BPF List
 help / color / mirror / Atom feed
From: Alexei Starovoitov <ast@fb.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>, bpf <bpf@vger.kernel.org>,
	Networking <netdev@vger.kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Kernel Team <kernel-team@fb.com>
Subject: Re: [PATCH bpf-next 12/17] libbpf: support extern resolution for BTF-defined maps in .maps section
Date: Thu, 15 Apr 2021 13:57:17 -0700	[thread overview]
Message-ID: <df0201be-219e-7e75-dcef-bf60112c5137@fb.com> (raw)
In-Reply-To: <CAEf4BzZXLi8Z=4fy5TpH-po-d__7eg6PrgBJWk_3epmT-n3SMA@mail.gmail.com>

On 4/15/21 1:35 PM, Andrii Nakryiko wrote:
> 
> How about we start in the most restrictive way first. Each extern
> would need to specify all the attributes that should match the map
> definition. That includes max_entries. That way the typedef struct {
> ... } my_map_t re-use will work right out of the box. Later, if we see
> this is not sufficient, we can start relaxing the rules.

+1

>>
>> btw for signed progs I'm thinking to allow override of max_entries only,
>> since this attribute doesn't affect safety, correctness, behavior.
>> Meaning max_entries will and will not be part of a signature at the same time.
>> In other words it's necessary to support existing bcc/libbpf-tools.
>> If we go with 'allow max_entries in extern' that would match that behavior.
> 
> Ok, unless I misunderstood, allowing and checking all map attributes
> as a starting point should work, right?

yes. thanks!

  reply	other threads:[~2021-04-15 20:57 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-14 20:01 [PATCH bpf-next 00/17] BPF static linker: support externs Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 01/17] bpftool: support dumping BTF VAR's "extern" linkage Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 02/17] bpftool: dump more info about DATASEC members Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 03/17] libbpf: suppress compiler warning when using SEC() macro with externs Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 04/17] libbpf: mark BPF subprogs with hidden visibility as static for BPF verifier Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 05/17] libbpf: allow gaps in BPF program sections to support overriden weak functions Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 06/17] libbpf: refactor BTF map definition parsing Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 07/17] libbpf: factor out symtab and relos sanity checks Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 08/17] libbpf: make few internal helpers available outside of libbpf.c Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 09/17] libbpf: extend sanity checking ELF symbols with externs validation Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 10/17] libbpf: tighten BTF type ID rewriting with error checking Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 11/17] libbpf: add linker extern resolution support for functions and global variables Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 12/17] libbpf: support extern resolution for BTF-defined maps in .maps section Andrii Nakryiko
2021-04-14 22:00   ` Alexei Starovoitov
2021-04-14 23:48     ` Andrii Nakryiko
2021-04-15  2:01       ` Alexei Starovoitov
2021-04-15 20:35         ` Andrii Nakryiko
2021-04-15 20:57           ` Alexei Starovoitov [this message]
2021-04-14 20:01 ` [PATCH bpf-next 13/17] selftests/bpf: use -O0 instead of -Og in selftests builds Andrii Nakryiko
2021-04-14 22:02   ` Alexei Starovoitov
2021-04-14 22:15   ` David Laight
2021-04-15  0:03     ` Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 14/17] selftests/bpf: omit skeleton generation for multi-linked BPF object files Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 15/17] selftests/bpf: add function linking selftest Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 16/17] selftests/bpf: add global variables " Andrii Nakryiko
2021-04-14 20:01 ` [PATCH bpf-next 17/17] sleftests/bpf: add map " Andrii Nakryiko
2021-04-15  0:21 ` [PATCH bpf-next 00/17] BPF static linker: support externs Andrii Nakryiko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=df0201be-219e-7e75-dcef-bf60112c5137@fb.com \
    --to=ast@fb.com \
    --cc=alexei.starovoitov@gmail.com \
    --cc=andrii.nakryiko@gmail.com \
    --cc=andrii@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=kernel-team@fb.com \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox