From: Souptick Joarder <jrdr.linux@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>,
Andrew Morton <akpm@linux-foundation.org>,
alex.bou9@gmail.com, gustavoars@kernel.org,
Ira Weiny <ira.weiny@intel.com>,
linux-kernel@vger.kernel.org, madhuparnabhowmik10@gmail.com,
mporter@kernel.crashing.org, Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH] mm/gup: protect unpin_user_pages() against npages==-ERRNO
Date: Sun, 20 Sep 2020 08:33:43 +0530 [thread overview]
Message-ID: <CAFqt6zYFjGTJ=KUjHd5jf-ri5tCmo4HOLP1j3nsELFgcoEoLHQ@mail.gmail.com> (raw)
In-Reply-To: <20200917074054.GO18329@kadam>
On Thu, Sep 17, 2020 at 1:11 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Wed, Sep 16, 2020 at 11:57:06PM -0700, John Hubbard wrote:
> > As suggested by Dan Carpenter, fortify unpin_user_pages() just a bit,
> > against a typical caller mistake: check if the npages arg is really a
> > -ERRNO value, which would blow up the unpinning loop: WARN and return.
> >
> > If this new WARN_ON() fires, then the system *might* be leaking pages
> > (by leaving them pinned), but probably not. More likely, gup/pup
> > returned a hard -ERRNO error to the caller, who erroneously passed it
> > here.
> >
> > Cc: Ira Weiny <ira.weiny@intel.com>
> > Cc: Souptick Joarder <jrdr.linux@gmail.com>
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> > ---
> >
> > Hi Dan,
> >
> > Is is OK to use your signed-off-by here? Since you came up with this.
> >
>
> Yeah. That's fine.
Do we need a similar check inside unpin_user_pages_dirty_lock(),
when make_dirty set to false ?
next prev parent reply other threads:[~2020-09-20 3:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-16 3:42 [linux-next PATCH] rapidio: Fix error handling path Souptick Joarder
2020-09-16 6:37 ` John Hubbard
2020-09-16 10:02 ` Dan Carpenter
2020-09-16 10:07 ` Dan Carpenter
2020-09-16 15:16 ` Ira Weiny
2020-09-16 15:27 ` Dan Carpenter
2020-09-17 6:57 ` [PATCH] mm/gup: protect unpin_user_pages() against npages==-ERRNO John Hubbard
2020-09-17 7:40 ` Dan Carpenter
2020-09-20 3:03 ` Souptick Joarder [this message]
2020-09-20 4:13 ` John Hubbard
2020-09-21 9:34 ` Dan Carpenter
2020-09-17 12:39 ` [linux-next PATCH] rapidio: Fix error handling path Dan Carpenter
2020-09-17 17:34 ` Ira Weiny
2020-09-17 17:47 ` John Hubbard
2020-09-18 2:21 ` Souptick Joarder
2020-09-18 6:33 ` John Hubbard
2020-09-18 2:25 ` Souptick Joarder
2020-09-18 6:15 ` Dan Carpenter
2020-09-16 15:20 ` Ira Weiny
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAFqt6zYFjGTJ=KUjHd5jf-ri5tCmo4HOLP1j3nsELFgcoEoLHQ@mail.gmail.com' \
--to=jrdr.linux@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=alex.bou9@gmail.com \
--cc=dan.carpenter@oracle.com \
--cc=gustavoars@kernel.org \
--cc=ira.weiny@intel.com \
--cc=jhubbard@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=madhuparnabhowmik10@gmail.com \
--cc=mporter@kernel.crashing.org \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.