Re: v5 of seccomp filter c/r patches

From	Daniel Borkmann <daniel@iogearbox.net>
Newsgroups	linux.kernel
Subject	Re: v5 of seccomp filter c/r patches
Date	2015-10-03 01:00 +0200
Message-ID	<qfht0-oF-23@gated-at.bofh.it> (permalink)
References	<qfbnA-cS-5@gated-at.bofh.it> <qffUd-6LS-1@gated-at.bofh.it> <qfhjk-de-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 10/03/2015 12:44 AM, Tycho Andersen wrote:
> On Fri, Oct 02, 2015 at 02:10:24PM -0700, Kees Cook wrote:
...
> Ok, how about,
>
> struct sock_filter insns[BPF_MAXINSNS];
> insn_cnt = ptrace(PTRACE_SECCOMP_GET_FILTER, pid, insns, i);

Would also be good that when the storage buffer (insns) is NULL,
it just returns you the number of sock_filter insns (or 0 when
nothing attached).

That would be consistent with classic socket filters (see
sk_get_filter()), and user space could allocate a specific
size instead of always passing in max insns.

> when asking for the ith filter? It returns either the number of
> instructions, -EINVAL if something was wrong (i, pid,
> CONFIG_CHECKPOINT_RESTORE isn't enabled). While it would always
> succeed now, if/when the underlying filter was not created from a bpf
> classic filter, we can return -EMEDIUMTYPE? (Suggestions welcome, I
> picked this mostly based on what sounds nice.)
>
> Tycho
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

v5 of seccomp filter c/r patches Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-02 18:30 +0200
  Re: v5 of seccomp filter c/r patches Kees Cook <keescook@chromium.org> - 2015-10-02 23:20 +0200
    Re: v5 of seccomp filter c/r patches Andy Lutomirski <luto@amacapital.net> - 2015-10-02 23:40 +0200
      Re: v5 of seccomp filter c/r patches Kees Cook <keescook@chromium.org> - 2015-10-03 00:10 +0200
        Re: v5 of seccomp filter c/r patches Andy Lutomirski <luto@amacapital.net> - 2015-10-03 00:20 +0200
      Re: v5 of seccomp filter c/r patches Andy Lutomirski <luto@amacapital.net> - 2015-10-03 00:10 +0200
      Re: v5 of seccomp filter c/r patches Kees Cook <keescook@chromium.org> - 2015-10-03 00:10 +0200
    Re: v5 of seccomp filter c/r patches Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-03 00:50 +0200
      Re: v5 of seccomp filter c/r patches Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-03 01:00 +0200
      Re: v5 of seccomp filter c/r patches Daniel Borkmann <daniel@iogearbox.net> - 2015-10-03 01:00 +0200
        Re: v5 of seccomp filter c/r patches Tycho Andersen <tycho.andersen@canonical.com> - 2015-10-03 01:00 +0200
        Re: v5 of seccomp filter c/r patches Kees Cook <keescook@chromium.org> - 2015-10-03 01:10 +0200
      Re: v5 of seccomp filter c/r patches Andy Lutomirski <luto@amacapital.net> - 2015-10-03 01:00 +0200

csiph-web