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linux-tkg/linux-tkg-patches/5.10/0007-v5.10-futex2_interface.patch

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linux510/511-tkg: Offer futex2 patchset as a toggle option - Enables CONFIG_EXPERT automatically when futex2 is enabled - Adds the necessary entries to the config for unattended building (suppress prompts from having CONFIG_EXPERT enabled)
2021-02-18 10:28:55 -06:00
diff --git a/MAINTAINERS b/MAINTAINERS
index 281de213e..51ee1cb84 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7279,7 +7279,7 @@ F: Documentation/locking/*futex*
F: include/asm-generic/futex.h
F: include/linux/futex.h
F: include/uapi/linux/futex.h
-F: kernel/futex.c
+F: kernel/futex*
F: tools/perf/bench/futex*
F: tools/testing/selftests/futex/
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 0d0667a9f..65734d5e1 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -445,3 +445,6 @@
438 i386 pidfd_getfd sys_pidfd_getfd
439 i386 faccessat2 sys_faccessat2
440 i386 process_madvise sys_process_madvise
+441 i386 futex_wait sys_futex_wait
+442 i386 futex_wake sys_futex_wake
+443 i386 futex_waitv sys_futex_waitv
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 379819244..f30811b56 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -362,6 +362,9 @@
438 common pidfd_getfd sys_pidfd_getfd
439 common faccessat2 sys_faccessat2
440 common process_madvise sys_process_madvise
+441 common futex_wait sys_futex_wait
+442 common futex_wake sys_futex_wake
+443 common futex_waitv sys_futex_waitv
#
# Due to a historical design error, certain syscalls are numbered differently
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index aea0ce9f3..ca03850ce 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -613,6 +613,13 @@ asmlinkage long sys_get_robust_list(int pid,
asmlinkage long sys_set_robust_list(struct robust_list_head __user *head,
size_t len);
+/* kernel/futex2.c */
+asmlinkage long sys_futex_wait(void __user *uaddr, unsigned long val,
+ unsigned long flags,
+ struct __kernel_timespec __user __user *timo);
+asmlinkage long sys_futex_wake(void __user *uaddr, unsigned long nr_wake,
+ unsigned long flags);
+
/* kernel/hrtimer.c */
asmlinkage long sys_nanosleep(struct __kernel_timespec __user *rqtp,
struct __kernel_timespec __user *rmtp);
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 205631898..81a90b697 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -860,8 +860,17 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
#define __NR_process_madvise 440
__SYSCALL(__NR_process_madvise, sys_process_madvise)
+#define __NR_futex_wait 441
+__SYSCALL(__NR_futex_wait, sys_futex_wait)
+
+#define __NR_futex_wake 442
+__SYSCALL(__NR_futex_wake, sys_futex_wake)
+
+#define __NR_futex_waitv 443
+__SYSCALL(__NR_futex_waitv, sys_futex_waitv)
+
#undef __NR_syscalls
-#define __NR_syscalls 441
+#define __NR_syscalls 444
/*
* 32 bit systems traditionally used different
diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
index a3e760886..60f14769e 100644
--- a/include/uapi/linux/futex.h
+++ b/include/uapi/linux/futex.h
@@ -44,6 +44,46 @@
#define FUTEX_WAIT_MULTIPLE_PRIVATE (FUTEX_WAIT_MULTIPLE | \
FUTEX_PRIVATE_FLAG)
+/* Size argument to futex2 syscall */
+#define FUTEX_8 0
+#define FUTEX_16 1
+#define FUTEX_32 2
+
+#define FUTEX_SIZE_MASK 0x3
+
+#define FUTEX_SHARED_FLAG 8
+
+#define FUTEX_NUMA_FLAG 16
+
+/*
+ * struct futexXX_numa - struct for NUMA-aware futex operation
+ * @value: futex value
+ * @hint: node id to operate
+ */
+
+struct futex8_numa {
+ __u8 value;
+ __u8 hint;
+};
+
+struct futex16_numa {
+ __u16 value;
+ __u16 hint;
+};
+
+struct futex32_numa {
+ __u32 value;
+ __u32 hint;
+};
+
+#define FUTEX_WAITV_MAX 128
+
+struct futex_waitv {
+ void *uaddr;
+ unsigned int val;
+ unsigned int flags;
+};
+
/*
* Support for robust futexes: the kernel cleans up held futexes at
* thread exit time.
diff --git a/init/Kconfig b/init/Kconfig
index a40d8afeb..07bce9696 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1548,6 +1548,13 @@ config FUTEX
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
+config FUTEX2
+ bool "Enable futex2 support" if EXPERT
+ depends on FUTEX
+ default n
+ help
+ Experimental support for futex2 interface.
+
config FUTEX_PI
bool
depends on FUTEX && RT_MUTEXES
diff --git a/kernel/Makefile b/kernel/Makefile
index 6c9f19911..daacc0a16 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_PROFILING) += profile.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += time/
obj-$(CONFIG_FUTEX) += futex.o
+obj-$(CONFIG_FUTEX2) += futex2.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += smp.o
ifneq ($(CONFIG_SMP),y)
diff --git a/kernel/futex2.c b/kernel/futex2.c
new file mode 100644
index 000000000..58cd8a868
--- /dev/null
+++ b/kernel/futex2.c
@@ -0,0 +1,833 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * futex2 system call interface by André Almeida <andrealmeid@collabora.com>
+ *
+ * Copyright 2020 Collabora Ltd.
+ */
+
+#include <linux/freezer.h>
+#include <linux/hugetlb.h>
+#include <linux/jhash.h>
+#include <linux/pagemap.h>
+#include <linux/sched/wake_q.h>
+#include <linux/spinlock.h>
+#include <linux/syscalls.h>
+#include <linux/memblock.h>
+#include <uapi/linux/futex.h>
+
+/**
+ * struct futex_waiter - List entry for a waiter
+ * @uaddr: Memory address of userspace futex
+ * @key.address: Memory address of userspace futex
+ * @key.mm: Pointer to memory management struct of this process
+ * @key: Stores information that uniquely identify a futex
+ * @list: List node struct
+ * @val: Expected value for this waiter
+ * @flags: Flags
+ * @bucket: Pointer to the bucket for this waiter
+ * @index: Index of waiter in futexv list
+ */
+struct futex_waiter {
+ uintptr_t uaddr;
+ struct futex_key {
+ uintptr_t address;
+ struct mm_struct *mm;
+ unsigned long int offset;
+ } key;
+ struct list_head list;
+ unsigned int val;
+ unsigned int flags;
+ struct futex_bucket *bucket;
+ unsigned int index;
+};
+
+/**
+ * struct futex_bucket - A bucket of futex's hash table
+ * @waiters: Number of waiters in the bucket
+ * @lock: Bucket lock
+ * @list: List of waiters on this bucket
+ */
+struct futex_bucket {
+ atomic_t waiters;
+ spinlock_t lock;
+ struct list_head list;
+};
+
+/**
+ * struct futexv - List of futexes to be waited
+ * @task: Task to be awaken
+ * @hint: Was someone on this list awaken?
+ * @objects: List of futexes
+ */
+struct futexv {
+ struct task_struct *task;
+ bool hint;
+ struct futex_waiter objects[0];
+};
+
+/**
+ * struct futex_single_waiter - Wrapper for a futexv of one element
+ * @futexv: TODO
+ * @waiter: TODO
+ */
+struct futex_single_waiter {
+ struct futexv futexv;
+ struct futex_waiter waiter;
+} __packed;
+
+struct futex_bucket *futex_table;
+
+/* mask for futex2 flag operations */
+#define FUTEX2_MASK (FUTEX_SIZE_MASK | FUTEX_SHARED_FLAG | \
+ FUTEX_CLOCK_REALTIME)
+
+/* mask for sys_futex_waitv flag */
+#define FUTEXV_MASK (FUTEX_CLOCK_REALTIME)
+
+/* mask for each futex in futex_waitv list */
+#define FUTEXV_WAITER_MASK (FUTEX_SIZE_MASK | FUTEX_SHARED_FLAG)
+
+int futex2_hashsize;
+
+/*
+ * Reflects a new waiter being added to the waitqueue.
