From: Matthew Wilcox <willy@infradead.org>
To: Christopher Lameter <cl@linux.com>
Cc: William Kucharski <william.kucharski@oracle.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] mm: ksize() should silently accept a NULL pointer
Date: Wed, 17 Jun 2020 09:26:43 -0700 [thread overview]
Message-ID: <20200617162643.GK8681@bombadil.infradead.org> (raw)
In-Reply-To: <alpine.DEB.2.22.394.2006171621140.1574@www.lameter.com>
On Wed, Jun 17, 2020 at 04:23:04PM +0000, Christopher Lameter wrote:
> On Tue, 16 Jun 2020, William Kucharski wrote:
>
> > Other mm routines such as kfree() and kzfree() silently do the right
> > thing if passed a NULL pointer, so ksize() should do the same.
>
> Ok so the size of an no object pointer is zero? Ignoring the freeing
> of a nonexisting object makes sense. But determining it size?
ksize() is misnamed. It's not the size of the object, it's the number
of bytes allocated for that object.
A NULL pointer represents a freed object, or one that was never
allocated in the first place. Clearly that's 0 bytes. What other
answer would make sense?
prev parent reply other threads:[~2020-06-17 16:26 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-16 22:54 [PATCH] mm: ksize() should silently accept a NULL pointer William Kucharski
2020-06-17 0:45 ` Matthew Wilcox
2020-06-17 7:09 ` David Hildenbrand
2020-06-17 16:23 ` Christopher Lameter
2020-06-17 16:26 ` Matthew Wilcox [this message]
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