[PATCH 3/5] PCI: maintain backwards compatibility with aer-inject user-land tool

[Andrew Patterson <andrew.patterson@hp.com>]

PCI: maintain backwards compatibility with aer-inject user-land tool

Maintain backwards compatibility with the 0.1 version  of the aer-inject
user-land tool.

Signed-off-by: Andrew Patterson<andrew.patterson@hp.com>
---

diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
index 5fc5b3e..ac0b5e7 100644
--- a/drivers/pci/pcie/aer/aer_inject.c
+++ b/drivers/pci/pcie/aer/aer_inject.c
@@ -23,10 +23,10 @@
 #include <linux/pci.h>
 #include <linux/fs.h>
 #include <linux/uaccess.h>
+#include <linux/stddef.h>
 #include "aerdrv.h"
 
 struct aer_error_inj {
-	u16 domain;
 	u8 bus;
 	u8 dev;
 	u8 fn;
@@ -36,6 +36,7 @@ struct aer_error_inj {
 	u32 header_log1;
 	u32 header_log2;
 	u32 header_log3;
+	u16 domain;
 };
 
 struct aer_error {
@@ -431,10 +432,11 @@ static ssize_t aer_inject_write(struct file *filp, const char __user *ubuf,
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
-
-	if (usize != sizeof(struct aer_error_inj))
+	if (usize < offsetof(struct aer_error_inj, domain) ||
+	    usize > sizeof(einj))
 		return -EINVAL;
 
+	memset(&einj, 0, sizeof(einj));
 	if (copy_from_user(&einj, ubuf, usize))
 		return -EFAULT;