+ */
+static inline void bucket_inc_waiters(struct futex_bucket *bucket)
+{
+#ifdef CONFIG_SMP
+ atomic_inc(&bucket->waiters);
+ /*
+ * Full barrier (A), see the ordering comment above.
+ */
+ smp_mb__after_atomic();
+#endif
+}
+
+/*
+ * Reflects a waiter being removed from the waitqueue by wakeup
+ * paths.
+ */
+static inline void bucket_dec_waiters(struct futex_bucket *bucket)
+{
+#ifdef CONFIG_SMP
+ atomic_dec(&bucket->waiters);
+#endif
+}
+
+/*
+ * Get the number of waiters in a bucket
+ */
+static inline int bucket_get_waiters(struct futex_bucket *bucket)
+{
+#ifdef CONFIG_SMP
+ /*
+ * Full barrier (B), see the ordering comment above.
+ */
+ smp_mb();
+ return atomic_read(&bucket->waiters);
+#else
+ return 1;
+#endif
+}
+
+static u64 get_inode_sequence_number(struct inode *inode)
+{
+ static atomic64_t i_seq;
+ u64 old;
+
+ /* Does the inode already have a sequence number? */
+ old = atomic64_read(&inode->i_sequence);
+ if (likely(old))
+ return old;
+
+ for (;;) {
+ u64 new = atomic64_add_return(1, &i_seq);
+ if (WARN_ON_ONCE(!new))
+ continue;
+
+ old = atomic64_cmpxchg_relaxed(&inode->i_sequence, 0, new);
+ if (old)
+ return old;
+ return new;
+ }
+}
+
+#define FUT_OFF_INODE 1 /* We set bit 0 if key has a reference on inode */
+#define FUT_OFF_MMSHARED 2 /* We set bit 1 if key has a reference on mm */
+
+static int futex_get_shared_key(uintptr_t address, struct mm_struct *mm,
+ struct futex_key *key)
+{
+ int err;
+ struct page *page, *tail;
+ struct address_space *mapping;
+
+again:
+ err = get_user_pages_fast(address, 1, 0, &page);
+
+ if (err < 0)
+ return err;
+ else
+ err = 0;
+
+
+ tail = page;
+ page = compound_head(page);
+ mapping = READ_ONCE(page->mapping);
+
+
+ if (unlikely(!mapping)) {
+ int shmem_swizzled;
+
+ lock_page(page);
+ shmem_swizzled = PageSwapCache(page) || page->mapping;
+ unlock_page(page);
+ put_page(page);
+
+ if (shmem_swizzled)
+ goto again;
+
+ return -EFAULT;
+ }
+
+ if (PageAnon(page)) {
+
+ key->mm = mm;
+ key->address = address;
+
+ key->offset |= FUT_OFF_MMSHARED;
+
+ } else {
+ struct inode *inode;
+
+ rcu_read_lock();
+
+ if (READ_ONCE(page->mapping) != mapping) {
+ rcu_read_unlock();
+ put_page(page);
+
+ goto again;
+ }
+
+ inode = READ_ONCE(mapping->host);
+ if (!inode) {
+ rcu_read_unlock();
+ put_page(page);
+
+ goto again;
+ }
+
+ key->address = get_inode_sequence_number(inode);
+ key->mm = (struct mm_struct *) basepage_index(tail);
+ key->offset |= FUT_OFF_INODE;
+
+ rcu_read_unlock();
+ }
+
+ put_page(page);
+ return err;
+}
+
+/**
+ * futex_get_bucket - Check if the user address is valid, prepare internal
+ * data and calculate the hash
+ * @uaddr: futex user address
+ * @key: data that uniquely identifies a futex
+ * @shared: is this a shared futex?
+ *
+ * Return: address of bucket on success, error code otherwise
+ */
+static struct futex_bucket *futex_get_bucket(void __user *uaddr,
+ struct futex_key *key,
+ bool shared)
+{
+ uintptr_t address = (uintptr_t) uaddr;
+ u32 hash_key;
+
+ /* Checking if uaddr is valid and accessible */
+ if (unlikely(!IS_ALIGNED(address, sizeof(u32))))
+ return ERR_PTR(-EINVAL);
+ if (unlikely(!access_ok(address, sizeof(u32))))
+ return ERR_PTR(-EFAULT);
+
+ key->offset = address % PAGE_SIZE;
+ address -= key->offset;
+
+ if (!shared) {
+ key->address = address;
+ key->mm = current->mm;
+ } else {
+ futex_get_shared_key(address, current->mm, key);
+ }
+
+ /* Generate hash key for this futex using uaddr and current->mm */
+ hash_key = jhash2((u32 *) key, sizeof(*key) / sizeof(u32), 0);
+
+ /* Since HASH_SIZE is 2^n, subtracting 1 makes a perfect bit mask */
+ return &futex_table[hash_key & (futex2_hashsize - 1)];
+}
+
+/**
+ * futex_get_user - Get the userspace value on this address
+ * @uval: variable to store the value
+ * @uaddr: userspace address
+ *
+ * Check the comment at futex_get_user_val for more information.
+ */
+static int futex_get_user(u32 *uval, u32 __user *uaddr)
+{
+ int ret;
+
+ pagefault_disable();
+ ret = __get_user(*uval, uaddr);
+ pagefault_enable();
+
+ return ret;
+}
+
+/**
+ * futex_setup_time - Prepare the timeout mechanism, without starting it.
+ * @timo: Timeout value from userspace
+ * @timeout: Pointer to hrtimer handler
+ * @flags: Flags from userspace, to decide which clockid to use
+ *
+ * Return: 0 on success, error code otherwise
+ */
+static int futex_setup_time(struct __kernel_timespec __user *timo,
+ struct hrtimer_sleeper *timeout,
+ unsigned int flags)
+{
+ ktime_t time;
+ struct timespec64 ts;
+ clockid_t clockid = (flags & FUTEX_CLOCK_REALTIME) ?
+ CLOCK_REALTIME : CLOCK_MONOTONIC;
+
+ if (get_timespec64(&ts, timo))
+ return -EFAULT;
+
+ if (!timespec64_valid(&ts))
+ return -EINVAL;
+
+ time = timespec64_to_ktime(ts);
+
+ hrtimer_init_sleeper(timeout, clockid, HRTIMER_MODE_ABS);
+
+ hrtimer_set_expires(&timeout->timer, time);
+
+ return 0;
+}
+
+/**
+ * futex_dequeue_multiple - Remove multiple futexes from hash table
+ * @futexv: list of waiters
+ * @nr: number of futexes to be removed
+ *
+ * This function should be used after we found that this futex was in a queue.
+ * Thus, it needs to be removed before the next step. However, someone could
+ * wake it between the time of the first check and the time to get the lock for
+ * the bucket. Check one more time if the futex is there with the bucket locked.
+ * If it's there, just remove it and return true. Else, mark the removal as
+ * false and do nothing.
+ *
+ * Return:
+ * * -1 if no futex was woken during the removal
+ * * =< 0 at least one futex was found woken, index of the last one
+ */
+static int futex_dequeue_multiple(struct futexv *futexv, unsigned int nr)
+{
+ int i, ret = -1;
+
+ for (i = 0; i < nr; i++) {
+ spin_lock(&futexv->objects[i].bucket->lock);
+ if (!list_empty_careful(&futexv->objects[i].list)) {
+ list_del_init_careful(&futexv->objects[i].list);
+ bucket_dec_waiters(futexv->objects[i].bucket);
+ } else {
+ ret = i;
+ }
+ spin_unlock(&futexv->objects[i].bucket->lock);
+ }
+
+ return ret;
+}
+
+/**
+ * futex_enqueue - Check the value and enqueue a futex on a wait list
+ *
+ * @futexv: List of futexes
+ * @nr_futexes: Number of futexes in the list
+ * @awaken: If a futex was awaken during enqueueing, store the index here
+ *
+ * Get the value from the userspace address and compares with the expected one.
+ * In success, enqueue the futex in the correct bucket
+ *
+ * Get the value from user futex address.
+ *
+ * Since we are in a hurry, we use a spin lock and we can't sleep.
+ * Try to get the value with page fault disabled (when enable, we might
+ * sleep).
+ *
+ * If we fail, we aren't sure if the address is invalid or is just a
+ * page fault. Then, release the lock (so we can sleep) and try to get
+ * the value with page fault enabled. In order to trigger a page fault
+ * handling, we just call __get_user() again. If we sleep with enqueued
+ * futexes, we might miss a wake, so dequeue everything before sleeping.
