Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

Pull scheduler fixes from Ingo Molnar:
 "Three small fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/clock: Prevent tracing recursion in sched_clock_cpu()
  stop_machine: Fix^2 race between stop_two_cpus() and stop_cpus()
  sched/deadline: Deny unprivileged users to set/change SCHED_DEADLINE policy

diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index 43c2bcc35761e40c9342522b4fa87b92cdefd8f4..b30a2924ef1429a60152a40101ec4828c5e23268 100644 (file)
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -301,14 +301,14 @@ u64 sched_clock_cpu(int cpu)
        if (unlikely(!sched_clock_running))
                return 0ull;
 
-       preempt_disable();
+       preempt_disable_notrace();
        scd = cpu_sdc(cpu);
 
        if (cpu != smp_processor_id())
                clock = sched_clock_remote(scd);
        else
                clock = sched_clock_local(scd);
-       preempt_enable();
+       preempt_enable_notrace();
 
        return clock;
 }

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6edbef296ece25a6ee68facac279445414692368..f5c6635b806c56550bcee17aa0c2490c96b16ff7 100644 (file)
--- 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.

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 84571e09c9079e8887f73a0f24beefe58e00ff77..01fbae5b97b765199feccfbb6f985c1309dc3475 100644 (file)
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -293,7 +293,7 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void *
         */
        smp_call_function_single(min(cpu1, cpu2),
                                 &irq_cpu_stop_queue_work,
-                                &call_args, 0);
+                                &call_args, 1);
        lg_local_unlock(&stop_cpus_lock);
        preempt_enable();