On Sun, 2023-07-02 at 15:40 -0400, Sasha Levin wrote:
From: David Woodhouse dwmw@amazon.co.uk
[ Upstream commit 6d712b9b3a58018259fb40ddd498d1f7dfa1f4ec ]
Commit dce1ca0525bf ("sched/scs: Reset task stack state in bringup_cpu()") ensured that the shadow call stack and KASAN poisoning were removed from a CPU's stack each time that CPU is brought up, not just once.
This is not incorrect.
No really, it *wasn't* incorrect. This isn't a bugfix that needs backporting; it's preparation for the parallel CPU bringup which I *hope* you aren't planning to backport in its entirety :)
Unless I'm missing something, I don't think you want this for stable (in any of the trees it was just sent out for).