posix-timers: Make them configurable
Some embedded systems have no use for them. This removes about
25KB from the kernel binary size when configured out.
Corresponding syscalls are routed to a stub logging the attempt to
use those syscalls which should be enough of a clue if they were
disabled without proper consideration. They are: timer_create,
timer_gettime: timer_getoverrun, timer_settime, timer_delete,
clock_adjtime, setitimer, getitimer, alarm.
The clock_settime, clock_gettime, clock_getres and clock_nanosleep
syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME,
CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast
majority of use cases with very little code.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-kbuild@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: Michal Marek <mmarek@suse.com>
Cc: Edward Cree <ecree@solarflare.com>
Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/kernel/sys.c b/kernel/sys.c
index 89d5be4..78c9fb7 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1416,7 +1416,8 @@ int do_prlimit(struct task_struct *tsk, unsigned int resource,
* applications, so we live with it
*/
if (!retval && new_rlim && resource == RLIMIT_CPU &&
- new_rlim->rlim_cur != RLIM_INFINITY)
+ new_rlim->rlim_cur != RLIM_INFINITY &&
+ IS_ENABLED(CONFIG_POSIX_TIMERS))
update_rlimit_cpu(tsk, new_rlim->rlim_cur);
out:
read_unlock(&tasklist_lock);