[RFC,08/10] futex: Propagate flags into futex_get_value_locked()

Commit Message

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

In order to facilitate variable sized futexes propagate the flags into
futex_get_value_locked().

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
---
 kernel/futex/core.c     |    4 ++--
 kernel/futex/futex.h    |    2 +-
 kernel/futex/pi.c       |    8 ++++----
 kernel/futex/requeue.c  |    4 ++--
 kernel/futex/waitwake.c |    4 ++--
 5 files changed, 11 insertions(+), 11 deletions(-)

Patch

--- a/kernel/futex/core.c
+++ b/kernel/futex/core.c
@@ -506,12 +506,12 @@  int futex_cmpxchg_value_locked(u32 *curv
 	return ret;
 }
 
-int futex_get_value_locked(u32 *dest, u32 __user *from)
+int futex_get_value_locked(u32 *dest, u32 __user *from, unsigned int flags)
 {
 	int ret;
 
 	pagefault_disable();
-	ret = __get_user(*dest, from);
+	ret = futex_get_value(dest, from, flags);
 	pagefault_enable();
 
 	return ret ? -EFAULT : 0;
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -190,7 +190,7 @@  extern void futex_wake_mark(struct wake_
 
 extern int fault_in_user_writeable(u32 __user *uaddr);
 extern int futex_cmpxchg_value_locked(u32 *curval, u32 __user *uaddr, u32 uval, u32 newval);
-extern int futex_get_value_locked(u32 *dest, u32 __user *from);
+extern int futex_get_value_locked(u32 *dest, u32 __user *from, unsigned int flags);
 extern struct futex_q *futex_top_waiter(struct futex_hash_bucket *hb, union futex_key *key);
 
 extern void __futex_unqueue(struct futex_q *q);
--- a/kernel/futex/pi.c
+++ b/kernel/futex/pi.c
@@ -239,7 +239,7 @@  static int attach_to_pi_state(u32 __user
 	 * still is what we expect it to be, otherwise retry the entire
 	 * operation.
 	 */
-	if (futex_get_value_locked(&uval2, uaddr))
+	if (futex_get_value_locked(&uval2, uaddr, FLAGS_SIZE_32))
 		goto out_efault;
 
 	if (uval != uval2)
@@ -358,7 +358,7 @@  static int handle_exit_race(u32 __user *
 	 * The same logic applies to the case where the exiting task is
 	 * already gone.
 	 */
-	if (futex_get_value_locked(&uval2, uaddr))
+	if (futex_get_value_locked(&uval2, uaddr, FLAGS_SIZE_32))
 		return -EFAULT;
 
 	/* If the user space value has changed, try again. */
@@ -526,7 +526,7 @@  int futex_lock_pi_atomic(u32 __user *uad
 	 * Read the user space value first so we can validate a few
 	 * things before proceeding further.
 	 */
-	if (futex_get_value_locked(&uval, uaddr))
+	if (futex_get_value_locked(&uval, uaddr, FLAGS_SIZE_32))
 		return -EFAULT;
 
 	if (unlikely(should_fail_futex(true)))
@@ -762,7 +762,7 @@  static int __fixup_pi_state_owner(u32 __
 	if (!pi_state->owner)
 		newtid |= FUTEX_OWNER_DIED;
 
-	err = futex_get_value_locked(&uval, uaddr);
+	err = futex_get_value_locked(&uval, uaddr, FLAGS_SIZE_32);
 	if (err)
 		goto handle_err;
 
--- a/kernel/futex/requeue.c
+++ b/kernel/futex/requeue.c
@@ -273,7 +273,7 @@  futex_proxy_trylock_atomic(u32 __user *p
 	u32 curval;
 	int ret;
 
-	if (futex_get_value_locked(&curval, pifutex))
+	if (futex_get_value_locked(&curval, pifutex, FLAGS_SIZE_32))
 		return -EFAULT;
 
 	if (unlikely(should_fail_futex(true)))
@@ -449,7 +449,7 @@  int futex_requeue(u32 __user *uaddr1, un
 	if (likely(cmpval != NULL)) {
 		u32 curval;
 
-		ret = futex_get_value_locked(&curval, uaddr1);
+		ret = futex_get_value_locked(&curval, uaddr1, FLAGS_SIZE_32);
 
 		if (unlikely(ret)) {
 			double_unlock_hb(hb1, hb2);
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -439,7 +439,7 @@  static int futex_wait_multiple_setup(str
 		u32 val = vs[i].w.val;
 
 		hb = futex_q_lock(q);
-		ret = futex_get_value_locked(&uval, uaddr);
+		ret = futex_get_value_locked(&uval, uaddr, FLAGS_SIZE_32);
 
 		if (!ret && uval == val) {
 			/*
@@ -607,7 +607,7 @@  int futex_wait_setup(u32 __user *uaddr,
 retry_private:
 	*hb = futex_q_lock(q);
 
-	ret = futex_get_value_locked(&uval, uaddr);
+	ret = futex_get_value_locked(&uval, uaddr, FLAGS_SIZE_32);
 
 	if (ret) {
 		futex_q_unlock(*hb);