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

From: Yu, Yu-cheng
Date: Mon Dec 07 2020 - 12:12:40 EST


On 12/7/2020 8:36 AM, Borislav Petkov wrote:
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.


Thanks for your feedback. I will improve the commit logs.

--
Yu-cheng