selftests: bpf: add zero extend checks for ALU32 and/or/xor

Add three tests to test_verifier/basic_instr that make sure that the
high 32-bits of the destination register is cleared after an ALU32
and/or/xor.
Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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

@@ -132,3 +132,42 @@
 	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 	.result = ACCEPT,
 },
+{
+	"and32 reg zero extend check",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, -1),
+	BPF_MOV64_IMM(BPF_REG_2, -2),
+	BPF_ALU32_REG(BPF_AND, BPF_REG_0, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_RSH, BPF_REG_0, 32),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+	.retval = 0,
+},
+{
+	"or32 reg zero extend check",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, -1),
+	BPF_MOV64_IMM(BPF_REG_2, -2),
+	BPF_ALU32_REG(BPF_OR, BPF_REG_0, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_RSH, BPF_REG_0, 32),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+	.retval = 0,
+},
+{
+	"xor32 reg zero extend check",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_0, -1),
+	BPF_MOV64_IMM(BPF_REG_2, 0),
+	BPF_ALU32_REG(BPF_XOR, BPF_REG_0, BPF_REG_2),
+	BPF_ALU64_IMM(BPF_RSH, BPF_REG_0, 32),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+	.retval = 0,
+},