From: Kees Cook <keescook@chromium.org>
To: Joe Perches <joe@perches.com>
Cc: SF Markus Elfring <elfring@users.sourceforge.net>,
Paolo Bonzini <pbonzini@redhat.com>,
Ingo Molnar <mingo@redhat.com>, "x86@kernel.org" <x86@kernel.org>,
Dave Young <dyoung@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Matt Fleming <matt.fleming@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
kernel-janitors@vger.kernel.org,
Julia Lawall <julia.lawall@lip6.fr>
Subject: Re: x86-ksysfs: Use kmalloc_array() in create_setup_data_nodes()
Date: Wed, 7 Sep 2016 10:01:27 -0700 [thread overview]
Message-ID: <CAGXu5j+Wv7YXJRm-9kYCSLQbkWoXTXJKU++qsVUrjOUDGg4rpg@mail.gmail.com> (raw)
In-Reply-To: <1473266220.29864.17.camel@perches.com>
On Wed, Sep 7, 2016 at 9:37 AM, Joe Perches <joe@perches.com> wrote:
> On Wed, 2016-09-07 at 09:23 -0700, Kees Cook wrote:
>> Fixing these kmalloc calls would be a nice thing to clean up
>> everywhere.
>
> Dubious as gcc cannot currently optimize known small fixed size
> allocations with alloc_array and will always perform the
> multiplication.
Oh, that's sad. Is it not able to tell what the types are to basic
overflow validation? Could we help gcc in some way?
> Also the style of sizeof(*ptr) is not always as clear, obvious
> nor as easy to grep as sizeof(type).
I've always been on the fence about this (I like being able to see
destination:thing, sizeof(*thing) for easy scanning), but having the
type right there can be easier for text searches.
-Kees
--
Kees Cook
Nexus Security
next prev parent reply other threads:[~2016-09-07 17:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-04 20:23 [PATCH] x86-ksysfs: Use kmalloc_array() in create_setup_data_nodes() SF Markus Elfring
2016-09-06 21:49 ` Kees Cook
2016-09-07 7:49 ` SF Markus Elfring
2016-09-07 10:36 ` Paolo Bonzini
2016-09-07 11:17 ` SF Markus Elfring
2016-09-07 11:20 ` Paolo Bonzini
2016-09-07 11:45 ` SF Markus Elfring
2016-09-07 16:23 ` Kees Cook
2016-09-07 16:37 ` Joe Perches
2016-09-07 17:01 ` Kees Cook [this message]
2016-09-07 16:55 ` SF Markus Elfring
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