Merge branch 'linus' into perfcounters/core

Conflicts:
	fs/exec.c
	include/linux/init_task.h

Simple context conflicts.

1 files changed, 332 insertions, 254 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
index 0f66633be31..1544c305751 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -113,12 +113,17 @@ EXPORT_SYMBOL(cad_pid);
 
 void (*pm_power_off_prepare)(void);
 
+/*
+ * set the priority of a task
+ * - the caller must hold the RCU read lock
+ */
 static int set_one_prio(struct task_struct *p, int niceval, int error)
 {
+	const struct cred *cred = current_cred(), *pcred = __task_cred(p);
 	int no_nice;
 
-	if (p->uid != current->euid &&
-		p->euid != current->euid && !capable(CAP_SYS_NICE)) {
+	if (pcred->uid  != cred->euid &&
+	    pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) {
 		error = -EPERM;
 		goto out;
 	}
@@ -142,6 +147,7 @@ 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;
 
@@ -175,18 +181,18 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
 			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 			break;
 		case PRIO_USER:
-			user = current->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->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;
 	}
@@ -206,6 +212,7 @@ 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;
 
@@ -237,21 +244,21 @@ asmlinkage long sys_getpriority(int which, int who)
 			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 			break;
 		case PRIO_USER:
-			user = current->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->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;
 	}
@@ -473,46 +480,48 @@ void ctrl_alt_del(void)
  */
 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
 {
-	int old_rgid = current->gid;
-	int old_egid = current->egid;
-	int new_rgid = old_rgid;
-	int new_egid = old_egid;
+	const struct cred *old;
+	struct cred *new;
 	int retval;
 
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
 	retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
 	if (retval)
-		return retval;
+		goto error;
 
+	retval = -EPERM;
 	if (rgid != (gid_t) -1) {
-		if ((old_rgid == rgid) ||
-		    (current->egid==rgid) ||
+		if (old->gid == rgid ||
+		    old->egid == rgid ||
 		    capable(CAP_SETGID))
-			new_rgid = rgid;
+			new->gid = rgid;
 		else
-			return -EPERM;
+			goto error;
 	}
 	if (egid != (gid_t) -1) {
-		if ((old_rgid == egid) ||
-		    (current->egid == egid) ||
-		    (current->sgid == egid) ||
+		if (old->gid == egid ||
+		    old->egid == egid ||
+		    old->sgid == egid ||
 		    capable(CAP_SETGID))
-			new_egid = egid;
+			new->egid = egid;
 		else
-			return -EPERM;
-	}
-	if (new_egid != old_egid) {
-		set_dumpable(current->mm, suid_dumpable);
-		smp_wmb();
+			goto error;
 	}
+
 	if (rgid != (gid_t) -1 ||
-	    (egid != (gid_t) -1 && egid != old_rgid))
-		current->sgid = new_egid;
-	current->fsgid = new_egid;
-	current->egid = new_egid;
-	current->gid = new_rgid;
-	key_fsgid_changed(current);
-	proc_id_connector(current, PROC_EVENT_GID);
-	return 0;
+	    (egid != (gid_t) -1 && egid != old->gid))
+		new->sgid = new->egid;
+	new->fsgid = new->egid;
+
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
 }
 
 /*
@@ -522,56 +531,54 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
  */
 asmlinkage long sys_setgid(gid_t gid)
 {
-	int old_egid = current->egid;
+	const struct cred *old;
+	struct cred *new;
 	int retval;
 
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
 	retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
 	if (retval)
-		return retval;
+		goto error;
 
-	if (capable(CAP_SETGID)) {
-		if (old_egid != gid) {
-			set_dumpable(current->mm, suid_dumpable);
-			smp_wmb();
-		}
-		current->gid = current->egid = current->sgid = current->fsgid = gid;
-	} else if ((gid == current->gid) || (gid == current->sgid)) {
-		if (old_egid != gid) {
-			set_dumpable(current->mm, suid_dumpable);
-			smp_wmb();
-		}
-		current->egid = current->fsgid = gid;
-	}
+	retval = -EPERM;
+	if (capable(CAP_SETGID))
+		new->gid = new->egid = new->sgid = new->fsgid = gid;
+	else if (gid == old->gid || gid == old->sgid)
+		new->egid = new->fsgid = gid;
 	else
-		return -EPERM;
+		goto error;
 
