CRED: Wrap task credential accesses in the filesystem subsystem

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 9 insertions, 9 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 4e834f16d9da..604834f3b208 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -980,7 +980,7 @@ int flush_old_exec(struct linux_binprm * bprm)
         /* This is the point of no return */
         current->sas_ss_sp = current->sas_ss_size = 0;
 
-        if (current->euid == current->uid && current->egid == current->gid)
+        if (current_euid() == current_uid() && current_egid() == current_gid())
                 set_dumpable(current->mm, 1);
         else
                 set_dumpable(current->mm, suid_dumpable);
@@ -1007,7 +1007,7 @@ int flush_old_exec(struct linux_binprm * bprm)
          */
         current->mm->task_size = TASK_SIZE;
 
-        if (bprm->e_uid != current->euid || bprm->e_gid != current->egid) {
+        if (bprm->e_uid != current_euid() || bprm->e_gid != current_egid()) {
                 suid_keys(current);
                 set_dumpable(current->mm, suid_dumpable);
                 current->pdeath_signal = 0;
@@ -1047,8 +1047,8 @@ int prepare_binprm(struct linux_binprm *bprm)
         if (bprm->file->f_op == NULL)
                 return -EACCES;
 
-        bprm->e_uid = current->euid;
-        bprm->e_gid = current->egid;
+        bprm->e_uid = current_euid();
+        bprm->e_gid = current_egid();
 
         if(!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) {
                 /* Set-uid? */
@@ -1096,7 +1096,7 @@ void compute_creds(struct linux_binprm *bprm)
 {
         int unsafe;
 
-        if (bprm->e_uid != current->uid) {
+        if (bprm->e_uid != current_uid()) {
                 suid_keys(current);
                 current->pdeath_signal = 0;
         }
@@ -1424,7 +1424,7 @@ static int format_corename(char *corename, long signr)
                         /* uid */
                         case 'u':
                                 rc = snprintf(out_ptr, out_end - out_ptr,
-                                              "%d", current->uid);
+                                              "%d", current_uid());
                                 if (rc > out_end - out_ptr)
                                         goto out;
                                 out_ptr += rc;
@@ -1432,7 +1432,7 @@ static int format_corename(char *corename, long signr)
                         /* gid */
                         case 'g':
                                 rc = snprintf(out_ptr, out_end - out_ptr,
-                                              "%d", current->gid);
+                                              "%d", current_gid());
                                 if (rc > out_end - out_ptr)
                                         goto out;
                                 out_ptr += rc;
@@ -1709,7 +1709,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
         struct inode * inode;
         struct file * file;
         int retval = 0;
-        int fsuid = current->fsuid;
+        int fsuid = current_fsuid();
         int flag = 0;
         int ispipe = 0;
         unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
@@ -1815,7 +1815,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
          * Dont allow local users get cute and trick others to coredump
          * into their pre-created files:
          */
-        if (inode->i_uid != current->fsuid)
+        if (inode->i_uid != current_fsuid())
                 goto close_fail;
         if (!file->f_op)
                 goto close_fail;