#include <linux/hrtimer.h>
#include <linux/anon_inodes.h>
#include <linux/timerfd.h>
+#include <linux/syscalls.h>
struct timerfd_ctx {
struct hrtimer tmr;
ktime_t tintv;
wait_queue_head_t wqh;
+ u64 ticks;
int expired;
+ int clockid;
};
/*
* 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 read.
+ * tintv.tv64 != 0) until the timer is accessed.
*/
static enum hrtimer_restart timerfd_tmrproc(struct hrtimer *htmr)
{
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;
}
-static void timerfd_setup(struct timerfd_ctx *ctx, int clockid, int flags,
+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 void timerfd_setup(struct timerfd_ctx *ctx, int flags,
const struct itimerspec *ktmr)
{
enum hrtimer_mode htmode;
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);
- ctx->tmr.expires = texp;
+ hrtimer_init(&ctx->tmr, ctx->clockid, htmode);
+ hrtimer_set_expires(&ctx->tmr, texp);
ctx->tmr.function = timerfd_tmrproc;
if (texp.tv64 != 0)
hrtimer_start(&ctx->tmr, texp, htmode);
poll_wait(file, &ctx->wqh, wait);
spin_lock_irqsave(&ctx->wqh.lock, flags);
- if (ctx->expired)
+ if (ctx->ticks)
events |= POLLIN;
spin_unlock_irqrestore(&ctx->wqh.lock, flags);
{
struct timerfd_ctx *ctx = file->private_data;
ssize_t res;
- u32 ticks = 0;
+ u64 ticks = 0;
DECLARE_WAITQUEUE(wait, current);
if (count < sizeof(ticks))
return -EINVAL;
spin_lock_irq(&ctx->wqh.lock);
res = -EAGAIN;
- if (!ctx->expired && !(file->f_flags & O_NONBLOCK)) {
+ if (!ctx->ticks && !(file->f_flags & O_NONBLOCK)) {
__add_wait_queue(&ctx->wqh, &wait);
for (res = 0;;) {
set_current_state(TASK_INTERRUPTIBLE);
- if (ctx->expired) {
+ if (ctx->ticks) {
res = 0;
break;
}
__remove_wait_queue(&ctx->wqh, &wait);
__set_current_state(TASK_RUNNING);
}
- if (ctx->expired) {
- ctx->expired = 0;
- if (ctx->tintv.tv64 != 0) {
+ 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 = (u32)
- hrtimer_forward(&ctx->tmr,
- hrtimer_cb_get_time(&ctx->tmr),
- ctx->tintv);
+ ticks += hrtimer_forward_now(&ctx->tmr,
+ ctx->tintv) - 1;
hrtimer_restart(&ctx->tmr);
- } else
- ticks = 1;
+ }
+ ctx->expired = 0;
+ ctx->ticks = 0;
}
spin_unlock_irq(&ctx->wqh.lock);
if (ticks)
- res = put_user(ticks, buf) ? -EFAULT: sizeof(ticks);
+ res = put_user(ticks, (u64 __user *) buf) ? -EFAULT: sizeof(ticks);
return res;
}
.read = timerfd_read,
};
-asmlinkage long sys_timerfd(int ufd, int clockid, int flags,
- const struct itimerspec __user *utmr)
+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 error;
+ 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);
+ ctx->clockid = clockid;
+ hrtimer_init(&ctx->tmr, clockid, HRTIMER_MODE_ABS);
+
+ 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 inode *inode;
- struct itimerspec ktmr;
+ struct timerfd_ctx *ctx;
+ struct itimerspec ktmr, kotmr;
if (copy_from_user(&ktmr, utmr, sizeof(ktmr)))
return -EFAULT;
- if (clockid != CLOCK_MONOTONIC &&
- clockid != CLOCK_REALTIME)
- return -EINVAL;
- if (!timespec_valid(&ktmr.it_value) ||
+ if ((flags & ~TFD_SETTIME_FLAGS) ||
+ !timespec_valid(&ktmr.it_value) ||
!timespec_valid(&ktmr.it_interval))
return -EINVAL;
- if (ufd == -1) {
- ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
- if (!ctx)
- return -ENOMEM;
-
- init_waitqueue_head(&ctx->wqh);
-
- timerfd_setup(ctx, clockid, flags, &ktmr);
-
- /*
- * When we call this, the initialization must be complete, since
- * anon_inode_getfd() will install the fd.
- */
- error = anon_inode_getfd(&ufd, &inode, &file, "[timerfd]",
- &timerfd_fops, ctx);
- if (error)
- goto err_tmrcancel;
- } else {
- file = fget(ufd);
- if (!file)
- return -EBADF;
- ctx = file->private_data;
- if (file->f_op != &timerfd_fops) {
- fput(file);
- return -EINVAL;
- }
- /*
- * 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);
- cpu_relax();
- }
- /*
- * Re-program the timer to the new value ...
- */
- timerfd_setup(ctx, clockid, flags, &ktmr);
+ file = timerfd_fget(ufd);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+ ctx = file->private_data;
+ /*
+ * 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);
- fput(file);
+ cpu_relax();
}
- return ufd;
+ /*
+ * 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);
-err_tmrcancel:
- hrtimer_cancel(&ctx->tmr);
- kfree(ctx);
- return error;
+ 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 ...
+ */
+ 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 0;
+}
+
+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;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff