From: Kees Cook <keescook@chromium.org>
To: David Laight <David.Laight@ACULAB.COM>
Cc: 'Jan Kara' <jack@suse.cz>,
Dan Williams <dan.j.williams@intel.com>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
Jeff Moyer <jmoyer@redhat.com>, Ingo Molnar <mingo@redhat.com>,
Christoph Hellwig <hch@lst.de>, Al Viro <viro@zeniv.linux.org.uk>,
Thomas Gleixner <tglx@linutronix.de>,
Matthew Wilcox <willy@infradead.org>,
Jeff Smits <jeff.smits@intel.com>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] libnvdimm/pmem: Bypass CONFIG_HARDENED_USERCOPY overhead
Date: Fri, 17 May 2019 09:40:31 -0700 [thread overview]
Message-ID: <201905170938.99AACF0D@keescook> (raw)
In-Reply-To: <ac76e29576b14fcb9a18e5a9e6ab8394@AcuMS.aculab.com>
On Fri, May 17, 2019 at 04:14:03PM +0000, David Laight wrote:
> From: Kees Cook
> > Sent: 17 May 2019 16:54
> ...
> > > I've changed some of our code to use __get_user() to avoid
> > > these stupid overheads.
> >
> > __get_user() skips even access_ok() checking too, so that doesn't seem
> > like a good idea. Did you run access_ok() checks separately? (This
> > generally isn't recommended.)
>
> Of course, I'm not THAT stupid :-)
Right, yes, I know. :) I just wanted to double-check since accidents
can happen. The number of underscores on these function is not really
a great way to indicate what they're doing. ;)
--
Kees Cook
next prev parent reply other threads:[~2019-05-17 16:40 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-17 0:33 [PATCH] libnvdimm/pmem: Bypass CONFIG_HARDENED_USERCOPY overhead Dan Williams
2019-05-17 0:33 ` Dan Williams
2019-05-17 8:47 ` Jan Kara
2019-05-17 8:47 ` Jan Kara
2019-05-17 9:06 ` David Laight
2019-05-17 9:06 ` David Laight
2019-05-17 15:53 ` Kees Cook
2019-05-17 15:53 ` Kees Cook
2019-05-17 16:14 ` David Laight
2019-05-17 16:14 ` David Laight
2019-05-17 16:40 ` Kees Cook [this message]
2019-05-17 15:08 ` Dan Williams
2019-05-17 15:08 ` Dan Williams
2019-05-17 15:56 ` Kees Cook
2019-05-17 15:56 ` Kees Cook
2019-05-17 17:28 ` Dan Williams
2019-05-17 17:28 ` Dan Williams
2019-05-17 19:25 ` Kees Cook
2019-05-17 19:25 ` Kees Cook
2019-05-19 4:46 ` Dan Williams
2019-05-19 4:46 ` Dan Williams
2019-05-20 7:52 ` Jan Kara
2019-05-20 7:52 ` Jan Kara
2019-05-20 15:40 ` Dan Williams
2019-05-20 15:40 ` Dan Williams
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