-	key_fsgid_changed(current);
-	proc_id_connector(current, PROC_EVENT_GID);
-	return 0;
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
 }
   
-static int set_user(uid_t new_ruid, int dumpclear)
+/*
+ * change the user struct in a credentials set to match the new UID
+ */
+static int set_user(struct cred *new)
 {
 	struct user_struct *new_user;
 
-	new_user = alloc_uid(current->nsproxy->user_ns, new_ruid);
+	new_user = alloc_uid(current_user_ns(), new->uid);
 	if (!new_user)
 		return -EAGAIN;
 
 	if (atomic_read(&new_user->processes) >=
 				current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
-			new_user != current->nsproxy->user_ns->root_user) {
+			new_user != INIT_USER) {
 		free_uid(new_user);
 		return -EAGAIN;
 	}
 
-	switch_uid(new_user);
-
-	if (dumpclear) {
-		set_dumpable(current->mm, suid_dumpable);
-		smp_wmb();
-	}
-	current->uid = new_ruid;
+	free_uid(new->user);
+	new->user = new_user;
 	return 0;
 }
 
@@ -592,54 +599,56 @@ static int set_user(uid_t new_ruid, int dumpclear)
  */
 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
 {
-	int old_ruid, old_euid, old_suid, new_ruid, new_euid;
+	const struct cred *old;
+	struct cred *new;
 	int retval;
 
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
 	retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
 	if (retval)
-		return retval;
-
-	new_ruid = old_ruid = current->uid;
-	new_euid = old_euid = current->euid;
-	old_suid = current->suid;
+		goto error;
 
+	retval = -EPERM;
 	if (ruid != (uid_t) -1) {
-		new_ruid = ruid;
-		if ((old_ruid != ruid) &&
-		    (current->euid != ruid) &&
+		new->uid = ruid;
+		if (old->uid != ruid &&
+		    old->euid != ruid &&
 		    !capable(CAP_SETUID))
-			return -EPERM;
+			goto error;
 	}
 
 	if (euid != (uid_t) -1) {
-		new_euid = euid;
-		if ((old_ruid != euid) &&
-		    (current->euid != euid) &&
-		    (current->suid != euid) &&
+		new->euid = euid;
+		if (old->uid != euid &&
+		    old->euid != euid &&
+		    old->suid != euid &&
 		    !capable(CAP_SETUID))
-			return -EPERM;
+			goto error;
 	}
 
-	if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
-		return -EAGAIN;
+	retval = -EAGAIN;
+	if (new->uid != old->uid && set_user(new) < 0)
+		goto error;
 
-	if (new_euid != old_euid) {
-		set_dumpable(current->mm, suid_dumpable);
-		smp_wmb();
-	}
-	current->fsuid = current->euid = new_euid;
 	if (ruid != (uid_t) -1 ||
-	    (euid != (uid_t) -1 && euid != old_ruid))
-		current->suid = current->euid;
-	current->fsuid = current->euid;
+	    (euid != (uid_t) -1 && euid != old->uid))
+		new->suid = new->euid;
+	new->fsuid = new->euid;
 
-	key_fsuid_changed(current);
-	proc_id_connector(current, PROC_EVENT_UID);
-
-	return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
-}
+	retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
+	if (retval < 0)
+		goto error;
 
+	return commit_creds(new);
 
+error:
+	abort_creds(new);
+	return retval;
+}
 		
 /*
  * setuid() is implemented like SysV with SAVED_IDS 
@@ -654,36 +663,41 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
  */
 asmlinkage long sys_setuid(uid_t uid)
 {
-	int old_euid = current->euid;
-	int old_ruid, old_suid, new_suid;
+	const struct cred *old;
+	struct cred *new;
 	int retval;
 
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
 	retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
 	if (retval)
-		return retval;
+		goto error;
 
