[PATCH bpf-next v2 2/2] selftests/bpf: check if verifier tracks dst_reg bound for BPF_MOD

From: Xu Kuohai
Date: Thu Mar 23 2023 - 11:59:45 EST


From: Xu Kuohai <xukuohai@xxxxxxxxxx>

Test cases to check if verifier tracks dst_reg bound for BPF_MOD.

Signed-off-by: Xu Kuohai <xukuohai@xxxxxxxxxx>
---
tools/testing/selftests/bpf/verifier/mod.c | 320 +++++++++++++++++++++
1 file changed, 320 insertions(+)
create mode 100644 tools/testing/selftests/bpf/verifier/mod.c

diff --git a/tools/testing/selftests/bpf/verifier/mod.c b/tools/testing/selftests/bpf/verifier/mod.c
new file mode 100644
index 000000000000..3aec856d5c9f
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/mod.c
@@ -0,0 +1,320 @@
+{
+ "mod64 positive imm",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_ALU64_IMM(BPF_MOD, BPF_REG_0, 1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 0 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod64 positive reg",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_MOV64_IMM(BPF_REG_1, 1),
+ BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 0 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod64 zero",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 0 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod64 negative 1",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_MOV64_IMM(BPF_REG_1, -1),
+ BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 1 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ .retval = 1,
+},
+{
+ "mod64 negative 2",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, -4),
+ BPF_MOV32_IMM(BPF_REG_1, 5),
+ BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 2 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ .retval = 2,
+},
+{
+ "mod64 negative 3",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, -4),
+ BPF_MOV32_IMM(BPF_REG_1, -5),
+ BPF_ALU64_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 1 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ .retval = 1,
+},
+{
+ "mod64 variable dividend cross signed boundary, with JLT",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 11),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_LD_IMM64(BPF_REG_0, 0x7fffffffffffff10),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+ BPF_LD_IMM64(BPF_REG_0, 0x80000000000000ff),
+ BPF_ALU64_REG(BPF_MOD, BPF_REG_1, BPF_REG_0),
+
+ BPF_LD_IMM64(BPF_REG_0, 0x8000000000000000),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 unsigned range is [0x7fffffffffffff10, 0x800000000000000f] */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod64 variable dividend cross signed boundary, with JSLT",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 11),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_LD_IMM64(BPF_REG_0, 0x7fffffffffffff10),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+ BPF_LD_IMM64(BPF_REG_0, 0x80000000000000ff),
+ BPF_ALU64_REG(BPF_MOD, BPF_REG_1, BPF_REG_0),
+
+ BPF_LD_IMM64(BPF_REG_0, 0x8000000000000000),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 signed range is [S64_MIN, S64_MAX] */
+ BPF_JMP_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "BPF program is too large.",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod32 positive imm",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ BPF_ALU32_IMM(BPF_MOD, BPF_REG_0, 1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 0 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod32 positive reg",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ BPF_MOV32_IMM(BPF_REG_1, 1),
+ BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 0 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod32 zero",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ BPF_MOV32_IMM(BPF_REG_1, 0),
+ BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 0 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod32 negative 1",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, 1),
+ BPF_MOV32_IMM(BPF_REG_1, -1),
+ BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 1 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ .retval = 1,
+},
+{
+ "mod32 negative 2",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, -4),
+ BPF_MOV32_IMM(BPF_REG_1, 5),
+ BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 2 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ .retval = 2,
+},
+{
+ "mod32 negative 3",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, -4),
+ BPF_MOV32_IMM(BPF_REG_1, -5),
+ BPF_ALU32_REG(BPF_MOD, BPF_REG_0, BPF_REG_1),
+
+ BPF_MOV64_IMM(BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ /* r0 = 1 */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_0, -2),
+
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ .retval = 1,
+},
+{
+ "mod32 variable dividend cross signed boundary, with JLT",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 7),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0x7fffff10),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+ BPF_ALU32_IMM(BPF_MOD, BPF_REG_1, 0x800000ff),
+
+ BPF_MOV32_IMM(BPF_REG_0, 0x80000000),
+ BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 unsigned 32-bit range is [0x7fffff10, 0x8000000f] */
+ BPF_JMP32_REG(BPF_JLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "mod32 variable dividend cross signed boundary, with JSLT",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+ offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+ offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 7),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0x7fffff10),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+ BPF_ALU32_IMM(BPF_MOD, BPF_REG_1, 0x800000ff),
+
+ BPF_MOV32_IMM(BPF_REG_0, 0x80000000),
+ BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 signed 32-bit range is [S32_MIN, S32_MAX] */
+ BPF_JMP32_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "BPF program is too large.",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
--
2.30.2