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From: Al Viro <viro@zeniv.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	the arch/x86 maintainers <x86@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: objtool clac/stac handling change..
Date: Wed, 1 Jul 2020 20:59:14 +0100	[thread overview]
Message-ID: <20200701195914.GK2786714@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAHk-=wj_2v9m+yZioE4vOLGW1mc9SBa5+++LdeJ86aEeB5OXcw@mail.gmail.com>

On Wed, Jul 01, 2020 at 12:04:36PM -0700, Linus Torvalds wrote:
> On Wed, Jul 1, 2020 at 11:41 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > Rather nasty for ppc; they have separate user_read_access_end() and
> > user_write_access_end().
> 
> That's actually for the access granting. Shutting the access down ends
> up always doing the same thing anyway..

#define user_read_access_end            prevent_current_read_from_user
#define user_write_access_end           prevent_current_write_to_user
static inline void prevent_current_read_from_user(void)
{
        prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ);
}

static inline void prevent_current_write_to_user(void)
{
        prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE);
}

and prevent_user_access() has instances that do care about the direction...

  reply	other threads:[~2020-07-01 19:59 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-01 18:22 objtool clac/stac handling change Linus Torvalds
2020-07-01 18:29 ` Andy Lutomirski
2020-07-01 19:35   ` Linus Torvalds
2020-07-01 20:36     ` Andy Lutomirski
2020-07-01 20:51       ` Josh Poimboeuf
2020-07-01 21:02         ` Linus Torvalds
2020-07-02  0:00           ` Josh Poimboeuf
2020-07-02  8:05             ` Peter Zijlstra
2020-07-01 20:51       ` Linus Torvalds
2020-07-02  0:47         ` Andy Lutomirski
2020-07-02  2:30           ` Linus Torvalds
2020-07-02  2:35             ` Linus Torvalds
2020-07-02  3:08             ` Andy Lutomirski
2020-07-01 18:41 ` Al Viro
2020-07-01 19:04   ` Linus Torvalds
2020-07-01 19:59     ` Al Viro [this message]
2020-07-01 20:25       ` Linus Torvalds
2020-07-02 13:34         ` Michael Ellerman
2020-07-02 14:01           ` Al Viro
2020-07-02 14:04             ` Al Viro
2020-07-02 15:13           ` Christophe Leroy
2020-07-02 20:13             ` Linus Torvalds
2020-07-03  3:59               ` Michael Ellerman
2020-07-03  3:17             ` Michael Ellerman
2020-07-03  5:27               ` Christophe Leroy
2020-07-03  5:27                 ` Christophe Leroy
2020-07-02 19:52           ` Linus Torvalds
2020-07-02 20:17             ` Al Viro
2020-07-02 20:32               ` Linus Torvalds
2020-07-02 20:59                 ` Al Viro
2020-07-02 21:55                   ` Linus Torvalds
2020-07-03  1:33                     ` Al Viro
2020-07-03  3:32                       ` Linus Torvalds
2020-07-03 21:02                       ` Al Viro
2020-07-03 21:10                         ` Linus Torvalds
2020-07-03 21:41                           ` Andy Lutomirski
2020-07-03 22:25                             ` Al Viro
2020-07-03 21:59                           ` Al Viro
2020-07-03 22:04                             ` Al Viro
2020-07-03 22:12                           ` Al Viro
2020-07-04  0:49                         ` Al Viro
2020-07-04  1:54                           ` Linus Torvalds
2020-07-04  2:30                             ` Al Viro
2020-07-04  3:06                               ` Linus Torvalds
2020-07-04  2:11                           ` Al Viro
2020-07-07 12:35                             ` David Laight
2020-07-10 22:37                               ` Linus Torvalds
2020-07-13  9:32                                 ` David Laight

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