From: "tip-bot2 for Dan Carpenter" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Dan Carpenter <dan.carpenter@oracle.com>,
Thomas Gleixner <tglx@linutronix.de>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
stable@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org
Subject: [tip: locking/urgent] futex: Don't enable IRQs unconditionally in put_pi_state()
Date: Mon, 09 Nov 2020 13:34:57 -0000 [thread overview]
Message-ID: <160492889756.11244.1763664400047325043.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20201106085205.GA1159983@mwanda>
The following commit has been merged into the locking/urgent branch of tip:
Commit-ID: 1e106aa3509b86738769775969822ffc1ec21bf4
Gitweb: https://git.kernel.org/tip/1e106aa3509b86738769775969822ffc1ec21bf4
Author: Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Fri, 06 Nov 2020 11:52:05 +03:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 09 Nov 2020 14:30:30 +01:00
futex: Don't enable IRQs unconditionally in put_pi_state()
The exit_pi_state_list() function calls put_pi_state() with IRQs disabled
and is not expecting that IRQs will be enabled inside the function.
Use the _irqsave() variant so that IRQs are restored to the original state
instead of being enabled unconditionally.
Fixes: 153fbd1226fb ("futex: Fix more put_pi_state() vs. exit_pi_state_list() races")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201106085205.GA1159983@mwanda
---
kernel/futex.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/futex.c b/kernel/futex.c
index ac32887..00259c7 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -788,8 +788,9 @@ static void put_pi_state(struct futex_pi_state *pi_state)
*/
if (pi_state->owner) {
struct task_struct *owner;
+ unsigned long flags;
- raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
+ raw_spin_lock_irqsave(&pi_state->pi_mutex.wait_lock, flags);
owner = pi_state->owner;
if (owner) {
raw_spin_lock(&owner->pi_lock);
@@ -797,7 +798,7 @@ static void put_pi_state(struct futex_pi_state *pi_state)
raw_spin_unlock(&owner->pi_lock);
}
rt_mutex_proxy_unlock(&pi_state->pi_mutex, owner);
- raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
+ raw_spin_unlock_irqrestore(&pi_state->pi_mutex.wait_lock, flags);
}
if (current->pi_state_cache) {
prev parent reply other threads:[~2020-11-09 13:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-06 8:52 [PATCH] futex: Don't enable IRQs unconditionally in put_pi_state() Dan Carpenter
2020-11-06 8:52 ` Dan Carpenter
2020-11-09 11:21 ` Peter Zijlstra
2020-11-09 11:21 ` Peter Zijlstra
2020-11-09 13:34 ` tip-bot2 for Dan Carpenter [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=160492889756.11244.1763664400047325043.tip-bot2@tip-bot2 \
--to=tip-bot2@linutronix.de \
--cc=dan.carpenter@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=stable@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.