--- zzzz-none-000/linux-3.10.107/fs/timerfd.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/fs/timerfd.c 2021-02-04 17:41:59.000000000 +0000 @@ -8,6 +8,7 @@ * */ +#include #include #include #include @@ -26,29 +27,39 @@ #include struct timerfd_ctx { - struct hrtimer tmr; + union { + struct hrtimer tmr; + struct alarm alarm; + } t; ktime_t tintv; ktime_t moffs; wait_queue_head_t wqh; u64 ticks; - int expired; int clockid; + short unsigned expired; + short unsigned settime_flags; /* to show in fdinfo */ struct rcu_head rcu; struct list_head clist; + spinlock_t cancel_lock; bool might_cancel; }; static LIST_HEAD(cancel_list); static DEFINE_SPINLOCK(cancel_lock); +static inline bool isalarm(struct timerfd_ctx *ctx) +{ + return ctx->clockid == CLOCK_REALTIME_ALARM || + ctx->clockid == CLOCK_BOOTTIME_ALARM; +} + /* * This gets called when the timer event triggers. We set the "expired" * flag, but we do not re-arm the timer (in case it's necessary, * tintv.tv64 != 0) until the timer is accessed. */ -static enum hrtimer_restart timerfd_tmrproc(struct hrtimer *htmr) +static void timerfd_triggered(struct timerfd_ctx *ctx) { - struct timerfd_ctx *ctx = container_of(htmr, struct timerfd_ctx, tmr); unsigned long flags; spin_lock_irqsave(&ctx->wqh.lock, flags); @@ -56,10 +67,25 @@ ctx->ticks++; wake_up_locked(&ctx->wqh); spin_unlock_irqrestore(&ctx->wqh.lock, flags); +} +static enum hrtimer_restart timerfd_tmrproc(struct hrtimer *htmr) +{ + struct timerfd_ctx *ctx = container_of(htmr, struct timerfd_ctx, + t.tmr); + timerfd_triggered(ctx); return HRTIMER_NORESTART; } +static enum alarmtimer_restart timerfd_alarmproc(struct alarm *alarm, + ktime_t now) +{ + struct timerfd_ctx *ctx = container_of(alarm, struct timerfd_ctx, + t.alarm); + timerfd_triggered(ctx); + return ALARMTIMER_NORESTART; +} + /* * Called when the clock was set to cancel the timers in the cancel * list. This will wake up processes waiting on these timers. The @@ -68,7 +94,7 @@ */ void timerfd_clock_was_set(void) { - ktime_t moffs = ktime_get_monotonic_offset(); + ktime_t moffs = ktime_mono_to_real((ktime_t){ .tv64 = 0 }); struct timerfd_ctx *ctx; unsigned long flags; @@ -87,7 +113,7 @@ rcu_read_unlock(); } -static void timerfd_remove_cancel(struct timerfd_ctx *ctx) +static void __timerfd_remove_cancel(struct timerfd_ctx *ctx) { if (ctx->might_cancel) { ctx->might_cancel = false; @@ -97,34 +123,48 @@ } } +static void timerfd_remove_cancel(struct timerfd_ctx *ctx) +{ + spin_lock(&ctx->cancel_lock); + __timerfd_remove_cancel(ctx); + spin_unlock(&ctx->cancel_lock); +} + static bool timerfd_canceled(struct timerfd_ctx *ctx) { if (!ctx->might_cancel || ctx->moffs.tv64 != KTIME_MAX) return false; - ctx->moffs = ktime_get_monotonic_offset(); + ctx->moffs = ktime_mono_to_real((ktime_t){ .tv64 = 0 }); return true; } static void timerfd_setup_cancel(struct timerfd_ctx *ctx, int flags) { - if (ctx->clockid == CLOCK_REALTIME && (flags & TFD_TIMER_ABSTIME) && - (flags & TFD_TIMER_CANCEL_ON_SET)) { + spin_lock(&ctx->cancel_lock); + if ((ctx->clockid == CLOCK_REALTIME || + ctx->clockid == CLOCK_REALTIME_ALARM) && + (flags & TFD_TIMER_ABSTIME) && (flags & TFD_TIMER_CANCEL_ON_SET)) { if (!ctx->might_cancel) { ctx->might_cancel = true; spin_lock(&cancel_lock); list_add_rcu(&ctx->clist, &cancel_list); spin_unlock(&cancel_lock); } - } else if (ctx->might_cancel) { - timerfd_remove_cancel(ctx); + } else { + __timerfd_remove_cancel(ctx); } + spin_unlock(&ctx->cancel_lock); } static ktime_t timerfd_get_remaining(struct timerfd_ctx *ctx) { ktime_t remaining; - remaining = hrtimer_expires_remaining(&ctx->tmr); + if (isalarm(ctx)) + remaining = alarm_expires_remaining(&ctx->t.alarm); + else + remaining = hrtimer_expires_remaining_adjusted(&ctx->t.tmr); + return remaining.tv64 < 0 ? ktime_set(0, 0): remaining; } @@ -142,14 +182,33 @@ ctx->expired = 0; ctx->ticks = 0; ctx->tintv = timespec_to_ktime(ktmr->it_interval); - hrtimer_init(&ctx->tmr, clockid, htmode); - hrtimer_set_expires(&ctx->tmr, texp); - ctx->tmr.function = timerfd_tmrproc; + + if (isalarm(ctx)) { + alarm_init(&ctx->t.alarm, + ctx->clockid == CLOCK_REALTIME_ALARM ? + ALARM_REALTIME : ALARM_BOOTTIME, + timerfd_alarmproc); + } else { + hrtimer_init(&ctx->t.tmr, clockid, htmode); + hrtimer_set_expires(&ctx->t.tmr, texp); + ctx->t.tmr.function = timerfd_tmrproc; + } + if (texp.tv64 != 0) { - hrtimer_start(&ctx->tmr, texp, htmode); + if (isalarm(ctx)) { + if (flags & TFD_TIMER_ABSTIME) + alarm_start(&ctx->t.alarm, texp); + else + alarm_start_relative(&ctx->t.alarm, texp); + } else { + hrtimer_start(&ctx->t.tmr, texp, htmode); + } + if (timerfd_canceled(ctx)) return -ECANCELED; } + + ctx->settime_flags = flags & TFD_SETTIME_FLAGS; return 0; } @@ -158,7 +217,11 @@ struct timerfd_ctx *ctx = file->private_data; timerfd_remove_cancel(ctx); - hrtimer_cancel(&ctx->tmr); + + if (isalarm(ctx)) + alarm_cancel(&ctx->t.alarm); + else + hrtimer_cancel(&ctx->t.tmr); kfree_rcu(ctx, rcu); return 0; } @@ -215,9 +278,15 @@ * callback to avoid DoS attacks specifying a very * short timer period. */ - ticks += hrtimer_forward_now(&ctx->tmr, - ctx->tintv) - 1; - hrtimer_restart(&ctx->tmr); + if (isalarm(ctx)) { + ticks += alarm_forward_now( + &ctx->t.alarm, ctx->tintv) - 1; + alarm_restart(&ctx->t.alarm); + } else { + ticks += hrtimer_forward_now(&ctx->t.tmr, + ctx->tintv) - 1; + hrtimer_restart(&ctx->t.tmr); + } } ctx->expired = 0; ctx->ticks = 0; @@ -228,11 +297,77 @@ return res; } +#ifdef CONFIG_PROC_FS +static void timerfd_show(struct seq_file *m, struct file *file) +{ + struct timerfd_ctx *ctx = file->private_data; + struct itimerspec t; + + spin_lock_irq(&ctx->wqh.lock); + t.it_value = ktime_to_timespec(timerfd_get_remaining(ctx)); + t.it_interval = ktime_to_timespec(ctx->tintv); + spin_unlock_irq(&ctx->wqh.lock); + + seq_printf(m, + "clockid: %d\n" + "ticks: %llu\n" + "settime flags: 0%o\n" + "it_value: (%llu, %llu)\n" + "it_interval: (%llu, %llu)\n", + ctx->clockid, + (unsigned long long)ctx->ticks, + ctx->settime_flags, + (unsigned long long)t.it_value.tv_sec, + (unsigned long long)t.it_value.tv_nsec, + (unsigned long long)t.it_interval.tv_sec, + (unsigned long long)t.it_interval.tv_nsec); +} +#else +#define timerfd_show NULL +#endif + +#ifdef CONFIG_CHECKPOINT_RESTORE +static long