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oasis-root

Compiled tree of Oasis Linux based on own branch at <https://hacktivis.me/git/oasis/> git clone https://anongit.hacktivis.me/git/oasis-root.git

futex.h (6127B)


  1. /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
  2. #ifndef _LINUX_FUTEX_H
  3. #define _LINUX_FUTEX_H
  4. #include <linux/types.h>
  5. /* Second argument to futex syscall */
  6. #define FUTEX_WAIT 0
  7. #define FUTEX_WAKE 1
  8. #define FUTEX_FD 2
  9. #define FUTEX_REQUEUE 3
  10. #define FUTEX_CMP_REQUEUE 4
  11. #define FUTEX_WAKE_OP 5
  12. #define FUTEX_LOCK_PI 6
  13. #define FUTEX_UNLOCK_PI 7
  14. #define FUTEX_TRYLOCK_PI 8
  15. #define FUTEX_WAIT_BITSET 9
  16. #define FUTEX_WAKE_BITSET 10
  17. #define FUTEX_WAIT_REQUEUE_PI 11
  18. #define FUTEX_CMP_REQUEUE_PI 12
  19. #define FUTEX_LOCK_PI2 13
  20. #define FUTEX_PRIVATE_FLAG 128
  21. #define FUTEX_CLOCK_REALTIME 256
  22. #define FUTEX_CMD_MASK ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
  23. #define FUTEX_WAIT_PRIVATE (FUTEX_WAIT | FUTEX_PRIVATE_FLAG)
  24. #define FUTEX_WAKE_PRIVATE (FUTEX_WAKE | FUTEX_PRIVATE_FLAG)
  25. #define FUTEX_REQUEUE_PRIVATE (FUTEX_REQUEUE | FUTEX_PRIVATE_FLAG)
  26. #define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE | FUTEX_PRIVATE_FLAG)
  27. #define FUTEX_WAKE_OP_PRIVATE (FUTEX_WAKE_OP | FUTEX_PRIVATE_FLAG)
  28. #define FUTEX_LOCK_PI_PRIVATE (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
  29. #define FUTEX_LOCK_PI2_PRIVATE (FUTEX_LOCK_PI2 | FUTEX_PRIVATE_FLAG)
  30. #define FUTEX_UNLOCK_PI_PRIVATE (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
  31. #define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
  32. #define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG)
  33. #define FUTEX_WAKE_BITSET_PRIVATE (FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG)
  34. #define FUTEX_WAIT_REQUEUE_PI_PRIVATE (FUTEX_WAIT_REQUEUE_PI | \
  35. FUTEX_PRIVATE_FLAG)
  36. #define FUTEX_CMP_REQUEUE_PI_PRIVATE (FUTEX_CMP_REQUEUE_PI | \
  37. FUTEX_PRIVATE_FLAG)
  38. /*
  39. * Flags for futex2 syscalls.
  40. *
  41. * NOTE: these are not pure flags, they can also be seen as:
  42. *
  43. * union {
  44. * u32 flags;
  45. * struct {
  46. * u32 size : 2,
  47. * numa : 1,
  48. * : 4,
  49. * private : 1;
  50. * };
  51. * };
  52. */
  53. #define FUTEX2_SIZE_U8 0x00
  54. #define FUTEX2_SIZE_U16 0x01
  55. #define FUTEX2_SIZE_U32 0x02
  56. #define FUTEX2_SIZE_U64 0x03
  57. #define FUTEX2_NUMA 0x04
  58. /* 0x08 */
  59. /* 0x10 */
  60. /* 0x20 */
  61. /* 0x40 */
  62. #define FUTEX2_PRIVATE FUTEX_PRIVATE_FLAG
  63. #define FUTEX2_SIZE_MASK 0x03
  64. /* do not use */
  65. #define FUTEX_32 FUTEX2_SIZE_U32 /* historical accident :-( */
  66. /*
  67. * Max numbers of elements in a futex_waitv array
  68. */
  69. #define FUTEX_WAITV_MAX 128
  70. /**
  71. * struct futex_waitv - A waiter for vectorized wait
  72. * @val: Expected value at uaddr
  73. * @uaddr: User address to wait on
  74. * @flags: Flags for this waiter
  75. * @__reserved: Reserved member to preserve data alignment. Should be 0.
  76. */
  77. struct futex_waitv {
  78. __u64 val;
  79. __u64 uaddr;
  80. __u32 flags;
  81. __u32 __reserved;
  82. };
  83. /*
  84. * Support for robust futexes: the kernel cleans up held futexes at
  85. * thread exit time.
  86. */
  87. /*
  88. * Per-lock list entry - embedded in user-space locks, somewhere close
  89. * to the futex field. (Note: user-space uses a double-linked list to
  90. * achieve O(1) list add and remove, but the kernel only needs to know