-	old_ruid = current->uid;
-	old_suid = current->suid;
-	new_suid = old_suid;
-	
+	retval = -EPERM;
 	if (capable(CAP_SETUID)) {
-		if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
-			return -EAGAIN;
-		new_suid = uid;
-	} else if ((uid != current->uid) && (uid != new_suid))
-		return -EPERM;
-
-	if (old_euid != uid) {
-		set_dumpable(current->mm, suid_dumpable);
-		smp_wmb();
+		new->suid = new->uid = uid;
+		if (uid != old->uid && set_user(new) < 0) {
+			retval = -EAGAIN;
+			goto error;
+		}
+	} else if (uid != old->uid && uid != new->suid) {
+		goto error;
 	}
-	current->fsuid = current->euid = uid;
-	current->suid = new_suid;
 
-	key_fsuid_changed(current);
-	proc_id_connector(current, PROC_EVENT_UID);
+	new->fsuid = new->euid = uid;
+
+	retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
+	if (retval < 0)
+		goto error;
 
-	return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
 }
 
 
@@ -693,54 +707,63 @@ asmlinkage long sys_setuid(uid_t uid)
  */
 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 {
-	int old_ruid = current->uid;
-	int old_euid = current->euid;
-	int old_suid = current->suid;
+	const struct cred *old;
+	struct cred *new;
 	int retval;
 
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
 	retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
 	if (retval)
-		return retval;
+		goto error;
+	old = current_cred();
 
+	retval = -EPERM;
 	if (!capable(CAP_SETUID)) {
-		if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
-		    (ruid != current->euid) && (ruid != current->suid))
-			return -EPERM;
-		if ((euid != (uid_t) -1) && (euid != current->uid) &&
-		    (euid != current->euid) && (euid != current->suid))
-			return -EPERM;
-		if ((suid != (uid_t) -1) && (suid != current->uid) &&
-		    (suid != current->euid) && (suid != current->suid))
-			return -EPERM;
+		if (ruid != (uid_t) -1 && ruid != old->uid &&
+		    ruid != old->euid  && ruid != old->suid)
+			goto error;
+		if (euid != (uid_t) -1 && euid != old->uid &&
+		    euid != old->euid  && euid != old->suid)
+			goto error;
+		if (suid != (uid_t) -1 && suid != old->uid &&
+		    suid != old->euid  && suid != old->suid)
+			goto error;
 	}
+
+	retval = -EAGAIN;
 	if (ruid != (uid_t) -1) {
-		if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
-			return -EAGAIN;
+		new->uid = ruid;
+		if (ruid != old->uid && set_user(new) < 0)
+			goto error;
 	}
-	if (euid != (uid_t) -1) {
-		if (euid != current->euid) {
-			set_dumpable(current->mm, suid_dumpable);
-			smp_wmb();
-		}
-		current->euid = euid;
-	}
-	current->fsuid = current->euid;
+	if (euid != (uid_t) -1)
+		new->euid = euid;
 	if (suid != (uid_t) -1)
-		current->suid = suid;
+		new->suid = suid;
+	new->fsuid = new->euid;
+
+	retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
+	if (retval < 0)
+		goto error;
 
-	key_fsuid_changed(current);
-	proc_id_connector(current, PROC_EVENT_UID);
+	return commit_creds(new);
 
-	return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
+error:
+	abort_creds(new);
+	return retval;
 }
 
 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
 {
+	const struct cred *cred = current_cred();
 	int retval;
 
-	if (!(retval = put_user(current->uid, ruid)) &&
-	    !(retval = put_user(current->euid, euid)))
-		retval = put_user(current->suid, suid);
+	if (!(retval   = put_user(cred->uid,  ruid)) &&
+	    !(retval   = put_user(cred->euid, euid)))
+		retval = put_user(cred->suid, suid);
 
 	return retval;
 }
@@ -750,48 +773,55 @@ asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __us
  */
 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 {
+	const struct cred *old;
+	struct cred *new;
 	int retval;
 
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
 	retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
 	if (retval)
-		return retval;
+		goto error;
 
