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-rw-r--r--SOURCES/fsync.patch597
1 files changed, 0 insertions, 597 deletions
diff --git a/SOURCES/fsync.patch b/SOURCES/fsync.patch
deleted file mode 100644
index ef1446c..0000000
--- a/SOURCES/fsync.patch
+++ /dev/null
@@ -1,597 +0,0 @@
-From 7b5df0248ce255ef5b7204d65a7b3783ebb76a3d Mon Sep 17 00:00:00 2001
-From: Gabriel Krisman Bertazi <krisman@collabora.com>
-Date: Fri, 13 Dec 2019 11:08:02 -0300
-Subject: [PATCH 1/2] futex: Implement mechanism to wait on any of several
- futexes
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-This is a new futex operation, called FUTEX_WAIT_MULTIPLE, which allows
-a thread to wait on several futexes at the same time, and be awoken by
-any of them. In a sense, it implements one of the features that was
-supported by pooling on the old FUTEX_FD interface.
-
-The use case lies in the Wine implementation of the Windows NT interface
-WaitMultipleObjects. This Windows API function allows a thread to sleep
-waiting on the first of a set of event sources (mutexes, timers, signal,
-console input, etc) to signal. Considering this is a primitive
-synchronization operation for Windows applications, being able to quickly
-signal events on the producer side, and quickly go to sleep on the
-consumer side is essential for good performance of those running over Wine.
-
-Wine developers have an implementation that uses eventfd, but it suffers
-from FD exhaustion (there is applications that go to the order of
-multi-milion FDs), and higher CPU utilization than this new operation.
-
-The futex list is passed as an array of `struct futex_wait_block`
-(pointer, value, bitset) to the kernel, which will enqueue all of them
-and sleep if none was already triggered. It returns a hint of which
-futex caused the wake up event to userspace, but the hint doesn't
-guarantee that is the only futex triggered. Before calling the syscall
-again, userspace should traverse the list, trying to re-acquire any of
-the other futexes, to prevent an immediate -EWOULDBLOCK return code from
-the kernel.
-
-This was tested using three mechanisms:
-
-1) By reimplementing FUTEX_WAIT in terms of FUTEX_WAIT_MULTIPLE and
-running the unmodified tools/testing/selftests/futex and a full linux
-distro on top of this kernel.
-
-2) By an example code that exercises the FUTEX_WAIT_MULTIPLE path on a
-multi-threaded, event-handling setup.
-
-3) By running the Wine fsync implementation and executing multi-threaded
-applications, in particular modern games, on top of this implementation.
-
-Changes were tested for the following ABIs: x86_64, i386 and x32.
-Support for x32 applications is not implemented since it would
-take a major rework adding a new entry point and splitting the current
-futex 64 entry point in two and we can't change the current x32 syscall
-number without breaking user space compatibility.
-
-CC: Steven Rostedt <rostedt@goodmis.org>
-Cc: Richard Yao <ryao@gentoo.org>
-Cc: Thomas Gleixner <tglx@linutronix.de>
-Cc: Peter Zijlstra <peterz@infradead.org>
-Co-developed-by: Zebediah Figura <z.figura12@gmail.com>
-Signed-off-by: Zebediah Figura <z.figura12@gmail.com>
-Co-developed-by: Steven Noonan <steven@valvesoftware.com>
-Signed-off-by: Steven Noonan <steven@valvesoftware.com>
-Co-developed-by: Pierre-Loup A. Griffais <pgriffais@valvesoftware.com>
-Signed-off-by: Pierre-Loup A. Griffais <pgriffais@valvesoftware.com>
-Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
-[Added compatibility code]
-Co-developed-by: André Almeida <andrealmeid@collabora.com>
-Signed-off-by: André Almeida <andrealmeid@collabora.com>
-
-Adjusted for v5.9: Removed `put_futex_key` calls.
