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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2016-11-11 00:10:10 -0500 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-11-16 09:26:35 +0100 |
| commit | baa73d9e478ff32d62f3f9422822b59dd9a95a21 (patch) | |
| tree | ec1ac1b90e4a6c6337acb564d7fb518418fc510f /kernel/compat.c | |
| parent | 53d3eaa31508222e445b489f3c3ac4c63542a4ef (diff) | |
| download | linux-baa73d9e478ff32d62f3f9422822b59dd9a95a21.tar.bz2 | |
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>
Diffstat (limited to 'kernel/compat.c')
| -rw-r--r-- | kernel/compat.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/compat.c b/kernel/compat.c index 333d364be29d..b3a047f208a7 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -307,12 +307,17 @@ static inline long put_compat_itimerval(struct compat_itimerval __user *o, __put_user(i->it_value.tv_usec, &o->it_value.tv_usec))); } +asmlinkage long sys_ni_posix_timers(void); + COMPAT_SYSCALL_DEFINE2(getitimer, int, which, struct compat_itimerval __user *, it) { struct itimerval kit; int error; + if (!IS_ENABLED(CONFIG_POSIX_TIMERS)) + return sys_ni_posix_timers(); + error = do_getitimer(which, &kit); if (!error && put_compat_itimerval(it, &kit)) error = -EFAULT; @@ -326,6 +331,9 @@ COMPAT_SYSCALL_DEFINE3(setitimer, int, which, struct itimerval kin, kout; int error; + if (!IS_ENABLED(CONFIG_POSIX_TIMERS)) + return sys_ni_posix_timers(); + if (in) { if (get_compat_itimerval(&kin, in)) return -EFAULT; |