From: Sebastian Andrzej Siewior <bige...@linutronix.de> arch_hw_breakpoint_init() holds get_online_cpus() while registerring the hotplug callbacks.
cpuhp_setup_state() invokes get_online_cpus() as well. This is correct, but prevents the conversion of the hotplug locking to a percpu rwsem. Use cpuhp_setup_state_locked() to avoid the nested call. Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Cc: Will Deacon <will.dea...@arm.com> Cc: Mark Rutland <mark.rutl...@arm.com> Cc: Russell King <li...@armlinux.org.uk> Cc: linux-arm-ker...@lists.infradead.org --- arch/arm/kernel/hw_breakpoint.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -1098,8 +1098,9 @@ static int __init arch_hw_breakpoint_ini * assume that a halting debugger will leave the world in a nice state * for us. */ - ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "arm/hw_breakpoint:online", - dbg_reset_online, NULL); + ret = cpuhp_setup_state_locked(CPUHP_AP_ONLINE_DYN, + "arm/hw_breakpoint:online", + dbg_reset_online, NULL); unregister_undef_hook(&debug_reg_hook); if (WARN_ON(ret < 0) || !cpumask_empty(&debug_err_mask)) { core_num_brps = 0;