bpf: add couple of test cases for div/mod by zero

Add couple of missing test cases for eBPF div/mod by zero to the
new test_verifier prog runtime feature. Also one for an empty prog
and only exit.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 87 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 6c22edb1f006..efca10de64e9 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -102,6 +102,93 @@ static struct bpf_test tests[] = {
                 .retval = -3,
         },
         {
+                "DIV32 by 0, zero check 1",
+                .insns = {
+                        BPF_MOV32_IMM(BPF_REG_0, 42),
+                        BPF_MOV32_IMM(BPF_REG_1, 0),
+                        BPF_MOV32_IMM(BPF_REG_2, 1),
+                        BPF_ALU32_REG(BPF_DIV, BPF_REG_2, BPF_REG_1),
+                        BPF_EXIT_INSN(),
+                },
+                .result = ACCEPT,
+                .retval = 0,
+        },
+        {
+                "DIV32 by 0, zero check 2",
+                .insns = {
+                        BPF_MOV32_IMM(BPF_REG_0, 42),
+                        BPF_LD_IMM64(BPF_REG_1, 0xffffffff00000000LL),
+                        BPF_MOV32_IMM(BPF_REG_2, 1),
+                        BPF_ALU32_REG(BPF_DIV, BPF_REG_2, BPF_REG_1),
+                        BPF_EXIT_INSN(),
+                },
+                .result = ACCEPT,
+                .retval = 0,
+        },
+        {
+                "DIV64 by 0, zero check",
+                .insns = {
+                        BPF_MOV32_IMM(BPF_REG_0, 42),
+                        BPF_MOV32_IMM(BPF_REG_1, 0),
+                        BPF_MOV32_IMM(BPF_REG_2, 1),
+                        BPF_ALU64_REG(BPF_DIV, BPF_REG_2, BPF_REG_1),
+                        BPF_EXIT_INSN(),
+                },
+                .result = ACCEPT,
+                .retval = 0,
+        },
+        {
+                "MOD32 by 0, zero check 1",
+                .insns = {
+                        BPF_MOV32_IMM(BPF_REG_0, 42),
+                        BPF_MOV32_IMM(BPF_REG_1, 0),
+                        BPF_MOV32_IMM(BPF_REG_2, 1),
+                        BPF_ALU32_REG(BPF_MOD, BPF_REG_2, BPF_REG_1),
+                        BPF_EXIT_INSN(),
+                },
+                .result = ACCEPT,
+                .retval = 0,
+        },
+        {
+                "MOD32 by 0, zero check 2",
+                .insns = {
+                        BPF_MOV32_IMM(BPF_REG_0, 42),
+                        BPF_LD_IMM64(BPF_REG_1, 0xffffffff00000000LL),
+                        BPF_MOV32_IMM(BPF_REG_2, 1),
+                        BPF_ALU32_REG(BPF_MOD, BPF_REG_2, BPF_REG_1),
+                        BPF_EXIT_INSN(),
+                },
+                .result = ACCEPT,
+                .retval = 0,
+        },
+        {
+                "MOD64 by 0, zero check",
+                .insns = {
+                        BPF_MOV32_IMM(BPF_REG_0, 42),
+                        BPF_MOV32_IMM(BPF_REG_1, 0),
+                        BPF_MOV32_IMM(BPF_REG_2, 1),
+                        BPF_ALU64_REG(BPF_MOD, BPF_REG_2, BPF_REG_1),
+                        BPF_EXIT_INSN(),
+                },
+                .result = ACCEPT,
+                .retval = 0,
+        },
+        {
+                "empty prog",
+                .insns = {
+                },
+                .errstr = "last insn is not an exit or jmp",
+                .result = REJECT,
+        },
+        {
+                "only exit insn",
+                .insns = {
+                        BPF_EXIT_INSN(),
+                },
+                .errstr = "R0 !read_ok",
+                .result = REJECT,
+        },
+        {
                 "unreachable",
                 .insns = {
                         BPF_EXIT_INSN(),