From 4452cb8252bac5d3e4b0717365226f3cc237d5fe Mon Sep 17 00:00:00 2001
From: Wei Li <liwei391@huawei.com>
Date: Wed, 13 Feb 2019 19:53:55 +0800
Subject: [PATCH] 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: Wei Li <liwei391@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 arch/arm64/kernel/kgdb.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index a20de58061a8..119fbf2c0788 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/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();
-- 
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