diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2017-06-02 16:27:14 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-14 15:06:04 +0200 |
| commit | 106c77e82572921fa53483235a55adb7cb9452c0 (patch) | |
| tree | 48eb3813c494bac6c619ef2fd35f514138726652 /kernel/cpu.c | |
| parent | eb8fa317cb0184f5179e29bab8c62a4a4087cd4a (diff) | |
cpu/hotplug: Drop the device lock on error
commit 40da1b11f01e43aad1aa6cea64681b6125e8a2a7 upstream.
If a custom CPU target is specified and that one is not available _or_
can't be interrupted then the code returns to userland without dropping a
lock as notices by lockdep:
|echo 133 > /sys/devices/system/cpu/cpu7/hotplug/target
| ================================================
| [ BUG: lock held when returning to user space! ]
| ------------------------------------------------
| bash/503 is leaving the kernel with locks still held!
| 1 lock held by bash/503:
| #0: (device_hotplug_lock){+.+...}, at: [<ffffffff815b5650>] lock_device_hotplug_sysfs+0x10/0x40
So release the lock then.
Fixes: 757c989b9994 ("cpu/hotplug: Make target state writeable")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170602142714.3ogo25f2wbq6fjpj@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 99c6c568bc55..8f52977aad59 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1765,13 +1765,13 @@ static ssize_t write_cpuhp_target(struct device *dev, ret = !sp->name || sp->cant_stop ? -EINVAL : 0; mutex_unlock(&cpuhp_state_mutex); if (ret) - return ret; + goto out; if (st->state < target) ret = do_cpu_up(dev->id, target); else ret = do_cpu_down(dev->id, target); - +out: unlock_device_hotplug(); return ret ? ret : count; } |