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authorJens Axboe <[email protected]>2023-09-28 07:47:07 -0600
committerJens Axboe <[email protected]>2023-09-28 07:47:07 -0600
commit52e856c38761bae0cea09b25cfbb4d46cd930d45 (patch)
treee94c5b41e4ea4c8f95b993c6d875e2e7db78bbf8 /include/uapi/linux
parent73c7e7a91f041f4c2e3c0db1e727163b331c60c9 (diff)
parentcfa92b6d52071aaa8f27d21affdcb14e7448fbc1 (diff)
Merge branch 'locking/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into io_uring-futex
Pull in locking/core from the tip tree, to get the futex2 dependencies from Peter Zijlstra. * 'locking/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) locking/ww_mutex/test: Make sure we bail out instead of livelock locking/ww_mutex/test: Fix potential workqueue corruption locking/ww_mutex/test: Use prng instead of rng to avoid hangs at bootup futex: Add sys_futex_requeue() futex: Add flags2 argument to futex_requeue() futex: Propagate flags into get_futex_key() futex: Add sys_futex_wait() futex: FLAGS_STRICT futex: Add sys_futex_wake() futex: Validate futex value against futex size futex: Flag conversion futex: Extend the FUTEX2 flags futex: Clarify FUTEX2 flags asm-generic: ticket-lock: Optimize arch_spin_value_unlocked() futex/pi: Fix recursive rt_mutex waiter state locking/rtmutex: Add a lockdep assert to catch potential nested blocking locking/rtmutex: Use rt_mutex specific scheduler helpers sched: Provide rt_mutex specific scheduler helpers sched: Extract __schedule_loop() locking/rtmutex: Avoid unconditional slowpath for DEBUG_RT_MUTEXES ...
Diffstat (limited to 'include/uapi/linux')
-rw-r--r--include/uapi/linux/futex.h31
1 files changed, 28 insertions, 3 deletions
diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
index 71a5df8d2689..d2ee625ea189 100644
--- a/include/uapi/linux/futex.h
+++ b/include/uapi/linux/futex.h
@@ -44,10 +44,35 @@
FUTEX_PRIVATE_FLAG)
/*
- * Flags to specify the bit length of the futex word for futex2 syscalls.
- * Currently, only 32 is supported.
+ * Flags for futex2 syscalls.
+ *
+ * NOTE: these are not pure flags, they can also be seen as:
+ *
+ * union {
+ * u32 flags;
+ * struct {
+ * u32 size : 2,
+ * numa : 1,
+ * : 4,
+ * private : 1;
+ * };
+ * };
*/
-#define FUTEX_32 2
+#define FUTEX2_SIZE_U8 0x00
+#define FUTEX2_SIZE_U16 0x01
+#define FUTEX2_SIZE_U32 0x02
+#define FUTEX2_SIZE_U64 0x03
+#define FUTEX2_NUMA 0x04
+ /* 0x08 */
+ /* 0x10 */
+ /* 0x20 */
+ /* 0x40 */
+#define FUTEX2_PRIVATE FUTEX_PRIVATE_FLAG
+
+#define FUTEX2_SIZE_MASK 0x03
+
+/* do not use */
+#define FUTEX_32 FUTEX2_SIZE_U32 /* historical accident :-( */
/*
* Max numbers of elements in a futex_waitv array