linux-kernel - [PATCH v2 5/7] regulator/core: regulator_lock_contended: wrap ww

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <85bcd0af56521209f40e76e0cac626c4f02b7df5.1693416477.git.mirq-linux@rere.qmqm.pl>
Date:   Wed, 30 Aug 2023 19:35:32 +0200
From:   Michał Mirosław <mirq-linux@...e.qmqm.pl>
To:     Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>
Cc:     Douglas Anderson <dianders@...omium.org>,
        linux-kernel@...r.kernel.org, Stephen Boyd <swboyd@...omium.org>
Subject: [PATCH v2 5/7] regulator/core: regulator_lock_contended: wrap
 ww_mutex lock sequence restart

Wrap locking a regulator after a failed ww_mutex locking sequence with a
new function.  This is to deduplicate occurrences of the pattern and make
it self-documenting.

Signed-off-by: Michał Mirosław <mirq-linux@...e.qmqm.pl>
---
 drivers/regulator/core.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index e89c12d27a9d..7201927c5d5b 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -154,6 +154,22 @@ static inline int regulator_lock_nested(struct regulator_dev *rdev,
 	return 0;
 }
 
+/**
+ * regulator_lock_contended - retry locking a regulator
+ * @rdev:		regulator source
+ * @ww_ctx:		w/w mutex acquire context
+ *
+ * Locks a regulator after a failed locking sequence (aborted
+ * with -EDEADLK).
+ */
+static inline void regulator_lock_contended(struct regulator_dev *rdev,
+					    struct ww_acquire_ctx *ww_ctx)
+{
+	ww_mutex_lock_slow(&rdev->mutex, ww_ctx);
+	rdev->ref_cnt++;
+	rdev->mutex_owner = current;
+}
+
 /**
  * regulator_lock - lock a single regulator
  * @rdev:		regulator source
@@ -218,9 +234,7 @@ static void regulator_lock_two(struct regulator_dev *rdev1,
 	while (true) {
 		regulator_unlock(held);
 
-		ww_mutex_lock_slow(&contended->mutex, ww_ctx);
-		contended->ref_cnt++;
-		contended->mutex_owner = current;
+		regulator_lock_contended(contended, ww_ctx);
 		swap(held, contended);
 		ret = regulator_lock_nested(contended, ww_ctx);
 
@@ -376,10 +390,8 @@ static void regulator_lock_dependent(struct regulator_dev *rdev,
 
 	do {
 		if (new_contended_rdev) {
-			ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
+			regulator_lock_contended(new_contended_rdev, ww_ctx);
 			old_contended_rdev = new_contended_rdev;
-			old_contended_rdev->ref_cnt++;
-			old_contended_rdev->mutex_owner = current;
 		}
 
 		err = regulator_lock_recursive(rdev,
@@ -6085,10 +6097,8 @@ static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx)
 
 	do {
 		if (new_contended_rdev) {
-			ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
+			regulator_lock_contended(new_contended_rdev, ww_ctx);
 			old_contended_rdev = new_contended_rdev;
-			old_contended_rdev->ref_cnt++;
-			old_contended_rdev->mutex_owner = current;
 		}
 
 		err = regulator_summary_lock_all(ww_ctx,
-- 
2.39.2