Re: [PATCH v15 07/26] x86/mm: Remove _PAGE_DIRTY_HW from kernel RO pages

Borislav Petkov
2020-12-07T16:37:28Z

On Tue, Nov 10, 2020 at 08:21:52AM -0800, Yu-cheng Yu wrote:
> Kernel read-only PTEs are setup as _PAGE_DIRTY_HW. Since these become
> shadow stack PTEs, remove the dirty bit.

This commit message is laconic to say the least. You need to start
explaining what you're doing because everytime I look at a patch of
yours, I'm always grepping the SDM and looking forward in the patchset,
trying to rhyme up what that is all about.

Like for this one. I had to fast-forward to the next patch where all
that is explained. But this is not how review works - each patch's
commit message needs to be understandable on its own because when
they land upstream, they're not in a patchset like here. And review
should be done in the order the patches are numbered - not by jumping
back'n'forth.

So please think of the readers of your patches when writing those commit
messages. Latter are *not* write-only and not unimportant.

And those readers haven't spent copious amounts of time on the
technology so being more verbose and explaining things is a Good
Thing(tm). Don't worry about explaining too much - better too much than
too little.

And last but not least, having understandable and properly written
commit messages increases the chances of your patches landing upstream
considerably.

Thx.

--
Regards/Gruss,
Boris.