Re: [RFC PATCH 3/3] module: pre-test setting ro_after_init data read-only

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 09/11/2024 à 22:03, Daniel Gomez a écrit :
> On Sat Nov 9, 2024 at 11:35 AM CET, Christophe Leroy wrote:
>> To be on the safe side, try to set ro_after_init data section readonly
>> at the same time as rodata. If it fails it will likely fail again
>> later so let's cancel module loading while we still can do it.
>> If it doesn't fail, put it back to read-only, continue module loading
> 
> I think you mean put it back to rw?

Indeed

> 
>> and cross fingers so that it still works after module init. Then it
>> should in principle never fail so add a WARN_ON_ONCE() to get a big
>> fat warning in case it happens anyway.
> 
> I agree this is the best we can do. But I don't think there's any
> guarantee that we won't fail on the second try?

I think if it works once it will always work, see my response to patch 
2/3. But I added that WARN_ON_ONCE() so that if it doesn't at least we 
know it.