On Fri, Mar 26, 2021 at 5:24 AM Yauheni Kaliuta
<yauheni.kaliuta@xxxxxxxxxx> wrote:
>
> Since there is no convenient way for bpf program to get PAGE_SIZE
> from inside of the kernel, pass the value from userspace.
>
> Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@xxxxxxxxxx>
> ---
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
But I'd also shorten the subject to:
selftests/bpf: pass page size from userspace in sockopt_sk
It's just as clear and doesn't include unnecessary prog_tests/ path.
> tools/testing/selftests/bpf/prog_tests/sockopt_sk.c | 2 ++
> tools/testing/selftests/bpf/progs/sockopt_sk.c | 10 ++++------
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c
> index 114c1a622ffa..6a7cb5f23db2 100644
> --- a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c
> +++ b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c
> @@ -201,6 +201,8 @@ static void run_test(int cgroup_fd)
> if (CHECK(!skel, "skel_load", "sockopt_sk skeleton failed\n"))
> goto cleanup;
>
> + skel->bss->page_size = getpagesize();
> +
> skel->links._setsockopt =
> bpf_program__attach_cgroup(skel->progs._setsockopt, cgroup_fd);
> if (CHECK(IS_ERR(skel->links._setsockopt),
> diff --git a/tools/testing/selftests/bpf/progs/sockopt_sk.c b/tools/testing/selftests/bpf/progs/sockopt_sk.c
> index d3597f81e6e9..55dfbe53c24e 100644
> --- a/tools/testing/selftests/bpf/progs/sockopt_sk.c
> +++ b/tools/testing/selftests/bpf/progs/sockopt_sk.c
> @@ -8,9 +8,7 @@
> char _license[] SEC("license") = "GPL";
> __u32 _version SEC("version") = 1;
>
> -#ifndef PAGE_SIZE
> -#define PAGE_SIZE 4096
> -#endif
> +int page_size; /* userspace should set it */
>
> #ifndef SOL_TCP
> #define SOL_TCP IPPROTO_TCP
> @@ -90,7 +88,7 @@ int _getsockopt(struct bpf_sockopt *ctx)
> * program can only see the first PAGE_SIZE
> * bytes of data.
> */
> - if (optval_end - optval != PAGE_SIZE)
> + if (optval_end - optval != page_size)
> return 0; /* EPERM, unexpected data size */
>
> return 1;
> @@ -161,7 +159,7 @@ int _setsockopt(struct bpf_sockopt *ctx)
>
> if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) {
> /* Original optlen is larger than PAGE_SIZE. */
> - if (ctx->optlen != PAGE_SIZE * 2)
> + if (ctx->optlen != page_size * 2)
> return 0; /* EPERM, unexpected data size */
>
> if (optval + 1 > optval_end)
> @@ -175,7 +173,7 @@ int _setsockopt(struct bpf_sockopt *ctx)
> * program can only see the first PAGE_SIZE
> * bytes of data.
> */
> - if (optval_end - optval != PAGE_SIZE)
> + if (optval_end - optval != page_size)
> return 0; /* EPERM, unexpected data size */
>
> return 1;
> --
> 2.29.2
>
