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* [PATCH bpf-next v4 0/4] bpftool: btf: Support dumping a single type from file
@ 2024-12-13  1:24 Daniel Xu
  2024-12-13  1:24 ` [PATCH bpf-next v4 1/4] bpftool: man: Add missing format argument to command description Daniel Xu
                   ` (3 more replies)
  0 siblings, 4 replies; 12+ messages in thread
From: Daniel Xu @ 2024-12-13  1:24 UTC (permalink / raw)
  To: bpf, linux-kernel, netdev, qmo; +Cc: andrii.nakryiko, antony, toke, martin.lau

Some projects, for example xdp-tools [0], prefer to check in a minimized
vmlinux.h rather than the complete file which can get rather large.

However, when you try to add a minimized version of a complex struct (eg
struct xfrm_state), things can get quite complex if you're trying to
manually untangle and deduplicate the dependencies.

This commit teaches bpftool to do a minimized dump of a single type by
providing an optional root_id argument.

Example usage:

    $ ./bpftool btf dump file ~/dev/linux/vmlinux | rg "STRUCT 'xfrm_state'"
    [12643] STRUCT 'xfrm_state' size=912 vlen=58

    $ ./bpftool btf dump file ~/dev/linux/vmlinux root_id 12643 format c
    #ifndef __VMLINUX_H__
    #define __VMLINUX_H__

    [..]

    struct xfrm_type_offload;

    struct xfrm_sec_ctx;

    struct xfrm_state {
            possible_net_t xs_net;
            union {
                    struct hlist_node gclist;
                    struct hlist_node bydst;
            };
            union {
                    struct hlist_node dev_gclist;
                    struct hlist_node bysrc;
            };
            struct hlist_node byspi;
    [..]

[0]: https://github.com/xdp-project/xdp-tools/blob/master/headers/bpf/vmlinux.h

=== Changelog ===
Changes in v4:
* Support multiple instances of root_id

Changes in v3:
* Make `root_id` a top level btf-dump argument rather than attached to `file`
* Update bash completion script
* Refactor root_type_ids checking to after btf handle creation
* Update help messages and fix existing man page inconsistency

Changes in v2:
* Add early error check for invalid BTF ID

Daniel Xu (4):
  bpftool: man: Add missing format argument to command description
  bpftool: btf: Validate root_type_ids early
  bpftool: btf: Support dumping a specific types from file
  bpftool: bash: Add bash completion for root_id argument

 .../bpf/bpftool/Documentation/bpftool-btf.rst |  8 ++-
 tools/bpf/bpftool/bash-completion/bpftool     |  7 ++-
 tools/bpf/bpftool/btf.c                       | 51 ++++++++++++++++++-
 3 files changed, 60 insertions(+), 6 deletions(-)

-- 
2.46.0


^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2024-12-13 18:01 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-12-13  1:24 [PATCH bpf-next v4 0/4] bpftool: btf: Support dumping a single type from file Daniel Xu
2024-12-13  1:24 ` [PATCH bpf-next v4 1/4] bpftool: man: Add missing format argument to command description Daniel Xu
2024-12-13 15:15   ` Quentin Monnet
2024-12-13  1:24 ` [PATCH bpf-next v4 2/4] bpftool: btf: Validate root_type_ids early Daniel Xu
2024-12-13 15:15   ` Quentin Monnet
2024-12-13  1:24 ` [PATCH bpf-next v4 3/4] bpftool: btf: Support dumping a specific types from file Daniel Xu
2024-12-13 15:17   ` Quentin Monnet
2024-12-13 16:45     ` Daniel Xu
2024-12-13 16:55       ` Quentin Monnet
2024-12-13 18:01         ` Daniel Xu
2024-12-13  1:24 ` [PATCH bpf-next v4 4/4] bpftool: bash: Add bash completion for root_id argument Daniel Xu
2024-12-13 15:17   ` Quentin Monnet

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