[PATCH 4.4 06/38] futex: Replace pointless printk in fixup_owner()

Greg Kroah-Hartman
2021-02-08T15:08:40Z

From: Lee Jones <lee.jones@linaro.org>

From: Thomas Gleixner <tglx@linutronix.de>

[ Upstream commit 04b79c55201f02ffd675e1231d731365e335c307 ]

If that unexpected case of inconsistent arguments ever happens then the
futex state is left completely inconsistent and the printk is not really
helpful. Replace it with a warning and make the state consistent.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/futex.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2412,14 +2412,10 @@ static int fixup_owner(u32 __user *uaddr

/*
* Paranoia check. If we did not take the lock, then we should not be
- * the owner of the rt_mutex.
+ * the owner of the rt_mutex. Warn and establish consistent state.
*/
- if (rt_mutex_owner(&q->pi_state->pi_mutex) == current) {
- printk(KERN_ERR "fixup_owner: ret = %d pi-mutex: %p "
- "pi-state %p\n", ret,
- q->pi_state->pi_mutex.owner,
- q->pi_state->owner);
- }
+ if (WARN_ON_ONCE(rt_mutex_owner(&q->pi_state->pi_mutex) == current))
+ return fixup_pi_state_owner(uaddr, q, current);

out:
return ret ? ret : locked;