1 files changed, 184 insertions, 51 deletions

diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c
index a8074079b0..4b6da9116a 100644
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-#include <linux/compat.h>
 #include <linux/syscalls.h>
 #include <linux/time_namespace.h>
 
@@ -85,15 +84,12 @@ err_unlock:
 long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
 		u32 __user *uaddr2, u32 val2, u32 val3)
 {
+	unsigned int flags = futex_to_flags(op);
 	int cmd = op & FUTEX_CMD_MASK;
-	unsigned int flags = 0;
 
-	if (!(op & FUTEX_PRIVATE_FLAG))
-		flags |= FLAGS_SHARED;
-
-	if (op & FUTEX_CLOCK_REALTIME) {
-		flags |= FLAGS_CLOCKRT;
-		if (cmd != FUTEX_WAIT_BITSET && cmd != FUTEX_WAIT_REQUEUE_PI &&
+	if (flags & FLAGS_CLOCKRT) {
+		if (cmd != FUTEX_WAIT_BITSET &&
+		    cmd != FUTEX_WAIT_REQUEUE_PI &&
 		    cmd != FUTEX_LOCK_PI2)
 			return -ENOSYS;
 	}
@@ -110,9 +106,9 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
 	case FUTEX_WAKE_BITSET:
 		return futex_wake(uaddr, flags, val, val3);
 	case FUTEX_REQUEUE:
-		return futex_requeue(uaddr, flags, uaddr2, val, val2, NULL, 0);
+		return futex_requeue(uaddr, flags, uaddr2, flags, val, val2, NULL, 0);
 	case FUTEX_CMP_REQUEUE:
-		return futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 0);
+		return futex_requeue(uaddr, flags, uaddr2, flags, val, val2, &val3, 0);
 	case FUTEX_WAKE_OP:
 		return futex_wake_op(uaddr, flags, uaddr2, val, val2, val3);
 	case FUTEX_LOCK_PI:
@@ -129,7 +125,7 @@ long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
 		return futex_wait_requeue_pi(uaddr, flags, val, timeout, val3,
 					     uaddr2);
 	case FUTEX_CMP_REQUEUE_PI:
-		return futex_requeue(uaddr, flags, uaddr2, val, val2, &val3, 1);
+		return futex_requeue(uaddr, flags, uaddr2, flags, val, val2, &val3, 1);
 	}
 	return -ENOSYS;
 }
@@ -183,43 +179,91 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
 	return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
 }
 
-/* Mask of available flags for each futex in futex_waitv list */
-#define FUTEXV_WAITER_MASK (FUTEX_32 | FUTEX_PRIVATE_FLAG)
-
 /**
  * futex_parse_waitv - Parse a waitv array from userspace
  * @futexv:	Kernel side list of waiters to be filled
  * @uwaitv:     Userspace list to be parsed
  * @nr_futexes: Length of futexv
+ * @wake:	Wake to call when futex is woken
+ * @wake_data:	Data for the wake handler
  *
  * Return: Error code on failure, 0 on success
  */
-static int futex_parse_waitv(struct futex_vector *futexv,
-			     struct futex_waitv __user *uwaitv,
-			     unsigned int nr_futexes)
+int futex_parse_waitv(struct futex_vector *futexv,
+		      struct futex_waitv __user *uwaitv,
+		      unsigned int nr_futexes, futex_wake_fn *wake,
+		      void *wake_data)
 {
 	struct futex_waitv aux;
 	unsigned int i;
 
 	for (i = 0; i < nr_futexes; i++) {
+		unsigned int flags;
+
 		if (copy_from_user(&aux, &uwaitv[i], sizeof(aux)))
 			return -EFAULT;
 
-		if ((aux.flags & ~FUTEXV_WAITER_MASK) || aux.__reserved)
+		if ((aux.flags & ~FUTEX2_VALID_MASK) || aux.__reserved)
+			return -EINVAL;
+
+		flags = futex2_to_flags(aux.flags);
+		if (!futex_flags_valid(flags))
 			return -EINVAL;
 
-		if (!(aux.flags & FUTEX_32))
+		if (!futex_validate_input(flags, aux.val))
 			return -EINVAL;
 
