Re: [PATCH] arm64: replace read_lock to rcu lock in call_break_hook

On Wed, Sep 30, 2015 at 03:59:04PM -0700, Yang Shi wrote:

diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c index cebf786..eb520d0 100644 --- a/arch/arm64/kernel/debug-monitors.c +++ b/arch/arm64/kernel/debug-monitors.c @@ -292,11 +292,11 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr) struct break_hook *hook; int (*fn)(struct pt_regs *regs, unsigned int esr) = NULL;

• read_lock(&break_hook_lock);

• rcu_read_lock(); list_for_each_entry(hook, &break_hook, node) if ((esr & hook->esr_mask) == hook->esr_val) fn = hook->fn;

• read_unlock(&break_hook_lock);

• rcu_read_unlock();

return fn ? fn(regs, esr) : DBG_HOOK_ERROR; }

That's not enough, you also need list_(add|del)_rcu where the list is modified, together with list_for_each_entry_rcu() here.