[PATCH] nice and rt-prio rlimits
Add a pair of rlimits for allowing non-root tasks to raise nice and rt
priorities. Defaults to traditional behavior. Originally written by
Chris Wright.
The patch implements a simple rlimit ceiling for the RT (and nice) priorities
a task can set. The rlimit defaults to 0, meaning no change in behavior by
default. A value of 50 means RT priority levels 1-50 are allowed. A value of
100 means all 99 privilege levels from 1 to 99 are allowed. CAP_SYS_NICE is
blanket permission.
(akpm: see http://www.uwsg.iu.edu/hypermail/linux/kernel/0503.1/1921.html for
tips on integrating this with PAM).
Signed-off-by: Matt Mackall <mpm@selenic.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h
index b1fcda9..cfe3692 100644
--- a/include/asm-generic/resource.h
+++ b/include/asm-generic/resource.h
@@ -41,8 +41,11 @@
#define RLIMIT_LOCKS 10 /* maximum file locks held */
#define RLIMIT_SIGPENDING 11 /* max number of pending signals */
#define RLIMIT_MSGQUEUE 12 /* maximum bytes in POSIX mqueues */
+#define RLIMIT_NICE 13 /* max nice prio allowed to raise to
+ 0-39 for nice level 19 .. -20 */
+#define RLIMIT_RTPRIO 14 /* maximum realtime priority */
-#define RLIM_NLIMITS 13
+#define RLIM_NLIMITS 15
/*
* SuS says limits have to be unsigned.
@@ -81,6 +84,8 @@
[RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, \
[RLIMIT_SIGPENDING] = { 0, 0 }, \
[RLIMIT_MSGQUEUE] = { MQ_BYTES_MAX, MQ_BYTES_MAX }, \
+ [RLIMIT_NICE] = { 0, 0 }, \
+ [RLIMIT_RTPRIO] = { 0, 0 }, \
}
#endif /* __KERNEL__ */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1cced97..8960f99 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -845,6 +845,7 @@
extern void set_user_nice(task_t *p, long nice);
extern int task_prio(const task_t *p);
extern int task_nice(const task_t *p);
+extern int can_nice(const task_t *p, const int nice);
extern int task_curr(const task_t *p);
extern int idle_cpu(int cpu);
extern int sched_setscheduler(struct task_struct *, int, struct sched_param *);