Re: [PATCH v2] arm: eBPF JIT compiler

From: Kees Cook
Date: Fri Jul 07 2017 - 00:42:48 EST

On Wed, Jul 5, 2017 at 8:49 PM, Shubham Bansal
<illusionist.neo@xxxxxxxxx> wrote:
> Hi Kees,
> Problem is my ARM machine don't have clang and iproute2 which is
> keeping me from testing the bpf tail calls.
> You should do the following to test it,.
> 1. tools/testing/selftests/bpf/
> 2. make
> 3. sudo ./test_progs
> And, before testing, you have to do "make headers_install".
> These tests are for tail calls with the attached patch. If its too
> much work, Can you please upload your arm image so that I can test it?
> I just need a good machine.

I've got all this set up now, and it faults during the test:

Unable to handle kernel NULL pointer dereference at virtual address 00000008
CPU: 0 PID: 1922 Comm: test_progs Not tainted 4.12.0+ #60
PC is at __htab_map_lookup_elem+0x54/0x1f4

I'll see if I can send you this disk image...


Kees Cook
Pixel Security