[PATCH] arm64/entry: Don't disable preemption in debug_exception_enter() with RT kernel

[Waiman Long]

On 5/20/26 2:19 AM, Sebastian Andrzej Siewior wrote:
> On 2026-05-19 18:25:24 [-0400], Waiman Long wrote:
>> Commit d8bb6718c4db ("arm64: Make debug exception handlers visible from
>> RCU") introduces debug_exception_enter() and debug_exception_exit()
>> where preemption is explicitly disabled. With a PREEMPT_RT debug kernel,
>> the following bug report can happen.
> …
>
> What kernel is this? I have backport (which is being tested) for v6.6
> and v6.12, the patches are from v6.17-rc1.

The kernel backtrace is produced using the latest v7.1-rc4 kernel. There 
are a number of changes to the debug_exception_enter() and 
debug_exception_exit() functions over the years, but the preemption 
disable code remains since its introduction in v5.3.

BTW, what v6.17-rc1 patches are you talking about?

-Longman