On Mon, Jan 3, 2022 at 9:18 AM Manfred Spraul manfred@colorfullife.com wrote:
Hi Jiri,
On 1/3/22 10:27, Jiri Slaby wrote:
On 23. 12. 21, 4:12, cgel.zte@gmail.com wrote:
From: Minghao Chi chi.minghao@zte.com.cn
We can't call kvfree() with a spin lock held, so defer it.
Sorry, defer what?
First drop the spinlock, then call kvfree().
There are attempts to fix kvfree instead, not sure which of these approaches (fix kvfree or its callers) won in the end?
Exactly. We have three options - but noone volunteered yet to decide:
- change ipc/sem.c [minimal change]
Let's go with the minimal change for now which can easily be cherry-picked for the stable tree. It seems other approaches need more work/discussion.
- change kvfree() to use vfree_atomic() [would also fix other changes
that did s/kfree/kvfree/]
- Modify the vma handling so that it becomes safe to call vfree() while
holding a spinlock. [perfect approach, but I'm concerned about side effects]
--
Manfred