// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright © International Business Machines Corp., 2009 * Copyright (C) 2015 Cyril Hrubis * * DESCRIPTION * Glibc independent futex library for testing kernel functionality. * * AUTHOR * Darren Hart */ #ifndef FUTEXTEST_H #define FUTEXTEST_H #include #include #include #include "lapi/futex.h" #include "tst_timer.h" #define FUTEX_INITIALIZER 0 enum futex_fn_type { FUTEX_FN_FUTEX, FUTEX_FN_FUTEX64, }; struct futex_test_variants { enum futex_fn_type fntype; enum tst_ts_type tstype; int (*gettime)(clockid_t clk_id, void *ts); char *desc; }; static inline void futex_supported_by_kernel(enum futex_fn_type fntype) { if (fntype != FUTEX_FN_FUTEX64) return; /* Check if the syscall is implemented on the platform */ TEST(sys_futex_time64(NULL, 0, 0, NULL, NULL, 0)); if (TST_RET == -1 && TST_ERR == ENOSYS) tst_brk(TCONF, "Test not supported on kernel/platform"); } /** * futex_syscall() - futex syscall wrapper * @fntype: Futex function type * @uaddr: address of first futex * @op: futex op code * @val: typically expected value of uaddr, but varies by op * @timeout: typically an absolute struct tst_ts (except where noted * otherwise). Overloaded by some ops * @uaddr2: address of second futex for some ops\ * @val3: varies by op * @opflags: flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG * * futex_syscall() is used by all the following futex op wrappers. It can also be * used for misuse and abuse testing. Generally, the specific op wrappers * should be used instead. It is a macro instead of an static inline function as * some of the types over overloaded (timeout is used for nr_requeue for * example). * * These argument descriptions are the defaults for all * like-named arguments in the following wrappers except where noted below. */ static inline int futex_syscall(enum futex_fn_type fntype, futex_t *uaddr, int futex_op, futex_t val, void *timeout, futex_t *uaddr2, int val3, int opflags) { int (*func)(int *uaddr, int futex_op, int val, void *to, int *uaddr2, int val3); if (fntype == FUTEX_FN_FUTEX) func = sys_futex; else func = sys_futex_time64; return func((int *)uaddr, futex_op | opflags, val, timeout, (int *)uaddr2, val3); } /** * futex_wait() - block on uaddr with optional timeout * @timeout: relative timeout */ static inline int futex_wait(enum futex_fn_type fntype, futex_t *uaddr, futex_t val, struct tst_ts *timeout, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_WAIT, val, tst_ts_get(timeout), NULL, 0, opflags); } /** * futex_wake() - wake one or more tasks blocked on uaddr * @nr_wake: wake up to this many tasks */ static inline int futex_wake(enum futex_fn_type fntype, futex_t *uaddr, int nr_wake, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags); } /** * futex_wait_bitset() - block on uaddr with bitset * @bitset: bitset to be used with futex_wake_bitset */ static inline int futex_wait_bitset(enum futex_fn_type fntype, futex_t *uaddr, futex_t val, struct tst_ts *timeout, u_int32_t bitset, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_WAIT_BITSET, val, tst_ts_get(timeout), NULL, bitset, opflags); } /** * futex_wake_bitset() - wake one or more tasks blocked on uaddr with bitset * @bitset: bitset to compare with that used in futex_wait_bitset */ static inline int futex_wake_bitset(enum futex_fn_type fntype, futex_t *uaddr, int nr_wake, u_int32_t bitset, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_WAKE_BITSET, nr_wake, NULL, NULL, bitset, opflags); } /** * futex_lock_pi() - block on uaddr as a PI mutex * @detect: whether (1) or not (0) to perform deadlock detection */ static inline int futex_lock_pi(enum futex_fn_type fntype, futex_t *uaddr, struct tst_ts *timeout, int detect, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_LOCK_PI, detect, tst_ts_get(timeout), NULL, 0, opflags); } /** * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter */ static inline int futex_unlock_pi(enum futex_fn_type