Re: [patch V5 09/16] futex: Add support for unlocking robust futexes

[Peter Zijlstra <peterz@infradead.org>]

On Wed, Jun 03, 2026 at 10:22:20AM +0200, Peter Zijlstra wrote:

> Would you mind terribly if I did: 's/UNLOCK_ROBUST/ROBUST_UNLOCK/g' on
> the whole series?

--- a/include/uapi/linux/futex.h
+++ b/include/uapi/linux/futex.h
@@ -25,11 +25,11 @@
 
 #define FUTEX_PRIVATE_FLAG	128
 #define FUTEX_CLOCK_REALTIME	256
-#define FUTEX_UNLOCK_ROBUST	512
+#define FUTEX_ROBUST_UNLOCK	512
 #define FUTEX_ROBUST_LIST32	1024
 
 #define FUTEX_CMD_MASK			~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME | \
-					  FUTEX_UNLOCK_ROBUST | FUTEX_ROBUST_LIST32)
+					  FUTEX_ROBUST_UNLOCK | FUTEX_ROBUST_LIST32)
 
 #define FUTEX_WAIT_PRIVATE		(FUTEX_WAIT | FUTEX_PRIVATE_FLAG)
 #define FUTEX_WAKE_PRIVATE		(FUTEX_WAKE | FUTEX_PRIVATE_FLAG)
@@ -49,23 +49,23 @@
  * Operations to unlock a futex, clear the robust list pending op pointer and
  * wake waiters.
  */
-#define FUTEX_UNLOCK_PI_LIST64			(FUTEX_UNLOCK_PI | FUTEX_UNLOCK_ROBUST)
+#define FUTEX_UNLOCK_PI_LIST64			(FUTEX_UNLOCK_PI | FUTEX_ROBUST_UNLOCK)
 #define FUTEX_UNLOCK_PI_LIST64_PRIVATE		(FUTEX_UNLOCK_PI_LIST64 | FUTEX_PRIVATE_FLAG)
-#define FUTEX_UNLOCK_PI_LIST32			(FUTEX_UNLOCK_PI | FUTEX_UNLOCK_ROBUST | \
+#define FUTEX_UNLOCK_PI_LIST32			(FUTEX_UNLOCK_PI | FUTEX_ROBUST_UNLOCK | \
 						 FUTEX_ROBUST_LIST32)
 #define FUTEX_UNLOCK_PI_LIST32_PRIVATE		(FUTEX_UNLOCK_PI_LIST32 | FUTEX_PRIVATE_FLAG)
 
-#define FUTEX_UNLOCK_WAKE_LIST64		(FUTEX_WAKE | FUTEX_UNLOCK_ROBUST)
+#define FUTEX_UNLOCK_WAKE_LIST64		(FUTEX_WAKE | FUTEX_ROBUST_UNLOCK)
 #define FUTEX_UNLOCK_WAKE_LIST64_PRIVATE	(FUTEX_UNLOCK_WAKE_LIST64 | FUTEX_PRIVATE_FLAG)
 
-#define FUTEX_UNLOCK_WAKE_LIST32		(FUTEX_WAKE | FUTEX_UNLOCK_ROBUST | \
+#define FUTEX_UNLOCK_WAKE_LIST32		(FUTEX_WAKE | FUTEX_ROBUST_UNLOCK | \
 						 FUTEX_ROBUST_LIST32)
 #define FUTEX_UNLOCK_WAKE_LIST32_PRIVATE	(FUTEX_UNLOCK_WAKE_LIST32 | FUTEX_PRIVATE_FLAG)
 
-#define FUTEX_UNLOCK_BITSET_LIST64		(FUTEX_WAKE_BITSET | FUTEX_UNLOCK_ROBUST)
+#define FUTEX_UNLOCK_BITSET_LIST64		(FUTEX_WAKE_BITSET | FUTEX_ROBUST_UNLOCK)
 #define FUTEX_UNLOCK_BITSET_LIST64_PRIVATE	(FUTEX_UNLOCK_BITSET_LIST64 | FUTEX_PRIVATE_FLAG)
 
-#define FUTEX_UNLOCK_BITSET_LIST32		(FUTEX_WAKE_BITSET | FUTEX_UNLOCK_ROBUST | \
+#define FUTEX_UNLOCK_BITSET_LIST32		(FUTEX_WAKE_BITSET | FUTEX_ROBUST_UNLOCK | \
 						 FUTEX_ROBUST_LIST32)
 #define FUTEX_UNLOCK_BITSET_LIST32_PRIVATE	(FUTEX_UNLOCK_BITSET_LIST32 | FUTEX_PRIVATE_FLAG)
 
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -40,7 +40,7 @@
 #define FLAGS_NUMA		0x0080
 #define FLAGS_STRICT		0x0100
 #define FLAGS_MPOL		0x0200
-#define FLAGS_UNLOCK_ROBUST	0x0400
+#define FLAGS_ROBUST_UNLOCK	0x0400
 #define FLAGS_ROBUST_LIST32	0x0800
 
 /* FUTEX_ to FLAGS_ */
@@ -54,8 +54,8 @@ static inline unsigned int futex_to_flag
 	if (op & FUTEX_CLOCK_REALTIME)
 		flags |= FLAGS_CLOCKRT;
 
-	if (op & FUTEX_UNLOCK_ROBUST)
-		flags |= FLAGS_UNLOCK_ROBUST;
+	if (op & FUTEX_ROBUST_UNLOCK)
+		flags |= FLAGS_ROBUST_UNLOCK;
 
 	if (op & FUTEX_ROBUST_LIST32)
 		flags |= FLAGS_ROBUST_LIST32;
--- a/kernel/futex/pi.c
+++ b/kernel/futex/pi.c
@@ -1305,7 +1305,7 @@ int futex_unlock_pi(u32 __user *uaddr, u
 {
 	int ret = __futex_unlock_pi(uaddr, flags);
 
-	if (ret || !(flags & FLAGS_UNLOCK_ROBUST))
+	if (ret || !(flags & FLAGS_ROBUST_UNLOCK))
 		return ret;
 
 	if (!futex_robust_list_clear_pending(pop, flags))
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -118,7 +118,7 @@ long do_futex(u32 __user *uaddr, int op,
 			return -ENOSYS;
 	}
 
-	if (flags & FLAGS_UNLOCK_ROBUST) {
+	if (flags & FLAGS_ROBUST_UNLOCK) {
 		if (cmd != FUTEX_WAKE &&
 		    cmd != FUTEX_WAKE_BITSET &&
 		    cmd != FUTEX_UNLOCK_PI)
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -154,7 +154,7 @@ void futex_wake_mark(struct wake_q_head
  */
 static bool futex_robust_unlock(u32 __user *uaddr, unsigned int flags, void __user *pop)
 {
-	if (!(flags & FLAGS_UNLOCK_ROBUST))
+	if (!(flags & FLAGS_ROBUST_UNLOCK))
 		return true;
 
 	/* First unlock the futex, which requires release semantics. */