Re: [PATCH] kexec: change locking mechanism to a mutex

From: Eric DeVolder
Date: Thu Sep 21 2023 - 21:00:38 EST




On 9/21/23 19:22, Andrew Morton wrote:
On Thu, 21 Sep 2023 17:59:38 -0400 Eric DeVolder <eric.devolder@xxxxxxxxxx> wrote:

Scaled up testing has revealed that the kexec_trylock()
implementation leads to failures within the crash hotplug
infrastructure due to the inability to acquire the lock,
specifically the message:

...

Convert the atomic lock to a mutex.


Do you think this problem is serious enough to warrant a backport into
-stable kernels?

I do not since it will be the lock traffic created by the crash hotplug infrastructure that will reveal the weak locking mechanism. Until this crash hotplug shows up in a stable kernel, it should not be an issue; there isn't anything else that easily exercise it to reveal the problem.

eric