[PATCH] nice and rt-prio rlimits

[linux-2.6-omap-h63xx.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 9bb7489ee64509eca180fe3cfe755db49b153702..5dadcc6df7dd111b94473877da3b69ae2176094a 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3223,6 +3223,19 @@ out_unlock:
 
 EXPORT_SYMBOL(set_user_nice);
 
+/*
+ * can_nice - check if a task can reduce its nice value
+ * @p: task
+ * @nice: nice value
+ */
+int can_nice(const task_t *p, const int nice)
+{
+       /* convert nice value [19,-20] to rlimit style value [0,39] */
+       int nice_rlim = 19 - nice;
+       return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
+               capable(CAP_SYS_NICE));
+}
+
 #ifdef __ARCH_WANT_SYS_NICE
 
 /*
@@ -3242,12 +3255,8 @@ asmlinkage long sys_nice(int increment)
         * We don't have to worry. Conceptually one call occurs first
         * and we have a single winner.
         */
-       if (increment < 0) {
-               if (!capable(CAP_SYS_NICE))
-                       return -EPERM;
-               if (increment < -40)
-                       increment = -40;
-       }
+       if (increment < -40)
+               increment = -40;
        if (increment > 40)
                increment = 40;
 
@@ -3257,6 +3266,9 @@ asmlinkage long sys_nice(int increment)
        if (nice > 19)
                nice = 19;
 
+       if (increment < 0 && !can_nice(current, nice))
+               return -EPERM;
+
        retval = security_task_setnice(current, nice);
        if (retval)
                return retval;
@@ -3372,6 +3384,7 @@ recheck:
                return -EINVAL;
 
        if ((policy == SCHED_FIFO || policy == SCHED_RR) &&
+           param->sched_priority > p->signal->rlim[RLIMIT_RTPRIO].rlim_cur &&
            !capable(CAP_SYS_NICE))
                return -EPERM;
        if ((current->euid != p->euid) && (current->euid != p->uid) &&