Re: [PATCH v9 03/15] kallsyms: Hide layout

Borislav Petkov
2021-12-30T22:36:09Z

On Thu, Dec 23, 2021 at 01:21:57AM +0100, Alexander Lobakin wrote:
> Subject: Re: [PATCH v9 03/15] kallsyms: Hide layout

That title is kinda laconic...

> From: Kristen Carlson Accardi <kristen@linux.intel.com>
>
> This patch makes /proc/kallsyms display in a random order, rather

Avoid having "This patch" or "This commit" in the commit message. It is
tautologically useless.

Also, do

$ git grep 'This patch' Documentation/process

for more details.

> than sorted by address in order to hide the newly randomized address
> layout.

Sorted by address?

My /proc/kallsyms says

$ awk '{ print $1 }' /proc/kallsyms | uniq -c
119086 0000000000000000

so all the addresses are 0. Aha, and when I list them as root, only then
I see non-null addresses.

So why do we that patch at all?

> alobakin:
> Don't depend FG-KASLR and always do that for unpriviledged accesses

Unknown word [unpriviledged] in commit message, suggestions:
['unprivileged', 'underprivileged', 'privileged']

> as suggested by several folks.
> Also, introduce and use a shuffle_array() macro which shuffles an
> array using Fisher-Yates.

Fisher-Yates what?

/me goes and looks at the wikipedia article.

Aha, a Fisher-Yates shuffle algoithm.

Don't be afraid to explain more in your commit messages and make them
more reader-friendly.

> We'll make use of it several more times
> later on.

Not important for this commit.

...

--
Regards/Gruss,
Boris.