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Commit 7b9d1b22 authored by Heiko Carstens's avatar Heiko Carstens Committed by David S. Miller
Browse files

iucv: prevent cpu hotplug when walking cpu_online_map. 



The code used preempt_disable() to prevent cpu hotplug, however that
doesn't protect for cpus being added. So use get_online_cpus() instead.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarUrsula Braun <braunu@de.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f1494ed1

net/iucv/iucv.c

+7 −4
Original line number Diff line number Diff line
@@ -474,14 +474,14 @@ static void iucv_setmask_mp(void) 
{

	int cpu;



	preempt_disable();

	get_online_cpus();

	for_each_online_cpu(cpu)

		/* Enable all cpus with a declared buffer. */

		if (cpu_isset(cpu, iucv_buffer_cpumask) &&

		    !cpu_isset(cpu, iucv_irq_cpumask))

			smp_call_function_single(cpu, iucv_allow_cpu,

						 NULL, 0, 1);

	preempt_enable();

	put_online_cpus();

}



/**
@@ -521,16 +521,17 @@ static int iucv_enable(void) 
		goto out;

	/* Declare per cpu buffers. */

	rc = -EIO;

	preempt_disable();

	get_online_cpus();

	for_each_online_cpu(cpu)

		smp_call_function_single(cpu, iucv_declare_cpu, NULL, 0, 1);

	preempt_enable();

	if (cpus_empty(iucv_buffer_cpumask))

		/* No cpu could declare an iucv buffer. */

		goto out_path;

	put_online_cpus();

	return 0;



out_path:

	put_online_cpus();

	kfree(iucv_path_table);

out:

	return rc;
@@ -545,7 +546,9 @@ static int iucv_enable(void) 
 */

static void iucv_disable(void)

{

	get_online_cpus();

	on_each_cpu(iucv_retrieve_cpu, NULL, 0, 1);

	put_online_cpus();

	kfree(iucv_path_table);

}