fntype, futex_t *uaddr, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags); } /** * futex_wake_op() - FIXME: COME UP WITH A GOOD ONE LINE DESCRIPTION */ static inline int futex_wake_op(enum futex_fn_type fntype, futex_t *uaddr, futex_t *uaddr2, int nr_wake, int nr_wake2, int wake_op, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_WAKE_OP, nr_wake, (void *)((unsigned long)nr_wake2), uaddr2, wake_op, opflags); } /** * futex_requeue() - requeue without expected value comparison, deprecated * @nr_wake: wake up to this many tasks * @nr_requeue: requeue up to this many tasks * * Due to its inherently racy implementation, futex_requeue() is deprecated in * favor of futex_cmp_requeue(). */ static inline int futex_requeue(enum futex_fn_type fntype, futex_t *uaddr, futex_t *uaddr2, int nr_wake, int nr_requeue, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_REQUEUE, nr_wake, (void *)((unsigned long)nr_requeue), uaddr2, 0, opflags); } /** * futex_cmp_requeue() - requeue tasks from uaddr to uaddr2 * @nr_wake: wake up to this many tasks * @nr_requeue: requeue up to this many tasks */ static inline int futex_cmp_requeue(enum futex_fn_type fntype, futex_t *uaddr, futex_t val, futex_t *uaddr2, int nr_wake, int nr_requeue, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_CMP_REQUEUE, nr_wake, (void *)((unsigned long)nr_requeue), uaddr2, val, opflags); } /** * futex_wait_requeue_pi() - block on uaddr and prepare to requeue to uaddr2 * @uaddr: non-PI futex source * @uaddr2: PI futex target * * This is the first half of the requeue_pi mechanism. It shall always be * paired with futex_cmp_requeue_pi(). */ static inline int futex_wait_requeue_pi(enum futex_fn_type fntype, futex_t *uaddr, futex_t val, futex_t *uaddr2, struct tst_ts *timeout, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_WAIT_REQUEUE_PI, val, tst_ts_get(timeout), uaddr2, 0, opflags); } /** * futex_cmp_requeue_pi() - requeue tasks from uaddr to uaddr2 (PI aware) * @uaddr: non-PI futex source * @uaddr2: PI futex target * @nr_wake: wake up to this many tasks * @nr_requeue: requeue up to this many tasks */ static inline int futex_cmp_requeue_pi(enum futex_fn_type fntype, futex_t *uaddr, futex_t val, futex_t *uaddr2, int nr_wake, int nr_requeue, int opflags) { return futex_syscall(fntype, uaddr, FUTEX_CMP_REQUEUE_PI, nr_wake, (void *)((unsigned long)nr_requeue), uaddr2, val, opflags); } /** * futex_cmpxchg() - atomic compare and exchange * @uaddr: The address of the futex to be modified * @oldval: The expected value of the futex * @newval: The new value to try and assign the futex * * Implement cmpxchg using gcc atomic builtins. * http://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html * * Return the old futex value. */ static inline u_int32_t futex_cmpxchg(futex_t *uaddr, u_int32_t oldval, u_int32_t newval) { return __sync_val_compare_and_swap(uaddr, oldval, newval); } /** * futex_dec() - atomic decrement of the futex value * @uaddr: The address of the futex to be modified * * Return the new futex value. */ static inline u_int32_t futex_dec(futex_t *uaddr) { return __sync_sub_and_fetch(uaddr, 1); } /** * futex_inc() - atomic increment of the futex value * @uaddr: the address of the futex to be modified * * Return the new futex value. */ static inline u_int32_t futex_inc(futex_t *uaddr) { return __sync_add_and_fetch(uaddr, 1); } /** * futex_set() - atomic decrement of the futex value * @uaddr: the address of the futex to be modified * @newval: New value for the atomic_t * * Return the new futex value. */ static inline u_int32_t futex_set(futex_t *uaddr, u_int32_t newval) { *uaddr = newval; return newval; } /** * futex_waked_someone() - ECHCK func for TST_RETRY_FUNC * @ret: return value of futex_wake * * Return value drives TST_RETRY_FUNC macro. */ static inline int futex_waked_someone(int ret) { if (ret < 0) tst_brk(TBROK | TERRNO, "futex_wake returned: %d", ret); return ret; } #endif /* _FUTEXTEST_H */