userns: Convert ipc to use kuid and kgid where appropriate

- Store the ipc owner and creator with a kuid
- Store the ipc group and the crators group with a kgid.
- Add error handling to ipc_update_perms, allowing it to
  fail if the uids and gids can not be converted to kuids
  or kgids.
- Modify the proc files to display the ipc creator and
  owner in the user namespace of the opener of the proc file.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/include/linux/ipc.h b/include/linux/ipc.h
index 30e816148df4..ca833fdc3138 100644
--- a/include/linux/ipc.h
+++ b/include/linux/ipc.h
@@ -79,6 +79,7 @@ struct ipc_kludge {
 
 #ifdef __KERNEL__
 #include <linux/spinlock.h>
+#include <linux/uidgid.h>
 
 #define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
 
@@ -89,10 +90,10 @@ struct kern_ipc_perm
         int             deleted;
         int             id;
         key_t           key;
-        uid_t           uid;
-        gid_t           gid;
-        uid_t           cuid;
-        gid_t           cgid;
+        kuid_t          uid;
+        kgid_t          gid;
+        kuid_t          cuid;
+        kgid_t          cgid;
         umode_t         mode; 
         unsigned long   seq;
         void            *security;