selftests/bpf: Add a testcase for 64-bit bounds propagation issue.

./test_progs-no_alu32 -vv -t twfw

Before the 64-bit_into_32-bit fix:
19: (25) if r1 > 0x3f goto pc+6
 R1_w=inv(id=0,umax_value=63,var_off=(0x0; 0xff),s32_max_value=255,u32_max_value=255)

and eventually:

invalid access to map value, value_size=8 off=7 size=8
R6 max value is outside of the allowed memory range
libbpf: failed to load object 'no_alu32/twfw.o'

After the fix:
19: (25) if r1 > 0x3f goto pc+6
 R1_w=inv(id=0,umax_value=63,var_off=(0x0; 0x3f))

verif_twfw:OK

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211101222153.78759-3-alexei.starovoitov@gmail.com

1 files changed, 5 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
index 867349e4ed9e..27f5d8ea7964 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c
@@ -202,3 +202,8 @@ void test_verif_scale_seg6_loop()
 {
 	scale_test("test_seg6_loop.o", BPF_PROG_TYPE_LWT_SEG6LOCAL, false);
 }
+
+void test_verif_twfw()
+{
+	scale_test("twfw.o", BPF_PROG_TYPE_CGROUP_SKB, false);
+}