1 files changed, 152 insertions, 0 deletions

diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
new file mode 100644
index 000000000000..0b1f716373c7
--- /dev/null
+++ b/include/uapi/linux/futex.h
@@ -0,0 +1,152 @@
+#ifndef _UAPI_LINUX_FUTEX_H
+#define _UAPI_LINUX_FUTEX_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+/* Second argument to futex syscall */
+
+
+#define FUTEX_WAIT              0
+#define FUTEX_WAKE              1
+#define FUTEX_FD                2
+#define FUTEX_REQUEUE           3
+#define FUTEX_CMP_REQUEUE       4
+#define FUTEX_WAKE_OP           5
+#define FUTEX_LOCK_PI           6
+#define FUTEX_UNLOCK_PI         7
+#define FUTEX_TRYLOCK_PI        8
+#define FUTEX_WAIT_BITSET       9
+#define FUTEX_WAKE_BITSET       10
+#define FUTEX_WAIT_REQUEUE_PI   11
+#define FUTEX_CMP_REQUEUE_PI    12
+
+#define FUTEX_PRIVATE_FLAG      128
+#define FUTEX_CLOCK_REALTIME    256
+#define FUTEX_CMD_MASK          ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
+
+#define FUTEX_WAIT_PRIVATE      (FUTEX_WAIT | FUTEX_PRIVATE_FLAG)
+#define FUTEX_WAKE_PRIVATE      (FUTEX_WAKE | FUTEX_PRIVATE_FLAG)
+#define FUTEX_REQUEUE_PRIVATE   (FUTEX_REQUEUE | FUTEX_PRIVATE_FLAG)
+#define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE | FUTEX_PRIVATE_FLAG)
+#define FUTEX_WAKE_OP_PRIVATE   (FUTEX_WAKE_OP | FUTEX_PRIVATE_FLAG)
+#define FUTEX_LOCK_PI_PRIVATE   (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
+#define FUTEX_UNLOCK_PI_PRIVATE (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
+#define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
+#define FUTEX_WAIT_BITSET_PRIVATE       (FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG)
+#define FUTEX_WAKE_BITSET_PRIVATE       (FUTEX_WAKE_BITSET | FUTEX_PRIVATE_FLAG)
+#define FUTEX_WAIT_REQUEUE_PI_PRIVATE   (FUTEX_WAIT_REQUEUE_PI | \
+                                         FUTEX_PRIVATE_FLAG)
+#define FUTEX_CMP_REQUEUE_PI_PRIVATE    (FUTEX_CMP_REQUEUE_PI | \
+                                         FUTEX_PRIVATE_FLAG)
+
+/*
+ * Support for robust futexes: the kernel cleans up held futexes at
+ * thread exit time.
+ */
+
+/*
+ * Per-lock list entry - embedded in user-space locks, somewhere close
+ * to the futex field. (Note: user-space uses a double-linked list to
+ * achieve O(1) list add and remove, but the kernel only needs to know
+ * about the forward link)
+ *
+ * NOTE: this structure is part of the syscall ABI, and must not be
+ * changed.
+ */
+struct robust_list {
+        struct robust_list __user *next;
+};
+
+/*
+ * Per-thread list head:
+ *
+ * NOTE: this structure is part of the syscall ABI, and must only be
+ * changed if the change is first communicated with the glibc folks.
+ * (When an incompatible change is done, we'll increase the structure
+ *  size, which glibc will detect)
+ */
+struct robust_list_head {
+        /*
+         * The head of the list. Points back to itself if empty:
+         */
+        struct robust_list list;
+
+        /*
+         * This relative offset is set by user-space, it gives the kernel
+         * the relative position of the futex field to examine. This way
+         * we keep userspace flexible, to freely shape its data-structure,
+         * without hardcoding any particular offset into the kernel:
+         */
+        long futex_offset;
+
+        /*
+         * The death of the thread may race with userspace setting
+         * up a lock's links. So to handle this race, userspace first
+         * sets this field to the address of the to-be-taken lock,
+         * then does the lock acquire, and then adds itself to the
+         * list, and then clears this field. Hence the kernel will
+         * always have full knowledge of all locks that the thread
+         * _might_ have taken. We check the owner TID in any case,
+         * so only truly owned locks will be handled.
+         */
+        struct robust_list __user *list_op_pending;
+};
+
+/*
+ * Are there any waiters for this robust futex:
+ */
+#define FUTEX_WAITERS           0x80000000
+
+/*
+ * The kernel signals via this bit that a thread holding a futex
+ * has exited without unlocking the futex. The kernel also does
+ * a FUTEX_WAKE on such futexes, after setting the bit, to wake
+ * up any possible waiters:
+ */
+#define FUTEX_OWNER_DIED        0x40000000
+
+/*
+ * The rest of the robust-futex field is for the TID:
+ */
+#define FUTEX_TID_MASK          0x3fffffff
+
+/*
+ * This limit protects against a deliberately circular list.
+ * (Not worth introducing an rlimit for it)
+ */
+#define ROBUST_LIST_LIMIT       2048
+
+/*
+ * bitset with all bits set for the FUTEX_xxx_BITSET OPs to request a
+ * match of any bit.
+ */
+#define FUTEX_BITSET_MATCH_ANY  0xffffffff
+
+
+#define FUTEX_OP_SET            0       /* *(int *)UADDR2 = OPARG; */
+#define FUTEX_OP_ADD            1       /* *(int *)UADDR2 += OPARG; */
+#define FUTEX_OP_OR             2       /* *(int *)UADDR2 |= OPARG; */
+#define FUTEX_OP_ANDN           3       /* *(int *)UADDR2 &= ~OPARG; */
+#define FUTEX_OP_XOR            4       /* *(int *)UADDR2 ^= OPARG; */
+
+#define FUTEX_OP_OPARG_SHIFT    8       /* Use (1 << OPARG) instead of OPARG.  */
+
+#define FUTEX_OP_CMP_EQ         0       /* if (oldval == CMPARG) wake */
+#define FUTEX_OP_CMP_NE         1       /* if (oldval != CMPARG) wake */
+#define FUTEX_OP_CMP_LT         2       /* if (oldval < CMPARG) wake */
+#define FUTEX_OP_CMP_LE         3       /* if (oldval <= CMPARG) wake */
+#define FUTEX_OP_CMP_GT         4       /* if (oldval > CMPARG) wake */
+#define FUTEX_OP_CMP_GE         5       /* if (oldval >= CMPARG) wake */
+
+/* FUTEX_WAKE_OP will perform atomically
+   int oldval = *(int *)UADDR2;
+   *(int *)UADDR2 = oldval OP OPARG;
+   if (oldval CMP CMPARG)
+     wake UADDR2;  */
+
+#define FUTEX_OP(op, oparg, cmp, cmparg) \
+  (((op & 0xf) << 28) | ((cmp & 0xf) << 24)             \
+   | ((oparg & 0xfff) << 12) | (cmparg & 0xfff))
+
+#endif /* _UAPI_LINUX_FUTEX_H */