From: Dan Williams <dan.j.williams@intel.com>
To: Jan Kara <jack@suse.cz>
Cc: Kees Cook <keescook@chromium.org>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
stable <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 <linux-fsdevel@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] libnvdimm/pmem: Bypass CONFIG_HARDENED_USERCOPY overhead
Date: Mon, 20 May 2019 08:40:48 -0700 [thread overview]
Message-ID: <CAPcyv4hwiKGDtkT7-r8Ei3kOQBMA3LwDGBNM9H8N6HC5fxi6tw@mail.gmail.com> (raw)
In-Reply-To: <20190520075232.GA30972@quack2.suse.cz>
On Mon, May 20, 2019 at 12:52 AM Jan Kara <jack@suse.cz> wrote:
>
> On Sat 18-05-19 21:46:03, Dan Williams wrote:
> > On Fri, May 17, 2019 at 12:25 PM Kees Cook <keescook@chromium.org> wrote:
> > > On Fri, May 17, 2019 at 10:28:48AM -0700, Dan Williams wrote:
> > > > It seems dax_iomap_actor() is not a path where we'd be worried about
> > > > needing hardened user copy checks.
> > >
> > > I would agree: I think the proposed patch makes sense. :)
> >
> > Sounds like an acked-by to me.
>
> Yeah, if Kees agrees, I'm fine with skipping the checks as well. I just
> wanted that to be clarified. Also it helped me that you wrote:
>
> That routine (dax_iomap_actor()) validates that the logical file offset is
> within bounds of the file, then it does a sector-to-pfn translation which
> validates that the physical mapping is within bounds of the block device.
>
> That is more specific than "dax_iomap_actor() takes care of necessary
> checks" which was in the changelog. And the above paragraph helped me
> clarify which checks in dax_iomap_actor() you think replace those usercopy
> checks. So I think it would be good to add that paragraph to those
> copy_from_pmem() functions as a comment just in case we are wondering in
> the future why we are skipping the checks... Also feel free to add:
>
> Acked-by: Jan Kara <jack@suse.cz>
Will do, thanks Jan.
prev parent reply other threads:[~2019-05-20 15:41 UTC|newest]
Thread overview: 13+ 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 8:47 ` Jan Kara
2019-05-17 9:06 ` David Laight
2019-05-17 15:53 ` Kees Cook
2019-05-17 16:14 ` David Laight
2019-05-17 16:40 ` Kees Cook
2019-05-17 15:08 ` Dan Williams
2019-05-17 15:56 ` Kees Cook
2019-05-17 17:28 ` Dan Williams
2019-05-17 19:25 ` Kees Cook
2019-05-19 4:46 ` Dan Williams
2019-05-20 7:52 ` Jan Kara
2019-05-20 15:40 ` Dan Williams [this message]
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