From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>,
Eric Biggers <ebiggers@kernel.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Steffen Klassert <steffen.klassert@secunet.com>,
linux-crypto@vger.kernel.org, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.5 194/542] padata: always acquire cpu_hotplug_lock before pinst->lock
Date: Fri, 14 Feb 2020 10:43:06 -0500 [thread overview]
Message-ID: <20200214154854.6746-194-sashal@kernel.org> (raw)
In-Reply-To: <20200214154854.6746-1-sashal@kernel.org>
From: Daniel Jordan <daniel.m.jordan@oracle.com>
[ Upstream commit 38228e8848cd7dd86ccb90406af32de0cad24be3 ]
lockdep complains when padata's paths to update cpumasks via CPU hotplug
and sysfs are both taken:
# echo 0 > /sys/devices/system/cpu/cpu1/online
# echo ff > /sys/kernel/pcrypt/pencrypt/parallel_cpumask
======================================================
WARNING: possible circular locking dependency detected
5.4.0-rc8-padata-cpuhp-v3+ #1 Not tainted
------------------------------------------------------
bash/205 is trying to acquire lock:
ffffffff8286bcd0 (cpu_hotplug_lock.rw_sem){++++}, at: padata_set_cpumask+0x2b/0x120
but task is already holding lock:
ffff8880001abfa0 (&pinst->lock){+.+.}, at: padata_set_cpumask+0x26/0x120
which lock already depends on the new lock.
padata doesn't take cpu_hotplug_lock and pinst->lock in a consistent
order. Which should be first? CPU hotplug calls into padata with
cpu_hotplug_lock already held, so it should have priority.
Fixes: 6751fb3c0e0c ("padata: Use get_online_cpus/put_online_cpus")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/padata.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/padata.c b/kernel/padata.c
index fda7a7039422d..fdbbe96547713 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -643,8 +643,8 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
struct cpumask *serial_mask, *parallel_mask;
int err = -EINVAL;
- mutex_lock(&pinst->lock);
get_online_cpus();
+ mutex_lock(&pinst->lock);
switch (cpumask_type) {
case PADATA_CPU_PARALLEL:
@@ -662,8 +662,8 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
out:
- put_online_cpus();
mutex_unlock(&pinst->lock);
+ put_online_cpus();
return err;
}
--
2.20.1
next prev parent reply other threads:[~2020-02-14 18:12 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200214154854.6746-1-sashal@kernel.org>
2020-02-14 15:40 ` [PATCH AUTOSEL 5.5 017/542] crypto: testmgr - don't try to decrypt uninitialized buffers Sasha Levin
2020-02-14 15:41 ` [PATCH AUTOSEL 5.5 092/542] crypto: arm/chacha - fix build failured when kernel mode NEON is disabled Sasha Levin
2020-02-14 15:43 ` [PATCH AUTOSEL 5.5 193/542] padata: validate cpumask without removed CPU during offline Sasha Levin
2020-02-14 15:43 ` Sasha Levin [this message]
2020-02-14 15:43 ` [PATCH AUTOSEL 5.5 242/542] crypto: inside-secure - add unspecified HAS_IOMEM dependency Sasha Levin
2020-02-14 15:43 ` [PATCH AUTOSEL 5.5 243/542] crypto: amlogic " Sasha Levin
2020-02-14 15:44 ` [PATCH AUTOSEL 5.5 265/542] crypto: chtls - Fixed memory leak Sasha Levin
2020-02-14 15:44 ` [PATCH AUTOSEL 5.5 303/542] crypto: artpec6 - return correct error code for failed setkey() Sasha Levin
2020-02-14 15:44 ` [PATCH AUTOSEL 5.5 304/542] crypto: atmel-sha - fix error handling when setting hmac key Sasha Levin
2020-02-14 15:46 ` [PATCH AUTOSEL 5.5 378/542] crypto: hisilicon - Update debugfs usage of SEC V2 Sasha Levin
2020-02-14 15:46 ` [PATCH AUTOSEL 5.5 379/542] crypto: hisilicon - Bugfixed tfm leak Sasha Levin
2020-02-14 15:46 ` [PATCH AUTOSEL 5.5 380/542] crypto: essiv - fix AEAD capitalization and preposition use in help text Sasha Levin
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