+ *
+ * If get_user succeeds, this mean that the address is valid and we do
+ * the work again. Since we just handled the page fault, the page is
+ * likely pinned in memory and we should be luckier this time and be
+ * able to get the value. If we fail anyway, we will try again.
+ *
+ * If even with page faults enabled we get and error, this means that
+ * the address is not valid and we return from the syscall.
+ *
+ * If we got an unexpected value or need to treat a page fault and realized that
+ * a futex was awaken, we can priority this and return success.
+ *
+ * Return: 0 on success, error code otherwise
+ */
+static int futex_enqueue(struct futexv *futexv, unsigned int nr_futexes,
+ int *awaken)
+{
+ int i, ret;
+ bool shared, retry = false;
+ u32 uval, *uaddr, val;
+ struct futex_bucket *bucket;
+
+retry:
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ for (i = 0; i < nr_futexes; i++) {
+ uaddr = (u32 * __user) futexv->objects[i].uaddr;
+ val = (u32) futexv->objects[i].val;
+ shared = (futexv->objects[i].flags & FUTEX_SHARED_FLAG) ? true : false;
+
+ if (shared && retry) {
+ futexv->objects[i].bucket =
+ futex_get_bucket((void *) uaddr,
+ &futexv->objects[i].key, true);
+ if (IS_ERR(futexv->objects[i].bucket))
+ return PTR_ERR(futexv->objects[i].bucket);
+ }
+
+ bucket = futexv->objects[i].bucket;
+
+ bucket_inc_waiters(bucket);
+ spin_lock(&bucket->lock);
+
+ ret = futex_get_user(&uval, uaddr);
+
+ if (unlikely(ret)) {
+ spin_unlock(&bucket->lock);
+
+ bucket_dec_waiters(bucket);
+ __set_current_state(TASK_RUNNING);
+ *awaken = futex_dequeue_multiple(futexv, i);
+
+ if (shared) {
+ retry = true;
+ goto retry;
+ }
+
+ if (__get_user(uval, uaddr))
+ return -EFAULT;
+
+ if (*awaken >= 0)
+ return 1;
+
+ retry = true;
+ goto retry;
+ }
+
+ if (uval != val) {
+ spin_unlock(&bucket->lock);
+
+
+ bucket_dec_waiters(bucket);
+ __set_current_state(TASK_RUNNING);
+ *awaken = futex_dequeue_multiple(futexv, i);
+
+ if (*awaken >= 0) {
+ return 1;
+ }
+
+ return -EWOULDBLOCK;
+ }
+
+ list_add_tail(&futexv->objects[i].list, &bucket->list);
+ spin_unlock(&bucket->lock);
+ }
+
+ return 0;
+}
+
+
+static int __futex_wait(struct futexv *futexv,
+ unsigned int nr_futexes,
+ struct hrtimer_sleeper *timeout)
+{
+ int ret;
+
+
+ while (1) {
+ int awaken = -1;
+
+ ret = futex_enqueue(futexv, nr_futexes, &awaken);
+ if (ret) {
+ if (awaken >= 0)
+ return awaken;
+ return ret;
+ }
+
+ /* Before sleeping, check if someone was woken */
+ if (!futexv->hint && (!timeout || timeout->task))
+ freezable_schedule();
+
+ __set_current_state(TASK_RUNNING);
+
+ /*
+ * One of those things triggered this wake:
+ *
+ * * We have been removed from the bucket. futex_wake() woke
+ * us. We just need to dequeue return 0 to userspace.
+ *
+ * However, if no futex was dequeued by a futex_wake():
+ *
+ * * If the there's a timeout and it has expired,
+ * return -ETIMEDOUT.
+ *
+ * * If there is a signal pending, something wants to kill our
+ * thread, return -ERESTARTSYS.
+ *
+ * * If there's no signal pending, it was a spurious wake
+ * (scheduler gave us a change to do some work, even if we
+ * don't want to). We need to remove ourselves from the
+ * bucket and add again, to prevent losing wakeups in the
+ * meantime.
+ */
+
+ ret = futex_dequeue_multiple(futexv, nr_futexes);
+
+ /* Normal wake */
+ if (ret >= 0)
+ break;
+
+ if (timeout && !timeout->task)
+ return -ETIMEDOUT;
+
+ /* signal */
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+
+ /* spurious wake, do everything again */
+ }
+
+ return ret;
+}
+
+/**
+ * futex_wait - Setup the timer and wait on a list of futexes
+ * @futexv: List of waiters
+ * @nr_futexes: Number of waiters
+ * @timo: Timeout
+ * @timeout: Timeout
+ * @flags: Timeout flags
+ *
+ * Return: error code, or a hint of one of the waiters
+ */
+static int futex_wait(struct futexv *futexv, unsigned int nr_futexes,
+ struct __kernel_timespec __user *timo,
+ struct hrtimer_sleeper *timeout, unsigned int flags)
+{
+ int ret;
+
+ if (timo) {
+ ret = futex_setup_time(timo, timeout, flags);
+ if (ret)
+ return ret;
+
+ hrtimer_sleeper_start_expires(timeout, HRTIMER_MODE_ABS);
+ }
+
+
+ ret = __futex_wait(futexv, nr_futexes, timo ? timeout : NULL);
+
+
+ if (timo)
+ hrtimer_cancel(&timeout->timer);
+
+ return ret;
+}
+
+/**
+ * sys_futex_wait - Wait on a futex address if (*uaddr) == val
+ * @uaddr: User address of futex
+ * @val: Expected value of futex
+ * @flags: Specify the size of futex and the clockid
+ * @timo: Optional absolute timeout. Supports only 64bit time.
+ */
+SYSCALL_DEFINE4(futex_wait, void __user *, uaddr, unsigned int, val,
+ unsigned int, flags, struct __kernel_timespec __user *, timo)
+{
+ bool shared = (flags & FUTEX_SHARED_FLAG) ? true : false;
+ unsigned int size = flags & FUTEX_SIZE_MASK;
+ struct futex_single_waiter wait_single;
+ struct hrtimer_sleeper timeout;
+ struct futex_waiter *waiter;
+ struct futexv *futexv;
+ int ret;
+
+ futexv = &wait_single.futexv;
+ futexv->task = current;
+ futexv->hint = false;
+
+ waiter = &wait_single.waiter;
+ waiter->index = 0;
+ waiter->val = val;
+ waiter->uaddr = (uintptr_t) uaddr;
+
+ INIT_LIST_HEAD(&waiter->list);
+
+ if (flags & ~FUTEX2_MASK)
+ return -EINVAL;
+
+ if (size != FUTEX_32)
+ return -EINVAL;
+
+ /* Get an unlocked hash bucket */
+ waiter->bucket = futex_get_bucket(uaddr, &waiter->key, shared);
+ if (IS_ERR(waiter->bucket)) {
+ return PTR_ERR(waiter->bucket);
+ }
+
+ ret = futex_wait(futexv, 1, timo, &timeout, flags);
+ if (ret > 0)
+ ret = 0;
+
+ return ret;
+}
+
+/**
+ * futex_parse_waitv - Parse a waitv array from userspace
+ * @futexv: list of waiters
+ * @uwaitv: userspace list
+ * @nr_futexes: number of waiters in the list
+ *
+ * Return: Error code on failure, pointer to a prepared futexv otherwise
+ */
+static int futex_parse_waitv(struct futexv *futexv,
+ struct futex_waitv __user *uwaitv,
+ unsigned int nr_futexes)
+{
+ struct futex_waitv waitv;
+ unsigned int i;
+ struct futex_bucket *bucket;
+ bool shared;
+
+ for (i = 0; i < nr_futexes; i++) {
+
+ if (copy_from_user(&waitv, &uwaitv[i], sizeof(waitv)))
+ return -EFAULT;
+
+ if ((waitv.flags & ~FUTEXV_WAITER_MASK) ||
+ (waitv.flags & FUTEX_SIZE_MASK) != FUTEX_32)
+ return -EINVAL;
+
+ shared = (waitv.flags & FUTEX_SHARED_FLAG) ? true : false;
+
+ bucket = futex_get_bucket(waitv.uaddr,
+ &futexv->objects[i].key, shared);
+ if (IS_ERR(bucket))
+ return PTR_ERR(bucket);
+
+ futexv->objects[i].bucket = bucket;
+ futexv->objects[i].val = waitv.val;
+ futexv->objects[i].flags = waitv.flags;
+ futexv->objects[i].index = i;
+ INIT_LIST_HEAD(&futexv->objects[i].list);
+ futexv->objects[i].uaddr = (uintptr_t) waitv.uaddr;
+ }
+
+ return 0;
+}
+
+/**
+ * sys_futex_waitv - function
+ * @waiters: TODO
+ * @nr_futexes: TODO
+ * @flags: TODO
+ * @timo: TODO
+ */
+SYSCALL_DEFINE4(futex_waitv, struct futex_waitv __user *, waiters,
+ unsigned int, nr_futexes, unsigned int, flags,
+ struct __kernel_timespec __user *, timo)
+{
+ struct hrtimer_sleeper timeout;
+ struct futexv *futexv;
+ int ret;
+
+ if (flags & ~FUTEXV_MASK)
+ return -EINVAL;
+
+ if (!nr_futexes || nr_futexes > FUTEX_WAITV_MAX || !waiters)
+ return -EINVAL;
