[PATCH] fix sched_setscheduler semantics

Currently, a negative policy argument passed into the
'sys_sched_setscheduler()' system call, will return with success.  However,
the manpage for 'sys_sched_setscheduler' says:

EINVAL The scheduling policy is not one of the recognized policies, or the
              parameter p does not make sense for the policy.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 788ecce1e0e4..3ee2ae45125f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3850,6 +3850,10 @@ do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
 asmlinkage long sys_sched_setscheduler(pid_t pid, int policy,
                                        struct sched_param __user *param)
 {
+        /* negative values for policy are not valid */
+        if (policy < 0)
+                return -EINVAL;
+
         return do_sched_setscheduler(pid, policy, param);
 }