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From: Yonghong Song <yhs@fb.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>, <davem@davemloft.net>
Cc: <daniel@iogearbox.net>, <andrii@kernel.org>,
	<netdev@vger.kernel.org>, <bpf@vger.kernel.org>,
	<kernel-team@fb.com>
Subject: Re: [PATCH v2 bpf-next 00/16] bpf: syscall program, FD array, loader program, light skeleton.
Date: Fri, 23 Apr 2021 14:36:43 -0700	[thread overview]
Message-ID: <4142514b-3a0f-f931-9a8c-fb72be9c66b3@fb.com> (raw)
In-Reply-To: <20210423002646.35043-1-alexei.starovoitov@gmail.com>



On 4/22/21 5:26 PM, Alexei Starovoitov wrote:
> From: Alexei Starovoitov <ast@kernel.org>
> 
> v1->v2: Addressed comments from Al, Yonghong and Andrii.
> - documented sys_close fdget/fdput requirement and non-recursion check.
> - reduced internal api leaks between libbpf and bpftool.
>    Now bpf_object__gen_loader() is the only new libbf api with minimal fields.
> - fixed light skeleton __destroy() method to munmap and close maps and progs.
> - refactored bpf_btf_find_by_name_kind to return btf_id | (btf_obj_fd << 32).
> - refactored use of bpf_btf_find_by_name_kind from loader prog.
> - moved auto-gen like code into skel_internal.h that is used by *.lskel.h
>    It has minimal static inline bpf_load_and_run() method used by lskel.
> - added lksel.h example in patch 15.
> - replaced union bpf_map_prog_desc with struct bpf_map_desc and struct bpf_prog_desc.
> - removed mark_feat_supported and added a patch to pass 'obj' into kernel_supports.
> - added proper tracking of temporary FDs in loader prog and their cleanup via bpf_sys_close.
> - rename gen_trace.c into gen_loader.c to better align the naming throughout.
> - expanded number of available helpers in new prog type.
> - added support for raw_tp attaching in lskel.
>    lskel supports tracing and raw_tp progs now.
>    It correctly loads all networking prog types too, but __attach() method is tbd.
> - converted progs/test_ksyms_module.c to lskel.
> - minor feedback fixes all over.
> 
> One thing that was not addressed from feedback is the name of new program type.
> Currently it's still:
> BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */

Do you have plan for other non-bpf syscalls? Maybe use the name
BPF_PROG_TYPE_BPF_SYSCALL? It will be really clear this is
the program type you can execute bpf syscalls.

> 
> The concern raised was that it sounds like a program that should be attached
> to a syscall. Like BPF_PROG_TYPE_KPROBE is used to process kprobes.
> I've considered and rejected:
> BPF_PROG_TYPE_USER - too generic
> BPF_PROG_TYPE_USERCTX - ambiguous with uprobes

USERCTX probably not a good choice. People can write a program without
context and put the ctx into a map and use it.

> BPF_PROG_TYPE_LOADER - ok-ish, but imo TYPE_SYSCALL is cleaner.

User can write a program to do more than loading although I am not sure
how useful it is compared to implementation in user space.

> Other suggestions?
> 
> The description of V1 set is still valid:
> ----
[...]

  parent reply	other threads:[~2021-04-23 21:37 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-23  0:26 [PATCH v2 bpf-next 00/16] bpf: syscall program, FD array, loader program, light skeleton Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 01/16] bpf: Introduce bpf_sys_bpf() helper and program type Alexei Starovoitov
2021-04-23 18:15   ` Yonghong Song
2021-04-23 18:28     ` Alexei Starovoitov
2021-04-23 19:32       ` Yonghong Song
2021-04-26 16:51   ` Andrii Nakryiko
2021-04-27 18:45   ` John Fastabend
2021-04-23  0:26 ` [PATCH v2 bpf-next 02/16] bpf: Introduce bpfptr_t user/kernel pointer Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 03/16] bpf: Prepare bpf syscall to be used from kernel and user space Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 04/16] libbpf: Support for syscall program type Alexei Starovoitov
2021-04-26 22:24   ` Andrii Nakryiko
2021-04-23  0:26 ` [PATCH v2 bpf-next 05/16] selftests/bpf: Test " Alexei Starovoitov
2021-04-26 17:02   ` Andrii Nakryiko
2021-04-27  2:43     ` Alexei Starovoitov
2021-04-27 16:28       ` Andrii Nakryiko
2021-04-23  0:26 ` [PATCH v2 bpf-next 06/16] bpf: Make btf_load command to be bpfptr_t compatible Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 07/16] selftests/bpf: Test for btf_load command Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 08/16] bpf: Introduce fd_idx Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 09/16] libbpf: Support for fd_idx Alexei Starovoitov
2021-04-26 17:14   ` Andrii Nakryiko
2021-04-27  2:53     ` Alexei Starovoitov
2021-04-27 16:36       ` Andrii Nakryiko
2021-04-28  1:32         ` Alexei Starovoitov
2021-04-28 18:40           ` Andrii Nakryiko
2021-04-23  0:26 ` [PATCH v2 bpf-next 10/16] bpf: Add bpf_btf_find_by_name_kind() helper Alexei Starovoitov
2021-04-26 22:46   ` Andrii Nakryiko
2021-04-27  3:37     ` Alexei Starovoitov
2021-04-27 17:45       ` Andrii Nakryiko
2021-04-28  1:55         ` Alexei Starovoitov
2021-04-28 18:44           ` Andrii Nakryiko
2021-04-27 21:00   ` John Fastabend
2021-04-27 21:05     ` John Fastabend
2021-04-28  2:10     ` Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 11/16] bpf: Add bpf_sys_close() helper Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 12/16] libbpf: Change the order of data and text relocations Alexei Starovoitov
2021-04-26 17:29   ` Andrii Nakryiko
2021-04-27  3:00     ` Alexei Starovoitov
2021-04-27 16:47       ` Andrii Nakryiko
2021-04-23  0:26 ` [PATCH v2 bpf-next 13/16] libbpf: Add bpf_object pointer to kernel_supports() Alexei Starovoitov
2021-04-26 17:30   ` Andrii Nakryiko
2021-04-23  0:26 ` [PATCH v2 bpf-next 14/16] libbpf: Generate loader program out of BPF ELF file Alexei Starovoitov
2021-04-26 22:22   ` Andrii Nakryiko
2021-04-27  3:25     ` Alexei Starovoitov
2021-04-27 17:34       ` Andrii Nakryiko
2021-04-28  1:42         ` Alexei Starovoitov
2021-04-23  0:26 ` [PATCH v2 bpf-next 15/16] bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command Alexei Starovoitov
2021-04-26 22:35   ` Andrii Nakryiko
2021-04-27  3:28     ` Alexei Starovoitov
2021-04-27 17:38       ` Andrii Nakryiko
2021-04-23  0:26 ` [PATCH v2 bpf-next 16/16] selftests/bpf: Convert few tests to light skeleton Alexei Starovoitov
2021-04-23 21:36 ` Yonghong Song [this message]
2021-04-23 23:16   ` [PATCH v2 bpf-next 00/16] bpf: syscall program, FD array, loader program, " Alexei Starovoitov

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