On Wed, 7 Nov 2018 12:54:54 +0000 "Ananyev, Konstantin" <konstantin.anan...@intel.com> wrote:
> > -----Original Message----- > > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Stephen Hemminger > > Sent: Tuesday, November 6, 2018 9:49 PM > > To: dev@dpdk.org > > Cc: Stephen Hemminger <step...@networkplumber.org> > > Subject: [dpdk-dev] [RFC 3/5] bpf: fix validation of eal_divmod > > > > Coverity spotted self assignment in BPF eval_divmod. > > Yep, there is one. > As I remember I have to add it because one of old versions > of compiler (clang???) complained about 'variable being used uninitialized'. > > > This looks like a bug where the incoming source register > > should have been used instead. > > Nope, that's a wrong guess. > We shouldn't do it here. > Konstantin > > > > > Coverity issue: 302850 > > Fixes: 8021917293d0 ("bpf: add extra validation for input BPF program") > > Signed-off-by: Stephen Hemminger <step...@networkplumber.org> > > --- > > lib/librte_bpf/bpf_validate.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/lib/librte_bpf/bpf_validate.c b/lib/librte_bpf/bpf_validate.c > > index 83983efc4e5c..b768f72c4c02 100644 > > --- a/lib/librte_bpf/bpf_validate.c > > +++ b/lib/librte_bpf/bpf_validate.c > > @@ -512,7 +512,7 @@ eval_divmod(uint32_t op, struct bpf_reg_val *rd, struct > > bpf_reg_val *rs, > > if (op == BPF_MOD) > > rd->u.max = RTE_MIN(rd->u.max, rs->u.max - 1); > > else > > - rd->u.max = rd->u.max; > > + rd->u.max = rs->u.max; > > rd->u.min = 0; > > } > > > > -- > > 2.17.1 > Well it was being used unintialized, your trick of self assignment fooled clang but did not fool Coverity. What does the other BPF validator do?
