From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jason Wang <jasowang@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH RFC] uaccess: user_access_begin_after_access_ok()
Date: Tue, 2 Jun 2020 18:44:30 +0100 [thread overview]
Message-ID: <20200602174430.GN23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAHk-=wjgg0bpD0qjYF=twJNXmRXYPjXqO1EFLL-mS8qUphe0AQ@mail.gmail.com>
On Tue, Jun 02, 2020 at 10:18:09AM -0700, Linus Torvalds wrote:
> You have exactly two cases:
>
> (a) the access_ok() would be right above the code and can't be missed
>
> (b) not
(c) what you really want is not quite access_ok().
Again, that "not quite access_ok()" should be right next to STAC, and
come from the same primitive - I'm not saying the current model is
anywhere near sane. We need a range-checking primitive right next
to memory access; it's just that for KVM and vhost we might want
a different check and, for things like s390 and sparc (mips as well,
in some configs), potentially different part that would do the memory
access itself as well.
next prev parent reply other threads:[~2020-06-02 17:44 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 [this message]
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
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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