Re: [PATCH v3 0/2] Fix kallsyms with CONFIG_LTO_CLANG

[Kees Cook]

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?

-- 
Kees Cook