  91. * about the forward link)
  92. *
  93. * NOTE: this structure is part of the syscall ABI, and must not be
  94. * changed.
  95. */
  96. struct robust_list {
  97. struct robust_list *next;
  98. };
  99. /*
  100. * Per-thread list head:
  101. *
  102. * NOTE: this structure is part of the syscall ABI, and must only be
  103. * changed if the change is first communicated with the glibc folks.
  104. * (When an incompatible change is done, we'll increase the structure
  105. * size, which glibc will detect)
  106. */
  107. struct robust_list_head {
  108. /*
  109. * The head of the list. Points back to itself if empty:
  110. */
  111. struct robust_list list;
  112. /*
  113. * This relative offset is set by user-space, it gives the kernel
  114. * the relative position of the futex field to examine. This way
  115. * we keep userspace flexible, to freely shape its data-structure,
  116. * without hardcoding any particular offset into the kernel:
  117. */
  118. long futex_offset;
  119. /*
  120. * The death of the thread may race with userspace setting
  121. * up a lock's links. So to handle this race, userspace first
  122. * sets this field to the address of the to-be-taken lock,
  123. * then does the lock acquire, and then adds itself to the
  124. * list, and then clears this field. Hence the kernel will
  125. * always have full knowledge of all locks that the thread
  126. * _might_ have taken. We check the owner TID in any case,
  127. * so only truly owned locks will be handled.
  128. */
  129. struct robust_list *list_op_pending;
  130. };
  131. /*
  132. * Are there any waiters for this robust futex:
  133. */
  134. #define FUTEX_WAITERS 0x80000000
  135. /*
  136. * The kernel signals via this bit that a thread holding a futex
  137. * has exited without unlocking the futex. The kernel also does
  138. * a FUTEX_WAKE on such futexes, after setting the bit, to wake
  139. * up any possible waiters:
  140. */
  141. #define FUTEX_OWNER_DIED 0x40000000
  142. /*
  143. * The rest of the robust-futex field is for the TID:
  144. */
  145. #define FUTEX_TID_MASK 0x3fffffff
  146. /*
  147. * This limit protects against a deliberately circular list.
  148. * (Not worth introducing an rlimit for it)
  149. */
  150. #define ROBUST_LIST_LIMIT 2048
  151. /*
  152. * bitset with all bits set for the FUTEX_xxx_BITSET OPs to request a
  153. * match of any bit.
  154. */
  155. #define FUTEX_BITSET_MATCH_ANY 0xffffffff
  156. #define FUTEX_OP_SET 0 /* *(int *)UADDR2 = OPARG; */
  157. #define FUTEX_OP_ADD 1 /* *(int *)UADDR2 += OPARG; */
  158. #define FUTEX_OP_OR 2 /* *(int *)UADDR2 |= OPARG; */
  159. #define FUTEX_OP_ANDN 3 /* *(int *)UADDR2 &= ~OPARG; */
  160. #define FUTEX_OP_XOR 4 /* *(int *)UADDR2 ^= OPARG; */
  161. #define FUTEX_OP_OPARG_SHIFT 8 /* Use (1 << OPARG) instead of OPARG. */
  162. #define FUTEX_OP_CMP_EQ 0 /* if (oldval == CMPARG) wake */
  163. #define FUTEX_OP_CMP_NE 1 /* if (oldval != CMPARG) wake */
  164. #define FUTEX_OP_CMP_LT 2 /* if (oldval < CMPARG) wake */
  165. #define FUTEX_OP_CMP_LE 3 /* if (oldval <= CMPARG) wake */
  166. #define FUTEX_OP_CMP_GT 4 /* if (oldval > CMPARG) wake */
  167. #define FUTEX_OP_CMP_GE 5 /* if (oldval >= CMPARG) wake */
  168. /* FUTEX_WAKE_OP will perform atomically
  169. int oldval = *(int *)UADDR2;
  170. *(int *)UADDR2 = oldval OP OPARG;
  171. if (oldval CMP CMPARG)
  172. wake UADDR2; */
  173. #define FUTEX_OP(op, oparg, cmp, cmparg) \
  174. (((op & 0xf) << 28) | ((cmp & 0xf) << 24) \
  175. | ((oparg & 0xfff) << 12) | (cmparg & 0xfff))
  176. #endif /* _LINUX_FUTEX_H */