From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 22 Mar 2018 16:22:42 +0100
Subject: iommu/amd: Return proper error code in irq_remapping_alloc()
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: d9fa995242046ec72c5f2b0a7c115ec4f53c225a
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension

Upstream commit 29d049be9438278c47253a74cf8d0ddf36bd5d68

In the unlikely case when alloc_irq_table() is not able to return a
remap table then "ret" will be assigned with an error code. Later, the
code checks `index' and if it is negative (which it is because it is
initialized with `-1') and then then function properly aborts but
returns `-1' instead `-ENOMEM' what was intended.
In order to correct this, I assign -ENOMEM to index.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
 drivers/iommu/amd_iommu.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -4299,7 +4299,7 @@ static int irq_remapping_alloc(struct ir
 	struct amd_ir_data *data = NULL;
 	struct irq_cfg *cfg;
 	int i, ret, devid;
-	int index = -1;
+	int index;
 
 	if (!info)
 		return -EINVAL;
@@ -4341,7 +4341,7 @@ static int irq_remapping_alloc(struct ir
 			WARN_ON(table->min_index != 32);
 			index = info->ioapic_pin;
 		} else {
-			ret = -ENOMEM;
+			index = -ENOMEM;
 		}
 	} else {
 		bool align = (info->type == X86_IRQ_ALLOC_TYPE_MSI);