From: Jiri Olsa <jolsa@redhat.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
Martin KaFai Lau <kafai@fb.com>, David Miller <davem@redhat.com>,
John Fastabend <john.fastabend@gmail.com>,
Wenbo Zhang <ethercflow@gmail.com>,
KP Singh <kpsingh@chromium.org>, Andrii Nakryiko <andriin@fb.com>,
Brendan Gregg <bgregg@netflix.com>,
Florent Revest <revest@chromium.org>,
Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH 05/11] bpf: Remove btf_id helpers resolving
Date: Fri, 19 Jun 2020 15:18:00 +0200 [thread overview]
Message-ID: <20200619131800.GF2465907@krava> (raw)
In-Reply-To: <CAEf4BzYw0VciF-7CS164Nk8LLnZ4odtdYQyX1MS4eWDN5WbcSg@mail.gmail.com>
On Thu, Jun 18, 2020 at 06:10:29PM -0700, Andrii Nakryiko wrote:
> On Tue, Jun 16, 2020 at 3:06 AM Jiri Olsa <jolsa@kernel.org> wrote:
> >
> > Now when we moved the helpers btf_id into .BTF_ids section,
> > we can remove the code that resolve those IDs in runtime.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
>
> Nice! :)
>
> BTW, have you looked at bpf_ctx_convert stuff? Would we be able to
> replace it with your btfids thing as well?
good, another usage ;-) I'll check
>
>
> > kernel/bpf/btf.c | 88 +++---------------------------------------------
> > 1 file changed, 4 insertions(+), 84 deletions(-)
> >
> > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> > index 58c9af1d4808..aea7b2cc8d26 100644
> > --- a/kernel/bpf/btf.c
> > +++ b/kernel/bpf/btf.c
> > @@ -4049,96 +4049,16 @@ int btf_struct_access(struct bpf_verifier_log *log,
> > return -EINVAL;
> > }
> >
>
> [...]
>
> > int btf_resolve_helper_id(struct bpf_verifier_log *log,
> > const struct bpf_func_proto *fn, int arg)
> > {
> > - int *btf_id = &fn->btf_id[arg];
> > - int ret;
> > -
> > if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID)
> > return -EINVAL;
> >
> > - ret = READ_ONCE(*btf_id);
> > - if (ret)
> > - return ret;
> > - /* ok to race the search. The result is the same */
> > - ret = __btf_resolve_helper_id(log, fn->func, arg);
> > - if (!ret) {
> > - /* Function argument cannot be type 'void' */
> > - bpf_log(log, "BTF resolution bug\n");
> > - return -EFAULT;
> > - }
> > - WRITE_ONCE(*btf_id, ret);
> > - return ret;
> > + if (WARN_ON_ONCE(!fn->btf_id))
> > + return -EINVAL;
> > +
> > + return fn->btf_id[arg];
>
> It probably would be a good idea to add some sanity checking here,
> making sure that btf_id is >0 (void is never a right type) and <=
> nr_types in vmlinux_btf?
yep, will add it ;-)
jirka
next prev parent reply other threads:[~2020-06-19 13:18 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-16 10:05 [PATCHv3 0/9] bpf: Add d_path helper Jiri Olsa
2020-06-16 10:05 ` [PATCH 01/11] bpf: Add btfid tool to resolve BTF IDs in ELF object Jiri Olsa
2020-06-19 0:38 ` Andrii Nakryiko
2020-06-19 13:03 ` Jiri Olsa
2020-06-19 18:12 ` Andrii Nakryiko
2020-06-22 8:59 ` Jiri Olsa
2020-06-16 10:05 ` [PATCH 02/11] bpf: Compile btfid tool at kernel compilation start Jiri Olsa
2020-06-18 20:40 ` John Fastabend
2020-06-18 21:17 ` John Fastabend
2020-06-19 13:23 ` Jiri Olsa
2020-06-19 0:40 ` Andrii Nakryiko
2020-06-19 0:47 ` Arnaldo Carvalho de Melo
2020-06-19 2:08 ` Alexei Starovoitov
2020-06-19 3:51 ` Andrii Nakryiko
2020-06-16 10:05 ` [PATCH 03/11] bpf: Add btf_ids object Jiri Olsa
2020-06-19 0:56 ` Andrii Nakryiko
2020-06-19 1:06 ` Andrii Nakryiko
2020-06-19 13:16 ` Jiri Olsa
2020-06-19 13:13 ` Jiri Olsa
2020-06-19 18:15 ` Andrii Nakryiko
2020-06-19 1:02 ` Andrii Nakryiko
2020-06-19 13:05 ` Jiri Olsa
2020-06-16 10:05 ` [PATCH 04/11] bpf: Resolve BTF IDs in vmlinux image Jiri Olsa
2020-06-16 10:05 ` [PATCH 05/11] bpf: Remove btf_id helpers resolving Jiri Olsa
2020-06-19 1:10 ` Andrii Nakryiko
2020-06-19 13:18 ` Jiri Olsa [this message]
2020-06-16 10:05 ` [PATCH 06/11] bpf: Do not pass enum bpf_access_type to btf_struct_access Jiri Olsa
2020-06-19 3:58 ` Andrii Nakryiko
2020-06-19 13:23 ` Jiri Olsa
2020-06-16 10:05 ` [PATCH 07/11] bpf: Allow nested BTF object to be refferenced by BTF object + offset Jiri Olsa
2020-06-16 10:05 ` [PATCH 08/11] bpf: Add BTF whitelist support Jiri Olsa
2020-06-19 4:29 ` Andrii Nakryiko
2020-06-19 13:29 ` Jiri Olsa
2020-06-16 10:05 ` [PATCH 09/11] bpf: Add d_path helper Jiri Olsa
2020-06-19 4:35 ` Andrii Nakryiko
2020-06-19 13:31 ` Jiri Olsa
2020-06-19 18:25 ` Andrii Nakryiko
2020-06-22 9:02 ` Jiri Olsa
2020-06-22 19:18 ` Andrii Nakryiko
2020-06-23 10:02 ` Jiri Olsa
2020-06-23 18:58 ` Andrii Nakryiko
2020-06-23 20:14 ` Jiri Olsa
2020-06-23 20:17 ` Andrii Nakryiko
2020-06-16 10:05 ` [PATCH 10/11] selftests/bpf: Add verifier test for " Jiri Olsa
2020-06-19 4:38 ` Andrii Nakryiko
2020-06-19 13:32 ` Jiri Olsa
2020-06-16 10:05 ` [PATCH 11/11] selftests/bpf: Add " Jiri Olsa
2020-06-19 4:44 ` Andrii Nakryiko
2020-06-19 13:34 ` Jiri Olsa
2020-06-18 20:57 ` [PATCHv3 0/9] bpf: Add " John Fastabend
2020-06-19 12:35 ` Jiri Olsa
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