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>

1 files changed, 29 insertions, 30 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index 5d81f07c0150..c4d6b59553e9 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -143,6 +143,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
 {
         struct task_struct *g, *p;
         struct user_struct *user;
+        const struct cred *cred = current_cred();
         int error = -EINVAL;
         struct pid *pgrp;
 
@@ -176,18 +177,18 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
                         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
                         break;
                 case PRIO_USER:
-                        user = current->cred->user;
+                        user = cred->user;
                         if (!who)
-                                who = current_uid();
-                        else
-                                if (who != current_uid() && !(user = find_user(who)))
-                                        goto out_unlock;        /* No processes for this user */
+                                who = cred->uid;
+                        else if ((who != cred->uid) &&
+                                 !(user = find_user(who)))
+                                goto out_unlock;        /* No processes for this user */
 
                         do_each_thread(g, p)
-                                if (p->cred->uid == who)
+                                if (__task_cred(p)->uid == who)
                                         error = set_one_prio(p, niceval, error);
                         while_each_thread(g, p);
-                        if (who != current_uid())
+                        if (who != cred->uid)
                                 free_uid(user);         /* For find_user() */
                         break;
         }
@@ -207,6 +208,7 @@ asmlinkage long sys_getpriority(int which, int who)
 {
         struct task_struct *g, *p;
         struct user_struct *user;
+        const struct cred *cred = current_cred();
         long niceval, retval = -ESRCH;
         struct pid *pgrp;
 
@@ -238,21 +240,21 @@ asmlinkage long sys_getpriority(int which, int who)
                         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
                         break;
                 case PRIO_USER:
-                        user = current->cred->user;
+                        user = (struct user_struct *) cred->user;
                         if (!who)
-                                who = current_uid();
-                        else
-                                if (who != current_uid() && !(user = find_user(who)))
-                                        goto out_unlock;        /* No processes for this user */
+                                who = cred->uid;
+                        else if ((who != cred->uid) &&
+                                 !(user = find_user(who)))
+                                goto out_unlock;        /* No processes for this user */
 
                         do_each_thread(g, p)
-                                if (p->cred->uid == who) {
+                                if (__task_cred(p)->uid == who) {
                                         niceval = 20 - task_nice(p);
                                         if (niceval > retval)
                                                 retval = niceval;
                                 }
                         while_each_thread(g, p);
-                        if (who != current_uid())
+                        if (who != cred->uid)
                                 free_uid(user);         /* for find_user() */
                         break;
         }
@@ -743,11 +745,11 @@ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 
 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
 {
-        struct cred *cred = current->cred;
+        const struct cred *cred = current_cred();
         int retval;
 
-        if (!(retval = put_user(cred->uid, ruid)) &&
-            !(retval = put_user(cred->euid, euid)))
+        if (!(retval   = put_user(cred->uid,  ruid)) &&
+            !(retval   = put_user(cred->euid, euid)))
                 retval = put_user(cred->suid, suid);
 
         return retval;
@@ -796,11 +798,11 @@ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 
 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
 {
-        struct cred *cred = current->cred;
+        const struct cred *cred = current_cred();
         int retval;
 
-        if (!(retval = put_user(cred->gid, rgid)) &&
-            !(retval = put_user(cred->egid, egid)))
+        if (!(retval   = put_user(cred->gid,  rgid)) &&
+            !(retval   = put_user(cred->egid, egid)))
                 retval = put_user(cred->sgid, sgid);
 
         return retval;
@@ -1199,7 +1201,7 @@ static void groups_sort(struct group_info *group_info)
 }
 
 /* a simple bsearch */
-int groups_search(struct group_info *group_info, gid_t grp)
+int groups_search(const struct group_info *group_info, gid_t grp)
 {
         unsigned int left, right;
 
@@ -1268,13 +1270,8 @@ EXPORT_SYMBOL(set_current_groups);
 
 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
 {
-        struct cred *cred = current->cred;
-        int i = 0;
-
-        /*
-         *      SMP: Nobody else can change our grouplist. Thus we are
-         *      safe.
-         */
+        const struct cred *cred = current_cred();
+        int i;
 
         if (gidsetsize < 0)
                 return -EINVAL;
@@ -1330,8 +1327,9 @@ asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
  */
 int in_group_p(gid_t grp)
 {
-        struct cred *cred = current->cred;
+        const struct cred *cred = current_cred();
         int retval = 1;
+
         if (grp != cred->fsgid)
                 retval = groups_search(cred->group_info, grp);
         return retval;
@@ -1341,8 +1339,9 @@ EXPORT_SYMBOL(in_group_p);
 
 int in_egroup_p(gid_t grp)
 {
-        struct cred *cred = current->cred;
+        const struct cred *cred = current_cred();
         int retval = 1;
+
         if (grp != cred->egid)
                 retval = groups_search(cred->group_info, grp);
         return retval;