diff options
Diffstat (limited to 'kernel/futex/syscalls.c')
| -rw-r--r-- | kernel/futex/syscalls.c | 221 |
1 files changed, 175 insertions, 46 deletions
diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c index a8074079b09e..8200d86d30e1 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; } @@ -183,8 +179,7 @@ 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) +#define FUTEX2_VALID_MASK (FUTEX2_SIZE_MASK | FUTEX2_PRIVATE) /** * futex_parse_waitv - Parse a waitv array from userspace @@ -202,16 +197,22 @@ static int futex_parse_waitv(struct futex_vector *futexv, 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; - if (!(aux.flags & FUTEX_32)) + flags = futex2_to_flags(aux.flags); + if (!futex_flags_valid(flags)) return -EINVAL; - futexv[i].w.flags = aux.flags; + if (!futex_validate_input(flags, aux.val)) + return -EINVAL; + + futexv[i].w.flags = flags; futexv[i].w.val = aux.val; futexv[i].w.uaddr = aux.uaddr; futexv[i].q = futex_q_init; @@ -220,6 +221,46 @@ static int futex_parse_waitv(struct futex_vector *futexv, 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 +290,6 @@ 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 +299,8 @@ 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) { @@ -298,13 +315,125 @@ SYSCALL_DEFINE5(futex_waitv, struct futex_waitv __user *, waiters, 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); + 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, |