[PATCH 02/10] futex: Extend the FUTEX2 flags

Jens Axboe
2023-07-20T22:19:14Z

From: Peter Zijlstra <peterz@infradead.org>

Add the definition for the missing but always intended extra sizes,
and add a NUMA flag for the planned numa extention.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/uapi/linux/futex.h | 7 ++++---
kernel/futex/syscalls.c | 4 ++--
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/uapi/linux/futex.h b/include/uapi/linux/futex.h
index 0c5abb6aa8f8..0ed021acc1d9 100644
--- a/include/uapi/linux/futex.h
+++ b/include/uapi/linux/futex.h
@@ -46,10 +46,11 @@
/*
* Flags for futex2 syscalls.
*/
- /* 0x00 */
- /* 0x01 */
+#define FUTEX2_8 0x00
+#define FUTEX2_16 0x01
#define FUTEX2_32 0x02
- /* 0x04 */
+#define FUTEX2_64 0x03
+#define FUTEX2_NUMA 0x04
/* 0x08 */
/* 0x10 */
/* 0x20 */
diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c
index 42b6c2fac7db..d5bb6dad22fe 100644
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -183,7 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
return do_futex(uaddr, op, val, tp, uaddr2, (unsigned long)utime, val3);
}

-#define FUTEX2_MASK (FUTEX2_32 | FUTEX2_PRIVATE)
+#define FUTEX2_MASK (FUTEX2_64 | FUTEX2_PRIVATE)

/**
* futex_parse_waitv - Parse a waitv array from userspace
@@ -207,7 +207,7 @@ static int futex_parse_waitv(struct futex_vector *futexv,
if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved)
return -EINVAL;

- if (!(aux.flags & FUTEX2_32))
+ if ((aux.flags & FUTEX2_64) != FUTEX2_32)
return -EINVAL;

futexv[i].w.flags = aux.flags;
--
2.40.1