+	retval = -EPERM;
 	if (!capable(CAP_SETGID)) {
-		if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
-		    (rgid != current->egid) && (rgid != current->sgid))
-			return -EPERM;
-		if ((egid != (gid_t) -1) && (egid != current->gid) &&
-		    (egid != current->egid) && (egid != current->sgid))
-			return -EPERM;
-		if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
-		    (sgid != current->egid) && (sgid != current->sgid))
-			return -EPERM;
+		if (rgid != (gid_t) -1 && rgid != old->gid &&
+		    rgid != old->egid  && rgid != old->sgid)
+			goto error;
+		if (egid != (gid_t) -1 && egid != old->gid &&
+		    egid != old->egid  && egid != old->sgid)
+			goto error;
+		if (sgid != (gid_t) -1 && sgid != old->gid &&
+		    sgid != old->egid  && sgid != old->sgid)
+			goto error;
 	}
-	if (egid != (gid_t) -1) {
-		if (egid != current->egid) {
-			set_dumpable(current->mm, suid_dumpable);
-			smp_wmb();
-		}
-		current->egid = egid;
-	}
-	current->fsgid = current->egid;
+
 	if (rgid != (gid_t) -1)
-		current->gid = rgid;
+		new->gid = rgid;
+	if (egid != (gid_t) -1)
+		new->egid = egid;
 	if (sgid != (gid_t) -1)
-		current->sgid = sgid;
+		new->sgid = sgid;
+	new->fsgid = new->egid;
 
-	key_fsgid_changed(current);
-	proc_id_connector(current, PROC_EVENT_GID);
-	return 0;
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
 }
 
 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
 {
+	const struct cred *cred = current_cred();
 	int retval;
 
-	if (!(retval = put_user(current->gid, rgid)) &&
-	    !(retval = put_user(current->egid, egid)))
-		retval = put_user(current->sgid, sgid);
+	if (!(retval   = put_user(cred->gid,  rgid)) &&
+	    !(retval   = put_user(cred->egid, egid)))
+		retval = put_user(cred->sgid, sgid);
 
 	return retval;
 }
@@ -805,27 +835,35 @@ asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __us
  */
 asmlinkage long sys_setfsuid(uid_t uid)
 {
-	int old_fsuid;
+	const struct cred *old;
+	struct cred *new;
+	uid_t old_fsuid;
 
-	old_fsuid = current->fsuid;
-	if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
-		return old_fsuid;
+	new = prepare_creds();
+	if (!new)
+		return current_fsuid();
+	old = current_cred();
+	old_fsuid = old->fsuid;
 
-	if (uid == current->uid || uid == current->euid ||
-	    uid == current->suid || uid == current->fsuid || 
+	if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0)
+		goto error;
+
+	if (uid == old->uid  || uid == old->euid  ||
+	    uid == old->suid || uid == old->fsuid ||
 	    capable(CAP_SETUID)) {
 		if (uid != old_fsuid) {
-			set_dumpable(current->mm, suid_dumpable);
-			smp_wmb();
+			new->fsuid = uid;
+			if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
+				goto change_okay;
 		}
-		current->fsuid = uid;
 	}
 
-	key_fsuid_changed(current);
-	proc_id_connector(current, PROC_EVENT_UID);
-
-	security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
+error:
+	abort_creds(new);
+	return old_fsuid;
 
+change_okay:
+	commit_creds(new);
 	return old_fsuid;
 }
 
@@ -834,23 +872,34 @@ asmlinkage long sys_setfsuid(uid_t uid)
  */
 asmlinkage long sys_setfsgid(gid_t gid)
 {
-	int old_fsgid;
+	const struct cred *old;
+	struct cred *new;
+	gid_t old_fsgid;
+
+	new = prepare_creds();
+	if (!new)
+		return current_fsgid();
+	old = current_cred();
+	old_fsgid = old->fsgid;
 
-	old_fsgid = current->fsgid;
 	if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
-		return old_fsgid;
+		goto error;
 
