On Fri, Mar 17, 2023 at 03:52:27AM +0000, starmiku1207184332@xxxxxxxxx wrote:
> context because of its possible sleep operation. However, mmap_read_unlock()
> is unsafely called in a preempt disabled context when spin_lock() or
> rcu_read_lock() has been called.
Why is that unsafe?
See __up_read(). It's doing preempt_disable().
> - if (irqs_disabled()) {
> + if (in_atomic() || irqs_disabled()) {
We cannot do this. It will significantly hurt stack traces with build_id.
