uapi/linux/futex.h

1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
75 #define FUTEX_32		FUTEX2_SIZE_U32 /* historical accident :-( */
83  * struct futex_waitv - A waiter for vectorized wait
97  * Support for robust futexes: the kernel cleans up held futexes at
102  * Per-lock list entry - embedded in user-space locks, somewhere close
103  * to the futex field. (Note: user-space uses a double-linked list to
115  * Per-thread list head:
129 	 * This relative offset is set by user-space, it gives the kernel
131 	 * we keep userspace flexible, to freely shape its data-structure,
138 	 * up a lock's links. So to handle this race, userspace first
139 	 * sets this field to the address of the to-be-taken lock,
157  * a FUTEX_WAKE on such futexes, after setting the bit, to wake
158  * up any possible waiters:
163  * The rest of the robust-futex field is for the TID:
188 #define FUTEX_OP_CMP_EQ		0	/* if (oldval == CMPARG) wake */
189 #define FUTEX_OP_CMP_NE		1	/* if (oldval != CMPARG) wake */
190 #define FUTEX_OP_CMP_LT		2	/* if (oldval < CMPARG) wake */
191 #define FUTEX_OP_CMP_LE		3	/* if (oldval <= CMPARG) wake */
192 #define FUTEX_OP_CMP_GT		4	/* if (oldval > CMPARG) wake */
193 #define FUTEX_OP_CMP_GE		5	/* if (oldval >= CMPARG) wake */
199      wake UADDR2;  */