linux-kernel - [PATCH 1/2] xen-pciback: Fix error return in bar_write() and rom

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Date:   Sun,  2 Dec 2018 18:47:32 +0100
From:   Marek Marczykowski-Górecki 
        <marmarek@...isiblethingslab.com>
To:     Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>
Cc:     xen-devel@...ts.xenproject.org, linux-kernel@...r.kernel.org,
        Marek Marczykowski-Górecki 
        <marmarek@...isiblethingslab.com>,
        Dwayne Litzenberger <dlitz@...tz.net>
Subject: [PATCH 1/2] xen-pciback: Fix error return in bar_write() and rom_write()

From: Dwayne Litzenberger <dlitz@...tz.net>

Signed-off-by: Dwayne Litzenberger <dlitz@...tz.net>
---
 drivers/xen/xen-pciback/conf_space_header.c | 24 ++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/xen/xen-pciback/conf_space_header.c b/drivers/xen/xen-pciback/conf_space_header.c
index 10ae24b..697d0a8 100644
--- a/drivers/xen/xen-pciback/conf_space_header.c
+++ b/drivers/xen/xen-pciback/conf_space_header.c
@@ -135,6 +135,7 @@ static int command_write(struct pci_dev *dev, int offset, u16 value, void *data)
 
 static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data)
 {
+	int err = 0;
 	struct pci_bar_info *bar = data;
 
 	if (unlikely(!bar)) {
@@ -150,17 +151,22 @@ static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data)
 		bar->which = 1;
 	else {
 		u32 tmpval;
-		pci_read_config_dword(dev, offset, &tmpval);
+		err = pci_read_config_dword(dev, offset, &tmpval);
+		if (err)
+			goto out;
 		if (tmpval != bar->val && value == bar->val) {
 			/* Allow restoration of bar value. */
-			pci_write_config_dword(dev, offset, bar->val);
+			err = pci_write_config_dword(dev, offset, bar->val);
+			if (err)
+				goto out;
 		}
 		bar->which = 0;
 	}
 
 	/* Do we need to support enabling/disabling the rom address here? */
 
-	return 0;
+out:
+	return err;
 }
 
 /* For the BARs, only allow writes which write ~0 or
@@ -169,6 +175,7 @@ static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data)
  */
 static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data)
 {
+	int err = 0;
 	struct pci_bar_info *bar = data;
 	unsigned int pos = (offset - PCI_BASE_ADDRESS_0) / 4;
 	const struct resource *res = dev->resource;
@@ -193,15 +200,20 @@ static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data)
 		bar->which = 1;
 	else {
 		u32 tmpval;
-		pci_read_config_dword(dev, offset, &tmpval);
+		err = pci_read_config_dword(dev, offset, &tmpval);
+		if (err)
+			goto out;
 		if (tmpval != bar->val && value == bar->val) {
 			/* Allow restoration of bar value. */
-			pci_write_config_dword(dev, offset, bar->val);
+			err = pci_write_config_dword(dev, offset, bar->val);
+			if (err)
+				goto out;
 		}
 		bar->which = 0;
 	}
 
-	return 0;
+out:
+	return err;
 }
 
 static int bar_read(struct pci_dev *dev, int offset, u32 * value, void *data)
-- 
git-series 0.9.1