drm/hdcp: update content protection property with uevent

[sfrench/cifs-2.6.git] / kernel / smp.c

diff --git a/kernel/smp.c b/kernel/smp.c
index 616d4d1148475291a16167aee7e48890b13890ec..7dbcb402c2fc0af441d75d13eeaef7a642f4fd57 100644 (file)
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -291,6 +291,14 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info,
        WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
                     && !oops_in_progress);
 
+       /*
+        * When @wait we can deadlock when we interrupt between llist_add() and
+        * arch_send_call_function_ipi*(); when !@wait we can deadlock due to
+        * csd_lock() on because the interrupt context uses the same csd
+        * storage.
+        */
+       WARN_ON_ONCE(!in_task());
+
        csd = &csd_stack;
        if (!wait) {
                csd = this_cpu_ptr(&csd_data);
@@ -416,6 +424,14 @@ void smp_call_function_many(const struct cpumask *mask,
        WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
                     && !oops_in_progress && !early_boot_irqs_disabled);
 
+       /*
+        * When @wait we can deadlock when we interrupt between llist_add() and
+        * arch_send_call_function_ipi*(); when !@wait we can deadlock due to
+        * csd_lock() on because the interrupt context uses the same csd
+        * storage.
+        */
+       WARN_ON_ONCE(!in_task());
+
        /* Try to fastpath.  So, what's a CPU they want? Ignoring this one. */
        cpu = cpumask_first_and(mask, cpu_online_mask);
        if (cpu == this_cpu)