-		futexv[i].w.flags = aux.flags;
+		futexv[i].w.flags = flags;
 		futexv[i].w.val = aux.val;
 		futexv[i].w.uaddr = aux.uaddr;
 		futexv[i].q = futex_q_init;
+		futexv[i].q.wake = wake;
+		futexv[i].q.wake_data = wake_data;
 	}
 
 	return 0;
 }
 
+static int futex2_setup_timeout(struct __kernel_timespec __user *timeout,
+				clockid_t clockid, struct hrtimer_sleeper *to)
+{
+	int flag_clkid = 0, flag_init = 0;
+	struct timespec64 ts;
+	ktime_t time;
+	int ret;
+
+	if (!timeout)
+		return 0;
+
+	if (clockid == CLOCK_REALTIME) {
+		flag_clkid = FLAGS_CLOCKRT;
+		flag_init = FUTEX_CLOCK_REALTIME;
+	}
+
+	if (clockid != CLOCK_REALTIME && clockid != CLOCK_MONOTONIC)
+		return -EINVAL;
+
+	if (get_timespec64(&ts, timeout))
+		return -EFAULT;
+
+	/*
+	 * Since there's no opcode for futex_waitv, use
+	 * FUTEX_WAIT_BITSET that uses absolute timeout as well
+	 */
+	ret = futex_init_timeout(FUTEX_WAIT_BITSET, flag_init, &ts, &time);
+	if (ret)
+		return ret;
+
+	futex_setup_timer(&time, to, flag_clkid, 0);
+	return 0;
+}
+
+static inline void futex2_destroy_timeout(struct hrtimer_sleeper *to)
+{
+	hrtimer_cancel(&to->timer);
+	destroy_hrtimer_on_stack(&to->timer);
+}
+
 /**
  * sys_futex_waitv - Wait on a list of futexes
  * @waiters:    List of futexes to wait on
@@ -249,8 +293,6 @@ SYSCALL_DEFINE5(futex_waitv, struct futex_waitv __user *, waiters,
 {
 	struct hrtimer_sleeper to;
 	struct futex_vector *futexv;
-	struct timespec64 ts;
-	ktime_t time;
 	int ret;
 
 	/* This syscall supports no flags for now */
@@ -260,30 +302,8 @@ SYSCALL_DEFINE5(futex_waitv, struct futex_waitv __user *, waiters,
 	if (!nr_futexes || nr_futexes > FUTEX_WAITV_MAX || !waiters)
 		return -EINVAL;
 
-	if (timeout) {
-		int flag_clkid = 0, flag_init = 0;
-
-		if (clockid == CLOCK_REALTIME) {
-			flag_clkid = FLAGS_CLOCKRT;
-			flag_init = FUTEX_CLOCK_REALTIME;
-		}
-
-		if (clockid != CLOCK_REALTIME && clockid != CLOCK_MONOTONIC)
-			return -EINVAL;
-
-		if (get_timespec64(&ts, timeout))
-			return -EFAULT;
-
-		/*
-		 * Since there's no opcode for futex_waitv, use
-		 * FUTEX_WAIT_BITSET that uses absolute timeout as well
-		 */
-		ret = futex_init_timeout(FUTEX_WAIT_BITSET, flag_init, &ts, &time);
-		if (ret)
-			return ret;
-
-		futex_setup_timer(&time, &to, flag_clkid, 0);
-	}
+	if (timeout && (ret = futex2_setup_timeout(timeout, clockid, &to)))
+		return ret;
 
 	futexv = kcalloc(nr_futexes, sizeof(*futexv), GFP_KERNEL);
 	if (!futexv) {
@@ -291,20 +311,133 @@ SYSCALL_DEFINE5(futex_waitv, struct futex_waitv __user *, waiters,
 		goto destroy_timer;
 	}
 
-	ret = futex_parse_waitv(futexv, waiters, nr_futexes);
+	ret = futex_parse_waitv(futexv, waiters, nr_futexes, futex_wake_mark,
+				NULL);
 	if (!ret)
 		ret = futex_wait_multiple(futexv, nr_futexes, timeout ? &to : NULL);
 
 	kfree(futexv);
 
 destroy_timer:
-	if (timeout) {
-		hrtimer_cancel(&to.timer);
-		destroy_hrtimer_on_stack(&to.timer);
-	}
+	if (timeout)
+		futex2_destroy_timeout(&to);
 	return ret;
 }
 
