Re: [PATCH bpf-next 4/4] bpf: export bpf_jit_current

From: Lorenz Bauer
Date: Tue Sep 28 2021 - 05:02:57 EST

On Mon, 27 Sept 2021 at 15:01, Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> wrote:
> I find exposing stats via system configuration variables a bit
> unexpected. Not sure if there is any example today that we're following.
> Maybe an entry under /sys/kernel/debug would be a better fit?
> That way we don't have to commit to a sysctl that might go away if we
> start charging JIT allocs against memory cgroup quota.

I had a look around, there are no other obvious places in debugfs or
proc where we already have bpf info exposed. It currently all goes via

There are examples of readonly sysctls:
$ sudo find /proc/sys -perm 0444 | wc -l

There are no examples of sysctls with mode 0400 however:
$ sudo find /proc/sys -perm 0400 | wc -l

I find it kind of weird that the bpf sysctls are so tightly locked
down (CAP_SYS_ADMIN && root) even for reading. Maybe something I can

Lorenz Bauer | Systems Engineer
6th Floor, County Hall/The Riverside Building, SE1 7PB, UK