arm64: fix potential deadlock in arm64-provide-pseudo-NMI-with-GICv3

hulk inclusion
category: bugfix
bugzilla: 9291
CVE: NA

--------------------------------

In some exception handlers, the interrupt is not reenabled by daifclr at first.
The later process may call local_irq_enable() to enable the interrupt, like
gic_handle_irq(). As we known, function local_irq_enable() just change the pmr now.
The following codes what i found may cause a deadlock or some issues else.
Signed-off-by: NWei Li <liwei391@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/kernel/kgdb.c

@@ -25,6 +25,7 @@
 #include <linux/kgdb.h>
 #include <linux/kprobes.h>
 #include <linux/sched/task_stack.h>
+#include <linux/irqchip/arm-gic-v3.h>
 
 #include <asm/debug-monitors.h>
 #include <asm/insn.h>
@@ -291,6 +292,9 @@ static void kgdb_call_nmi_hook(void *ignored)
 
 void kgdb_roundup_cpus(unsigned long flags)
 {
+	if (gic_prio_masking_enabled())
+		gic_arch_enable_irqs();
+
 	local_irq_enable();
 	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
 	local_irq_disable();