CRED: Wrap current->cred and a few other accessors

Wrap current->cred and a few other accessors to hide their actual
implementation.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

2 files changed, 11 insertions, 7 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index b14e2025e221..55dc70c6b4db 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -702,6 +702,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
         struct tun_net *tn;
         struct tun_struct *tun;
         struct net_device *dev;
+        const struct cred *cred = current_cred();
         int err;
 
         tn = net_generic(net, tun_net_id);
@@ -712,11 +713,12 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 
                 /* Check permissions */
                 if (((tun->owner != -1 &&
-                      current_euid() != tun->owner) ||
+                      cred->euid != tun->owner) ||
                      (tun->group != -1 &&
-                      current_egid() != tun->group)) &&
-                     !capable(CAP_NET_ADMIN))
+                      cred->egid != tun->group)) &&
+                    !capable(CAP_NET_ADMIN)) {
                         return -EPERM;
+                }
         }
         else if (__dev_get_by_name(net, ifr->ifr_name))
                 return -EINVAL;
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 1aadb9387027..aa79280df15d 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -574,6 +574,7 @@ static int usbdev_open(struct inode *inode, struct file *file)
 {
         struct usb_device *dev = NULL;
         struct dev_state *ps;
+        const struct cred *cred = current_cred();
         int ret;
 
         lock_kernel();
@@ -617,8 +618,8 @@ static int usbdev_open(struct inode *inode, struct file *file)
         init_waitqueue_head(&ps->wait);
         ps->discsignr = 0;
         ps->disc_pid = get_pid(task_pid(current));
-        ps->disc_uid = current_uid();
-        ps->disc_euid = current_euid();
+        ps->disc_uid = cred->uid;
+        ps->disc_euid = cred->euid;
         ps->disccontext = NULL;
         ps->ifclaimed = 0;
         security_task_getsecid(current, &ps->secid);
@@ -967,6 +968,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
         struct usb_host_endpoint *ep;
         struct async *as;
         struct usb_ctrlrequest *dr = NULL;
+        const struct cred *cred = current_cred();
         unsigned int u, totlen, isofrmlen;
         int ret, ifnum = -1;
         int is_in;
@@ -1174,8 +1176,8 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
         as->signr = uurb->signr;
         as->ifnum = ifnum;
         as->pid = get_pid(task_pid(current));
-        as->uid = current_uid();
-        as->euid = current_euid();
+        as->uid = cred->uid;
+        as->euid = cred->euid;
         security_task_getsecid(current, &as->secid);
         if (!is_in) {
                 if (copy_from_user(as->urb->transfer_buffer, uurb->buffer,