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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Waiman Long <longman@redhat.com>
Cc: Joe Perches <joe@perches.com>,
	David Howells <dhowells@redhat.com>,
	 Andrew Morton <akpm@linux-foundation.org>,
	 Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	James Morris <jmorris@namei.org>,
	 "Serge E. Hallyn" <serge@hallyn.com>,
	Linux-MM <linux-mm@kvack.org>,
	keyrings@vger.kernel.org,
	 Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: Add kvfree_sensitive() for freeing sensitive data objects
Date: Mon, 6 Apr 2020 11:06:02 -0700	[thread overview]
Message-ID: <CAHk-=wgjiHUWLZWKZJ4eU+RrOc2xNZCHn4ETmJ0S+H=Eig28Cw@mail.gmail.com> (raw)
In-Reply-To: <19cbf3b1-2c3f-dd0f-a5c6-69ca3f77dd68@redhat.com>

On Mon, Apr 6, 2020 at 10:59 AM Waiman Long <longman@redhat.com> wrote:
>
> I have actually been thinking about that. I saw a couple of cases in the
> crypto code where a memzero_explicit() is followed by kfree(). Those can
> be replaced by kfree_sensitive.

Ack.

Doing that (and renaming kvzfree) should be a fairly straightforward
coccinelle patch.

Somebody (maybe you) asked whether we could just use
kvfree_sensitive() for everything, We probably could. The extra test
is cheap - much cheaper than the memzero_explicit().

That said, _there_ I think that consistency with regular kfree/kvfree
naming means that we might as well keep separate names, and keep the
kmalloc->kfree_sensitive and kvmalloc->kvfree_sensitive pairing. Even
if technically we could do with just the one function that works for
both cases.

            Linus


  reply	other threads:[~2020-04-06 18:06 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-06  2:37 [PATCH] mm: Add kvfree_sensitive() for freeing sensitive data objects Waiman Long
2020-04-06  4:20 ` David Rientjes
2020-04-06 14:36   ` Waiman Long
2020-04-06 14:39     ` Matthew Wilcox
2020-04-06  7:44 ` David Howells
2020-04-06 23:20   ` David Rientjes
2020-04-06 14:32 ` David Howells
2020-04-06 14:40   ` Waiman Long
2020-04-06 15:45 ` Joe Perches
2020-04-06 16:00 ` David Howells
2020-04-06 16:10   ` Joe Perches
2020-04-06 16:41     ` Linus Torvalds
2020-04-06 16:42       ` Joe Perches
2020-04-06 17:11         ` Linus Torvalds
2020-04-06 17:20           ` Joe Perches
2020-04-06 17:26             ` Matthew Wilcox
2020-04-06 17:33             ` Linus Torvalds
2020-04-06 17:46               ` Joe Perches
2020-04-06 17:58     ` Waiman Long
2020-04-06 18:06       ` Linus Torvalds [this message]
2020-04-06 18:46         ` Joe Perches
2020-04-06 16:26   ` David Howells
2020-04-06 16:38     ` Joe Perches
2020-04-06 17:10     ` Joe Perches
2020-04-06 17:24       ` Matthew Wilcox
2020-04-06 17:26       ` Linus Torvalds
2020-04-06 17:51       ` David Howells
2020-04-06 17:58         ` Linus Torvalds

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