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Commit 42eb088e authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

sched: Avoid NULL dereference on sd_busy 



Commit 37dc6b50 ("sched: Remove unnecessary iteration over sched
domains to update nr_busy_cpus") forgot to clear 'sd_busy' under some
conditions leading to a possible NULL deref in set_cpu_sd_state_idle().

Reported-by: default avatarAnton Blanchard <anton@samba.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131118113701.GF3866@twins.programming.kicks-ass.net


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 9abf24d4

kernel/sched/core.c

+2 −1
Original line number Diff line number Diff line
@@ -4910,8 +4910,9 @@ static void update_top_cache_domain(int cpu) 
	if (sd) {

		id = cpumask_first(sched_domain_span(sd));

		size = cpumask_weight(sched_domain_span(sd));

		rcu_assign_pointer(per_cpu(sd_busy, cpu), sd->parent);

		sd = sd->parent; /* sd_busy */

	}

	rcu_assign_pointer(per_cpu(sd_busy, cpu), sd);



	rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);

	per_cpu(sd_llc_size, cpu) = size;