Hi, Johan!
On Tue, Jul 5, 2022 at 11:06 AM Johan Almbladh
<johan.almbladh@xxxxxxxxxxxxxxxxx> wrote:
>
> On Mon, Jul 4, 2022 at 10:22 AM Yauheni Kaliuta <ykaliuta@xxxxxxxxxx> wrote:
> >
> > Hi!
> >
> > On Fri, Jul 1, 2022 at 2:05 PM Yauheni Kaliuta <ykaliuta@xxxxxxxxxx> wrote:
> > > >>>>> On Thu, 30 Jun 2022 22:57:37 +0200, Daniel Borkmann wrote:
> > >
> > > > On 6/30/22 3:19 PM, Yauheni Kaliuta wrote:
> > > >> Hi!
> > > >> test_kmod.sh fails for hardened 2 check with
> > > >> test_bpf: #964 Staggered jumps: JMP_JA FAIL to select_runtime
> > > >> err=-524
> > > >> (-ERANGE during constant blinding)
> > > >> Did I miss something?
> > >
> > > > That could be expected if one of bpf_adj_delta_to_imm() / bpf_adj_delta_to_off()
> > > > fails given the targets go out of range.
> > >
> > > I believe that, but how to fix the test? It should not fail.
> > >
> > > > How do the generated insn look?
> > >
> > > The instruction when it fails is
> > >
> > > (gdb) p/x insn[0]
> > > $8 = {code = 0xb7, dst_reg = 0x0, src_reg = 0x0, off = 0x0, imm = 0x2aaa}
> > >
> > > And it's rewritten as
> > >
> > > (gdb) p rewritten
> > > $9 = 3
> > > (gdb) p/x insn_buff[0]
> > > $10 = {code = 0xb7, dst_reg = 0xb, src_reg = 0x0, off = 0x0, imm = 0x68ad0283}
> > > (gdb) p/x insn_buff[1]
> > > $11 = {code = 0xa7, dst_reg = 0xb, src_reg = 0x0, off = 0x0, imm = 0x68ad2829}
> > > (gdb) p/x insn_buff[2]
> > > $12 = {code = 0xbf, dst_reg = 0x0, src_reg = 0xb, off = 0x0, imm = 0x0}
> > >
> > > IIUC.
> > >
> >
> > Johan, what do you think?
>
> Hmm, I can take a look at it. What is the target arch?
>
It fails even on x86.
--
WBR, Yauheni
