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Subject: [PATCH] PCI: Clean up resource allocation in
 devm_of_pci_get_host_bridge_resources()
To:     Bjorn Helgaas <bhelgaas@google.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc:     Andy Shevchenko <andy.shevchenko@gmail.com>,
        linux-pci@vger.kernel.org,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>,
        Jingoo Han <jingoohan1@gmail.com>,
        Joao Pinto <Joao.Pinto@synopsys.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
References: <cover.1526375226.git.jan.kiszka@siemens.com>
 <3aeb2ed038cbce8fe744b614dc19d414555a7e8f.1526375226.git.jan.kiszka@siemens.com>
 <CAHp75VeUbjobse6uLeM4h_xXRUw+YUQUN+EOye67AJy77a5euQ@mail.gmail.com>
 <CAHp75VeM7_8+9QJjOypXaiBhpWP4B5KACdUQ-p3frbS3jPh=OQ@mail.gmail.com>
From:   Jan Kiszka <jan.kiszka@siemens.com>
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Date:   Wed, 16 May 2018 14:31:44 +0200
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Instead of first allocating and then freeing memory for struct resource
in case we cannot parse a PCI resource from the device tree, work
against a local struct and kmemdup it when we decide to go with it.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 drivers/pci/of.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index b06585a1da75..fc0f906c5c25 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -266,7 +266,7 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
 			struct list_head *resources, resource_size_t *io_base)
 {
 	struct device_node *dev_node = dev->of_node;
-	struct resource *res;
+	struct resource *res, tmp_res;
 	struct resource *bus_range;
 	struct of_pci_range range;
 	struct of_pci_range_parser parser;
@@ -320,18 +320,16 @@ int devm_of_pci_get_host_bridge_resources(struct device *dev,
 		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 			continue;
 
-		res = devm_kzalloc(dev, sizeof(struct resource), GFP_KERNEL);
+		err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
+		if (err)
+			continue;
+
+		res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
 		if (!res) {
 			err = -ENOMEM;
 			goto failed;
 		}
 
-		err = of_pci_range_to_resource(&range, dev_node, res);
-		if (err) {
-			devm_kfree(dev, res);
-			continue;
-		}
-
 		if (resource_type(res) == IORESOURCE_IO) {
 			if (!io_base) {
 				dev_err(dev,
-- 
2.13.6