From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
Julia Cartwright <julia@ni.com>,
Daniel Wagner <daniel.wagner@siemens.com>,
tom.zanussi@linux.intel.com
Subject: [PATCH RT 16/22] crypto: cryptd - add a lock instead preempt_disable/local_bh_disable
Date: Wed, 05 Sep 2018 08:28:10 -0400 [thread overview]
Message-ID: <20180905122836.928502373@goodmis.org> (raw)
In-Reply-To: 20180905122754.443196118@goodmis.org
4.14.63-rt41-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Upstream commit 21aedb30d85979697f79a72a084e5d781e323663 ]
cryptd has a per-CPU lock which protected with local_bh_disable() and
preempt_disable().
Add an explicit spin_lock to make the locking context more obvious and
visible to lockdep. Since it is a per-CPU lock, there should be no lock
contention on the actual spinlock.
There is a small race-window where we could be migrated to another CPU
after the cpu_queue has been obtain. This is not a problem because the
actual ressource is protected by the spinlock.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
crypto/cryptd.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 248f6ba41688..54b7985c8caa 100644
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -37,6 +37,7 @@
struct cryptd_cpu_queue {
struct crypto_queue queue;
struct work_struct work;
+ spinlock_t qlock;
};
struct cryptd_queue {
@@ -115,6 +116,7 @@ static int cryptd_init_queue(struct cryptd_queue *queue,
cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
INIT_WORK(&cpu_queue->work, cryptd_queue_worker);
+ spin_lock_init(&cpu_queue->qlock);
}
return 0;
}
@@ -139,8 +141,10 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue,
atomic_t *refcnt;
bool may_backlog;
- cpu = get_cpu();
- cpu_queue = this_cpu_ptr(queue->cpu_queue);
+ cpu_queue = raw_cpu_ptr(queue->cpu_queue);
+ spin_lock_bh(&cpu_queue->qlock);
+ cpu = smp_processor_id();
+
err = crypto_enqueue_request(&cpu_queue->queue, request);
refcnt = crypto_tfm_ctx(request->tfm);
@@ -157,7 +161,7 @@ static int cryptd_enqueue_request(struct cryptd_queue *queue,
atomic_inc(refcnt);
out_put_cpu:
- put_cpu();
+ spin_unlock_bh(&cpu_queue->qlock);
return err;
}
@@ -173,16 +177,11 @@ static void cryptd_queue_worker(struct work_struct *work)
cpu_queue = container_of(work, struct cryptd_cpu_queue, work);
/*
* Only handle one request at a time to avoid hogging crypto workqueue.
- * preempt_disable/enable is used to prevent being preempted by
- * cryptd_enqueue_request(). local_bh_disable/enable is used to prevent
- * cryptd_enqueue_request() being accessed from software interrupts.
*/
- local_bh_disable();
- preempt_disable();
+ spin_lock_bh(&cpu_queue->qlock);
backlog = crypto_get_backlog(&cpu_queue->queue);
req = crypto_dequeue_request(&cpu_queue->queue);
- preempt_enable();
- local_bh_enable();
+ spin_unlock_bh(&cpu_queue->qlock);
if (!req)
return;
--
2.18.0
next prev parent reply other threads:[~2018-09-05 12:29 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-05 12:27 [PATCH RT 00/22] Linux 4.14.63-rt41-rc1 Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 01/22] sched/fair: Fix CFS bandwidth control lockdep DEADLOCK report Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 02/22] locallock: provide {get,put}_locked_ptr() variants Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 03/22] squashfs: make use of local lock in multi_cpu decompressor Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 04/22] PM / suspend: Prevent might sleep splats (updated) Steven Rostedt
2018-09-05 12:27 ` [PATCH RT 05/22] PM / wakeup: Make events_lock a RAW_SPINLOCK Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 06/22] PM / s2idle: Make s2idle_wait_head swait based Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 07/22] seqlock: provide the same ordering semantics as mainline Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 08/22] Revert "x86: UV: raw_spinlock conversion" Steven Rostedt
2018-09-06 7:35 ` Sebastian Andrzej Siewior
2018-09-06 8:38 ` Mike Galbraith
2018-09-06 12:58 ` Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 09/22] Revert "timer: delay waking softirqs from the jiffy tick" Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 10/22] irqchip/gic-v3-its: Make its_lock a raw_spin_lock_t Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 11/22] irqchip/gic-v3-its: Move ITS ->pend_page allocation into an early CPU up hook Steven Rostedt
2018-09-06 7:40 ` Sebastian Andrzej Siewior
2018-09-07 19:28 ` Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 12/22] sched/migrate_disable: fallback to preempt_disable() instead barrier() Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 13/22] x86/ioapic: Dont let setaffinity unmask threaded EOI interrupt too early Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 14/22] efi: Allow efi=runtime Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 15/22] efi: Disable runtime services on RT Steven Rostedt
2018-09-05 12:28 ` Steven Rostedt [this message]
2018-09-05 12:28 ` [PATCH RT 17/22] crypto: scompress - serialize RT percpu scratch buffer access with a local lock Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 18/22] sched/core: Avoid __schedule() being called twice in a row Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 19/22] Revert "arm64/xen: Make XEN depend on !RT" Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 20/22] sched: Allow pinned user tasks to be awakened to the CPU they pinned Steven Rostedt
2018-09-05 12:28 ` [PATCH RT 22/22] Linux 4.14.63-rt41-rc1 Steven Rostedt
[not found] ` <20180905122837.830614967@goodmis.org>
2018-09-05 12:34 ` [PATCH RT 21/22] Drivers: hv: vmbus: include header for get_irq_regs() Steven Rostedt
2018-09-06 7:54 ` [PATCH RT 00/22] Linux 4.14.63-rt41-rc1 Sebastian Andrzej Siewior
2018-09-06 16:43 ` Steven Rostedt
2018-09-06 19:30 ` Sebastian Andrzej Siewior
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=20180905122836.928502373@goodmis.org \
--to=rostedt@goodmis.org \
--cc=C.Emde@osadl.org \
--cc=bigeasy@linutronix.de \
--cc=daniel.wagner@siemens.com \
--cc=jkacur@redhat.com \
--cc=julia@ni.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=paul.gortmaker@windriver.com \
--cc=tglx@linutronix.de \
--cc=tom.zanussi@linux.intel.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).