+/*
+ * sys_futex_wake - Wake a number of futexes
+ * @uaddr:	Address of the futex(es) to wake
+ * @mask:	bitmask
+ * @nr:		Number of the futexes to wake
+ * @flags:	FUTEX2 flags
+ *
+ * Identical to the traditional FUTEX_WAKE_BITSET op, except it is part of the
+ * futex2 family of calls.
+ */
+
+SYSCALL_DEFINE4(futex_wake,
+		void __user *, uaddr,
+		unsigned long, mask,
+		int, nr,
+		unsigned int, flags)
+{
+	if (flags & ~FUTEX2_VALID_MASK)
+		return -EINVAL;
+
+	flags = futex2_to_flags(flags);
+	if (!futex_flags_valid(flags))
+		return -EINVAL;
+
+	if (!futex_validate_input(flags, mask))
+		return -EINVAL;
+
+	return futex_wake(uaddr, FLAGS_STRICT | flags, nr, mask);
+}
+
+/*
+ * sys_futex_wait - Wait on a futex
+ * @uaddr:	Address of the futex to wait on
+ * @val:	Value of @uaddr
+ * @mask:	bitmask
+ * @flags:	FUTEX2 flags
+ * @timeout:	Optional absolute timeout
+ * @clockid:	Clock to be used for the timeout, realtime or monotonic
+ *
+ * Identical to the traditional FUTEX_WAIT_BITSET op, except it is part of the
+ * futex2 familiy of calls.
+ */
+
+SYSCALL_DEFINE6(futex_wait,
+		void __user *, uaddr,
+		unsigned long, val,
+		unsigned long, mask,
+		unsigned int, flags,
+		struct __kernel_timespec __user *, timeout,
+		clockid_t, clockid)
+{
+	struct hrtimer_sleeper to;
+	int ret;
+
+	if (flags & ~FUTEX2_VALID_MASK)
+		return -EINVAL;
+
+	flags = futex2_to_flags(flags);
+	if (!futex_flags_valid(flags))
+		return -EINVAL;
+
+	if (!futex_validate_input(flags, val) ||
+	    !futex_validate_input(flags, mask))
+		return -EINVAL;
+
+	if (timeout && (ret = futex2_setup_timeout(timeout, clockid, &to)))
+		return ret;
+
+	ret = __futex_wait(uaddr, flags, val, timeout ? &to : NULL, mask);
+
+	if (timeout)
+		futex2_destroy_timeout(&to);
+
+	return ret;
+}
+
+/*
+ * sys_futex_requeue - Requeue a waiter from one futex to another
+ * @waiters:	array describing the source and destination futex
+ * @flags:	unused
+ * @nr_wake:	number of futexes to wake
+ * @nr_requeue:	number of futexes to requeue
+ *
+ * Identical to the traditional FUTEX_CMP_REQUEUE op, except it is part of the
+ * futex2 family of calls.
+ */
+
+SYSCALL_DEFINE4(futex_requeue,
+		struct futex_waitv __user *, waiters,
+		unsigned int, flags,
+		int, nr_wake,
+		int, nr_requeue)
+{
+	struct futex_vector futexes[2];
+	u32 cmpval;
+	int ret;
+
+	if (flags)
+		return -EINVAL;
+
+	if (!waiters)
+		return -EINVAL;
+
+	ret = futex_parse_waitv(futexes, waiters, 2, futex_wake_mark, NULL);
+	if (ret)
+		return ret;
+
+	cmpval = futexes[0].w.val;
+
+	return futex_requeue(u64_to_user_ptr(futexes[0].w.uaddr), futexes[0].w.flags,
+			     u64_to_user_ptr(futexes[1].w.uaddr), futexes[1].w.flags,
+			     nr_wake, nr_requeue, &cmpval, 0);
+}
+
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE2(set_robust_list,
 		struct compat_robust_list_head __user *, head,