diff options
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 25 |
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) && |