+
+ futexv = kmalloc(sizeof(struct futexv) +
+ (sizeof(struct futex_waiter) * nr_futexes),
+ GFP_KERNEL);
+ if (!futexv)
+ return -ENOMEM;
+
+ futexv->hint = false;
+ futexv->task = current;
+
+ ret = futex_parse_waitv(futexv, waiters, nr_futexes);
+ if (!ret)
+ ret = futex_wait(futexv, nr_futexes, timo, &timeout, flags);
+
+ kfree(futexv);
+
+ return ret;
+}
+
+/**
+ * futex_get_parent - Get parent
+ * @waiter: TODO
+ * @index: TODO
+ *
+ * Return: TODO
+ */
+static struct futexv *futex_get_parent(uintptr_t waiter, u8 index)
+{
+ uintptr_t parent = waiter - sizeof(struct futexv)
+ - (uintptr_t) (index * sizeof(struct futex_waiter));
+
+ return (struct futexv *) parent;
+}
+
+/**
+ * sys_futex_wake - Wake a number of futexes waiting on an address
+ * @uaddr: Address of futex to be woken up
+ * @nr_wake: Number of futexes to be woken up
+ * @flags: TODO
+ */
+SYSCALL_DEFINE3(futex_wake, void __user *, uaddr, unsigned int, nr_wake,
+ unsigned int, flags)
+{
+ bool shared = (flags & FUTEX_SHARED_FLAG) ? true : false;
+ unsigned int size = flags & FUTEX_SIZE_MASK;
+ struct futex_waiter waiter, *aux, *tmp;
+ struct futex_bucket *bucket;
+ struct task_struct *task;
+ DEFINE_WAKE_Q(wake_q);
+ int ret = 0;
+
+ if (flags & ~FUTEX2_MASK)
+ return -EINVAL;
+
+ if (size != FUTEX_32)
+ return -EINVAL;
+
+ bucket = futex_get_bucket(uaddr, &waiter.key, shared);
+ if (IS_ERR(bucket))
+ return PTR_ERR(bucket);
+
+ if (!bucket_get_waiters(bucket))
+ return 0;
+
+ spin_lock(&bucket->lock);
+ list_for_each_entry_safe(aux, tmp, &bucket->list, list) {
+ if (ret >= nr_wake)
+ break;
+
+ if (waiter.key.address == aux->key.address &&
+ waiter.key.mm == aux->key.mm &&
+ waiter.key.offset == aux->key.offset) {
+ struct futexv *parent =
+ futex_get_parent((uintptr_t) aux, aux->index);
+
+ parent->hint = true;
+ task = parent->task;
+ get_task_struct(task);
+ list_del_init_careful(&aux->list);
+ wake_q_add_safe(&wake_q, task);
+ ret++;
+ bucket_dec_waiters(bucket);
+ }
+ }
+ spin_unlock(&bucket->lock);
+
+ wake_up_q(&wake_q);
+
+ return ret;
+}
+
+static ssize_t wait_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", __NR_futex_wait);
+
+}
+static struct kobj_attribute futex2_wait_attr = __ATTR_RO(wait);
+
+static ssize_t wake_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", __NR_futex_wake);
+
+}
+static struct kobj_attribute futex2_wake_attr = __ATTR_RO(wake);
+
+static ssize_t waitv_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%u\n", __NR_futex_waitv);
+
+}
+static struct kobj_attribute futex2_waitv_attr = __ATTR_RO(waitv);
+
+static struct attribute *futex2_sysfs_attrs[] = {
+ &futex2_wait_attr.attr,
+ &futex2_wake_attr.attr,
+ &futex2_waitv_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group futex2_sysfs_attr_group = {
+ .attrs = futex2_sysfs_attrs,
+ .name = "futex2",
+};
+
+static int __init futex2_sysfs_init(void)
+{
+ return sysfs_create_group(kernel_kobj, &futex2_sysfs_attr_group);
+}
+subsys_initcall(futex2_sysfs_init);
+
+static int __init futex2_init(void)
+{
+ int i;
+ unsigned int futex_shift;
+
+#if CONFIG_BASE_SMALL
+ futex2_hashsize = 16;
+#else
+ futex2_hashsize = roundup_pow_of_two(256 * num_possible_cpus());
+#endif
+
+ futex_table = alloc_large_system_hash("futex2", sizeof(struct futex_bucket),
+ futex2_hashsize, 0,
+ futex2_hashsize < 256 ? HASH_SMALL : 0,
+ &futex_shift, NULL,
+ futex2_hashsize, futex2_hashsize);
+ futex2_hashsize = 1UL << futex_shift;
+
+ for (i = 0; i < futex2_hashsize; i++) {
+ INIT_LIST_HEAD(&futex_table[i].list);
+ spin_lock_init(&futex_table[i].lock);
+ atomic_set(&futex_table[i].waiters, 0);
+ }
+
+ return 0;
+}
+core_initcall(futex2_init);
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index f27ac94d5..1898e7340 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -148,6 +148,11 @@ COND_SYSCALL_COMPAT(set_robust_list);
COND_SYSCALL(get_robust_list);
COND_SYSCALL_COMPAT(get_robust_list);
+/* kernel/futex2.c */
+COND_SYSCALL(futex_wait);
+COND_SYSCALL(futex_wake);
+COND_SYSCALL(futex_waitv);
+
/* kernel/hrtimer.c */
/* kernel/itimer.c */
diff --git a/tools/arch/x86/include/asm/unistd_64.h b/tools/arch/x86/include/asm/unistd_64.h
index 4205ed415..151a41ceb 100644
--- a/tools/arch/x86/include/asm/unistd_64.h
+++ b/tools/arch/x86/include/asm/unistd_64.h
@@ -17,3 +17,11 @@
#ifndef __NR_setns
#define __NR_setns 308
#endif
+
+#ifndef __NR_futex_wait
+# define __NR_futex_wait 441
+#endif
+
+#ifndef __NR_futex_wake
+# define __NR_futex_wake 442
+#endif
diff --git a/tools/include/uapi/asm-generic/unistd.h b/tools/include/uapi/asm-generic/unistd.h
index 205631898..81a90b697 100644
--- a/tools/include/uapi/asm-generic/unistd.h
+++ b/tools/include/uapi/asm-generic/unistd.h
@@ -860,8 +860,17 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
#define __NR_process_madvise 440
__SYSCALL(__NR_process_madvise, sys_process_madvise)
+#define __NR_futex_wait 441
+__SYSCALL(__NR_futex_wait, sys_futex_wait)
+
+#define __NR_futex_wake 442
+__SYSCALL(__NR_futex_wake, sys_futex_wake)
+
+#define __NR_futex_waitv 443
+__SYSCALL(__NR_futex_waitv, sys_futex_waitv)
+
#undef __NR_syscalls
-#define __NR_syscalls 441
+#define __NR_syscalls 444
/*
* 32 bit systems traditionally used different
diff --git a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
index 379819244..bd47f368f 100644
--- a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
@@ -362,6 +362,9 @@
438 common pidfd_getfd sys_pidfd_getfd
439 common faccessat2 sys_faccessat2
440 common process_madvise sys_process_madvise
+441 common futex_wait sys_futex_wait
+442 common futex_wake sys_futex_wake
+443 common futex_waitv sys_futex_waitv
#
# Due to a historical design error, certain syscalls are numbered differently
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index eac36afab..f6f881a05 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -38,8 +38,11 @@ int bench_mem_memcpy(int argc, const char **argv);
int bench_mem_memset(int argc, const char **argv);
int bench_mem_find_bit(int argc, const char **argv);
int bench_futex_hash(int argc, const char **argv);
+int bench_futex2_hash(int argc, const char **argv);
int bench_futex_wake(int argc, const char **argv);
+int bench_futex2_wake(int argc, const char **argv);
int bench_futex_wake_parallel(int argc, const char **argv);
+int bench_futex2_wake_parallel(int argc, const char **argv);
int bench_futex_requeue(int argc, const char **argv);
/* pi futexes */
int bench_futex_lock_pi(int argc, const char **argv);
diff --git a/tools/perf/bench/futex-hash.c b/tools/perf/bench/futex-hash.c
index 915bf3da7..72921c22b 100644
--- a/tools/perf/bench/futex-hash.c
+++ b/tools/perf/bench/futex-hash.c
@@ -34,7 +34,7 @@ static unsigned int nthreads = 0;
static unsigned int nsecs = 10;
/* amount of futexes per thread */
static unsigned int nfutexes = 1024;
-static bool fshared = false, done = false, silent = false;
+static bool fshared = false, done = false, silent = false, futex2 = false;
static int futex_flag = 0;
struct timeval bench__start, bench__end, bench__runtime;
@@ -86,7 +86,10 @@ static void *workerfn(void *arg)
* such as internal waitqueue handling, thus enlarging
* the critical region protected by hb->lock.
