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?
--
WBR, Yauheni
