On 24/02/2025 20:32, Ihor Solodrai wrote: > On 2/21/25 6:47 AM, Alan Maguire wrote: >> On 19/02/2025 21:05, Ihor Solodrai wrote: >>> This patch series implements emitting appropriate BTF type tags for >>> argument and return types of kfuncs marked with KF_ARENA_* flags. >>> >>> For additional context see the description of BPF patch >>> "bpf: define KF_ARENA_* flags for bpf_arena kfuncs" [1]. >>> >>> The feature depends on recent changes in libbpf [2]. >>> >>> [1] https://lore.kernel.org/bpf/20250206003148.2308659-1-ihor.solodrai@xxxxxxxxx/ >>> [2] https://lore.kernel.org/bpf/20250130201239.1429648-1-ihor.solodrai@xxxxxxxxx/ >>> >> >> hi Ihor, just realized that given that this change depends on recent >> libbpf changes, we should look at updating the series to include a patch >> updating our libbpf subproject checkpoint commit for libbpf to get those >> changes for the case where the libbpf submodule is built (the default >> these days). We should probably have a patch (pahole: sync with >> libbpf-1.6) to cover this. An example of a subproject commit patch can >> be found at >> >> https://lore.kernel.org/dwarves/20240729111317.140816-2-alan.maguire@xxxxxxxxxx/ >> >> However I don't think those bpf-next libbpf changes have been synced >> with the github libbpf repo yet. If the next libbf sync won't be for a >> while, I don't think this has to block this work - we could just note >> that it needs to explicitly be built with latest v1.6 via shared library >> for testing purposes in the interim - but if there's a sync planned soon >> it'd be great to roll that in too. > > Hi Alan. I've just submitted a PR to sync libbpf with upstream. > https://github.com/libbpf/libbpf/pull/886 > > Will add a subproject commit patch. > Fantastic, thank you! > Andrii suggested pahole could use __weak declarations of libbpf API > and detect if they are linked at runtime. This way it's not necessary > to check for libbpf version. There are just a few places where we > currently do that. > > What do you think if I add patches for that too? > That would be great! The current approach of static build-time version checking isn't ideal, especially for folks using a dynamically linked libbpf. Alan > Thanks. > >> >> Thanks! >> >> Alan >> >> > v2->v3: >>> * Nits in patch #1 >>> >>> v1->v2: >>> * Rewrite patch #1 refactoring btf_encoder__tag_kfuncs(): now the >>> post-processing step is removed entirely, and kfuncs are tagged in >>> btf_encoder__add_func(). >>> * Nits and renames in patch #2 >>> * Add patch #4 editing man pages >>> >>> v2: https://lore.kernel.org/dwarves/20250212201552.1431219-1-ihor.solodrai@xxxxxxxxx/ >>> v1: https://lore.kernel.org/dwarves/20250207021442.155703-1-ihor.solodrai@xxxxxxxxx/ >>> >>> Ihor Solodrai (4): >>> btf_encoder: refactor btf_encoder__tag_kfuncs() >>> btf_encoder: emit type tags for bpf_arena pointers >>> pahole: introduce --btf_feature=attributes >>> man-pages: describe attributes and remove reproducible_build >>> >>> btf_encoder.c | 279 +++++++++++++++++++++++---------------------- >>> dwarves.h | 1 + >>> man-pages/pahole.1 | 7 +- >>> pahole.c | 11 ++ >>> 4 files changed, 158 insertions(+), 140 deletions(-) >>> >>
