lkml.org 
[lkml]   [2022]   [Jul]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC PATCH bpf-next 0/4] bpf_panic() helper
On Mon, Jul 11, 2022 at 10:32:16AM +0200, Artem Savkov wrote:
> eBPF is often used for kernel debugging, and one of the widely used and
> powerful debugging techniques is post-mortem debugging with a full memory dump.
> Triggering a panic at exactly the right moment allows the user to get such a
> dump and thus a better view at the system's state. This patchset adds
> bpf_panic() helper to do exactly that.

FWIW I was asked for such helper some time ago from Daniel Vacek, cc-ed

jirka

>
> I realize that even though there are multiple guards present, a helper like
> this is contrary to BPF being "safe", so this is sent as RFC to have a
> discussion on whether adding destructive capabilities is deemed acceptable.
>
> Artem Savkov (4):
> bpf: add a sysctl to enable destructive bpf helpers
> bpf: add BPF_F_DESTRUCTIVE flag for BPF_PROG_LOAD
> bpf: add bpf_panic() helper
> selftests/bpf: bpf_panic selftest
>
> include/linux/bpf.h | 8 +
> include/uapi/linux/bpf.h | 13 ++
> kernel/bpf/core.c | 1 +
> kernel/bpf/helpers.c | 13 ++
> kernel/bpf/syscall.c | 33 +++-
> kernel/bpf/verifier.c | 7 +
> kernel/trace/bpf_trace.c | 2 +
> tools/include/uapi/linux/bpf.h | 13 ++
> .../selftests/bpf/prog_tests/bpf_panic.c | 144 ++++++++++++++++++
> 9 files changed, 233 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/bpf_panic.c
>
> --
> 2.35.3
>

\
 
 \ /
  Last update: 2022-07-11 13:24    [W:0.112 / U:1.200 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site