-	if (gid == current->gid || gid == current->egid ||
-	    gid == current->sgid || gid == current->fsgid || 
+	if (gid == old->gid  || gid == old->egid  ||
+	    gid == old->sgid || gid == old->fsgid ||
 	    capable(CAP_SETGID)) {
 		if (gid != old_fsgid) {
-			set_dumpable(current->mm, suid_dumpable);
-			smp_wmb();
+			new->fsgid = gid;
+			goto change_okay;
 		}
-		current->fsgid = gid;
-		key_fsgid_changed(current);
-		proc_id_connector(current, PROC_EVENT_GID);
 	}
+
+error:
+	abort_creds(new);
+	return old_fsgid;
+
+change_okay:
+	commit_creds(new);
 	return old_fsgid;
 }
 
@@ -1119,7 +1168,7 @@ EXPORT_SYMBOL(groups_free);
 
 /* export the group_info to a user-space array */
 static int groups_to_user(gid_t __user *grouplist,
-    struct group_info *group_info)
+			  const struct group_info *group_info)
 {
 	int i;
 	unsigned int count = group_info->ngroups;
@@ -1187,7 +1236,7 @@ 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;
 
@@ -1209,51 +1258,74 @@ int groups_search(struct group_info *group_info, gid_t grp)
 	return 0;
 }
 
-/* validate and set current->group_info */
-int set_current_groups(struct group_info *group_info)
+/**
+ * set_groups - Change a group subscription in a set of credentials
+ * @new: The newly prepared set of credentials to alter
+ * @group_info: The group list to install
+ *
+ * Validate a group subscription and, if valid, insert it into a set
+ * of credentials.
+ */
+int set_groups(struct cred *new, struct group_info *group_info)
 {
 	int retval;
-	struct group_info *old_info;
 
 	retval = security_task_setgroups(group_info);
 	if (retval)
 		return retval;
 
+	put_group_info(new->group_info);
 	groups_sort(group_info);
 	get_group_info(group_info);
+	new->group_info = group_info;
+	return 0;
+}
+
+EXPORT_SYMBOL(set_groups);
 
-	task_lock(current);
-	old_info = current->group_info;
-	current->group_info = group_info;
-	task_unlock(current);
+/**
+ * set_current_groups - Change current's group subscription
+ * @group_info: The group list to impose
+ *
+ * Validate a group subscription and, if valid, impose it upon current's task
+ * security record.
+ */
+int set_current_groups(struct group_info *group_info)
+{
+	struct cred *new;
+	int ret;
 
-	put_group_info(old_info);
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
 
-	return 0;
+	ret = set_groups(new, group_info);
+	if (ret < 0) {
+		abort_creds(new);
+		return ret;
+	}
+
+	return commit_creds(new);
 }
 
 EXPORT_SYMBOL(set_current_groups);
 
 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
 {
-	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;
 
 	/* no need to grab task_lock here; it cannot change */
-	i = current->group_info->ngroups;
+	i = cred->group_info->ngroups;
 	if (gidsetsize) {
 		if (i > gidsetsize) {
 			i = -EINVAL;
 			goto out;
 		}
-		if (groups_to_user(grouplist, current->group_info)) {
+		if (groups_to_user(grouplist, cred->group_info)) {
 			i = -EFAULT;
 			goto out;
 		}
@@ -1297,9 +1369,11 @@ asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
  */
 int in_group_p(gid_t grp)
 {
+	const struct cred *cred = current_cred();
 	int retval = 1;
-	if (grp != current->fsgid)
-		retval = groups_search(current->group_info, grp);
+
+	if (grp != cred->fsgid)
+		retval = groups_search(cred->group_info, grp);
 	return retval;
 }
 
@@ -1307,9 +1381,11 @@ EXPORT_SYMBOL(in_group_p);
 
 int in_egroup_p(gid_t grp)
 {
+	const struct cred *cred = current_cred();
 	int retval = 1;
-	if (grp != current->egid)
-		retval = groups_search(current->group_info, grp);
+
+	if (grp != cred->egid)
+		retval = groups_search(cred->group_info, grp);
 	return retval;
 }
 
@@ -1625,50 +1701,56 @@ asmlinkage long sys_umask(int mask)
 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
 			  unsigned long arg4, unsigned long arg5)
 {
-	long error = 0;
+	struct task_struct *me = current;
+	unsigned char comm[sizeof(me->comm)];
+	long error;
 
