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[4.4,01/11] futex: Rename free_pi_state() to put_pi_state()

Message ID 20210802134624.1934-2-thunder.leizhen@huawei.com
State New
Headers show
Series Fix a potential infinite loop in RT futex-pi scenarios | expand

Commit Message

Zhen Lei Aug. 2, 2021, 1:46 p.m. UTC 
From: Thomas Gleixner <tglx@linutronix.de>


[ Upstream commit 29e9ee5d48c35d6cf8afe09bdf03f77125c9ac11 ]

free_pi_state() is confusing as it is in fact only freeing/caching the
pi state when the last reference is gone. Rename it to put_pi_state()
which reflects better what it is doing.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <darren@dvhart.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Bhuvanesh_Surachari@mentor.com
Cc: Andy Lowe <Andy_Lowe@mentor.com>
Link: http://lkml.kernel.org/r/20151219200607.259636467@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>

---
 kernel/futex.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

-- 
2.26.0.106.g9fadedd
diff mbox series

Patch

diff --git a/kernel/futex.c b/kernel/futex.c
index ff5499b0c5b34f7..dbb38e14f6fcc8e 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -859,9 +859,12 @@  static void pi_state_update_owner(struct futex_pi_state *pi_state,
 }
 
 /*
+ * Drops a reference to the pi_state object and frees or caches it
+ * when the last reference is gone.
+ *
  * Must be called with the hb lock held.
  */
-static void free_pi_state(struct futex_pi_state *pi_state)
+static void put_pi_state(struct futex_pi_state *pi_state)
 {
 	if (!pi_state)
 		return;
@@ -2121,7 +2124,7 @@  retry_private:
 		case 0:
 			break;
 		case -EFAULT:
-			free_pi_state(pi_state);
+			put_pi_state(pi_state);
 			pi_state = NULL;
 			double_unlock_hb(hb1, hb2);
 			hb_waiters_dec(hb2);
@@ -2139,7 +2142,7 @@  retry_private:
 			 *   exit to complete.
 			 * - EAGAIN: The user space value changed.
 			 */
-			free_pi_state(pi_state);
+			put_pi_state(pi_state);
 			pi_state = NULL;
 			double_unlock_hb(hb1, hb2);
 			hb_waiters_dec(hb2);
@@ -2214,7 +2217,7 @@  retry_private:
 			} else if (ret) {
 				/* -EDEADLK */
 				this->pi_state = NULL;
-				free_pi_state(pi_state);
+				put_pi_state(pi_state);
 				goto out_unlock;
 			}
 		}
@@ -2223,7 +2226,7 @@  retry_private:
 	}
 
 out_unlock:
-	free_pi_state(pi_state);
+	put_pi_state(pi_state);
 	double_unlock_hb(hb1, hb2);
 	wake_up_q(&wake_q);
 	hb_waiters_dec(hb2);
@@ -2376,7 +2379,7 @@  static void unqueue_me_pi(struct futex_q *q)
 	__unqueue_futex(q);
 
 	BUG_ON(!q->pi_state);
-	free_pi_state(q->pi_state);
+	put_pi_state(q->pi_state);
 	q->pi_state = NULL;
 
 	spin_unlock(q->lock_ptr);
@@ -3210,7 +3213,7 @@  static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
 			 * Drop the reference to the pi state which
 			 * the requeue_pi() code acquired for us.
 			 */
-			free_pi_state(q.pi_state);
+			put_pi_state(q.pi_state);
 			spin_unlock(q.lock_ptr);
 			/*
 			 * Adjust the return value. It's either -EFAULT or