Commit f73be6de authored by H. Peter Anvin's avatar H. Peter Anvin

smp: have smp_call_function_single() detect invalid CPUs

Have smp_call_function_single() return invalid CPU indicies and return
-ENXIO.  This function is already executed inside a
get_cpu()..put_cpu() which locks out CPU removal, so rather than
having the higher layers doing another layer of locking to guard
against unplugged CPUs do the test here.
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 2a61812a
......@@ -210,8 +210,10 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
{
struct call_single_data d;
unsigned long flags;
/* prevent preemption and reschedule on another processor */
/* prevent preemption and reschedule on another processor,
as well as CPU removal */
int me = get_cpu();
int err = 0;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
......@@ -220,7 +222,7 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
local_irq_save(flags);
func(info);
local_irq_restore(flags);
} else {
} else if ((unsigned)cpu < NR_CPUS && cpu_online(cpu)) {
struct call_single_data *data = NULL;
if (!wait) {
......@@ -236,10 +238,12 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
data->func = func;
data->info = info;
generic_exec_single(cpu, data);
} else {
err = -ENXIO; /* CPU not online */
}
put_cpu();
return 0;
return err;
}
EXPORT_SYMBOL(smp_call_function_single);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment