Re: bpf_probe_read and pagefaults


Hayden Livingston
 

I should have search. Short answer it fails and you're out of luck.

https://lists.iovisor.org/g/iovisor-dev/topic/accessing_user_memory_and/21386221

On Sun, Feb 16, 2020 at 9:29 PM Hayden Livingston
<halivingston@...> wrote:

I'm curios to know how bpf_probe_read is able to read user-mode memory
in the face of page faulting.

I know in the helper it disables page faulting, but what does that mean?

If the memory the probe is trying to read is paged out then how does
my probe work?

It seems bpf_probe_read is best effort then. Is that true?

Join iovisor-dev@lists.iovisor.org to automatically receive all group messages.