From: Al Viro <viro@zeniv.linux.org.uk>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org, Jason Wang <jasowang@redhat.com>,
netdev@vger.kernel.org
Subject: Re: [PATCH RFC] uaccess: user_access_begin_after_access_ok()
Date: Tue, 2 Jun 2020 17:30:48 +0100 [thread overview]
Message-ID: <20200602163048.GL23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200602084257.134555-1-mst@redhat.com>
On Tue, Jun 02, 2020 at 04:45:05AM -0400, Michael S. Tsirkin wrote:
> So vhost needs to poke at userspace *a lot* in a quick succession. It
> is thus benefitial to enable userspace access, do our thing, then
> disable. Except access_ok has already been pre-validated with all the
> relevant nospec checks, so we don't need that. Add an API to allow
> userspace access after access_ok and barrier_nospec are done.
This is the wrong way to do it, and this API is certain to be abused
elsewhere. NAK - we need to sort out vhost-related problems, but
this is not an acceptable solution. Sorry.
next prev parent reply other threads:[~2020-06-02 16:30 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-02 8:45 [PATCH RFC] uaccess: user_access_begin_after_access_ok() Michael S. Tsirkin
2020-06-02 10:15 ` Jason Wang
2020-06-02 16:33 ` Al Viro
2020-06-02 17:18 ` Linus Torvalds
2020-06-02 17:44 ` Al Viro
2020-06-02 17:46 ` Al Viro
2020-06-02 20:32 ` Michael S. Tsirkin
2020-06-02 20:41 ` David Laight
2020-06-02 21:58 ` Al Viro
2020-06-03 8:08 ` David Laight
2020-06-02 20:43 ` Linus Torvalds
2020-06-03 6:01 ` Michael S. Tsirkin
[not found] ` <CAHk-=wi3=QuD30fRq8fYYTj9WmkgeZ0VR_Sh3DQHU+nmwj-jMg@mail.gmail.com>
2020-06-03 16:59 ` Linus Torvalds
2020-06-02 16:30 ` Al Viro [this message]
2020-06-02 20:42 ` Michael S. Tsirkin
2020-06-02 22:10 ` Al Viro
2020-06-03 5:17 ` Michael S. Tsirkin
2020-06-03 1:48 ` Al Viro
2020-06-03 3:57 ` Jason Wang
2020-06-03 4:18 ` Al Viro
2020-06-03 5:18 ` Jason Wang
2020-06-03 5:46 ` Michael S. Tsirkin
2020-06-03 6:23 ` Jason Wang
2020-06-03 6:30 ` Michael S. Tsirkin
2020-06-03 6:36 ` Jason Wang
2020-06-04 16:49 ` Michael S. Tsirkin
2020-06-05 10:03 ` Jason Wang
2020-06-06 20:08 ` Michael S. Tsirkin
2020-06-03 6:25 ` Michael S. Tsirkin
2020-06-03 5:29 ` Michael S. Tsirkin
2020-06-03 16:52 ` Al Viro
2020-06-04 6:10 ` Jason Wang
2020-06-04 14:59 ` Al Viro
2020-06-04 16:46 ` Michael S. Tsirkin
2020-06-04 10:10 ` Michael S. Tsirkin
2020-06-04 15:03 ` Al Viro
2020-06-04 16:47 ` Michael S. Tsirkin
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