release/5.2.22/powerpc-mce-Schedule-work-from-irq_work.patch

From 3353464106e8971e5f1d297a71763166383bdfdf Mon Sep 17 00:00:00 2001
From: Santosh Sivaraj <santosh@fossix.org>
Date: Tue, 20 Aug 2019 13:43:46 +0530
Subject: [PATCH] powerpc/mce: Schedule work from irq_work

commit b5bda6263cad9a927e1a4edb7493d542da0c1410 upstream.

schedule_work() cannot be called from MCE exception context as MCE can
interrupt even in interrupt disabled context.

Fixes: 733e4a4c4467 ("powerpc/mce: hookup memory_failure for UE errors")
Cc: stable@vger.kernel.org # v4.15+
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-2-santosh@fossix.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index b18df633eae9..cff31d4a501f 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -33,6 +33,7 @@ static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
 					mce_ue_event_queue);
 
 static void machine_check_process_queued_event(struct irq_work *work);
+static void machine_check_ue_irq_work(struct irq_work *work);
 void machine_check_ue_event(struct machine_check_event *evt);
 static void machine_process_ue_event(struct work_struct *work);
 
@@ -40,6 +41,10 @@ static struct irq_work mce_event_process_work = {
         .func = machine_check_process_queued_event,
 };
 
+static struct irq_work mce_ue_event_irq_work = {
+	.func = machine_check_ue_irq_work,
+};
+
 DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
 
 static void mce_set_error_info(struct machine_check_event *mce,
@@ -199,6 +204,10 @@ void release_mce_event(void)
 	get_mce_event(NULL, true);
 }
 
+static void machine_check_ue_irq_work(struct irq_work *work)
+{
+	schedule_work(&mce_ue_event_work);
+}
 
 /*
  * Queue up the MCE event which then can be handled later.
@@ -216,7 +225,7 @@ void machine_check_ue_event(struct machine_check_event *evt)
 	memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
 
 	/* Queue work to process this event later. */
-	schedule_work(&mce_ue_event_work);
+	irq_work_queue(&mce_ue_event_irq_work);
 }
 
 /*
-- 
2.7.4