userns: Store uid and gid values in struct cred with kuid_t and kgid_t types

cred.h and a few trivial users of struct cred are changed.  The rest of the users
of struct cred are left for other patches as there are too many changes to make
in one go and leave the change reviewable.  If the user namespace is disabled and
CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile
and behave correctly.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 22 insertions, 14 deletions

diff --git a/kernel/cred.c b/kernel/cred.c
index 7a0d80669886..eddc5e2e9587 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -49,6 +49,14 @@ struct cred init_cred = {
         .subscribers            = ATOMIC_INIT(2),
         .magic                  = CRED_MAGIC,
 #endif
+        .uid                    = GLOBAL_ROOT_UID,
+        .gid                    = GLOBAL_ROOT_GID,
+        .suid                   = GLOBAL_ROOT_UID,
+        .sgid                   = GLOBAL_ROOT_GID,
+        .euid                   = GLOBAL_ROOT_UID,
+        .egid                   = GLOBAL_ROOT_GID,
+        .fsuid                  = GLOBAL_ROOT_UID,
+        .fsgid                  = GLOBAL_ROOT_GID,
         .securebits             = SECUREBITS_DEFAULT,
         .cap_inheritable        = CAP_EMPTY_SET,
         .cap_permitted          = CAP_FULL_SET,
@@ -488,10 +496,10 @@ int commit_creds(struct cred *new)
         get_cred(new); /* we will require a ref for the subj creds too */
 
         /* dumpability changes */
-        if (old->euid != new->euid ||
-            old->egid != new->egid ||
-            old->fsuid != new->fsuid ||
-            old->fsgid != new->fsgid ||
+        if (!uid_eq(old->euid, new->euid) ||
+            !gid_eq(old->egid, new->egid) ||
+            !uid_eq(old->fsuid, new->fsuid) ||
+            !gid_eq(old->fsgid, new->fsgid) ||
             !cap_issubset(new->cap_permitted, old->cap_permitted)) {
                 if (task->mm)
                         set_dumpable(task->mm, suid_dumpable);
@@ -500,9 +508,9 @@ int commit_creds(struct cred *new)
         }
 
         /* alter the thread keyring */
-        if (new->fsuid != old->fsuid)
+        if (!uid_eq(new->fsuid, old->fsuid))
                 key_fsuid_changed(task);
-        if (new->fsgid != old->fsgid)
+        if (!gid_eq(new->fsgid, old->fsgid))
                 key_fsgid_changed(task);
 
         /* do it
@@ -519,16 +527,16 @@ int commit_creds(struct cred *new)
         alter_cred_subscribers(old, -2);
 
         /* send notifications */
-        if (new->uid   != old->uid  ||
-            new->euid  != old->euid ||
-            new->suid  != old->suid ||
-            new->fsuid != old->fsuid)
+        if (!uid_eq(new->uid,   old->uid)  ||
+            !uid_eq(new->euid,  old->euid) ||
+            !uid_eq(new->suid,  old->suid) ||
+            !uid_eq(new->fsuid, old->fsuid))
                 proc_id_connector(task, PROC_EVENT_UID);
 
-        if (new->gid   != old->gid  ||
-            new->egid  != old->egid ||
-            new->sgid  != old->sgid ||
-            new->fsgid != old->fsgid)
+        if (!gid_eq(new->gid,   old->gid)  ||
+            !gid_eq(new->egid,  old->egid) ||
+            !gid_eq(new->sgid,  old->sgid) ||
+            !gid_eq(new->fsgid, old->fsgid))
                 proc_id_connector(task, PROC_EVENT_GID);
 
         /* release the old obj and subj refs both */