timerfd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct timerfd_ctx *ctx = file->private_data; + int ret = 0; + + switch (cmd) { + case TFD_IOC_SET_TICKS: { + u64 ticks; + + if (copy_from_user(&ticks, (u64 __user *)arg, sizeof(ticks))) + return -EFAULT; + if (!ticks) + return -EINVAL; + + spin_lock_irq(&ctx->wqh.lock); + if (!timerfd_canceled(ctx)) { + ctx->ticks = ticks; + wake_up_locked(&ctx->wqh); + } else + ret = -ECANCELED; + spin_unlock_irq(&ctx->wqh.lock); + break; + } + default: + ret = -ENOTTY; + break; + } + + return ret; +} +#else +#define timerfd_ioctl NULL +#endif + static const struct file_operations timerfd_fops = { .release = timerfd_release, .poll = timerfd_poll, .read = timerfd_read, .llseek = noop_llseek, + .show_fdinfo = timerfd_show, + .unlocked_ioctl = timerfd_ioctl, }; static int timerfd_fget(int fd, struct fd *p) @@ -259,7 +394,10 @@ if ((flags & ~TFD_CREATE_FLAGS) || (clockid != CLOCK_MONOTONIC && - clockid != CLOCK_REALTIME)) + clockid != CLOCK_REALTIME && + clockid != CLOCK_REALTIME_ALARM && + clockid != CLOCK_BOOTTIME && + clockid != CLOCK_BOOTTIME_ALARM)) return -EINVAL; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); @@ -267,9 +405,18 @@ return -ENOMEM; init_waitqueue_head(&ctx->wqh); + spin_lock_init(&ctx->cancel_lock); ctx->clockid = clockid; - hrtimer_init(&ctx->tmr, clockid, HRTIMER_MODE_ABS); - ctx->moffs = ktime_get_monotonic_offset(); + + if (isalarm(ctx)) + alarm_init(&ctx->t.alarm, + ctx->clockid == CLOCK_REALTIME_ALARM ? + ALARM_REALTIME : ALARM_BOOTTIME, + timerfd_alarmproc); + else + hrtimer_init(&ctx->t.tmr, clockid, HRTIMER_MODE_ABS); + + ctx->moffs = ktime_mono_to_real((ktime_t){ .tv64 = 0 }); ufd = anon_inode_getfd("[timerfd]", &timerfd_fops, ctx, O_RDWR | (flags & TFD_SHARED_FCNTL_FLAGS)); @@ -305,8 +452,14 @@ */ for (;;) { spin_lock_irq(&ctx->wqh.lock); - if (hrtimer_try_to_cancel(&ctx->tmr) >= 0) - break; + + if (isalarm(ctx)) { + if (alarm_try_to_cancel(&ctx->t.alarm) >= 0) + break; + } else { + if (hrtimer_try_to_cancel(&ctx->t.tmr) >= 0) + break; + } spin_unlock_irq(&ctx->wqh.lock); cpu_relax(); } @@ -317,8 +470,12 @@ * We do not update "ticks" and "expired" since the timer will be * re-programmed again in the following timerfd_setup() call. */ - if (ctx->expired && ctx->tintv.tv64) - hrtimer_forward_now(&ctx->tmr, ctx->tintv); + if (ctx->expired && ctx->tintv.tv64) { + if (isalarm(ctx)) + alarm_forward_now(&ctx->t.alarm, ctx->tintv); + else + hrtimer_forward_now(&ctx->t.tmr, ctx->tintv); + } old->it_value = ktime_to_timespec(timerfd_get_remaining(ctx)); old->it_interval = ktime_to_timespec(ctx->tintv); @@ -345,9 +502,18 @@ spin_lock_irq(&ctx->wqh.lock); if (ctx->expired && ctx->tintv.tv64) { ctx->expired = 0; - ctx->ticks += - hrtimer_forward_now(&ctx->tmr, ctx->tintv) - 1; - hrtimer_restart(&ctx->tmr); + + if (isalarm(ctx)) { + ctx->ticks += + alarm_forward_now( + &ctx->t.alarm, ctx->tintv) - 1; + alarm_restart(&ctx->t.alarm); + } else { + ctx->ticks += + hrtimer_forward_now(&ctx->t.tmr, ctx->tintv) + - 1; + hrtimer_restart(&ctx->t.tmr); + } } t->it_value = ktime_to_timespec(timerfd_get_remaining(ctx)); t->it_interval = ktime_to_timespec(ctx->tintv);