On Thu, Feb 08, 2024 at 08:47:37AM +0100, Marco Elver wrote:
> That's a good question, and I don't have the answer to that - maybe we
> need to ask Linus then.
Right, before that, lemme put my user hat on.
> We could argue that to improve memory safety of the Linux kernel more
> rapidly, enablement of KFENCE by default (on the "big" architectures
> like x86) might actually be a net benefit at ~zero performance
> overhead and the cost of 2 MiB of RAM (default config).
What about its benefit?
I haven't seen a bug fix saying "found by KFENCE" or so but that doesn't
mean a whole lot.
The more important question is would I, as a user, have a way of
reporting such issues, would those issues be taken seriously and so on.
We have a whole manual about it:
Documentation/admin-guide/reporting-issues.rst
maybe the kfence splat would have a pointer to that? Perhaps...
Personally, I don't mind running it if it really is a ~zero overhead
KASAN replacement. Maybe as a preliminary step we should enable it on
devs machines who know how to report such things.
/me goes and enables it in a guest...
[ 0.074294] kfence: initialized - using 2097152 bytes for 255 objects at
0xffff88807d600000-0xffff88807d800000
Guest looks ok to me, no reports.
What now? :-)
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
