On 10/04/15 10:51, Daniel Thompson wrote: > It is currently possible for FIQ handlers to re-enter gic_raise_softirq() > and lock up. > > gic_raise_softirq() > lock(x); > -~-> FIQ > handle_fiq() > gic_raise_softirq() > lock(x); <-- Lockup > > arch/arm/ uses IPIs to implement arch_irq_work_raise(), thus this issue > renders it difficult for FIQ handlers to safely defer work to less > restrictive calling contexts. > > This patch fixes the problem by converting the cpu_map_migration_lock > into a rwlock making it safe to re-enter the function. > > Note that having made it safe to re-enter gic_raise_softirq() we no > longer need to mask interrupts during gic_raise_softirq() because the > b.L migration is always performed from task context. > > Signed-off-by: Daniel Thompson <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: Jason Cooper <[email protected]> > Cc: Russell King <[email protected]> > Cc: Marc Zyngier <[email protected]> > Acked-by: Nicolas Pitre <[email protected]>
Acked-by: Marc Zyngier <[email protected]> M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
