From: Lukas Wunner <lukas@wunner.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
Alexander Duyck <alexander.h.duyck@linux.intel.com>,
Mark Brown <broonie@kernel.org>,
linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org
Subject: [PATCH 1/3] driver core: Avoid binding drivers to dead devices
Date: Wed, 8 Jul 2020 15:27:01 +0200 [thread overview]
Message-ID: <de88a23a6fe0ef70f7cfd13c8aea9ab51b4edab6.1594214103.git.lukas@wunner.de> (raw)
In-Reply-To: <cover.1594214103.git.lukas@wunner.de>
Commit 3451a495ef24 ("driver core: Establish order of operations for
device_add and device_del via bitflag") sought to prevent asynchronous
driver binding to a device which is being removed. It added a
per-device "dead" flag which is checked in the following code paths:
* asynchronous binding in __driver_attach_async_helper()
* synchronous binding in device_driver_attach()
* asynchronous binding in __device_attach_async_helper()
It did *not* check the flag upon:
* synchronous binding in __device_attach()
However __device_attach() may also be called asynchronously from:
deferred_probe_work_func()
bus_probe_device()
device_initial_probe()
__device_attach()
So if the commit's intention was to check the "dead" flag in all
asynchronous code paths, then a check is also necessary in
__device_attach(). Add the missing check.
Fixes: 3451a495ef24 ("driver core: Establish order of operations for device_add and device_del via bitflag")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v5.1+
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
---
drivers/base/dd.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 9a1d940342ac4..31c668651e824 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -848,7 +848,9 @@ static int __device_attach(struct device *dev, bool allow_async)
int ret = 0;
device_lock(dev);
- if (dev->driver) {
+ if (dev->p->dead) {
+ goto out_unlock;
+ } else if (dev->driver) {
if (device_is_bound(dev)) {
ret = 1;
goto out_unlock;
--
2.27.0
next prev parent reply other threads:[~2020-07-08 13:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 13:27 [PATCH 0/3] Fix races on device removal Lukas Wunner
2020-07-08 13:27 ` Lukas Wunner [this message]
2020-07-08 13:27 ` [PATCH 2/3] driver core: Use rwsem for kill_device() serialization Lukas Wunner
2020-07-30 6:53 ` Greg Kroah-Hartman
2020-07-30 9:56 ` Lukas Wunner
2020-07-31 6:45 ` Greg Kroah-Hartman
2020-07-31 9:53 ` Lukas Wunner
2020-07-08 13:27 ` [PATCH 3/3] driver core: Avoid adding children below a dead parent Lukas Wunner
2020-07-24 14:29 ` [driver core] e3b1cb5c89: WARNING:possible_recursive_locking_detected kernel test robot
2020-07-25 11:07 ` Lukas Wunner
2020-07-30 6:54 ` [PATCH 0/3] Fix races on device removal Greg Kroah-Hartman
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