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Diffstat (limited to 'kernel/futex/syscalls.c')
-rw-r--r--kernel/futex/syscalls.c235
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,