When inserting a wrong value to /sys/devices/system/memory/memoryX/state file,
following messages are shown. And device_hotplug_lock is never released.

================================================
[ BUG: lock held when returning to user space! ]
3.12.0-rc4-debug+ #3 Tainted: G        W
------------------------------------------------
bash/6442 is leaving the kernel with locks still held!
1 lock held by bash/6442:
 #0:  (device_hotplug_lock){+.+.+.}, at: [<ffffffff8146cbb5>] 
lock_device_hotplug_sysfs+0x15/0x50

This issue was introdued by commit fa2be40 (drivers: base: use standard
device online/offline for state change).

This patch releases device_hotplug_lcok when store_mem_state returns EINVAL.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasu...@jp.fujitsu.com>
CC: Toshi Kani <toshi.k...@hp.com>
CC: Seth Jennings <sjenn...@linux.vnet.ibm.com>
CC: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/base/memory.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 9e59f65..bece691 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -333,8 +333,10 @@ store_mem_state(struct device *dev,
                online_type = ONLINE_KEEP;
        else if (!strncmp(buf, "offline", min_t(int, count, 7)))
                online_type = -1;
-       else
-               return -EINVAL;
+       else {
+               ret = -EINVAL;
+               goto err;
+       }

        switch (online_type) {
        case ONLINE_KERNEL:
@@ -357,6 +359,7 @@ store_mem_state(struct device *dev,
                ret = -EINVAL; /* should never happen */
        }

+err:
        unlock_device_hotplug();

        if (ret)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to