This pull request contains a commit that fixes bf95b2bc3e ("rcu: Switch
polled grace-period APIs to ->gp_seq_polled"), which could incorrectly
leave interrupts enabled after an early-boot call to synchronize_rcu().
Such synchronize_rcu() calls must acquire leaf rcu_node locks in order to
properly interact with polled grace periods, but the code did not take
into account the possibility of synchronize_rcu() being invoked from
the portion of the boot sequence during which interrupts are disabled.
This commit therefore switches the lock acquisition and release from
irq to irqsave/irqrestore.
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Merge tag 'rcu-urgent.2022.10.20a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU fix from Paul McKenney:
"Fix a regression caused by commit bf95b2bc3e ("rcu: Switch polled
grace-period APIs to ->gp_seq_polled"), which could incorrectly leave
interrupts enabled after an early-boot call to synchronize_rcu().
Such synchronize_rcu() calls must acquire leaf rcu_node locks in order
to properly interact with polled grace periods, but the code did not
take into account the possibility of synchronize_rcu() being invoked
from the portion of the boot sequence during which interrupts are
disabled.
This commit therefore switches the lock acquisition and release from
irq to irqsave/irqrestore"
* tag 'rcu-urgent.2022.10.20a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
rcu: Keep synchronize_rcu() from enabling irqs in early boot
f6602a97a1