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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2017-06-02 16:27:14 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-06-03 09:35:04 +0200 |
| commit | 40da1b11f01e43aad1aa6cea64681b6125e8a2a7 (patch) | |
| tree | 8a7c467a91c77dcab9f1102b1a3ad755c7c4ea9b /kernel/cpu.c | |
| parent | 104c08ba8e921ef97abfdc10408d54921a6d9003 (diff) | |
| download | lwn-40da1b11f01e43aad1aa6cea64681b6125e8a2a7.tar.gz lwn-40da1b11f01e43aad1aa6cea64681b6125e8a2a7.zip | |
cpu/hotplug: Drop the device lock on error
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>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170602142714.3ogo25f2wbq6fjpj@linutronix.de
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 9ae6fbe5b5cf..cb5103413bd8 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1658,13 +1658,13 @@ 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; } |