From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Martin KaFai Lau <kafai@fb.com>
Cc: bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Kernel Team <kernel-team@fb.com>,
Networking <netdev@vger.kernel.org>
Subject: Re: [PATCH bpf-next 07/15] bpf: tcp: White list some tcp cong functions to be called by bpf-tcp-cc
Date: Thu, 18 Mar 2021 18:19:46 -0700 [thread overview]
Message-ID: <CAEf4BzYQrudAibsR8zp22dEuBF_iXgziAm46sVCO=98ATeqAqg@mail.gmail.com> (raw)
In-Reply-To: <20210316011420.4177709-1-kafai@fb.com>
On Tue, Mar 16, 2021 at 12:02 AM Martin KaFai Lau <kafai@fb.com> wrote:
>
> This patch white list some tcp cong helper functions, tcp_slow_start()
> and tcp_cong_avoid_ai(). They are allowed to be directly called by
> the bpf-tcp-cc program.
>
> A few tcp cc implementation functions are also white listed.
> A potential use case is the bpf-tcp-cc implementation may only
> want to override a subset of a tcp_congestion_ops. For others,
> the bpf-tcp-cc can directly call the kernel counter parts instead of
> re-implementing (or copy-and-pasting) them to the bpf program.
>
> They will only be available to the bpf-tcp-cc typed program.
> The white listed functions are not bounded to a fixed ABI contract.
> When any of them has changed, the bpf-tcp-cc program has to be changed
> like any in-tree/out-of-tree kernel tcp-cc implementations do also.
>
> Signed-off-by: Martin KaFai Lau <kafai@fb.com>
> ---
Just nits, of course :)
Whitelist is a single word, but see also 49decddd39e5 ("Merge tag
'inclusive-terminology' of
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/linux"),
allowlist/denylist is recommended for new code.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
> net/ipv4/bpf_tcp_ca.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c
> index d520e61649c8..ed6e6b5b762b 100644
> --- a/net/ipv4/bpf_tcp_ca.c
> +++ b/net/ipv4/bpf_tcp_ca.c
> @@ -5,6 +5,7 @@
> #include <linux/bpf_verifier.h>
> #include <linux/bpf.h>
> #include <linux/btf.h>
> +#include <linux/btf_ids.h>
> #include <linux/filter.h>
> #include <net/tcp.h>
> #include <net/bpf_sk_storage.h>
> @@ -178,10 +179,50 @@ bpf_tcp_ca_get_func_proto(enum bpf_func_id func_id,
> }
> }
>
> +BTF_SET_START(bpf_tcp_ca_kfunc_ids)
> +BTF_ID(func, tcp_reno_ssthresh)
> +BTF_ID(func, tcp_reno_cong_avoid)
> +BTF_ID(func, tcp_reno_undo_cwnd)
> +BTF_ID(func, tcp_slow_start)
> +BTF_ID(func, tcp_cong_avoid_ai)
> +#if IS_BUILTIN(CONFIG_TCP_CONG_CUBIC)
> +BTF_ID(func, cubictcp_init)
> +BTF_ID(func, cubictcp_recalc_ssthresh)
> +BTF_ID(func, cubictcp_cong_avoid)
> +BTF_ID(func, cubictcp_state)
> +BTF_ID(func, cubictcp_cwnd_event)
> +BTF_ID(func, cubictcp_acked)
> +#endif
> +#if IS_BUILTIN(CONFIG_TCP_CONG_DCTCP)
> +BTF_ID(func, dctcp_init)
> +BTF_ID(func, dctcp_update_alpha)
> +BTF_ID(func, dctcp_cwnd_event)
> +BTF_ID(func, dctcp_ssthresh)
> +BTF_ID(func, dctcp_cwnd_undo)
> +BTF_ID(func, dctcp_state)
> +#endif
> +#if IS_BUILTIN(CONFIG_TCP_CONG_BBR)
> +BTF_ID(func, bbr_init)
> +BTF_ID(func, bbr_main)
> +BTF_ID(func, bbr_sndbuf_expand)
> +BTF_ID(func, bbr_undo_cwnd)
> +BTF_ID(func, bbr_cwnd_even),
> +BTF_ID(func, bbr_ssthresh)
> +BTF_ID(func, bbr_min_tso_segs)
> +BTF_ID(func, bbr_set_state)
> +#endif
> +BTF_SET_END(bpf_tcp_ca_kfunc_ids)
see, kfunc here...
> +
> +static bool bpf_tcp_ca_check_kern_func_call(u32 kfunc_btf_id)
...but more verbose kern_func here. I like kfunc everywhere ;)
> +{
> + return btf_id_set_contains(&bpf_tcp_ca_kfunc_ids, kfunc_btf_id);
> +}
> +
> static const struct bpf_verifier_ops bpf_tcp_ca_verifier_ops = {
> .get_func_proto = bpf_tcp_ca_get_func_proto,
> .is_valid_access = bpf_tcp_ca_is_valid_access,
> .btf_struct_access = bpf_tcp_ca_btf_struct_access,
> + .check_kern_func_call = bpf_tcp_ca_check_kern_func_call,
> };
>
> static int bpf_tcp_ca_init_member(const struct btf_type *t,
> --
> 2.30.2
>
next prev parent reply other threads:[~2021-03-19 1:20 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 1:13 [PATCH bpf-next 00/15] Support calling kernel function Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 01/15] bpf: Simplify freeing logic in linfo and jited_linfo Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 02/15] bpf: btf: Support parsing extern func Martin KaFai Lau
2021-03-18 22:53 ` Andrii Nakryiko
2021-03-18 23:39 ` Martin KaFai Lau
2021-03-19 4:13 ` Andrii Nakryiko
2021-03-19 5:29 ` Martin KaFai Lau
2021-03-19 21:27 ` Andrii Nakryiko
2021-03-19 22:19 ` Martin KaFai Lau
2021-03-19 22:29 ` Andrii Nakryiko
2021-03-19 22:45 ` Martin KaFai Lau
2021-03-19 23:02 ` Andrii Nakryiko
2021-03-20 0:13 ` Martin KaFai Lau
2021-03-20 17:18 ` Andrii Nakryiko
2021-03-23 4:55 ` Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 03/15] bpf: Refactor btf_check_func_arg_match Martin KaFai Lau
2021-03-18 23:32 ` Andrii Nakryiko
2021-03-19 19:32 ` Martin KaFai Lau
2021-03-19 21:51 ` Andrii Nakryiko
2021-03-20 0:10 ` Alexei Starovoitov
2021-03-20 17:13 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 04/15] bpf: Support bpf program calling kernel function Martin KaFai Lau
2021-03-19 1:03 ` Andrii Nakryiko
2021-03-19 1:51 ` Alexei Starovoitov
2021-03-19 19:47 ` Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 05/15] bpf: Support kernel function call in x86-32 Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 06/15] tcp: Rename bictcp function prefix to cubictcp Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 07/15] bpf: tcp: White list some tcp cong functions to be called by bpf-tcp-cc Martin KaFai Lau
2021-03-19 1:19 ` Andrii Nakryiko [this message]
2021-03-16 1:14 ` [PATCH bpf-next 08/15] libbpf: Refactor bpf_object__resolve_ksyms_btf_id Martin KaFai Lau
2021-03-19 2:53 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 09/15] libbpf: Refactor codes for finding btf id of a kernel symbol Martin KaFai Lau
2021-03-19 3:14 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 10/15] libbpf: Rename RELO_EXTERN to RELO_EXTERN_VAR Martin KaFai Lau
2021-03-19 3:15 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 11/15] libbpf: Record extern sym relocation first Martin KaFai Lau
2021-03-19 3:16 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 12/15] libbpf: Support extern kernel function Martin KaFai Lau
2021-03-19 4:11 ` Andrii Nakryiko
2021-03-19 5:06 ` Martin KaFai Lau
2021-03-19 21:38 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 13/15] bpf: selftests: Rename bictcp to bpf_cubic Martin KaFai Lau
2021-03-19 4:14 ` Andrii Nakryiko
2021-03-16 1:15 ` [PATCH bpf-next 14/15] bpf: selftest: bpf_cubic and bpf_dctcp calling kernel functions Martin KaFai Lau
2021-03-19 4:15 ` Andrii Nakryiko
2021-03-16 1:15 ` [PATCH bpf-next 15/15] bpf: selftest: Add kfunc_call test Martin KaFai Lau
2021-03-16 3:39 ` kernel test robot
2021-03-19 4:21 ` Andrii Nakryiko
2021-03-19 5:40 ` Martin KaFai Lau
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