[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/fs/timerfd.c b/ap/os/linux/linux-3.4.x/fs/timerfd.c
new file mode 100755
index 0000000..eacd263
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/timerfd.c
@@ -0,0 +1,379 @@
+/*
+ * fs/timerfd.c
+ *
+ * Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
+ *
+ *
+ * Thanks to Thomas Gleixner for code reviews and useful comments.
+ *
+ */
+
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/time.h>
+#include <linux/hrtimer.h>
+#include <linux/anon_inodes.h>
+#include <linux/timerfd.h>
+#include <linux/syscalls.h>
+#include <linux/rcupdate.h>
+
+struct timerfd_ctx {
+ struct hrtimer tmr;
+ ktime_t tintv;
+ ktime_t moffs;
+ wait_queue_head_t wqh;
+ u64 ticks;
+ int expired;
+ int clockid;
+ 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);
+
+/*
+ * 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)
+{
+ struct timerfd_ctx *ctx = container_of(htmr, struct timerfd_ctx, tmr);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->wqh.lock, flags);
+ ctx->expired = 1;
+ ctx->ticks++;
+ wake_up_locked(&ctx->wqh);
+ spin_unlock_irqrestore(&ctx->wqh.lock, flags);
+
+ return HRTIMER_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
+ * wake-up requires ctx->ticks to be non zero, therefore we increment
+ * it before calling wake_up_locked().
+ */
+void timerfd_clock_was_set(void)
+{
+ ktime_t moffs = ktime_get_monotonic_offset();
+ struct timerfd_ctx *ctx;
+ unsigned long flags;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(ctx, &cancel_list, clist) {
+ if (!ctx->might_cancel)
+ continue;
+ spin_lock_irqsave(&ctx->wqh.lock, flags);
+ if (ctx->moffs.tv64 != moffs.tv64) {
+ ctx->moffs.tv64 = KTIME_MAX;
+ ctx->ticks++;
+ wake_up_locked(&ctx->wqh);
+ }
+ spin_unlock_irqrestore(&ctx->wqh.lock, flags);
+ }
+ rcu_read_unlock();
+}
+
+static void __timerfd_remove_cancel(struct timerfd_ctx *ctx)
+{
+ if (ctx->might_cancel) {
+ ctx->might_cancel = false;
+ spin_lock(&cancel_lock);
+ list_del_rcu(&ctx->clist);
+ spin_unlock(&cancel_lock);
+ }
+}
+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();
+ return true;
+}
+
+static void timerfd_setup_cancel(struct timerfd_ctx *ctx, int flags)
+{
+ spin_lock(&ctx->cancel_lock);
+ if (ctx->clockid == CLOCK_REALTIME && (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 {
+ __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);
+ return remaining.tv64 < 0 ? ktime_set(0, 0): remaining;
+}
+
+static int timerfd_setup(struct timerfd_ctx *ctx, int flags,
+ const struct itimerspec *ktmr)
+{
+ enum hrtimer_mode htmode;
+ ktime_t texp;
+ int clockid = ctx->clockid;
+
+ htmode = (flags & TFD_TIMER_ABSTIME) ?
+ HRTIMER_MODE_ABS: HRTIMER_MODE_REL;
+
+ texp = timespec_to_ktime(ktmr->it_value);
+ 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 (texp.tv64 != 0) {
+ hrtimer_start(&ctx->tmr, texp, htmode);
+ if (timerfd_canceled(ctx))
+ return -ECANCELED;
+ }
+ return 0;
+}
+
+static int timerfd_release(struct inode *inode, struct file *file)
+{
+ struct timerfd_ctx *ctx = file->private_data;
+
+ timerfd_remove_cancel(ctx);
+ hrtimer_cancel(&ctx->tmr);
+ kfree_rcu(ctx, rcu);
+ return 0;
+}
+
+static unsigned int timerfd_poll(struct file *file, poll_table *wait)
+{
+ struct timerfd_ctx *ctx = file->private_data;
+ unsigned int events = 0;
+ unsigned long flags;
+
+ poll_wait(file, &ctx->wqh, wait);
+
+ spin_lock_irqsave(&ctx->wqh.lock, flags);
+ if (ctx->ticks)
+ events |= POLLIN;
+ spin_unlock_irqrestore(&ctx->wqh.lock, flags);
+
+ return events;
+}
+
+static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct timerfd_ctx *ctx = file->private_data;
+ ssize_t res;
+ u64 ticks = 0;
+
+ if (count < sizeof(ticks))
+ return -EINVAL;
+ spin_lock_irq(&ctx->wqh.lock);
+ if (file->f_flags & O_NONBLOCK)
+ res = -EAGAIN;
+ else
+ res = wait_event_interruptible_locked_irq(ctx->wqh, ctx->ticks);
+
+ /*
+ * If clock has changed, we do not care about the
+ * ticks and we do not rearm the timer. Userspace must
+ * reevaluate anyway.
+ */
+ if (timerfd_canceled(ctx)) {
+ ctx->ticks = 0;
+ ctx->expired = 0;
+ res = -ECANCELED;
+ }
+
+ if (ctx->ticks) {
+ ticks = ctx->ticks;
+
+ if (ctx->expired && ctx->tintv.tv64) {
+ /*
+ * If tintv.tv64 != 0, this is a periodic timer that
+ * needs to be re-armed. We avoid doing it in the timer
+ * callback to avoid DoS attacks specifying a very
+ * short timer period.
+ */
+ ticks += hrtimer_forward_now(&ctx->tmr,
+ ctx->tintv) - 1;
+ hrtimer_restart(&ctx->tmr);
+ }
+ ctx->expired = 0;
+ ctx->ticks = 0;
+ }
+ spin_unlock_irq(&ctx->wqh.lock);
+ if (ticks)
+ res = put_user(ticks, (u64 __user *) buf) ? -EFAULT: sizeof(ticks);
+ return res;
+}
+
+static const struct file_operations timerfd_fops = {
+ .release = timerfd_release,
+ .poll = timerfd_poll,
+ .read = timerfd_read,
+ .llseek = noop_llseek,
+};
+
+static struct file *timerfd_fget(int fd)
+{
+ struct file *file;
+
+ file = fget(fd);
+ if (!file)
+ return ERR_PTR(-EBADF);
+ if (file->f_op != &timerfd_fops) {
+ fput(file);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return file;
+}
+
+SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags)
+{
+ int ufd;
+ struct timerfd_ctx *ctx;
+
+ /* Check the TFD_* constants for consistency. */
+ BUILD_BUG_ON(TFD_CLOEXEC != O_CLOEXEC);
+ BUILD_BUG_ON(TFD_NONBLOCK != O_NONBLOCK);
+
+ if ((flags & ~TFD_CREATE_FLAGS) ||
+ (clockid != CLOCK_MONOTONIC &&
+ clockid != CLOCK_REALTIME))
+ return -EINVAL;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ 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();
+
+ ufd = anon_inode_getfd("[timerfd]", &timerfd_fops, ctx,
+ O_RDWR | (flags & TFD_SHARED_FCNTL_FLAGS));
+ if (ufd < 0)
+ kfree(ctx);
+
+ return ufd;
+}
+
+SYSCALL_DEFINE4(timerfd_settime, int, ufd, int, flags,
+ const struct itimerspec __user *, utmr,
+ struct itimerspec __user *, otmr)
+{
+ struct file *file;
+ struct timerfd_ctx *ctx;
+ struct itimerspec ktmr, kotmr;
+ int ret;
+
+ if (copy_from_user(&ktmr, utmr, sizeof(ktmr)))
+ return -EFAULT;
+
+ if ((flags & ~TFD_SETTIME_FLAGS) ||
+ !timespec_valid(&ktmr.it_value) ||
+ !timespec_valid(&ktmr.it_interval))
+ return -EINVAL;
+
+ file = timerfd_fget(ufd);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+ ctx = file->private_data;
+
+ timerfd_setup_cancel(ctx, flags);
+
+ /*
+ * We need to stop the existing timer before reprogramming
+ * it to the new values.
+ */
+ for (;;) {
+ spin_lock_irq(&ctx->wqh.lock);
+ if (hrtimer_try_to_cancel(&ctx->tmr) >= 0)
+ break;
+ spin_unlock_irq(&ctx->wqh.lock);
+ hrtimer_wait_for_timer(&ctx->tmr);
+ }
+
+ /*
+ * If the timer is expired and it's periodic, we need to advance it
+ * because the caller may want to know the previous expiration time.
+ * 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);
+
+ kotmr.it_value = ktime_to_timespec(timerfd_get_remaining(ctx));
+ kotmr.it_interval = ktime_to_timespec(ctx->tintv);
+
+ /*
+ * Re-program the timer to the new value ...
+ */
+ ret = timerfd_setup(ctx, flags, &ktmr);
+
+ spin_unlock_irq(&ctx->wqh.lock);
+ fput(file);
+ if (otmr && copy_to_user(otmr, &kotmr, sizeof(kotmr)))
+ return -EFAULT;
+
+ return ret;
+}
+
+SYSCALL_DEFINE2(timerfd_gettime, int, ufd, struct itimerspec __user *, otmr)
+{
+ struct file *file;
+ struct timerfd_ctx *ctx;
+ struct itimerspec kotmr;
+
+ file = timerfd_fget(ufd);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+ ctx = file->private_data;
+
+ 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);
+ }
+ kotmr.it_value = ktime_to_timespec(timerfd_get_remaining(ctx));
+ kotmr.it_interval = ktime_to_timespec(ctx->tintv);
+ spin_unlock_irq(&ctx->wqh.lock);
+ fput(file);
+
+ return copy_to_user(otmr, &kotmr, sizeof(kotmr)) ? -EFAULT: 0;
+}
+