[PATCH v2 bpf-next 3/3] selftests/bpf: Add asm tests for pkt vs pkt_end comparison.

Alexei Starovoitov
2020-11-11T03:12:27Z

From: Alexei Starovoitov <ast@kernel.org>

Add few assembly tests for packet comparison.

Tested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
.../testing/selftests/bpf/verifier/ctx_skb.c | 42 +++++++++++++++++++
1 file changed, 42 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/ctx_skb.c b/tools/testing/selftests/bpf/verifier/ctx_skb.c
index 2e16b8e268f2..2022c0f2cd75 100644
--- a/tools/testing/selftests/bpf/verifier/ctx_skb.c
+++ b/tools/testing/selftests/bpf/verifier/ctx_skb.c
@@ -1089,3 +1089,45 @@
.errstr_unpriv = "R1 leaks addr",
.result = REJECT,
},
+{
+ "pkt > pkt_end taken check",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, // 0. r2 = *(u32 *)(r1 + data_end)
+ offsetof(struct __sk_buff, data_end)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, // 1. r4 = *(u32 *)(r1 + data)
+ offsetof(struct __sk_buff, data)),
+ BPF_MOV64_REG(BPF_REG_3, BPF_REG_4), // 2. r3 = r4
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 42), // 3. r3 += 42
+ BPF_MOV64_IMM(BPF_REG_1, 0), // 4. r1 = 0
+ BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_2, 2), // 5. if r3 > r2 goto 8
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 14), // 6. r4 += 14
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_4), // 7. r1 = r4
+ BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_2, 1), // 8. if r3 > r2 goto 10
+ BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1, 9), // 9. r2 = *(u8 *)(r1 + 9)
+ BPF_MOV64_IMM(BPF_REG_0, 0), // 10. r0 = 0
+ BPF_EXIT_INSN(), // 11. exit
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_SK_SKB,
+},
+{
+ "pkt_end < pkt taken check",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, // 0. r2 = *(u32 *)(r1 + data_end)
+ offsetof(struct __sk_buff, data_end)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, // 1. r4 = *(u32 *)(r1 + data)
+ offsetof(struct __sk_buff, data)),
+ BPF_MOV64_REG(BPF_REG_3, BPF_REG_4), // 2. r3 = r4
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 42), // 3. r3 += 42
+ BPF_MOV64_IMM(BPF_REG_1, 0), // 4. r1 = 0
+ BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_2, 2), // 5. if r3 > r2 goto 8
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 14), // 6. r4 += 14
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_4), // 7. r1 = r4
+ BPF_JMP_REG(BPF_JLT, BPF_REG_2, BPF_REG_3, 1), // 8. if r2 < r3 goto 10
+ BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_1, 9), // 9. r2 = *(u8 *)(r1 + 9)
+ BPF_MOV64_IMM(BPF_REG_0, 0), // 10. r0 = 0
+ BPF_EXIT_INSN(), // 11. exit
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_SK_SKB,
+},
--
2.24.1