*/
- ret = futex_wait(&w->futex[i], 1234, NULL, futex_flag);
+ if (!futex2)
+ ret = futex_wait(&w->futex[i], 1234, NULL, futex_flag);
+ else
+ ret = futex2_wait(&w->futex[i], 1234, futex_flag, NULL);
if (!silent &&
(!ret || errno != EAGAIN || errno != EWOULDBLOCK))
warn("Non-expected futex return call");
@@ -117,7 +120,7 @@ static void print_summary(void)
(int)bench__runtime.tv_sec);
}
-int bench_futex_hash(int argc, const char **argv)
+static int bench_futex_hash_common(int argc, const char **argv)
{
int ret = 0;
cpu_set_t cpuset;
@@ -149,7 +152,9 @@ int bench_futex_hash(int argc, const char **argv)
if (!worker)
goto errmem;
- if (!fshared)
+ if (futex2)
+ futex_flag = FUTEX_32 | (fshared * FUTEX_SHARED_FLAG);
+ else if (!fshared)
futex_flag = FUTEX_PRIVATE_FLAG;
printf("Run summary [PID %d]: %d threads, each operating on %d [%s] futexes for %d secs.\n\n",
@@ -229,3 +234,14 @@ int bench_futex_hash(int argc, const char **argv)
errmem:
err(EXIT_FAILURE, "calloc");
}
+
+int bench_futex_hash(int argc, const char **argv)
+{
+ return bench_futex_hash_common(argc, argv);
+}
+
+int bench_futex2_hash(int argc, const char **argv)
+{
+ futex2 = true;
+ return bench_futex_hash_common(argc, argv);
+}
diff --git a/tools/perf/bench/futex-wake-parallel.c b/tools/perf/bench/futex-wake-parallel.c
index cd2b81a84..540104538 100644
--- a/tools/perf/bench/futex-wake-parallel.c
+++ b/tools/perf/bench/futex-wake-parallel.c
@@ -17,6 +17,12 @@ int bench_futex_wake_parallel(int argc __maybe_unused, const char **argv __maybe
pr_err("%s: pthread_barrier_t unavailable, disabling this test...\n", __func__);
return 0;
}
+
+int bench_futex2_wake_parallel(int argc __maybe_unused, const char **argv __maybe_unused)
+{
+ pr_err("%s: pthread_barrier_t unavailable, disabling this test...\n", __func__);
+ return 0;
+}
#else /* HAVE_PTHREAD_BARRIER */
/* For the CLR_() macros */
#include <string.h>
@@ -48,7 +54,7 @@ static unsigned int nwakes = 1;
static u_int32_t futex = 0;
static pthread_t *blocked_worker;
-static bool done = false, silent = false, fshared = false;
+static bool done = false, silent = false, fshared = false, futex2 = false;
static unsigned int nblocked_threads = 0, nwaking_threads = 0;
static pthread_mutex_t thread_lock;
static pthread_cond_t thread_parent, thread_worker;
@@ -79,7 +85,11 @@ static void *waking_workerfn(void *arg)
gettimeofday(&start, NULL);
- waker->nwoken = futex_wake(&futex, nwakes, futex_flag);
+ if (!futex2)
+ waker->nwoken = futex_wake(&futex, nwakes, futex_flag);
+ else
+ waker->nwoken = futex2_wake(&futex, nwakes, futex_flag);
+
if (waker->nwoken != nwakes)
warnx("couldn't wakeup all tasks (%d/%d)",
waker->nwoken, nwakes);
@@ -130,8 +140,13 @@ static void *blocked_workerfn(void *arg __maybe_unused)
pthread_mutex_unlock(&thread_lock);
while (1) { /* handle spurious wakeups */
- if (futex_wait(&futex, 0, NULL, futex_flag) != EINTR)
- break;
+ if (!futex2) {
+ if (futex_wait(&futex, 0, NULL, futex_flag) != EINTR)
+ break;
+ } else {
+ if (futex2_wait(&futex, 0, futex_flag, NULL) != EINTR)
+ break;
+ }
}
pthread_exit(NULL);
@@ -218,7 +233,7 @@ static void toggle_done(int sig __maybe_unused,
done = true;
}
-int bench_futex_wake_parallel(int argc, const char **argv)
+static int bench_futex_wake_parallel_common(int argc, const char **argv)
{
int ret = 0;
unsigned int i, j;
@@ -262,7 +277,9 @@ int bench_futex_wake_parallel(int argc, const char **argv)
if (!blocked_worker)
err(EXIT_FAILURE, "calloc");
- if (!fshared)
+ if (futex2)
+ futex_flag = FUTEX_32 | (fshared * FUTEX_SHARED_FLAG);
+ else if (!fshared)
futex_flag = FUTEX_PRIVATE_FLAG;
printf("Run summary [PID %d]: blocking on %d threads (at [%s] "
@@ -322,4 +339,16 @@ int bench_futex_wake_parallel(int argc, const char **argv)
free(blocked_worker);
return ret;
}
+
+int bench_futex_wake_parallel(int argc, const char **argv)
+{
+ return bench_futex_wake_parallel_common(argc, argv);
+}
+
+int bench_futex2_wake_parallel(int argc, const char **argv)
+{
+ futex2 = true;
+ return bench_futex_wake_parallel_common(argc, argv);
+}
+
#endif /* HAVE_PTHREAD_BARRIER */
diff --git a/tools/perf/bench/futex-wake.c b/tools/perf/bench/futex-wake.c
index 2dfcef3e3..b98b84e7b 100644
--- a/tools/perf/bench/futex-wake.c
+++ b/tools/perf/bench/futex-wake.c
@@ -46,6 +46,9 @@ static struct stats waketime_stats, wakeup_stats;
static unsigned int threads_starting, nthreads = 0;
static int futex_flag = 0;
+/* Should we use futex2 API? */
+static bool futex2 = false;
+
static const struct option options[] = {
OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
OPT_UINTEGER('w', "nwakes", &nwakes, "Specify amount of threads to wake at once"),
@@ -69,8 +72,13 @@ static void *workerfn(void *arg __maybe_unused)
pthread_mutex_unlock(&thread_lock);
while (1) {
- if (futex_wait(&futex1, 0, NULL, futex_flag) != EINTR)
- break;
+ if (!futex2) {
+ if (futex_wait(&futex1, 0, NULL, futex_flag) != EINTR)
+ break;
+ } else {
+ if (futex2_wait(&futex1, 0, futex_flag, NULL) != EINTR)
+ break;
+ }
}
pthread_exit(NULL);
@@ -118,7 +126,7 @@ static void toggle_done(int sig __maybe_unused,
done = true;
}
