[PATCH v1 02/14] futex: Extend the FUTEX2 flags

[Peter Zijlstra]

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@xxxxxxxxxxxxx>
---
 include/uapi/linux/futex.h |    7 ++++---
 kernel/futex/syscalls.c    |    9 +++++++--
 2 files changed, 11 insertions(+), 5 deletions(-)

--- 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 */
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -183,7 +183,7 @@ SYSCALL_DEFINE6(futex, u32 __user *, uad
 	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 +207,12 @@ static int futex_parse_waitv(struct fute
 		if ((aux.flags & ~FUTEX2_MASK) || aux.__reserved)
 			return -EINVAL;
 
-		if (!(aux.flags & FUTEX2_32))
+		if (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall()) {
+			if ((aux.flags & FUTEX2_64) == FUTEX2_64)
+				return -EINVAL;
+		}
+
+		if ((aux.flags & FUTEX2_64) != FUTEX2_32)
 			return -EINVAL;
 
 		futexv[i].w.flags = aux.flags;