-	if (security_task_prctl(option, arg2, arg3, arg4, arg5, &error))
+	error = security_task_prctl(option, arg2, arg3, arg4, arg5);
+	if (error != -ENOSYS)
 		return error;
 
+	error = 0;
 	switch (option) {
 		case PR_SET_PDEATHSIG:
 			if (!valid_signal(arg2)) {
 				error = -EINVAL;
 				break;
 			}
-			current->pdeath_signal = arg2;
+			me->pdeath_signal = arg2;
+			error = 0;
 			break;
 		case PR_GET_PDEATHSIG:
-			error = put_user(current->pdeath_signal, (int __user *)arg2);
+			error = put_user(me->pdeath_signal, (int __user *)arg2);
 			break;
 		case PR_GET_DUMPABLE:
-			error = get_dumpable(current->mm);
+			error = get_dumpable(me->mm);
 			break;
 		case PR_SET_DUMPABLE:
 			if (arg2 < 0 || arg2 > 1) {
 				error = -EINVAL;
 				break;
 			}
-			set_dumpable(current->mm, arg2);
+			set_dumpable(me->mm, arg2);
+			error = 0;
 			break;
 
 		case PR_SET_UNALIGN:
-			error = SET_UNALIGN_CTL(current, arg2);
+			error = SET_UNALIGN_CTL(me, arg2);
 			break;
 		case PR_GET_UNALIGN:
-			error = GET_UNALIGN_CTL(current, arg2);
+			error = GET_UNALIGN_CTL(me, arg2);
 			break;
 		case PR_SET_FPEMU:
-			error = SET_FPEMU_CTL(current, arg2);
+			error = SET_FPEMU_CTL(me, arg2);
 			break;
 		case PR_GET_FPEMU:
-			error = GET_FPEMU_CTL(current, arg2);
+			error = GET_FPEMU_CTL(me, arg2);
 			break;
 		case PR_SET_FPEXC:
-			error = SET_FPEXC_CTL(current, arg2);
+			error = SET_FPEXC_CTL(me, arg2);
 			break;
 		case PR_GET_FPEXC:
-			error = GET_FPEXC_CTL(current, arg2);
+			error = GET_FPEXC_CTL(me, arg2);
 			break;
 		case PR_GET_TIMING:
 			error = PR_TIMING_STATISTICAL;
@@ -1676,33 +1758,28 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
 		case PR_SET_TIMING:
 			if (arg2 != PR_TIMING_STATISTICAL)
 				error = -EINVAL;
+			else
+				error = 0;
 			break;
 
-		case PR_SET_NAME: {
-			struct task_struct *me = current;
-			unsigned char ncomm[sizeof(me->comm)];
-
-			ncomm[sizeof(me->comm)-1] = 0;
-			if (strncpy_from_user(ncomm, (char __user *)arg2,
-						sizeof(me->comm)-1) < 0)
+		case PR_SET_NAME:
+			comm[sizeof(me->comm)-1] = 0;
+			if (strncpy_from_user(comm, (char __user *)arg2,
+					      sizeof(me->comm) - 1) < 0)
 				return -EFAULT;
-			set_task_comm(me, ncomm);
+			set_task_comm(me, comm);
 			return 0;
-		}
-		case PR_GET_NAME: {
-			struct task_struct *me = current;
-			unsigned char tcomm[sizeof(me->comm)];
-
-			get_task_comm(tcomm, me);
-			if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
+		case PR_GET_NAME:
+			get_task_comm(comm, me);
+			if (copy_to_user((char __user *)arg2, comm,
+					 sizeof(comm)))
 				return -EFAULT;
 			return 0;
-		}
 		case PR_GET_ENDIAN:
-			error = GET_ENDIAN(current, arg2);
+			error = GET_ENDIAN(me, arg2);
 			break;
 		case PR_SET_ENDIAN:
-			error = SET_ENDIAN(current, arg2);
+			error = SET_ENDIAN(me, arg2);
 			break;
 
 		case PR_GET_SECCOMP:
@@ -1732,6 +1809,7 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
 					current->default_timer_slack_ns;
 			else
 				current->timer_slack_ns = arg2;
+			error = 0;
 			break;
 		default:
 			error = -EINVAL;