signal: Remove no longer required irqsave/restore
authorAnna-Maria Gleixner <anna-maria@linutronix.de>
Fri, 25 May 2018 09:05:07 +0000 (11:05 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Sun, 10 Jun 2018 04:14:01 +0000 (06:14 +0200)
commit59dc6f3c6d81c0c4379025c4eb56919391d62b67
treee4a46207c2932db28237039791f11790f266a1d2
parentec84b27f9b3b569f9235413d1945a2006b97b0aa
signal: Remove no longer required irqsave/restore

Commit a841796f11c9 ("signal: align __lock_task_sighand() irq disabling and
RCU") introduced a rcu read side critical section with interrupts
disabled. The changelog suggested that a better long-term fix would be "to
make rt_mutex_unlock() disable irqs when acquiring the rt_mutex structure's
->wait_lock".

This long-term fix has been made in commit b4abf91047cf ("rtmutex: Make
wait_lock irq safe") for a different reason.

Therefore revert commit a841796f11c9 ("signal: align >
__lock_task_sighand() irq disabling and RCU") as the interrupt disable
dance is not longer required.

The change was tested on the base of b4abf91047cf ("rtmutex: Make wait_lock
irq safe") with a four hour run of rcutorture scenario TREE03 with lockdep
enabled as suggested by Paul McKenney.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: bigeasy@linutronix.de
Link: https://lkml.kernel.org/r/20180525090507.22248-3-anna-maria@linutronix.de
kernel/signal.c