----
- include/uapi/linux/futex.h | 20 +++
- kernel/futex.c | 352 ++++++++++++++++++++++++++++++++++++-
- 2 files changed, 370 insertions(+), 2 deletions(-)
-
-diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
-index a89eb0accd5e2..580001e89c6ca 100644
---- a/include/uapi/linux/futex.h
-+++ b/include/uapi/linux/futex.h
-@@ -21,6 +21,7 @@
- #define FUTEX_WAKE_BITSET 10
- #define FUTEX_WAIT_REQUEUE_PI 11
- #define FUTEX_CMP_REQUEUE_PI 12
-+#define FUTEX_WAIT_MULTIPLE 13
-
- #define FUTEX_PRIVATE_FLAG 128
- #define FUTEX_CLOCK_REALTIME 256
-@@ -40,6 +41,8 @@
- FUTEX_PRIVATE_FLAG)
- #define FUTEX_CMP_REQUEUE_PI_PRIVATE (FUTEX_CMP_REQUEUE_PI | \
- FUTEX_PRIVATE_FLAG)
-+#define FUTEX_WAIT_MULTIPLE_PRIVATE (FUTEX_WAIT_MULTIPLE | \
-+ FUTEX_PRIVATE_FLAG)
-
- /*
- * Support for robust futexes: the kernel cleans up held futexes at
-@@ -150,4 +153,21 @@ struct robust_list_head {
- (((op & 0xf) << 28) | ((cmp & 0xf) << 24) \
- | ((oparg & 0xfff) << 12) | (cmparg & 0xfff))
-
-+/*
-+ * Maximum number of multiple futexes to wait for
-+ */
-+#define FUTEX_MULTIPLE_MAX_COUNT 128
-+
-+/**
-+ * struct futex_wait_block - Block of futexes to be waited for
-+ * @uaddr: User address of the futex
-+ * @val: Futex value expected by userspace
-+ * @bitset: Bitset for the optional bitmasked wakeup
-+ */
-+struct futex_wait_block {
-+ __u32 __user *uaddr;
-+ __u32 val;
-+ __u32 bitset;
-+};
-+
- #endif /* _UAPI_LINUX_FUTEX_H */
-diff --git a/kernel/futex.c b/kernel/futex.c
-index a5876694a60eb..6f4bea76df460 100644
---- a/kernel/futex.c
-+++ b/kernel/futex.c
-@@ -197,6 +197,8 @@ struct futex_pi_state {
- * @rt_waiter: rt_waiter storage for use with requeue_pi
- * @requeue_pi_key: the requeue_pi target futex key
- * @bitset: bitset for the optional bitmasked wakeup
-+ * @uaddr: userspace address of futex
-+ * @uval: expected futex's value
- *
- * We use this hashed waitqueue, instead of a normal wait_queue_entry_t, so
- * we can wake only the relevant ones (hashed queues may be shared).
-@@ -219,6 +221,8 @@ struct futex_q {
- struct rt_mutex_waiter *rt_waiter;
- union futex_key *requeue_pi_key;
- u32 bitset;
-+ u32 __user *uaddr;
-+ u32 uval;
- } __randomize_layout;
-
- static const struct futex_q futex_q_init = {
-@@ -2304,6 +2308,29 @@ static int unqueue_me(struct futex_q *q)
- return ret;
- }
-
-+/**
-+ * unqueue_multiple() - Remove several futexes from their futex_hash_bucket
-+ * @q: The list of futexes to unqueue
-+ * @count: Number of futexes in the list
-+ *
-+ * Helper to unqueue a list of futexes. This can't fail.
-+ *
-+ * Return:
-+ * - >=0 - Index of the last futex that was awoken;
-+ * - -1 - If no futex was awoken
-+ */
-+static int unqueue_multiple(struct futex_q *q, int count)
-+{
-+ int ret = -1;
-+ int i;
-+
-+ for (i = 0; i < count; i++) {
-+ if (!unqueue_me(&q[i]))
-+ ret = i;
-+ }
-+ return ret;
-+}
-+
- /*
- * PI futexes can not be requeued and must remove themself from the
- * hash bucket. The hash bucket lock (i.e. lock_ptr) is held on entry
-@@ -2662,6 +2689,205 @@ static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
- return ret;
- }
-
-+/**
-+ * futex_wait_multiple_setup() - Prepare to wait and enqueue multiple futexes
-+ * @qs: The corresponding futex list
-+ * @count: The size of the lists
-+ * @flags: Futex flags (FLAGS_SHARED, etc.)
-+ * @awaken: Index of the last awoken futex
-+ *
-+ * Prepare multiple futexes in a single step and enqueue them. This may fail if
-+ * the futex list is invalid or if any futex was already awoken. On success the
-+ * task is ready to interruptible sleep.
-+ *
-+ * Return:
-+ * - 1 - One of the futexes was awaken by another thread
-+ * - 0 - Success
-+ * - <0 - -EFAULT, -EWOULDBLOCK or -EINVAL
-+ */
-+static int futex_wait_multiple_setup(struct futex_q *qs, int count,
-+ unsigned int flags, int *awaken)
-+{
-+ struct futex_hash_bucket *hb;
-+ int ret, i;
-+ u32 uval;
-+
-+ /*
-+ * Enqueuing multiple futexes is tricky, because we need to
-+ * enqueue each futex in the list before dealing with the next
-+ * one to avoid deadlocking on the hash bucket. But, before
-+ * enqueuing, we need to make sure that current->state is
-+ * TASK_INTERRUPTIBLE, so we don't absorb any awake events, which
-+ * cannot be done before the get_futex_key of the next key,
-+ * because it calls get_user_pages, which can sleep. Thus, we
-+ * fetch the list of futexes keys in two steps, by first pinning
-+ * all the memory keys in the futex key, and only then we read
-+ * each key and queue the corresponding futex.
-+ */
-+retry:
-+ for (i = 0; i < count; i++) {
-+ qs[i].key = FUTEX_KEY_INIT;
-+ ret = get_futex_key(qs[i].uaddr, flags & FLAGS_SHARED,
-+ &qs[i].key, FUTEX_READ);
-+ if (unlikely(ret)) {
-+ return ret;
-+ }
-+ }
-+
-+ set_current_state(TASK_INTERRUPTIBLE);
-+
-+ for (i = 0; i < count; i++) {
-+ struct futex_q *q = &qs[i];
-+
-+ hb = queue_lock(q);
-+
-+ ret = get_futex_value_locked(&uval, q->uaddr);
-+ if (ret) {
-+ /*
-+ * We need to try to handle the fault, which
-+ * cannot be done without sleep, so we need to
-+ * undo all the work already done, to make sure
-+ * we don't miss any wake ups. Therefore, clean
-+ * up, handle the fault and retry from the
-+ * beginning.
-+ */
-+ queue_unlock(hb);
-+
-+ /*
-+ * Keys 0..(i-1) are implicitly put
-+ * on unqueue_multiple.
-+ */
-+ *awaken = unqueue_multiple(qs, i);
-+
-+ __set_current_state(TASK_RUNNING);
-+
-+ /*
-+ * On a real fault, prioritize the error even if
-+ * some other futex was awoken. Userspace gave
-+ * us a bad address, -EFAULT them.
-+ */
-+ ret = get_user(uval, q->uaddr);
-+ if (ret)
-+ return ret;
-+
-+ /*
-+ * Even if the page fault was handled, If
-+ * something was already awaken, we can safely
-+ * give up and succeed to give a hint for userspace to
-+ * acquire the right futex faster.
-+ */
-+ if (*awaken >= 0)
-+ return 1;
-+
-+ goto retry;
-+ }
-+
-+ if (uval != q->uval) {
-+ queue_unlock(hb);
-+
-+ /*
-+ * If something was already awaken, we can
-+ * safely ignore the error and succeed.
-+ */
-+ *awaken = unqueue_multiple(qs, i);
-+ __set_current_state(TASK_RUNNING);
-+ if (*awaken >= 0)
-+ return 1;
-+
-+ return -EWOULDBLOCK;
-+ }
-+
-+ /*
-+ * The bucket lock can't be held while dealing with the
-+ * next futex. Queue each futex at this moment so hb can
-+ * be unlocked.
-+ */
-+ queue_me(&qs[i], hb);
-+ }
-+ return 0;
-+}
-+
-+/**
-+ * futex_wait_multiple() - Prepare to wait on and enqueue several futexes
-+ * @qs: The list of futexes to wait on
-+ * @op: Operation code from futex's syscall
-+ * @count: The number of objects
-+ * @abs_time: Timeout before giving up and returning to userspace
-+ *
-+ * Entry point for the FUTEX_WAIT_MULTIPLE futex operation, this function
-+ * sleeps on a group of futexes and returns on the first futex that
-+ * triggered, or after the timeout has elapsed.
-+ *
-+ * Return:
-+ * - >=0 - Hint to the futex that was awoken
-+ * - <0 - On error
-+ */
-+static int futex_wait_multiple(struct futex_q *qs, int op,
-+ u32 count, ktime_t *abs_time)
-+{
-+ struct hrtimer_sleeper timeout, *to;
-+ int ret, flags = 0, hint = 0;
-+ unsigned int i;
-+
-+ if (!(op & FUTEX_PRIVATE_FLAG))
-+ flags |= FLAGS_SHARED;
-+
-+ if (op & FUTEX_CLOCK_REALTIME)
-+ flags |= FLAGS_CLOCKRT;
-+
-+ to = futex_setup_timer(abs_time, &timeout, flags, 0);
-+ while (1) {
-+ ret = futex_wait_multiple_setup(qs, count, flags, &hint);
-+ if (ret) {
-+ if (ret > 0) {
-+ /* A futex was awaken during setup */
-+ ret = hint;
-+ }
-+ break;
-+ }
-+
-+ if (to)
-+ hrtimer_start_expires(&to->timer, HRTIMER_MODE_ABS);
-+
-+ /*
-+ * Avoid sleeping if another thread already tried to
-+ * wake us.
-+ */
-+ for (i = 0; i < count; i++) {
-+ if (plist_node_empty(&qs[i].list))
-+ break;
-+ }
-+
-+ if (i == count && (!to || to->task))
-+ freezable_schedule();
-+
-+ ret = unqueue_multiple(qs, count);
-+
-+ __set_current_state(TASK_RUNNING);
-+
-+ if (ret >= 0)
-+ break;
-+ if (to && !to->task) {
-+ ret = -ETIMEDOUT;
-+ break;
-+ } else if (signal_pending(current)) {
-+ ret = -ERESTARTSYS;
-+ break;
-+ }
-+ /*
-+ * The final case is a spurious wakeup, for
-+ * which just retry.
-+ */
-+ }
-+
-+ if (to) {
-+ hrtimer_cancel(&to->timer);
-+ destroy_hrtimer_on_stack(&to->timer);
-+ }
-+
-+ return ret;
-+}
-+
- static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val,
- ktime_t *abs_time, u32 bitset)
- {
-@@ -3774,6 +4000,43 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
- return -ENOSYS;
- }
-
-+/**
-+ * futex_read_wait_block - Read an array of futex_wait_block from userspace
-+ * @uaddr: Userspace address of the block
-+ * @count: Number of blocks to be read
-+ *
-+ * This function creates and allocate an array of futex_q (we zero it to
-+ * initialize the fields) and then, for each futex_wait_block element from
-+ * userspace, fill a futex_q element with proper values.
