Re: [PATCH v3 0/2] Fix kallsyms with CONFIG_LTO_CLANG
From: Song Liu
Date: Thu Aug 15 2024 - 12:09:20 EST
Hi Kees,
> On Aug 15, 2024, at 9:05 AM, Kees Cook <kees@xxxxxxxxxx> wrote:
>
> On Mon, Aug 12, 2024 at 06:13:22PM +0000, Song Liu wrote:
>> Hi Luis,
>>
>>> On Aug 12, 2024, at 9:57 AM, Luis Chamberlain <mcgrof@xxxxxxxxxx> wrote:
>>>
>>> On Mon, Aug 12, 2024 at 09:21:02AM -0700, Song Liu wrote:
>>>> Hi folks,
>>>>
>>>> Do we have more concerns and/or suggestions with this set? If not,
>>>> what would be the next step for it?
>>>
>>> I'm all for simplifying things, and this does just that, however,
>>> I'm not the one you need to convince, the folks who added the original
>>> hacks should provide their Reviewed-by / Tested-by not just for CONFIG_LTO_CLANG
>>> but also given this provides an alternative fix, don't we want to invert
>>> the order so we don't regress CONFIG_LTO_CLANG ? And shouldn't the patches
>>> also have their respective Fixes tag?
>>
>> kallsyms has got quite a few changes/improvements in the past few years:
>>
>> 1. Sami added logic to trim LTO hash in 2021 [1];
>> 2. Zhen added logic to sort kallsyms in 2022 [2];
>> 3. Yonghong changed cleanup_symbol_name() in 2023 [3].
>>
>> In this set, we are undoing 1 and 3, but we keep 2. Shall we point Fixes
>> tag to [1] or [3]? The patch won't apply to a kernel with only [1]
>> (without [2] and [3]); while this set is not just fixing [3]. So I think
>> it is not accurate either way. OTOH, the combination of CONFIG_LTO_CLANG
>> and livepatching is probably not used by a lot of users, so I guess we
>> are OK without Fixes tags? I personally don't have a strong preference
>> either way.
>>
>> It is not necessary to invert the order of the two patches. Only applying
>> one of the two patches won't cause more issues than what we have today.
>
> Which tree should carry this series?
I am looking through the commit log on kernel/kallsyms.c _just now_, and
found you took most of recent patches for kallsyms. Could you please take
this set as well?
Thanks,
Song