Ilya Leoshkevich <iii@xxxxxxxxxxxxx> [Tue, 2019-10-29 07:31 -0700]:
> There are tests for full and narrows loads from bpf_sysctl.file_pos, but
> for bpf_sysctl.write only full load is tested. Add the missing test.
>
> Suggested-by: Andrey Ignatov <rdna@xxxxxx>
> Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
Thank you!
Acked-by: Andrey Ignatov <rdna@xxxxxx>
> ---
> tools/testing/selftests/bpf/test_sysctl.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/test_sysctl.c b/tools/testing/selftests/bpf/test_sysctl.c
> index a320e3844b17..7aff907003d3 100644
> --- a/tools/testing/selftests/bpf/test_sysctl.c
> +++ b/tools/testing/selftests/bpf/test_sysctl.c
> @@ -120,6 +120,29 @@ static struct sysctl_test tests[] = {
> .newval = "(none)", /* same as default, should fail anyway */
> .result = OP_EPERM,
> },
> + {
> + .descr = "ctx:write sysctl:write read ok narrow",
> + .insns = {
> + /* u64 w = (u16)write & 1; */
> +#if __BYTE_ORDER == __LITTLE_ENDIAN
> + BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_1,
> + offsetof(struct bpf_sysctl, write)),
> +#else
> + BPF_LDX_MEM(BPF_H, BPF_REG_7, BPF_REG_1,
> + offsetof(struct bpf_sysctl, write) + 2),
> +#endif
> + BPF_ALU64_IMM(BPF_AND, BPF_REG_7, 1),
> + /* return 1 - w; */
> + BPF_MOV64_IMM(BPF_REG_0, 1),
> + BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_7),
> + BPF_EXIT_INSN(),
> + },
> + .attach_type = BPF_CGROUP_SYSCTL,
> + .sysctl = "kernel/domainname",
> + .open_flags = O_WRONLY,
> + .newval = "(none)", /* same as default, should fail anyway */
> + .result = OP_EPERM,
> + },
> {
> .descr = "ctx:write sysctl:read write reject",
> .insns = {
> --
> 2.23.0
>
--
Andrey Ignatov