-+ */
-+inline struct futex_q *futex_read_wait_block(u32 __user *uaddr, u32 count)
-+{
-+ unsigned int i;
-+ struct futex_q *qs;
-+ struct futex_wait_block fwb;
-+ struct futex_wait_block __user *entry =
-+ (struct futex_wait_block __user *)uaddr;
-+
-+ if (!count || count > FUTEX_MULTIPLE_MAX_COUNT)
-+ return ERR_PTR(-EINVAL);
-+
-+ qs = kcalloc(count, sizeof(*qs), GFP_KERNEL);
-+ if (!qs)
-+ return ERR_PTR(-ENOMEM);
-+
-+ for (i = 0; i < count; i++) {
-+ if (copy_from_user(&fwb, &entry[i], sizeof(fwb))) {
-+ kfree(qs);
-+ return ERR_PTR(-EFAULT);
-+ }
-+
-+ qs[i].uaddr = fwb.uaddr;
-+ qs[i].uval = fwb.val;
-+ qs[i].bitset = fwb.bitset;
-+ }
-+
-+ return qs;
-+}
-
- SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
- struct __kernel_timespec __user *, utime, u32 __user *, uaddr2,
-@@ -3786,7 +4049,8 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
-
- if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
- cmd == FUTEX_WAIT_BITSET ||
-- cmd == FUTEX_WAIT_REQUEUE_PI)) {
-+ cmd == FUTEX_WAIT_REQUEUE_PI ||
-+ cmd == FUTEX_WAIT_MULTIPLE)) {
- if (unlikely(should_fail_futex(!(op & FUTEX_PRIVATE_FLAG))))
- return -EFAULT;
- if (get_timespec64(&ts, utime))
-@@ -3807,6 +4071,25 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
- cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
- val2 = (u32) (unsigned long) utime;
-
-+ if (cmd == FUTEX_WAIT_MULTIPLE) {
-+ int ret;
-+ struct futex_q *qs;
-+
-+#ifdef CONFIG_X86_X32
-+ if (unlikely(in_x32_syscall()))
-+ return -ENOSYS;
-+#endif
-+ qs = futex_read_wait_block(uaddr, val);
-+
-+ if (IS_ERR(qs))
-+ return PTR_ERR(qs);
-+
-+ ret = futex_wait_multiple(qs, op, val, tp);
-+ kfree(qs);
-+
-+ return ret;
-+ }
-+
- return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
- }
-
-@@ -3969,6 +4252,57 @@ COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid,
- #endif /* CONFIG_COMPAT */
-
- #ifdef CONFIG_COMPAT_32BIT_TIME
-+/**
-+ * struct compat_futex_wait_block - Block of futexes to be waited for
-+ * @uaddr: User address of the futex (compatible pointer)
-+ * @val: Futex value expected by userspace
-+ * @bitset: Bitset for the optional bitmasked wakeup
-+ */
-+struct compat_futex_wait_block {
-+ compat_uptr_t uaddr;
-+ __u32 val;
-+ __u32 bitset;
-+};
-+
-+/**
-+ * compat_futex_read_wait_block - Read an array of futex_wait_block from
-+ * userspace
-+ * @uaddr: Userspace address of the block
-+ * @count: Number of blocks to be read
-+ *
-+ * This function does the same as futex_read_wait_block(), except that it
-+ * converts the pointer to the futex from the compat version to the regular one.
