linux/kernel/sched
Tejun Heo 14a40ffccd sched: replace PF_THREAD_BOUND with PF_NO_SETAFFINITY
PF_THREAD_BOUND was originally used to mark kernel threads which were
bound to a specific CPU using kthread_bind() and a task with the flag
set allows cpus_allowed modifications only to itself.  Workqueue is
currently abusing it to prevent userland from meddling with
cpus_allowed of workqueue workers.

What we need is a flag to prevent userland from messing with
cpus_allowed of certain kernel tasks.  In kernel, anyone can
(incorrectly) squash the flag, and, for worker-type usages,
restricting cpus_allowed modification to the task itself doesn't
provide meaningful extra proection as other tasks can inject work
items to the task anyway.

This patch replaces PF_THREAD_BOUND with PF_NO_SETAFFINITY.
sched_setaffinity() checks the flag and return -EINVAL if set.
set_cpus_allowed_ptr() is no longer affected by the flag.

This will allow simplifying workqueue worker CPU affinity management.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-03-19 13:45:20 -07:00
..
auto_group.c sched: split out css_online/css_offline from tg creation/destruction 2013-01-24 12:05:18 -08:00
auto_group.h Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled" 2012-12-11 10:23:45 +01:00
clock.c
core.c sched: replace PF_THREAD_BOUND with PF_NO_SETAFFINITY 2013-03-19 13:45:20 -07:00
cpupri.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
cpupri.h
cputime.c cputime: Use local_clock() for full dynticks cputime accounting 2013-02-24 12:57:16 +01:00
debug.c Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-26 19:42:08 -08:00
fair.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
features.h Automatic NUMA Balancing V11 2012-12-16 15:18:08 -08:00
idle_task.c sched/nohz: Rewrite and fix load-avg computation -- again 2012-07-05 20:58:13 +02:00
Makefile sched: Move cputime code to its own file 2012-08-20 13:05:17 +02:00
rt.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
sched.h sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
stats.c sched: Fix /proc/sched_stat failure on very very large systems 2013-02-22 10:27:24 +01:00
stats.h
stop_task.c sched: Fix migration thread runtime bogosity 2012-08-13 18:41:55 +02:00