Re: [PATCH 1/3] init: Declare rodata_enabled and mark_rodata_ro() at all time

[Christophe Leroy]

Le 30/01/2024 à 21:27, Luis Chamberlain a écrit :
> On Tue, Jan 30, 2024 at 06:48:11PM +0100, Marek Szyprowski wrote:
>> Dear All,
>>
>> On 30.01.2024 12:03, Christophe Leroy wrote:
>>> Le 30/01/2024 à 10:16, Chen-Yu Tsai a écrit :
>>>> [Vous ne recevez pas souvent de courriers de wenst@xxxxxxxxxxxx. D?couvrez pourquoi ceci est important ? https://aka.ms/LearnAboutSenderIdentification ]
>>>>
>>>> On Mon, Jan 29, 2024 at 12:09:50PM -0800, Luis Chamberlain wrote:
>>>>> On Thu, Dec 21, 2023 at 10:02:46AM +0100, Christophe Leroy wrote:
>>>>>> Declaring rodata_enabled and mark_rodata_ro() at all time
>>>>>> helps removing related #ifdefery in C files.
>>>>>>
>>>>>> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
>>>>> Very nice cleanup, thanks!, applied and pushed
>>>>>
>>>>>      Luis
>>>> On next-20240130, which has your modules-next branch, and thus this
>>>> series and the other "module: Use set_memory_rox()" series applied,
>>>> my kernel crashes in some very weird way. Reverting your branch
>>>> makes the crash go away.
>>>>
>>>> I thought I'd report it right away. Maybe you folks would know what's
>>>> happening here? This is on arm64.
>>> That's strange, it seems to bug in module_bug_finalize() which is
>>> _before_ calls to module_enable_ro() and such.
>>>
>>> Can you try to revert the 6 patches one by one to see which one
>>> introduces the problem ?
>>>
>>> In reality, only patch 677bfb9db8a3 really change things. Other ones are
>>> more on less only cleanup.
>>
>> I've also run into this issue with today's (20240130) linux-next on my
>> test farm. The issue is not fully reproducible, so it was a bit hard to
>> bisect it automatically. I've spent some time on manual testing and it
>> looks that reverting the following 2 commits on top of linux-next fixes
>> the problem:
>>
>> 65929884f868 ("modules: Remove #ifdef CONFIG_STRICT_MODULE_RWX around
>> rodata_enabled")
>> 677bfb9db8a3 ("module: Don't ignore errors from set_memory_XX()")
>>
>> This in fact means that commit 677bfb9db8a3 is responsible for this
>> regression, as 65929884f868 has to be reverted only because the latter
>> depends on it. Let me know what I can do to help debugging this issue.
> 
> Thanks for the bisect, I've reset my tree to commit
> 3559ad395bf02 ("module: Change module_enable_{nx/x/ro}() to more
> explicit names") for now then, so to remove those commits.
> 

The problem being identified in commit 677bfb9db8a3 ("module: Don't 
ignore errors from set_memory_XX()"), you can keep/re-apply the series 
[PATCH 1/3] init: Declare rodata_enabled and mark_rodata_ro() at all time.

Christophe