linux-kernel - [tip: sched/rt] dentry: Use preempt_[dis|en]able

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <166359107791.401.1079842493025213678.tip-bot2@tip-bot2>
Date:   Mon, 19 Sep 2022 12:37:57 -0000
From:   "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        "Christian Brauner (Microsoft)" <brauner@...nel.org>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: sched/rt] dentry: Use preempt_[dis|en]able_nested()

The following commit has been merged into the sched/rt branch of tip:

Commit-ID:     93f6d4e1893657f07ba3c9e2bfa74b355a0b32f9
Gitweb:        https://git.kernel.org/tip/93f6d4e1893657f07ba3c9e2bfa74b355a0b32f9
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Thu, 25 Aug 2022 18:41:25 +02:00
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Mon, 19 Sep 2022 14:35:07 +02:00

dentry: Use preempt_[dis|en]able_nested()

Replace the open coded CONFIG_PREEMPT_RT conditional
preempt_disable/enable() with the new helper.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Acked-by: Christian Brauner (Microsoft) <brauner@...nel.org>
Link: https://lore.kernel.org/r/20220825164131.402717-3-bigeasy@linutronix.de

---
 fs/dcache.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index bb0c4d0..2ee8636 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2597,15 +2597,7 @@ EXPORT_SYMBOL(d_rehash);
 
 static inline unsigned start_dir_add(struct inode *dir)
 {
-	/*
-	 * The caller holds a spinlock (dentry::d_lock). On !PREEMPT_RT
-	 * kernels spin_lock() implicitly disables preemption, but not on
-	 * PREEMPT_RT.  So for RT it has to be done explicitly to protect
-	 * the sequence count write side critical section against a reader
-	 * or another writer preempting, which would result in a live lock.
-	 */
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_disable();
+	preempt_disable_nested();
 	for (;;) {
 		unsigned n = dir->i_dir_seq;
 		if (!(n & 1) && cmpxchg(&dir->i_dir_seq, n, n + 1) == n)
@@ -2618,8 +2610,7 @@ static inline void end_dir_add(struct inode *dir, unsigned int n,
 			       wait_queue_head_t *d_wait)
 {
 	smp_store_release(&dir->i_dir_seq, n + 2);
-	if (IS_ENABLED(CONFIG_PREEMPT_RT))
-		preempt_enable();
+	preempt_enable_nested();
 	wake_up_all(d_wait);
 }