On Fri, Jul 23, 2021 at 10:13 PM Hengqi Chen <hengqi.chen@xxxxxxxxx> wrote: > > Add libbpf_load_vmlinux_btf/libbpf_load_module_btf APIs. > This is part of the libbpf v1.0. [1] > > [1] https://github.com/libbpf/libbpf/issues/280 Saying it's part of libbpf 1.0 effort and given a link to Github PR is not really a sufficient commit message. Please expand on what you are doing in the patch and why. > > Signed-off-by: Hengqi Chen <hengqi.chen@xxxxxxxxx> > --- > tools/lib/bpf/btf.c | 24 +++++++++++++++++++++++- > tools/lib/bpf/btf.h | 2 ++ > tools/lib/bpf/libbpf.c | 8 ++++---- > tools/lib/bpf/libbpf.map | 2 ++ > 4 files changed, 31 insertions(+), 5 deletions(-) > > diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c > index b46760b93bb4..414e1c5635ef 100644 > --- a/tools/lib/bpf/btf.c > +++ b/tools/lib/bpf/btf.c > @@ -4021,7 +4021,7 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d) > */ > if (d->hypot_adjust_canon) > continue; > - > + > if (t_kind == BTF_KIND_FWD && c_kind != BTF_KIND_FWD) > d->map[t_id] = c_id; > > @@ -4395,6 +4395,11 @@ static int btf_dedup_remap_types(struct btf_dedup *d) > * data out of it to use for target BTF. > */ > struct btf *libbpf_find_kernel_btf(void) > +{ > + return libbpf_load_vmlinux_btf(); > +} > + > +struct btf *libbpf_load_vmlinux_btf(void) > { > struct { > const char *path_fmt; > @@ -4440,6 +4445,23 @@ struct btf *libbpf_find_kernel_btf(void) > return libbpf_err_ptr(-ESRCH); > } > > +struct btf *libbpf_load_module_btf(const char *mod) So we probably need to allow user to pre-load and re-use vmlinux BTF for efficiency, especially if they have some use-case to load a lot of BTFs. > +{ > + char path[80]; > + struct btf *base; > + int err; > + > + base = libbpf_load_vmlinux_btf(); > + err = libbpf_get_error(base); > + if (err) { > + pr_warn("Error loading vmlinux BTF: %d\n", err); > + return base; libbpf_err_ptr() needs to be used here, pr_warn() could have destroyed errno already > + } > + > + snprintf(path, sizeof(path), "/sys/kernel/btf/%s", mod); > + return btf__parse_split(path, base); so who's freeing base BTF in this case? > +} > + > int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ctx) > { > int i, n, err; [...]