-int bench_futex_wake(int argc, const char **argv)
+static int bench_futex_wake_common(int argc, const char **argv)
{
int ret = 0;
unsigned int i, j;
@@ -148,7 +156,9 @@ int bench_futex_wake(int argc, const char **argv)
if (!worker)
err(EXIT_FAILURE, "calloc");
- if (!fshared)
+ if (futex2)
+ futex_flag = FUTEX_32 | (fshared * FUTEX_SHARED_FLAG);
+ else if (!fshared)
futex_flag = FUTEX_PRIVATE_FLAG;
printf("Run summary [PID %d]: blocking on %d threads (at [%s] futex %p), "
@@ -181,8 +191,13 @@ int bench_futex_wake(int argc, const char **argv)
/* Ok, all threads are patiently blocked, start waking folks up */
gettimeofday(&start, NULL);
while (nwoken != nthreads)
- nwoken += futex_wake(&futex1, nwakes, futex_flag);
+ if (!futex2) {
+ nwoken += futex_wake(&futex1, nwakes, futex_flag);
+ } else {
+ nwoken += futex2_wake(&futex1, nwakes, futex_flag);
+ }
gettimeofday(&end, NULL);
+
timersub(&end, &start, &runtime);
update_stats(&wakeup_stats, nwoken);
@@ -212,3 +227,14 @@ int bench_futex_wake(int argc, const char **argv)
free(worker);
return ret;
}
+
+int bench_futex_wake(int argc, const char **argv)
+{
+ return bench_futex_wake_common(argc, argv);
+}
+
+int bench_futex2_wake(int argc, const char **argv)
+{
+ futex2 = true;
+ return bench_futex_wake_common(argc, argv);
+}
diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h
index 31b53cc7d..5111799b5 100644
--- a/tools/perf/bench/futex.h
+++ b/tools/perf/bench/futex.h
@@ -86,4 +86,21 @@ futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wak
return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2,
val, opflags);
}
+
+/*
+ * wait for uaddr if (*uaddr == val)
+ */
+static inline int futex2_wait(volatile void *uaddr, unsigned long val,
+ unsigned long flags, struct timespec *timo)
+{
+ return syscall(__NR_futex_wait, uaddr, val, flags, timo);
+}
+
+/*
+ * wake nr futexes waiting for uaddr
+ */
+static inline int futex2_wake(volatile void *uaddr, unsigned int nr, unsigned long flags)
+{
+ return syscall(__NR_futex_wake, uaddr, nr, flags);
+}
#endif /* _FUTEX_H */
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 62a7b7420..200ecacad 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -12,10 +12,11 @@
*
* sched ... scheduler and IPC performance
* syscall ... System call performance
- * mem ... memory access performance
- * numa ... NUMA scheduling and MM performance
- * futex ... Futex performance
- * epoll ... Event poll performance
+ * mem ... memory access performance
+ * numa ... NUMA scheduling and MM performance
+ * futex ... Futex performance
+ * futex2 ... Futex2 performance
+ * epoll ... Event poll performance
*/
#include <subcmd/parse-options.h>
#include "builtin.h"
@@ -75,6 +76,13 @@ static struct bench futex_benchmarks[] = {
{ NULL, NULL, NULL }
};
+static struct bench futex2_benchmarks[] = {
+ { "hash", "Benchmark for futex2 hash table", bench_futex2_hash },
+ { "wake", "Benchmark for futex2 wake calls", bench_futex2_wake },
+ { "wake-parallel", "Benchmark for parallel futex2 wake calls", bench_futex2_wake_parallel },
+ { NULL, NULL, NULL }
+};
+
#ifdef HAVE_EVENTFD_SUPPORT
static struct bench epoll_benchmarks[] = {
{ "wait", "Benchmark epoll concurrent epoll_waits", bench_epoll_wait },
@@ -105,6 +113,7 @@ static struct collection collections[] = {
{ "numa", "NUMA scheduling and MM benchmarks", numa_benchmarks },
#endif
{"futex", "Futex stressing benchmarks", futex_benchmarks },
+ {"futex2", "Futex2 stressing benchmarks", futex2_benchmarks },
#ifdef HAVE_EVENTFD_SUPPORT
{"epoll", "Epoll stressing benchmarks", epoll_benchmarks },
#endif
diff --git a/tools/testing/selftests/futex/functional/.gitignore b/tools/testing/selftests/futex/functional/.gitignore
index 0efcd494d..d0b8f637b 100644
--- a/tools/testing/selftests/futex/functional/.gitignore
+++ b/tools/testing/selftests/futex/functional/.gitignore
@@ -6,3 +6,5 @@ futex_wait_private_mapped_file
futex_wait_timeout
futex_wait_uninitialized_heap
futex_wait_wouldblock
+futex2_wait
+futex2_waitv
diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile
index 23207829e..b857b9450 100644
--- a/tools/testing/selftests/futex/functional/Makefile
+++ b/tools/testing/selftests/futex/functional/Makefile
@@ -5,6 +5,7 @@ LDLIBS := -lpthread -lrt
HEADERS := \
../include/futextest.h \
+ ../include/futex2test.h \
../include/atomic.h \
../include/logging.h
TEST_GEN_FILES := \
@@ -14,7 +15,9 @@ TEST_GEN_FILES := \
futex_requeue_pi_signal_restart \
futex_requeue_pi_mismatched_ops \
futex_wait_uninitialized_heap \
- futex_wait_private_mapped_file
+ futex_wait_private_mapped_file \
+ futex2_wait \
+ futex2_waitv
TEST_PROGS := run.sh
diff --git a/tools/testing/selftests/futex/functional/futex2_wait.c b/tools/testing/selftests/futex/functional/futex2_wait.c
new file mode 100644
index 000000000..0646a24b7
--- /dev/null
+++ b/tools/testing/selftests/futex/functional/futex2_wait.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/******************************************************************************
+ *
+ * Copyright Collabora Ltd., 2020
+ *
+ * DESCRIPTION
+ * Test wait/wake mechanism of futex2, using 32bit sized futexes.
