bpf: add mod default A and X test cases

When running "mod X" operation, if X is 0 the filter has to be halt.
Add new test cases to cover A = A mod X if X is 0, and A = A mod 1.

CC: Xi Wang <xi.wang@gmail.com>
CC: Zi Shen Lim <zlim.lnx@gmail.com>
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Zi Shen Lim <zlim.lnx@gmail.com>
Acked-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index d137739..10cd186 100644 (file)
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -5055,6 +5055,36 @@ static struct bpf_test tests[] = {
                {},
                { {0x1, 0x0 } },
        },
+       {
+               "MOD default X",
+               .u.insns = {
+                       /*
+                        * A = 0x42
+                        * A = A mod X ; this halt the filter execution if X is 0
+                        * ret 0x42
+                        */
+                       BPF_STMT(BPF_LD | BPF_IMM, 0x42),
+                       BPF_STMT(BPF_ALU | BPF_MOD | BPF_X, 0),
+                       BPF_STMT(BPF_RET | BPF_K, 0x42),
+               },
+               CLASSIC | FLAG_NO_DATA,
+               {},
+               { {0x1, 0x0 } },
+       },
+       {
+               "MOD default A",
+               .u.insns = {
+                       /*
+                        * A = A mod 1
+                        * ret A
+                        */
+                       BPF_STMT(BPF_ALU | BPF_MOD | BPF_K, 0x1),
+                       BPF_STMT(BPF_RET | BPF_A, 0x0),
+               },
+               CLASSIC | FLAG_NO_DATA,
+               {},
+               { {0x1, 0x0 } },
+       },
        {
                "JMP EQ default A",
                .u.insns = {