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Stephen Boyd authored
If one process calls sys_reboot and that process then stops other CPUs while those CPUs are within a spin_lock() region we can potentially encounter a deadlock scenario like below. CPU 0 CPU 1 ----- ----- spin_lock(my_lock) smp_send_stop() <send IPI> handle_IPI() disable_preemption/irqs while(1); <PREEMPT> spin_lock(my_lock) <--- Waits forever We shouldn't attempt to run any other tasks after we send a stop IPI to a CPU so disable preemption so that this task runs to completion. We use local_irq_disable() here for cross-arch consistency with x86. Reported-by:
Sundarajan Srinivasan <sundaraj@codeaurora.com> Signed-off-by:
Stephen Boyd <sboyd@codeaurora.org> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk>
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