PCI: Allow access to VPD attributes with size 0

hreinecke · bjorn-helgaas · commit f52e5629f66d · 2016-02-29T17:46:50.000-06:00
It is not always possible to determine the actual size of the VPD
data, so allow access to them if the size is set to '0'.

Tested-by: Shane Seymour &lt;shane.seymour@hpe.com&gt;
Tested-by: Babu Moger &lt;babu.moger@oracle.com&gt;
Signed-off-by: Hannes Reinecke &lt;hare@suse.de&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Alexander Duyck &lt;alexander.duyck@gmail.com&gt;
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
@@ -769,10 +769,12 @@ static ssize_t read_vpd_attr(struct file *filp, struct kobject *kobj,
 {
 	struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
 
-	if (off > bin_attr->size)
-		count = 0;
-	else if (count > bin_attr->size - off)
-		count = bin_attr->size - off;
+	if (bin_attr->size > 0) {
+		if (off > bin_attr->size)
+			count = 0;
+		else if (count > bin_attr->size - off)
+			count = bin_attr->size - off;
+	}
 
 	return pci_read_vpd(dev, off, count, buf);
 }
@@ -783,10 +785,12 @@ static ssize_t write_vpd_attr(struct file *filp, struct kobject *kobj,
 {
 	struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
 
-	if (off > bin_attr->size)
-		count = 0;
-	else if (count > bin_attr->size - off)
-		count = bin_attr->size - off;
+	if (bin_attr->size > 0) {
+		if (off > bin_attr->size)
+			count = 0;
+		else if (count > bin_attr->size - off)
+			count = bin_attr->size - off;
+	}
 
 	return pci_write_vpd(dev, off, count, buf);
 }
