[RFC,06/10] futex: Propagate flags into get_futex_key()

Commit Message

Peter Zijlstra July 14, 2023, 1:39 p.m. UTC

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

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
---
 kernel/futex/core.c     |    5 ++++-
 kernel/futex/futex.h    |    2 +-
 kernel/futex/pi.c       |    4 ++--
 kernel/futex/requeue.c  |    6 +++---
 kernel/futex/waitwake.c |   15 ++++++++-------
 5 files changed, 18 insertions(+), 14 deletions(-)

Patch

--- a/kernel/futex/core.c
+++ b/kernel/futex/core.c
@@ -217,7 +217,7 @@  static u64 get_inode_sequence_number(str
  *
  * 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;
@@ -225,6 +225,9 @@  int get_futex_key(u32 __user *uaddr, boo
 	struct page *page, *tail;
 	struct address_space *mapping;
 	int err, ro = 0;
+	bool fshared;
+
+	fshared = flags & FLAGS_SHARED;
 
 	/*
 	 * The futex address must be "naturally" aligned.
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -158,7 +158,7 @@  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 *
--- a/kernel/futex/pi.c
+++ b/kernel/futex/pi.c
@@ -945,7 +945,7 @@  int futex_lock_pi(u32 __user *uaddr, uns
 	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;
 
@@ -1117,7 +1117,7 @@  int futex_unlock_pi(u32 __user *uaddr, u
 	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;
 
--- a/kernel/futex/requeue.c
+++ b/kernel/futex/requeue.c
@@ -424,10 +424,10 @@  int futex_requeue(u32 __user *uaddr1, un
 	}
 
 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 *ua
 	 */
 	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;
 
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -145,13 +145,13 @@  int futex_wake(u32 __user *uaddr, unsign
 	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;
 
@@ -245,10 +245,10 @@  int futex_wake_op(u32 __user *uaddr1, un
 	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;
 
@@ -423,7 +423,7 @@  static int futex_wait_multiple_setup(str
 			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))
@@ -435,7 +435,8 @@  static int futex_wait_multiple_setup(str
 	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;
+		unsigned int flags = vs[i].w.flags;
+		u32 val = vs[i].w.val;
 
 		hb = futex_q_lock(q);
 		ret = futex_get_value_locked(&uval, uaddr);
@@ -599,7 +600,7 @@  int futex_wait_setup(u32 __user *uaddr,
 	 * 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;