mm/oom_kill: remove weird use of ERR_PTR()/PTR_ERR() Rusty Russell
2013-06-16 18:11                   ` David Rientjes
2013-06-17  3:50                     ` Rusty Russell
2013-06-09  5:55     ` [RFC] PTR_ERR: return 0 if ptr isn't an error value Rusty Russell

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