+ *
+ * AUTHOR
+ * André Almeida <andrealmeid@collabora.com>
+ *
+ * HISTORY
+ * 2020-Jul-9: Initial version by André <andrealmeid@collabora.com>
+ *
+ *****************************************************************************/
+
+#include <errno.h>
+#include <error.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <pthread.h>
+#include <sys/shm.h>
+#include "futex2test.h"
+#include "logging.h"
+
+#define TEST_NAME "futex2-wait"
+#define timeout_ns 30000000
+#define WAKE_WAIT_US 10000
+futex_t *f1;
+
+void usage(char *prog)
+{
+ printf("Usage: %s\n", prog);
+ printf(" -c Use color\n");
+ printf(" -h Display this help message\n");
+ printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
+ VQUIET, VCRITICAL, VINFO);
+}
+
+void *waiterfn(void *arg)
+{
+ struct timespec64 to64;
+ unsigned int flags = 0;
+ if (arg)
+ flags = *((unsigned int *) arg);
+
+ /* setting absolute timeout for futex2 */
+ if (gettime64(CLOCK_MONOTONIC, &to64))
+ error("gettime64 failed\n", errno);
+
+ to64.tv_nsec += timeout_ns;
+
+ if (to64.tv_nsec >= 1000000000) {
+ to64.tv_sec++;
+ to64.tv_nsec -= 1000000000;
+ }
+
+ if (futex2_wait(f1, *f1, FUTEX_32 | flags, &to64))
+ printf("waiter failed errno %d\n", errno);
+
+ return NULL;
+}
+
+int main(int argc, char *argv[])
+{
+ pthread_t waiter;
+ unsigned int flags = FUTEX_SHARED_FLAG;
+ int res, ret = RET_PASS;
+ int c;
+ futex_t f_private = 0;
+ f1 = &f_private;
+
+ while ((c = getopt(argc, argv, "cht:v:")) != -1) {
+ switch (c) {
+ case 'c':
+ log_color(1);
+ break;
+ case 'h':
+ usage(basename(argv[0]));
+ exit(0);
+ case 'v':
+ log_verbosity(atoi(optarg));
+ break;
+ default:
+ usage(basename(argv[0]));
+ exit(1);
+ }
+ }
+
+ ksft_print_header();
+ ksft_set_plan(2);
+ ksft_print_msg("%s: Test FUTEX2_WAIT\n",
+ basename(argv[0]));
+
+ info("Calling private futex2_wait on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+
+ if (pthread_create(&waiter, NULL, waiterfn, NULL))
+ error("pthread_create failed\n", errno);
+
+ usleep(WAKE_WAIT_US);
+
+ info("Calling private futex2_wake on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+ res = futex2_wake(f1, 1, FUTEX_32);
+ if (res != 1) {
+ ksft_test_result_fail("futex2_wake private returned: %d %s\n",
+ res ? errno : res,
+ res ? strerror(errno) : "");
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wake private succeeds\n");
+ }
+
+ int shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666);
+ if (shm_id < 0) {
+ perror("shmget");
+ exit(1);
+ }
+
+ unsigned int *shared_data = shmat(shm_id, NULL, 0);
+ *shared_data = 0;
+ f1 = shared_data;
+
+ info("Calling shared futex2_wait on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+
+ if (pthread_create(&waiter, NULL, waiterfn, &flags))
+ error("pthread_create failed\n", errno);
+
+ usleep(WAKE_WAIT_US);
+
+ info("Calling shared futex2_wake on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+ res = futex2_wake(f1, 1, FUTEX_32 | FUTEX_SHARED_FLAG);
+ if (res != 1) {
+ ksft_test_result_fail("futex2_wake shared returned: %d %s\n",
+ res ? errno : res,
+ res ? strerror(errno) : "");
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wake shared succeeds\n");
+ }
+
+ shmdt(shared_data);
+
+ ksft_print_cnts();
+ return ret;
+}
diff --git a/tools/testing/selftests/futex/functional/futex2_waitv.c b/tools/testing/selftests/futex/functional/futex2_waitv.c
new file mode 100644
index 000000000..d4b116651
--- /dev/null
+++ b/tools/testing/selftests/futex/functional/futex2_waitv.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/******************************************************************************
+ *
+ * Copyright Collabora Ltd., 2020
+ *
+ * DESCRIPTION
+ * Test waitv/wake mechanism of futex2, using 32bit sized futexes.
+ *
+ * AUTHOR
+ * André Almeida <andrealmeid@collabora.com>
+ *
+ * HISTORY
+ * 2020-Jul-9: Initial version by André <andrealmeid@collabora.com>
+ *
+ *****************************************************************************/
+
+#include <errno.h>
+#include <error.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <pthread.h>
+#include <sys/shm.h>
+#include "futex2test.h"
+#include "logging.h"
+
+#define TEST_NAME "futex2-wait"
+#define timeout_ns 1000000000
+#define WAKE_WAIT_US 10000
+#define NR_FUTEXES 30
+struct futex_waitv waitv[NR_FUTEXES];
+u_int32_t futexes[NR_FUTEXES] = {0};
+
+void usage(char *prog)
+{
+ printf("Usage: %s\n", prog);
+ printf(" -c Use color\n");
+ printf(" -h Display this help message\n");
+ printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n",
+ VQUIET, VCRITICAL, VINFO);
+}
+
+void *waiterfn(void *arg)
+{
+ struct timespec64 to64;
+ int res;
+
+ /* setting absolute timeout for futex2 */
+ if (gettime64(CLOCK_MONOTONIC, &to64))
+ error("gettime64 failed\n", errno);
+
+ to64.tv_sec++;
+
+ res = futex2_waitv(waitv, NR_FUTEXES, 0, &to64);
+ if (res < 0) {
+ printf("waiter failed errno %d %s\n",
+ res ? errno : res,
+ res ? strerror(errno) : "");
+ }
+
+ return NULL;
+}
+
+int main(int argc, char *argv[])
+{
+ pthread_t waiter;
+ int res, ret = RET_PASS;
+ int c, i;
+
+ while ((c = getopt(argc, argv, "cht:v:")) != -1) {
+ switch (c) {
+ case 'c':
+ log_color(1);
+ break;
+ case 'h':
+ usage(basename(argv[0]));
+ exit(0);
+ case 'v':
+ log_verbosity(atoi(optarg));
+ break;
+ default:
+ usage(basename(argv[0]));
+ exit(1);
+ }
+ }
+
+ ksft_print_header();
+ ksft_set_plan(2);
+ ksft_print_msg("%s: Test FUTEX2_WAITV\n",
+ basename(argv[0]));
+
+ //info("Calling private futex2_wait on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+
+ for (i = 0; i < NR_FUTEXES; i++) {
+ waitv[i].uaddr = &futexes[i];
+ waitv[i].flags = FUTEX_32;
+ waitv[i].val = 0;
+ }
+
+ if (pthread_create(&waiter, NULL, waiterfn, NULL))
+ error("pthread_create failed\n", errno);
+
+ usleep(WAKE_WAIT_US);
+
+ // info("Calling private futex2_wake on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+ res = futex2_wake(waitv[NR_FUTEXES - 1].uaddr, 1, FUTEX_32);
+ if (res != 1) {
+ ksft_test_result_fail("futex2_wake private returned: %d %s\n",
+ res ? errno : res,
+ res ? strerror(errno) : "");
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_waitv private succeeds\n");
+ }
+
+ for (i = 0; i < NR_FUTEXES; i++) {
+ int shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666);
+ if (shm_id < 0) {
+ perror("shmget");
+ exit(1);
+ }
+
+ unsigned int *shared_data = shmat(shm_id, NULL, 0);
+ *shared_data = 0;
+
+ waitv[i].uaddr = shared_data;
+ waitv[i].flags = FUTEX_32 | FUTEX_SHARED_FLAG;
+ waitv[i].val = 0;
+ }
+
+ //info("Calling shared futex2_wait on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+
+ if (pthread_create(&waiter, NULL, waiterfn, NULL))
+ error("pthread_create failed\n", errno);
+
+ usleep(WAKE_WAIT_US);
+
+ // info("Calling shared futex2_wake on f1: %u @ %p with val=%u\n", *f1, f1, *f1);
+ res = futex2_wake(waitv[NR_FUTEXES - 1].uaddr, 1, FUTEX_32 | FUTEX_SHARED_FLAG);
+ if (res != 1) {
+ ksft_test_result_fail("futex2_wake shared returned: %d %s\n",
+ res ? errno : res,
+ res ? strerror(errno) : "");
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wake shared succeeds\n");
+ }
+
+ for (i = 0; i < NR_FUTEXES; i++)
+ shmdt(waitv[i].uaddr);
+
+ ksft_print_cnts();
+ return ret;
+}
diff --git a/tools/testing/selftests/futex/functional/futex_wait_timeout.c b/tools/testing/selftests/futex/functional/futex_wait_timeout.c
index ee55e6d38..245670e44 100644
--- a/tools/testing/selftests/futex/functional/futex_wait_timeout.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_timeout.c
@@ -11,6 +11,7 @@
*
* HISTORY
* 2009-Nov-6: Initial version by Darren Hart <dvhart@linux.intel.com>
