futex: Propagate flags into get_futex_key()

Instead of only passing FLAGS_SHARED as a boolean, pass down flags as
a whole.

No functional change intended.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230921105248.282857501@noisy.programming.kicks-ass.net

Author: peterz@infradead.org

kernel/futex/core.c

@@ -193,7 +193,7 @@ static u64 get_inode_sequence_number(struct inode *inode)
 /**
  * get_futex_key() - Get parameters which are the keys for a futex
  * @uaddr:	virtual address of the futex
- * @fshared:	false for a PROCESS_PRIVATE futex, true for PROCESS_SHARED
+ * @flags:	FLAGS_*
  * @key:	address where result is stored.
  * @rw:		mapping needs to be read/write (values: FUTEX_READ,
  *              FUTEX_WRITE)
@@ -217,7 +217,7 @@ static u64 get_inode_sequence_number(struct inode *inode)
  *
  * lock_page() might sleep, the caller should not hold a spinlock.
  */
-int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key,
+int get_futex_key(u32 __user *uaddr, unsigned int flags, union futex_key *key,
 		  enum futex_access rw)
 {
 	unsigned long address = (unsigned long)uaddr;
@@ -226,6 +226,9 @@ int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key,
 	struct folio *folio;
 	struct address_space *mapping;
 	int err, ro = 0;
+	bool fshared;
+
+	fshared = flags & FLAGS_SHARED;
 
 	/*
 	 * The futex address must be "naturally" aligned.

kernel/futex/futex.h

@@ -184,7 +184,7 @@ enum futex_access {
 	FUTEX_WRITE
 };
 
-extern int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key,
+extern int get_futex_key(u32 __user *uaddr, unsigned int flags, union futex_key *key,
 			 enum futex_access rw);
 
 extern struct hrtimer_sleeper *

kernel/futex/pi.c

@@ -933,7 +933,7 @@ int futex_lock_pi(u32 __user *uaddr, unsigned int flags, ktime_t *time, int tryl
 	to = futex_setup_timer(time, &timeout, flags, 0);
 
 retry:
-	ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q.key, FUTEX_WRITE);
+	ret = get_futex_key(uaddr, flags, &q.key, FUTEX_WRITE);
 	if (unlikely(ret != 0))
 		goto out;
 
@@ -1129,7 +1129,7 @@ int futex_unlock_pi(u32 __user *uaddr, unsigned int flags)
 	if ((uval & FUTEX_TID_MASK) != vpid)
 		return -EPERM;
 
-	ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key, FUTEX_WRITE);
+	ret = get_futex_key(uaddr, flags, &key, FUTEX_WRITE);
 	if (ret)
 		return ret;
 

kernel/futex/requeue.c

@@ -424,10 +424,10 @@ int futex_requeue(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
 	}
 
 retry:
-	ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ);
+	ret = get_futex_key(uaddr1, flags, &key1, FUTEX_READ);
 	if (unlikely(ret != 0))
 		return ret;
-	ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2,
+	ret = get_futex_key(uaddr2, flags, &key2,
 			    requeue_pi ? FUTEX_WRITE : FUTEX_READ);
 	if (unlikely(ret != 0))
 		return ret;
@@ -789,7 +789,7 @@ int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
 	 */
 	rt_mutex_init_waiter(&rt_waiter);
 
-	ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE);
+	ret = get_futex_key(uaddr2, flags, &key2, FUTEX_WRITE);
 	if (unlikely(ret != 0))
 		goto out;
 

kernel/futex/waitwake.c

@@ -145,13 +145,13 @@ int futex_wake(u32 __user *uaddr, unsigned int flags, int nr_wake, u32 bitset)
 	struct futex_hash_bucket *hb;
 	struct futex_q *this, *next;
 	union futex_key key = FUTEX_KEY_INIT;
-	int ret;
 	DEFINE_WAKE_Q(wake_q);
+	int ret;
 
 	if (!bitset)
 		return -EINVAL;
 
-	ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &key, FUTEX_READ);
+	ret = get_futex_key(uaddr, flags, &key, FUTEX_READ);
 	if (unlikely(ret != 0))
 		return ret;
 
@@ -248,10 +248,10 @@ int futex_wake_op(u32 __user *uaddr1, unsigned int flags, u32 __user *uaddr2,
 	DEFINE_WAKE_Q(wake_q);
 
 retry:
-	ret = get_futex_key(uaddr1, flags & FLAGS_SHARED, &key1, FUTEX_READ);
+	ret = get_futex_key(uaddr1, flags, &key1, FUTEX_READ);
 	if (unlikely(ret != 0))
 		return ret;
-	ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, FUTEX_WRITE);
+	ret = get_futex_key(uaddr2, flags, &key2, FUTEX_WRITE);
 	if (unlikely(ret != 0))
 		return ret;
 
@@ -426,7 +426,7 @@ static int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *wo
 			continue;
 
 		ret = get_futex_key(u64_to_user_ptr(vs[i].w.uaddr),
-				    vs[i].w.flags & FLAGS_SHARED,
+				    vs[i].w.flags,
 				    &vs[i].q.key, FUTEX_READ);
 
 		if (unlikely(ret))
@@ -438,7 +438,7 @@ static int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *wo
 	for (i = 0; i < count; i++) {
 		u32 __user *uaddr = (u32 __user *)(unsigned long)vs[i].w.uaddr;
 		struct futex_q *q = &vs[i].q;
-		u32 val = (u32)vs[i].w.val;
+		u32 val = vs[i].w.val;
 
 		hb = futex_q_lock(q);
 		ret = futex_get_value_locked(&uval, uaddr);
@@ -602,7 +602,7 @@ int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
 	 * while the syscall executes.
 	 */
 retry:
-	ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q->key, FUTEX_READ);
+	ret = get_futex_key(uaddr, flags, &q->key, FUTEX_READ);
 	if (unlikely(ret != 0))
 		return ret;