On Thu, 2 Nov 2017 17:14:00 +0100, Arnd Bergmann wrote:
> On Thu, Nov 2, 2017 at 4:59 PM, Alexei Starovoitov wrote:
> > On Thu, Nov 02, 2017 at 12:05:52PM +0100, Arnd Bergmann wrote:
> >> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> >> index 750aff880ecb..debb60ad08ee 100644
> >> --- a/kernel/bpf/verifier.c
> >> +++ b/kernel/bpf/verifier.c
> >> @@ -4447,6 +4447,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
> >> struct bpf_verifer_log *log;
> >> int ret = -EINVAL;
> >>
> >> + /* no program is valid */
> >> + if (ARRAY_SIZE(bpf_verifier_ops) == 0)
> >> + return -EINVAL;
> >
> > sorry I don't see how bpf_verifier_ops can be empty.
> > Did you mix it up with your previous patch when you made bpf_analyzer_ops empty?
>
> I confused the two a couple of times while creating the patches, but
> I'm still fairly
> sure I got it right in the end:
>
> bpf_verifier_ops is an array that gets generated by including linux/bpf_types.h.
> That file has two kinds of entries:
>
> - BPF_MAP_TYPE() entries are left out, as that macro is defined to an
> empty string
> here.
>
> - BPF_PROG_TYPE() entries are conditional depending on CONFIG_NET and
> CONFIG_BPF_EVENTS. In the configuration that produces the warning,
> both are disabled.
Right. My preferred fix was to add a NULL entry to the table so it's
never empty, but this is OK too. Thanks!
From 1582971529989026708@xxx Thu Nov 02 16:14:51 +0000 2017
X-GM-THRID: 1582952280708618442
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread