diff mbox

sched/deadline: Normal users can't set/change SCHED_DEADLINE policy

Message ID 1393844961-18097-1-git-send-email-juri.lelli@gmail.com
State New
Headers show

Commit Message

Juri Lelli March 3, 2014, 11:09 a.m. UTC
Deny the use of SCHED_DEADLINE policy to unprivileged users.
Even if root users can set the policy for normal users, we
don't want the latter to be able to change their parameters
(safest behavior).

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
---
 kernel/sched/core.c |    9 +++++++++
 1 file changed, 9 insertions(+)
diff mbox

Patch

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6edbef2..dbed360 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3338,6 +3338,15 @@  recheck:
 				return -EPERM;
 		}
 
+		 /*
+		  * can't set/change SCHED_DEADLINE policy at all for now
+		  * (safest behavior); in the future we would like to allow
+		  * unprivileged DL tasks to increase their relative deadline
+		  * or reduce their runtime (both ways reducing utilization)
+		  */
+		if (dl_policy(policy))
+			return -EPERM;
+
 		/*
 		 * Treat SCHED_IDLE as nice 20. Only allow a switch to
 		 * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.