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Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 9bb7489ee645..5dadcc6df7dd 100644
--- 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) &&