bpf/tests: Add JMP tests with small offsets

This patch adds a set of tests for JMP to verify that the JITed jump
offset is calculated correctly. We pretend that the verifier has inserted
any zero extensions to make the jump-over operations JIT to one
instruction each, in order to control the exact JITed jump offset.

Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210914091842.4186267-10-johan.almbladh@anyfinetworks.com
This commit is contained in:
Johan Almbladh 2021-09-14 11:18:37 +02:00 committed by Daniel Borkmann
parent 27cc6dac6e
commit d4ff9ee2dc

View File

@ -10709,6 +10709,77 @@ static struct bpf_test tests[] = {
.fill_helper = bpf_fill_jmp32_jsle_reg,
.nr_testruns = NR_PATTERN_RUNS,
},
/* Short relative jumps */
{
"Short relative jump: offset=0",
.u.insns_int = {
BPF_ALU64_IMM(BPF_MOV, R0, 0),
BPF_JMP_IMM(BPF_JEQ, R0, 0, 0),
BPF_EXIT_INSN(),
BPF_ALU32_IMM(BPF_MOV, R0, -1),
},
INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
{ },
{ { 0, 0 } },
},
{
"Short relative jump: offset=1",
.u.insns_int = {
BPF_ALU64_IMM(BPF_MOV, R0, 0),
BPF_JMP_IMM(BPF_JEQ, R0, 0, 1),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_EXIT_INSN(),
BPF_ALU32_IMM(BPF_MOV, R0, -1),
},
INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
{ },
{ { 0, 0 } },
},
{
"Short relative jump: offset=2",
.u.insns_int = {
BPF_ALU64_IMM(BPF_MOV, R0, 0),
BPF_JMP_IMM(BPF_JEQ, R0, 0, 2),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_EXIT_INSN(),
BPF_ALU32_IMM(BPF_MOV, R0, -1),
},
INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
{ },
{ { 0, 0 } },
},
{
"Short relative jump: offset=3",
.u.insns_int = {
BPF_ALU64_IMM(BPF_MOV, R0, 0),
BPF_JMP_IMM(BPF_JEQ, R0, 0, 3),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_EXIT_INSN(),
BPF_ALU32_IMM(BPF_MOV, R0, -1),
},
INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
{ },
{ { 0, 0 } },
},
{
"Short relative jump: offset=4",
.u.insns_int = {
BPF_ALU64_IMM(BPF_MOV, R0, 0),
BPF_JMP_IMM(BPF_JEQ, R0, 0, 4),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_ALU32_IMM(BPF_ADD, R0, 1),
BPF_EXIT_INSN(),
BPF_ALU32_IMM(BPF_MOV, R0, -1),
},
INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
{ },
{ { 0, 0 } },
},
/* Staggered jump sequences, immediate */
{
"Staggered jumps: JMP_JA",