Re: [PATCH v2] module: fix lost error code from codetag_load_module()

[Hao Ge <hao.ge@linux.dev>]

Hi Daniel


On 2026/9/10 06:00, Daniel Gomez wrote:
> On 2026-09-08T17:50:33+08:00, Hao Ge <hao.ge@linux.dev> wrote:
>> On 2026/9/8 03:42, Daniel Gomez wrote:
> 
>> I skipped it because alloc_tag is the only codetag type and it
>> already cleans up after itself.
>>
>> With a second codetag type the problem Sashiko reported could indeed
>> be triggered.
>>
>> My thinking at the time was to do it in codetag itself, as a separate patch,
>> since it feels odd to unload something whose load just failed.
> 
> Then, why returning an error at all? I don't see why not doing it inside

Codetag is a generic framework with a dedicated section in modules. We keep
this error path to account for possible future data stored in this section,
allowing us to perform security and validity checks for codetag within
codetag_load_module.

> codetag itself wouldn't work but it's a "bigger" change. IMO, the error
> is supposed to be handled at load_module() then, the unwinding as the
> rest.
> 
> 
I'm worried about this as well. Invoking codetag_unload_module () here brings
kvfree_rcu_barrier () into the error path and triggers two runs of ->free_section_mem (),
(used=true from the unload, used=false later from module_deallocate).

Perhaps we could put this patch on hold for now, until I come up with a proper solution?
The intention is to let codetag take care of its own cleanup, preserving the logic in our
existing patch.

How does this sound?

Thanks
Best Regards
Hao