Re: [PATCH v2 2/2] x86: Rewrite ret_from_fork() in C

[Joe Lawrence]

On 7/19/23 11:21, Petr Mladek wrote:
> On Fri 2023-06-23 18:55:29, Brian Gerst wrote:
>> When kCFI is enabled, special handling is needed for the indirect call
>> to the kernel thread function.  Rewrite the ret_from_fork() function in
>> C so that the compiler can properly handle the indirect call.
> 
> This patch broke livepatching. Kthreads never have a reliable stack.
> It works when I revert it.
> 

Just curious -- did the selftests catch this anywhere?  I'm not 100%
clear on what trees / frequency they all run, so maybe Petr you found
this by code inspection or other means?

-- 
Joe