baa73d9e47
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>
123 lines
3 KiB
C
123 lines
3 KiB
C
/*
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* Dummy stubs used when CONFIG_POSIX_TIMERS=n
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*
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* Created by: Nicolas Pitre, July 2016
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* Copyright: (C) 2016 Linaro Limited
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/linkage.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/syscalls.h>
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#include <linux/ktime.h>
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#include <linux/timekeeping.h>
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#include <linux/posix-timers.h>
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asmlinkage long sys_ni_posix_timers(void)
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{
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pr_err_once("process %d (%s) attempted a POSIX timer syscall "
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"while CONFIG_POSIX_TIMERS is not set\n",
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current->pid, current->comm);
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return -ENOSYS;
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}
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#define SYS_NI(name) SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
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SYS_NI(timer_create);
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SYS_NI(timer_gettime);
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SYS_NI(timer_getoverrun);
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SYS_NI(timer_settime);
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SYS_NI(timer_delete);
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SYS_NI(clock_adjtime);
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SYS_NI(getitimer);
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SYS_NI(setitimer);
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#ifdef __ARCH_WANT_SYS_ALARM
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SYS_NI(alarm);
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#endif
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/*
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* We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
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* as it is easy to remain compatible with little code. CLOCK_BOOTTIME
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* is also included for convenience as at least systemd uses it.
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*/
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SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
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const struct timespec __user *, tp)
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{
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struct timespec new_tp;
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if (which_clock != CLOCK_REALTIME)
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return -EINVAL;
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if (copy_from_user(&new_tp, tp, sizeof (*tp)))
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return -EFAULT;
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return do_sys_settimeofday(&new_tp, NULL);
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}
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SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
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struct timespec __user *,tp)
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{
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struct timespec kernel_tp;
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switch (which_clock) {
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case CLOCK_REALTIME: ktime_get_real_ts(&kernel_tp); break;
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case CLOCK_MONOTONIC: ktime_get_ts(&kernel_tp); break;
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case CLOCK_BOOTTIME: get_monotonic_boottime(&kernel_tp); break;
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default: return -EINVAL;
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}
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if (copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
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return -EFAULT;
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return 0;
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}
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SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
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{
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struct timespec rtn_tp = {
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.tv_sec = 0,
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.tv_nsec = hrtimer_resolution,
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};
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switch (which_clock) {
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case CLOCK_REALTIME:
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case CLOCK_MONOTONIC:
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case CLOCK_BOOTTIME:
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if (copy_to_user(tp, &rtn_tp, sizeof(rtn_tp)))
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return -EFAULT;
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return 0;
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default:
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return -EINVAL;
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}
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}
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SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
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const struct timespec __user *, rqtp,
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struct timespec __user *, rmtp)
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{
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struct timespec t;
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switch (which_clock) {
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case CLOCK_REALTIME:
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case CLOCK_MONOTONIC:
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case CLOCK_BOOTTIME:
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if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
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return -EFAULT;
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if (!timespec_valid(&t))
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return -EINVAL;
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return hrtimer_nanosleep(&t, rmtp, flags & TIMER_ABSTIME ?
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HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
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which_clock);
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default:
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return -EINVAL;
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}
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}
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#ifdef CONFIG_COMPAT
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long clock_nanosleep_restart(struct restart_block *restart_block)
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{
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return hrtimer_nanosleep_restart(restart_block);
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}
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#endif
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