[PATCH v3 bpf-next 19/21] selftests/bpf: Test ARG_PTR_TO_LONG arg type

From: Andrey Ignatov
Date: Fri Apr 05 2019 - 15:37:11 EST


Test that verifier handles new argument types properly, including
uninitialized or partially initialized value, misaligned stack access,
etc.

Example of output:
#456/p ARG_PTR_TO_LONG uninitialized OK
#457/p ARG_PTR_TO_LONG half-uninitialized OK
#458/p ARG_PTR_TO_LONG misaligned OK
#459/p ARG_PTR_TO_LONG size < sizeof(long) OK
#460/p ARG_PTR_TO_LONG initialized OK

Signed-off-by: Andrey Ignatov <rdna@xxxxxx>
---
.../testing/selftests/bpf/verifier/int_ptr.c | 160 ++++++++++++++++++
1 file changed, 160 insertions(+)
create mode 100644 tools/testing/selftests/bpf/verifier/int_ptr.c

diff --git a/tools/testing/selftests/bpf/verifier/int_ptr.c b/tools/testing/selftests/bpf/verifier/int_ptr.c
new file mode 100644
index 000000000000..ca3b4729df66
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/int_ptr.c
@@ -0,0 +1,160 @@
+{
+ "ARG_PTR_TO_LONG uninitialized",
+ .insns = {
+ /* bpf_strtoul arg1 (buf) */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+
+ /* bpf_strtoul arg2 (buf_len) */
+ BPF_MOV64_IMM(BPF_REG_2, 4),
+
+ /* bpf_strtoul arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+
+ /* bpf_strtoul arg4 (res) */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
+
+ /* bpf_strtoul() */
+ BPF_EMIT_CALL(BPF_FUNC_strtoul),
+
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL,
+ .errstr = "invalid indirect read from stack off -16+0 size 8",
+},
+{
+ "ARG_PTR_TO_LONG half-uninitialized",
+ .insns = {
+ /* bpf_strtoul arg1 (buf) */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+
+ /* bpf_strtoul arg2 (buf_len) */
+ BPF_MOV64_IMM(BPF_REG_2, 4),
+
+ /* bpf_strtoul arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+
+ /* bpf_strtoul arg4 (res) */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
+
+ /* bpf_strtoul() */
+ BPF_EMIT_CALL(BPF_FUNC_strtoul),
+
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL,
+ .errstr = "invalid indirect read from stack off -16+4 size 8",
+},
+{
+ "ARG_PTR_TO_LONG misaligned",
+ .insns = {
+ /* bpf_strtoul arg1 (buf) */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+
+ /* bpf_strtoul arg2 (buf_len) */
+ BPF_MOV64_IMM(BPF_REG_2, 4),
+
+ /* bpf_strtoul arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+
+ /* bpf_strtoul arg4 (res) */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -12),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 4),
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
+
+ /* bpf_strtoul() */
+ BPF_EMIT_CALL(BPF_FUNC_strtoul),
+
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL,
+ .errstr = "misaligned stack access off (0x0; 0x0)+-20+0 size 8",
+},
+{
+ "ARG_PTR_TO_LONG size < sizeof(long)",
+ .insns = {
+ /* bpf_strtoul arg1 (buf) */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -16),
+ BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+
+ /* bpf_strtoul arg2 (buf_len) */
+ BPF_MOV64_IMM(BPF_REG_2, 4),
+
+ /* bpf_strtoul arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+
+ /* bpf_strtoul arg4 (res) */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 12),
+ BPF_STX_MEM(BPF_W, BPF_REG_7, BPF_REG_0, 0),
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
+
+ /* bpf_strtoul() */
+ BPF_EMIT_CALL(BPF_FUNC_strtoul),
+
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL,
+ .errstr = "invalid stack type R4 off=-4 access_size=8",
+},
+{
+ "ARG_PTR_TO_LONG initialized",
+ .insns = {
+ /* bpf_strtoul arg1 (buf) */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ BPF_MOV64_IMM(BPF_REG_0, 0x00303036),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
+
+ /* bpf_strtoul arg2 (buf_len) */
+ BPF_MOV64_IMM(BPF_REG_2, 4),
+
+ /* bpf_strtoul arg3 (flags) */
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+
+ /* bpf_strtoul arg4 (res) */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0),
+ BPF_MOV64_REG(BPF_REG_4, BPF_REG_7),
+
+ /* bpf_strtoul() */
+ BPF_EMIT_CALL(BPF_FUNC_strtoul),
+
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SYSCTL,
+},
--
2.17.1