+ * 2020-Jul-9: Add futex2 test by André <andrealmeid@collabora.com>
*
*****************************************************************************/
@@ -20,7 +21,7 @@
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include "futextest.h"
+#include "futex2test.h"
#include "logging.h"
#define TEST_NAME "futex-wait-timeout"
@@ -40,7 +41,8 @@ void usage(char *prog)
int main(int argc, char *argv[])
{
futex_t f1 = FUTEX_INITIALIZER;
- struct timespec to;
+ struct timespec to = {.tv_sec = 0, .tv_nsec = timeout_ns};
+ struct timespec64 to64;
int res, ret = RET_PASS;
int c;
@@ -65,22 +67,60 @@ int main(int argc, char *argv[])
}
ksft_print_header();
- ksft_set_plan(1);
+ ksft_set_plan(3);
ksft_print_msg("%s: Block on a futex and wait for timeout\n",
basename(argv[0]));
ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns);
- /* initialize timeout */
- to.tv_sec = 0;
- to.tv_nsec = timeout_ns;
-
info("Calling futex_wait on f1: %u @ %p\n", f1, &f1);
res = futex_wait(&f1, f1, &to, FUTEX_PRIVATE_FLAG);
if (!res || errno != ETIMEDOUT) {
- fail("futex_wait returned %d\n", ret < 0 ? errno : ret);
+ ksft_test_result_fail("futex_wait returned %d\n", ret < 0 ? errno : ret);
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex_wait timeout succeeds\n");
+ }
+
+ /* setting absolute monotonic timeout for futex2 */
+ if (gettime64(CLOCK_MONOTONIC, &to64))
+ error("gettime64 failed\n", errno);
+
+ to64.tv_nsec += timeout_ns;
+
+ if (to64.tv_nsec >= 1000000000) {
+ to64.tv_sec++;
+ to64.tv_nsec -= 1000000000;
+ }
+
+ info("Calling futex2_wait on f1: %u @ %p\n", f1, &f1);
+ res = futex2_wait(&f1, f1, FUTEX_32, &to64);
+ if (!res || errno != ETIMEDOUT) {
+ ksft_test_result_fail("futex2_wait monotonic returned %d\n", ret < 0 ? errno : ret);
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wait monotonic timeout succeeds\n");
+ }
+
+ /* setting absolute realtime timeout for futex2 */
+ if (gettime64(CLOCK_REALTIME, &to64))
+ error("gettime64 failed\n", errno);
+
+ to64.tv_nsec += timeout_ns;
+
+ if (to64.tv_nsec >= 1000000000) {
+ to64.tv_sec++;
+ to64.tv_nsec -= 1000000000;
+ }
+
+ info("Calling futex2_wait on f1: %u @ %p\n", f1, &f1);
+ res = futex2_wait(&f1, f1, FUTEX_32 | FUTEX_CLOCK_REALTIME, &to64);
+ if (!res || errno != ETIMEDOUT) {
+ ksft_test_result_fail("futex2_wait realtime returned %d\n", ret < 0 ? errno : ret);
ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wait realtime timeout succeeds\n");
}
- print_result(TEST_NAME, ret);
+ ksft_print_cnts();
return ret;
}
diff --git a/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c b/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
index 0ae390ff8..1f72e5928 100644
--- a/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
@@ -12,6 +12,7 @@
*
* HISTORY
* 2009-Nov-14: Initial version by Gowrishankar <gowrishankar.m@in.ibm.com>
+ * 2020-Jul-9: Add futex2 test by André <andrealmeid@collabora.com>
*
*****************************************************************************/
@@ -21,7 +22,7 @@
#include <stdlib.h>
#include <string.h>
#include <time.h>
-#include "futextest.h"
+#include "futex2test.h"
#include "logging.h"
#define TEST_NAME "futex-wait-wouldblock"
@@ -39,6 +40,7 @@ void usage(char *prog)
int main(int argc, char *argv[])
{
struct timespec to = {.tv_sec = 0, .tv_nsec = timeout_ns};
+ struct timespec64 to64;
futex_t f1 = FUTEX_INITIALIZER;
int res, ret = RET_PASS;
int c;
@@ -61,18 +63,41 @@ int main(int argc, char *argv[])
}
ksft_print_header();
- ksft_set_plan(1);
+ ksft_set_plan(2);
ksft_print_msg("%s: Test the unexpected futex value in FUTEX_WAIT\n",
basename(argv[0]));
info("Calling futex_wait on f1: %u @ %p with val=%u\n", f1, &f1, f1+1);
res = futex_wait(&f1, f1+1, &to, FUTEX_PRIVATE_FLAG);
if (!res || errno != EWOULDBLOCK) {
- fail("futex_wait returned: %d %s\n",
+ ksft_test_result_fail("futex_wait returned: %d %s\n",
res ? errno : res, res ? strerror(errno) : "");
ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex_wait wouldblock succeeds\n");
}
- print_result(TEST_NAME, ret);
+ /* setting absolute timeout for futex2 */
+ if (gettime64(CLOCK_MONOTONIC, &to64))
+ error("gettime64 failed\n", errno);
+
+ to64.tv_nsec += timeout_ns;
+
+ if (to64.tv_nsec >= 1000000000) {
+ to64.tv_sec++;
+ to64.tv_nsec -= 1000000000;
+ }
+
+ info("Calling futex2_wait on f1: %u @ %p with val=%u\n", f1, &f1, f1+1);
+ res = futex2_wait(&f1, f1+1, FUTEX_32, &to64);
+ if (!res || errno != EWOULDBLOCK) {
+ ksft_test_result_fail("futex2_wait returned: %d %s\n",
+ res ? errno : res, res ? strerror(errno) : "");
+ ret = RET_FAIL;
+ } else {
+ ksft_test_result_pass("futex2_wait wouldblock succeeds\n");
+ }
+
+ ksft_print_cnts();
return ret;
}
diff --git a/tools/testing/selftests/futex/functional/run.sh b/tools/testing/selftests/futex/functional/run.sh
index 1acb6ace1..18b3883d7 100755
--- a/tools/testing/selftests/futex/functional/run.sh
+++ b/tools/testing/selftests/futex/functional/run.sh
@@ -73,3 +73,9 @@ echo
echo
./futex_wait_uninitialized_heap $COLOR
./futex_wait_private_mapped_file $COLOR
+
+echo
+./futex2_wait $COLOR
+
+echo
+./futex2_waitv $COLOR
diff --git a/tools/testing/selftests/futex/include/futex2test.h b/tools/testing/selftests/futex/include/futex2test.h
new file mode 100644
index 000000000..10be0c504
--- /dev/null
+++ b/tools/testing/selftests/futex/include/futex2test.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/******************************************************************************
+ *
+ * Copyright Collabora Ltd., 2020
+ *
+ * DESCRIPTION
+ * Futex2 library addons for old futex library
+ *
+ * AUTHOR
+ * André Almeida <andrealmeid@collabora.com>
+ *
+ * HISTORY
+ * 2020-Jul-9: Initial version by André <andrealmeid@collabora.com>
+ *
+ *****************************************************************************/
+#include "futextest.h"
+#include <stdio.h>
+
+#define NSEC_PER_SEC 1000000000L
+
+#ifndef FUTEX_8
+# define FUTEX_8 0
+#endif
+#ifndef FUTEX_16
+# define FUTEX_16 1
+#endif
+#ifndef FUTEX_32
+#define FUTEX_32 2
+#endif
+
+#ifndef FUTEX_SHARED_FLAG
+#define FUTEX_SHARED_FLAG 8
+#endif
+
+#ifndef FUTEX_WAITV_MAX
+#define FUTEX_WAITV_MAX 128
+struct futex_waitv {
+ void *uaddr;
+ unsigned int val;
+ unsigned int flags;
+};
+#endif
+
+/*
+ * - Y2038 section for 32-bit applications -
+ *
+ * Remove this when glibc is ready for y2038. Then, always compile with
+ * `-DTIME_BITS=64` or `-D__USE_TIME_BITS64`. glibc will provide both
+ * timespec64 and clock_gettime64 so we won't need to define here.
+ */
+#if defined(__i386__) || __TIMESIZE == 32
+# define NR_gettime __NR_clock_gettime64
+#else
+# define NR_gettime __NR_clock_gettime
+#endif
+
+struct timespec64 {
+ long long tv_sec; /* seconds */
+ long long tv_nsec; /* nanoseconds */
+};
+
+int gettime64(clock_t clockid, struct timespec64 *tv)
+{
+ return syscall(NR_gettime, clockid, tv);
+}
+/*
+ * - End of Y2038 section -
+ */
+
+/*
+ * wait for uaddr if (*uaddr == val)
+ */
+static inline int futex2_wait(volatile void *uaddr, unsigned long val,
+ unsigned long flags, struct timespec64 *timo)
+{
+ return syscall(__NR_futex_wait, uaddr, val, flags, timo);
+}
+
+/*
+ * wake nr futexes waiting for uaddr
+ */
+static inline int futex2_wake(volatile void *uaddr, unsigned int nr, unsigned long flags)
+{
+ return syscall(__NR_futex_wake, uaddr, nr, flags);
+}
+
+/*
+ * wait for uaddr if (*uaddr == val)
+ */
+static inline int futex2_waitv(volatile struct futex_waitv *waiters, unsigned long nr_waiters,
+ unsigned long flags, struct timespec64 *timo)
+{
+ return syscall(__NR_futex_waitv, waiters, nr_waiters, flags, timo);
+}
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