[3.17-rc5] Fix confusing PFA_NO_NEW_PRIVS constant.

Commit Message

Tetsuo Handa Sept. 20, 2014, 10:40 a.m. UTC

Can you apply below patch before new PFA_* are defined?
Cgroups code might want to define PFA_SPREAD_PAGE as 1 and PFA_SPREAD_SLAB as 2.
----------------------------------------
>From 8543e68adb210142fa347d8bc9d83df0bb2c5291 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <[e-mail]>
Date: Sat, 20 Sep 2014 19:24:23 +0900
Subject: [PATCH 3.17-rc5] Fix confusing PFA_NO_NEW_PRIVS constant.

Commit 1d4457f99928 ("sched: move no_new_privs into new atomic flags")
defined PFA_NO_NEW_PRIVS as hexadecimal value, but it is confusing
because it is used as bit number. Redefine it as decimal bit number.

Signed-off-by: Tetsuo Handa <[e-mail]>
---
 include/linux/sched.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Comments

Kees Cook Sept. 20, 2014, 5:19 p.m. UTC | #1

On Sat, Sep 20, 2014 at 3:40 AM, Tetsuo Handa
<[e-mail]> wrote:
> Can you apply below patch before new PFA_* are defined?
> Cgroups code might want to define PFA_SPREAD_PAGE as 1 and PFA_SPREAD_SLAB as 2.
> ----------------------------------------
> >From 8543e68adb210142fa347d8bc9d83df0bb2c5291 Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <[e-mail]>
> Date: Sat, 20 Sep 2014 19:24:23 +0900
> Subject: [PATCH 3.17-rc5] Fix confusing PFA_NO_NEW_PRIVS constant.
>
> Commit 1d4457f99928 ("sched: move no_new_privs into new atomic flags")
> defined PFA_NO_NEW_PRIVS as hexadecimal value, but it is confusing
> because it is used as bit number. Redefine it as decimal bit number.
>
> Signed-off-by: Tetsuo Handa <[e-mail]>
> ---
>  include/linux/sched.h |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 5c2c885..4557765 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1957,7 +1957,7 @@ static inline void memalloc_noio_restore(unsigned int flags)
>  }
>
>  /* Per-process atomic flags. */
> -#define PFA_NO_NEW_PRIVS 0x00000001    /* May not gain new privileges. */
> +#define PFA_NO_NEW_PRIVS 0     /* May not gain new privileges. */
>
>  static inline bool task_no_new_privs(struct task_struct *p)
>  {

Thanks, good catch.

Acked-by: Kees Cook <[e-mail]>

-Kees

Patch

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5c2c885..4557765 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1957,7 +1957,7 @@  static inline void memalloc_noio_restore(unsigned int flags)
 }
 
 /* Per-process atomic flags. */
-#define PFA_NO_NEW_PRIVS 0x00000001	/* May not gain new privileges. */
+#define PFA_NO_NEW_PRIVS 0	/* May not gain new privileges. */
 
 static inline bool task_no_new_privs(struct task_struct *p)
 {