cpu/hotplug: Handle unbalanced hotplug enable/disable (01b41159) · Commits · 戴 / test

When cpu_hotplug_enable() is called unbalanced w/o a preceeding cpu_hotplug_disable() the code emits a warning, but happily decrements the disabled counter. This causes the next operations to malfunction. Prevent the decrement and just emit a warning. Signed-off-by:

Lianwei Wang <lianwei.wang@gmail.com> Cc: peterz@infradead.org Cc: linux-pm@vger.kernel.org Cc: oleg@redhat.com Link: http://lkml.kernel.org/r/1465541008-12476-1-git-send-email-lianwei.wang@gmail.com Signed-off-by:

Thomas Gleixner <tglx@linutronix.de>

kernel/cpu.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -331,10 +331,17 @@ void cpu_hotplug_disable(void)
		}
		EXPORT_SYMBOL_GPL(cpu_hotplug_disable);

		static void __cpu_hotplug_enable(void)
		{
		if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n"))
		return;
		cpu_hotplug_disabled--;
		}

		void cpu_hotplug_enable(void)
		{
		cpu_maps_update_begin();
		WARN_ON(--cpu_hotplug_disabled < 0);
		__cpu_hotplug_enable();
		cpu_maps_update_done();
		}
		EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
		@@ -1160,7 +1167,7 @@ void enable_nonboot_cpus(void)

		/* Allow everyone to use the CPU hotplug again */
		cpu_maps_update_begin();
		WARN_ON(--cpu_hotplug_disabled < 0);
		__cpu_hotplug_enable();
		if (cpumask_empty(frozen_cpus))
		goto out;

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