tools/bpf: add a verifier test case for bpf_get_stack helper and ARSH

The test_verifier already has a few ARSH test cases.
This patch adds a new test case which takes advantage of newly
improved verifier behavior for bpf_get_stack and ARSH.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/test_verifier.c

@@ -11680,6 +11680,51 @@ static struct bpf_test tests[] = {
 		.errstr = "BPF_XADD stores into R2 packet",
 		.prog_type = BPF_PROG_TYPE_XDP,
 	},
+	{
+		"bpf_get_stack return R0 within range",
+		.insns = {
+			BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+			BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+			BPF_LD_MAP_FD(BPF_REG_1, 0),
+			BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				     BPF_FUNC_map_lookup_elem),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 28),
+			BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
+			BPF_MOV64_IMM(BPF_REG_9, sizeof(struct test_val)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+			BPF_MOV64_IMM(BPF_REG_3, sizeof(struct test_val)),
+			BPF_MOV64_IMM(BPF_REG_4, 256),
+			BPF_EMIT_CALL(BPF_FUNC_get_stack),
+			BPF_MOV64_IMM(BPF_REG_1, 0),
+			BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_8, 32),
+			BPF_ALU64_IMM(BPF_ARSH, BPF_REG_8, 32),
+			BPF_JMP_REG(BPF_JSLT, BPF_REG_1, BPF_REG_8, 16),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_9, BPF_REG_8),
+			BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_8),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_9),
+			BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 32),
+			BPF_ALU64_IMM(BPF_ARSH, BPF_REG_1, 32),
+			BPF_MOV64_REG(BPF_REG_3, BPF_REG_2),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_3, BPF_REG_1),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+			BPF_MOV64_IMM(BPF_REG_5, sizeof(struct test_val)),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_5),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_1, 4),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+			BPF_MOV64_REG(BPF_REG_3, BPF_REG_9),
+			BPF_MOV64_IMM(BPF_REG_4, 0),
+			BPF_EMIT_CALL(BPF_FUNC_get_stack),
+			BPF_EXIT_INSN(),
+		},
+		.fixup_map2 = { 4 },
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	},
 };
 
 static int probe_filter_length(const struct bpf_insn *fp)