On Fri, Sep 11, 2015 at 03:39:14PM +0200, Daniel Borkmann wrote: > On 09/11/2015 02:21 AM, Tycho Andersen wrote: > >This commit adds a way to dump eBPF programs. The initial implementation > >doesn't support maps, and therefore only allows dumping seccomp ebpf > >programs which themselves don't currently support maps. > > > >v2: don't export a prog_id for the filter > > > >Signed-off-by: Tycho Andersen <[email protected]> > >CC: Kees Cook <[email protected]> > >CC: Will Drewry <[email protected]> > >CC: Oleg Nesterov <[email protected]> > >CC: Andy Lutomirski <[email protected]> > >CC: Pavel Emelyanov <[email protected]> > >CC: Serge E. Hallyn <[email protected]> > >CC: Alexei Starovoitov <[email protected]> > >CC: Daniel Borkmann <[email protected]> > [...] > >diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > >index dc9b464..58ae9f4 100644 > >--- a/kernel/bpf/syscall.c > >+++ b/kernel/bpf/syscall.c > >@@ -586,6 +586,44 @@ free_prog: > > return err; > > } > > > >+static int bpf_prog_dump(union bpf_attr *attr, union bpf_attr __user *uattr) > >+{ > >+ int ufd = attr->prog_fd; > >+ struct fd f = fdget(ufd); > >+ struct bpf_prog *prog; > >+ int ret = -EINVAL; > >+ > >+ prog = get_prog(f); > >+ if (IS_ERR(prog)) > >+ return PTR_ERR(prog); > >+ > >+ /* For now, let's refuse to dump anything that isn't a seccomp program. > >+ * Other program types have support for maps, which our current dump > >+ * code doesn't support. > >+ */ > >+ if (prog->type != BPF_PROG_TYPE_SECCOMP) > >+ goto out; > > Yep, also when you start adding helper calls (next to map objects) you'd > need to undo kernel pointers that the verifier sets here.
Good point, I'll add that to the comment as well. Tycho -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
