Commit 234c7f1a authored Jun 28, 2013 by James Hogan

metag: smp: enable irqs after set_cpu_online



In secondary_start_kernel() interrupts should be enabled with
local_irq_enable() after the cpu is marked as online with
set_cpu_online(). Otherwise it's possible for a timer interrupt to
trigger a softirq, which if the cpu is marked as offline may have it's
affinity altered.

Reported-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>

parent 42748752

arch/metag/kernel/smp.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -379,12 +379,7 @@ asmlinkage void secondary_start_kernel(void)

		setup_priv();

		/*
		* Enable local interrupts.
		*/
		tbi_startup_interrupt(TBID_SIGNUM_TRT);
		notify_cpu_starting(cpu);
		local_irq_enable();

		pr_info("CPU%u (thread %u): Booted secondary processor\n",
		cpu, cpu_2_hwthread_id[cpu]);
		@@ -397,6 +392,12 @@ asmlinkage void secondary_start_kernel(void)
		*/
		set_cpu_online(cpu, true);

		/*
		* Enable local interrupts.
		*/
		tbi_startup_interrupt(TBID_SIGNUM_TRT);
		local_irq_enable();

		/*
		* OK, it's off to the idle thread for us
		*/