-+ */
-+inline struct futex_q *compat_futex_read_wait_block(u32 __user *uaddr,
-+ u32 count)
-+{
-+ unsigned int i;
-+ struct futex_q *qs;
-+ struct compat_futex_wait_block fwb;
-+ struct compat_futex_wait_block __user *entry =
-+ (struct compat_futex_wait_block __user *)uaddr;
-+
-+ if (!count || count > FUTEX_MULTIPLE_MAX_COUNT)
-+ return ERR_PTR(-EINVAL);
-+
-+ qs = kcalloc(count, sizeof(*qs), GFP_KERNEL);
-+ if (!qs)
-+ return ERR_PTR(-ENOMEM);
-+
-+ for (i = 0; i < count; i++) {
-+ if (copy_from_user(&fwb, &entry[i], sizeof(fwb))) {
-+ kfree(qs);
-+ return ERR_PTR(-EFAULT);
-+ }
-+
-+ qs[i].uaddr = compat_ptr(fwb.uaddr);
-+ qs[i].uval = fwb.val;
-+ qs[i].bitset = fwb.bitset;
-+ }
-+
-+ return qs;
-+}
-+
- SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
- struct old_timespec32 __user *, utime, u32 __user *, uaddr2,
- u32, val3)
-@@ -3980,7 +4314,8 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
-
- if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI ||
- cmd == FUTEX_WAIT_BITSET ||
-- cmd == FUTEX_WAIT_REQUEUE_PI)) {
-+ cmd == FUTEX_WAIT_REQUEUE_PI ||
-+ cmd == FUTEX_WAIT_MULTIPLE)) {
- if (get_old_timespec32(&ts, utime))
- return -EFAULT;
- if (!timespec64_valid(&ts))
-@@ -3995,6 +4330,19 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
- cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP)
- val2 = (int) (unsigned long) utime;
-
-+ if (cmd == FUTEX_WAIT_MULTIPLE) {
-+ int ret;
-+ struct futex_q *qs = compat_futex_read_wait_block(uaddr, val);
-+
-+ if (IS_ERR(qs))
-+ return PTR_ERR(qs);
-+
-+ ret = futex_wait_multiple(qs, op, val, tp);
-+ kfree(qs);
-+
-+ return ret;
-+ }
-+
- return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
- }
- #endif /* CONFIG_COMPAT_32BIT_TIME */
-
-From ccdddb50d330d2ee1a4d2cbfdd27bdd7fb10eec3 Mon Sep 17 00:00:00 2001
-From: =?UTF-8?q?Andr=C3=A9=20Almeida?= <andrealmeid@collabora.com>
-Date: Fri, 7 Feb 2020 23:28:02 -0300
-Subject: [PATCH 2/2] futex: Add Proton compatibility code
-
----
- include/uapi/linux/futex.h | 2 +-
- kernel/futex.c | 5 +++--
- 2 files changed, 4 insertions(+), 3 deletions(-)
-
-diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
-index 580001e..a3e7608 100644
---- a/include/uapi/linux/futex.h
-+++ b/include/uapi/linux/futex.h
-@@ -21,7 +21,7 @@
- #define FUTEX_WAKE_BITSET 10
- #define FUTEX_WAIT_REQUEUE_PI 11
- #define FUTEX_CMP_REQUEUE_PI 12
--#define FUTEX_WAIT_MULTIPLE 13
-+#define FUTEX_WAIT_MULTIPLE 31
-
- #define FUTEX_PRIVATE_FLAG 128
- #define FUTEX_CLOCK_REALTIME 256
-diff --git a/kernel/futex.c b/kernel/futex.c
-index caba751..84c520c 100644
---- a/kernel/futex.c
-+++ b/kernel/futex.c
-@@ -4074,7 +4074,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
- return -EINVAL;
-
- t = timespec64_to_ktime(ts);
-- if (cmd == FUTEX_WAIT)
-+ if (cmd == FUTEX_WAIT || cmd == FUTEX_WAIT_MULTIPLE)
- t = ktime_add_safe(ktime_get(), t);
- else if (!(op & FUTEX_CLOCK_REALTIME))
- t = timens_ktime_to_host(CLOCK_MONOTONIC, t);
-@@ -4277,6 +4277,7 @@ COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid,
- */
- struct compat_futex_wait_block {
- compat_uptr_t uaddr;
-+ __u32 pad;
- __u32 val;
- __u32 bitset;
- };
-@@ -4339,7 +4340,7 @@ SYSCALL_DEFINE6(futex_time32, u32 __user *, uaddr, int, op, u32, val,
- return -EINVAL;
-
- t = timespec64_to_ktime(ts);
-- if (cmd == FUTEX_WAIT)
-+ if (cmd == FUTEX_WAIT || cmd == FUTEX_WAIT_MULTIPLE)
- t = ktime_add_safe(ktime_get(), t);
- else if (!(op & FUTEX_CLOCK_REALTIME))
- t = timens_ktime_to_host(CLOCK_MONOTONIC, t);