On 12/13/2018 04:41 AM, Jakub Kicinski wrote:
> We seem to have no JSET instruction test, and LLVM does not
> generate it at all, so let's add a simple hand-coded test
> to make sure JIT implementations are correct.
>
> Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
> ---
> tools/testing/selftests/bpf/test_progs.c | 71 ++++++++++++++++++++++++
> 1 file changed, 71 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/test_progs.c
> b/tools/testing/selftests/bpf/test_progs.c
> index 126fc624290d..d9b7197fdf94 100644
> --- a/tools/testing/selftests/bpf/test_progs.c
> +++ b/tools/testing/selftests/bpf/test_progs.c
> @@ -1882,6 +1882,76 @@ static void test_queue_stack_map(int type)
> bpf_object__close(obj);
> }
>
> +static void test_jset(void)
> +{
> + /* LLVM does not seem to support JSET-like instructions so by hand.. */
> + static const struct bpf_insn insns[] = {
> + /* r0 = 0 */
> + BPF_MOV64_IMM(BPF_REG_0, 0),
> + /* prep for direct packet access via r2 */
> + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
> + offsetof(struct __sk_buff, data)),
> + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
> + offsetof(struct __sk_buff, data_end)),
> + BPF_MOV64_REG(BPF_REG_4, BPF_REG_2),
> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 8),
> + BPF_JMP_REG(BPF_JLE, BPF_REG_4, BPF_REG_3, 1),
> + BPF_EXIT_INSN(),
> +
> + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_2, 0),
> +
> + /* reg, bit 63 or bit 0 set, taken */
> + BPF_LD_IMM64(BPF_REG_8, 0x8000000000000001),
> + BPF_JMP_REG(BPF_JSET, BPF_REG_7, BPF_REG_8, 1),
> + BPF_EXIT_INSN(),
> +
> + /* reg, bit 62, not taken */
> + BPF_LD_IMM64(BPF_REG_8, 0x4000000000000000),
> + BPF_JMP_REG(BPF_JSET, BPF_REG_7, BPF_REG_8, 1),
> + BPF_JMP_IMM(BPF_JA, 0, 0, 1),
> + BPF_EXIT_INSN(),
> +
> + /* imm, any bit set, taken */
> + BPF_JMP_IMM(BPF_JSET, BPF_REG_7, -1, 1),
> + BPF_EXIT_INSN(),
> +
> + /* imm, bit 31 set, taken */
> + BPF_JMP_IMM(BPF_JSET, BPF_REG_7, 0x80000000, 1),
> + BPF_EXIT_INSN(),
> +
> + /* all good - return r0 == 2 */
> + BPF_MOV64_IMM(BPF_REG_0, 2),
> + BPF_EXIT_INSN(),
> + };
> + __u32 duration = 0, retval;
> + __u64 data[8] = {};
> + int err, prog_fd;
> +
> + prog_fd = bpf_load_program(BPF_PROG_TYPE_SCHED_CLS, insns,
> + ARRAY_SIZE(insns), "GPL", 0, NULL, 0);
> + if (CHECK(prog_fd < 0, "jset", "load fd %d errno %d\n", prog_fd, errno))
> + return;
> +
> +#define TEST(val, name, res) \
> + do { \
> + data[0] = (val); \
> + err = bpf_prog_test_run(prog_fd, 1, data, sizeof(data), \
> + NULL, NULL, &retval, &duration); \
> + CHECK(err || retval != (res), (name), \
> + "err %d errno %d retval %d duration %d\n", \
> + err, errno, retval, duration); \
> + } while (0)
> +
> + TEST((1ULL << 63) | (1U << 31) | (1U << 0), "bit63+31+0", 2);
> + TEST((1ULL << 63) | (1U << 31), "bit63+31", 2);
> + TEST((1ULL << 31) | (1U << 0), "bit31+0", 2);
> + TEST((__u32)-1, "u32", 2);
> + TEST(~0x4000000000000000ULL, "~bit62", 2);
> + TEST(0, "zero", 0);
> + TEST(~0ULL, "all", 0);
> +#undef TEST
Could we rather extend the test_verifier infrastructure in order to be able to
define data input for bpf_prog_test_run()? I think this would be very useful
for future tests there as well and avoid having to duplicate or split
functionality
into test_progs.c instead.
> +}
> +
> int main(void)
> {
> srand(time(NULL));
> @@ -1909,6 +1979,7 @@ int main(void)
> test_reference_tracking();
> test_queue_stack_map(QUEUE);
> test_queue_stack_map(STACK);
> + test_jset();
>
> printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt);
> return error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
Thanks,
Daniel
