Hi, Daniel!
>>>>> 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.
--
WBR,
Yauheni Kaliuta
