[PATCH AUTOSEL 4.14 08/13] PCI: xgene-msi: Fix race in installing chained irq handler

[PATCH AUTOSEL 4.14 08/13] PCI: xgene-msi: Fix race in installing chained irq handler

[Sasha Levin]

From: Martin Kaiser <martin@kaiser.cx>

[ Upstream commit a93c00e5f975f23592895b7e83f35de2d36b7633 ]

Fix a race where a pending interrupt could be received and the handler
called before the handler's data has been setup, by converting to
irq_set_chained_handler_and_data().

See also 2cf5a03cb29d ("PCI/keystone: Fix race in installing chained IRQ
handler").

Based on the mail discussion, it seems ok to drop the error handling.

Link: https://lore.kernel.org/r/20210115212435.19940-3-martin@kaiser.cx
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/host/pci-xgene-msi.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/host/pci-xgene-msi.c b/drivers/pci/host/pci-xgene-msi.c
index 1f42a202b021..784b3f61199e 100644
--- a/drivers/pci/host/pci-xgene-msi.c
+++ b/drivers/pci/host/pci-xgene-msi.c
@@ -393,13 +393,9 @@ static int xgene_msi_hwirq_alloc(unsigned int cpu)
 		if (!msi_group->gic_irq)
 			continue;
 
-		irq_set_chained_handler(msi_group->gic_irq,
-					xgene_msi_isr);
-		err = irq_set_handler_data(msi_group->gic_irq, msi_group);
-		if (err) {
-			pr_err("failed to register GIC IRQ handler\n");
-			return -EINVAL;
-		}
+		irq_set_chained_handler_and_data(msi_group->gic_irq,
+			xgene_msi_isr, msi_group);
+
 		/*
 		 * Statically allocate MSI GIC IRQs to each CPU core.
 		 * With 8-core X-Gene v1, 2 MSI GIC IRQs are allocated
-- 
2.30.1

[PATCH AUTOSEL 4.14 10/13] PCI: mediatek: Add missing of_node_put() to fix reference leak

[Sasha Levin]

From: Krzysztof Wilczyński <kw@linux.com>

[ Upstream commit 42814c438aac79746d310f413a27d5b0b959c5de ]

The for_each_available_child_of_node helper internally makes use of the
of_get_next_available_child() which performs an of_node_get() on each
iteration when searching for next available child node.

Should an available child node be found, then it would return a device
node pointer with reference count incremented, thus early return from
the middle of the loop requires an explicit of_node_put() to prevent
reference count leak.

To stop the reference leak, explicitly call of_node_put() before
returning after an error occurred.

Link: https://lore.kernel.org/r/20210120184810.3068794-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/host/pcie-mediatek.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/host/pcie-mediatek.c b/drivers/pci/host/pcie-mediatek.c
index c896bb9ef968..60c3110b5151 100644
--- a/drivers/pci/host/pcie-mediatek.c
+++ b/drivers/pci/host/pcie-mediatek.c
@@ -1042,14 +1042,14 @@ static int mtk_pcie_setup(struct mtk_pcie *pcie)
 		err = of_pci_get_devfn(child);
 		if (err < 0) {
 			dev_err(dev, "failed to parse devfn: %d\n", err);
-			return err;
+			goto error_put_node;
 		}
 
 		slot = PCI_SLOT(err);
 
 		err = mtk_pcie_parse_port(pcie, child, slot);
 		if (err)
-			return err;
+			goto error_put_node;
 	}
 
 	err = mtk_pcie_subsys_powerup(pcie);
@@ -1065,6 +1065,9 @@ static int mtk_pcie_setup(struct mtk_pcie *pcie)
 		mtk_pcie_subsys_powerdown(pcie);
 
 	return 0;
+error_put_node:
+	of_node_put(child);
+	return err;
 }
 
 static int mtk_pcie_request_resources(struct mtk_pcie *pcie)
-- 
2.30.1