selftests/bpf: Test ARG_PTR_TO_LONG arg type

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@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/verifier/int_ptr.c

+{
+	"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,
+},