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authorThomas Gleixner <tglx@linutronix.de>2021-01-19 18:26:38 +0300
committerThomas Gleixner <tglx@linutronix.de>2021-01-26 17:10:59 +0300
commitf2dac39d93987f7de1e20b3988c8685523247ae2 (patch)
tree794e359ec4dd352876cd9c5e62446179ff823af8 /kernel/futex.c
parent6ccc84f917d33312eb2846bd7b567639f585ad6d (diff)
downloadlinux-f2dac39d93987f7de1e20b3988c8685523247ae2.tar.xz
futex: Simplify fixup_pi_state_owner()
Too many gotos already and an upcoming fix would make it even more unreadable. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org
Diffstat (limited to 'kernel/futex.c')
-rw-r--r--kernel/futex.c53
1 files changed, 26 insertions, 27 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index a0fe63c34248..7a38ead96cae 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2329,18 +2329,13 @@ static void unqueue_me_pi(struct futex_q *q)
spin_unlock(q->lock_ptr);
}
-static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
- struct task_struct *argowner)
+static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
+ struct task_struct *argowner)
{
struct futex_pi_state *pi_state = q->pi_state;
- u32 uval, curval, newval;
struct task_struct *oldowner, *newowner;
- u32 newtid;
- int ret, err = 0;
-
- lockdep_assert_held(q->lock_ptr);
-
- raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
+ u32 uval, curval, newval, newtid;
+ int err = 0;
oldowner = pi_state->owner;
@@ -2374,14 +2369,12 @@ retry:
* We raced against a concurrent self; things are
* already fixed up. Nothing to do.
*/
- ret = 0;
- goto out_unlock;
+ return 0;
}
if (__rt_mutex_futex_trylock(&pi_state->pi_mutex)) {
/* We got the lock. pi_state is correct. Tell caller. */
- ret = 1;
- goto out_unlock;
+ return 1;
}
/*
@@ -2408,8 +2401,7 @@ retry:
* We raced against a concurrent self; things are
* already fixed up. Nothing to do.
*/
- ret = 1;
- goto out_unlock;
+ return 1;
}
newowner = argowner;
}
@@ -2440,7 +2432,6 @@ retry:
* itself.
*/
pi_state_update_owner(pi_state, newowner);
- raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
return argowner == current;
@@ -2463,17 +2454,16 @@ handle_err:
switch (err) {
case -EFAULT:
- ret = fault_in_user_writeable(uaddr);
+ err = fault_in_user_writeable(uaddr);
break;
case -EAGAIN:
cond_resched();
- ret = 0;
+ err = 0;
break;
default:
WARN_ON_ONCE(1);
- ret = err;
break;
}
@@ -2483,17 +2473,26 @@ handle_err:
/*
* Check if someone else fixed it for us:
*/
- if (pi_state->owner != oldowner) {
- ret = argowner == current;
- goto out_unlock;
- }
+ if (pi_state->owner != oldowner)
+ return argowner == current;
- if (ret)
- goto out_unlock;
+ /* Retry if err was -EAGAIN or the fault in succeeded */
+ if (!err)
+ goto retry;
- goto retry;
+ return err;
+}
-out_unlock:
+static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
+ struct task_struct *argowner)
+{
+ struct futex_pi_state *pi_state = q->pi_state;
+ int ret;
+
+ lockdep_assert_held(q->lock_ptr);
+
+ raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
+ ret = __fixup_pi_state_owner(uaddr, q, argowner);
raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
return ret;
}