On Wed, Jan 12, 2022 at 6:27 AM Mauricio Vásquez <mauricio@xxxxxxxxxx> wrote:
>
> This commit extends libbpf with the features that are needed to
> implement BTFGen:
>
> - Implement bpf_core_create_cand_cache() and bpf_core_free_cand_cache()
> to handle candidates cache.
> - Expose bpf_core_add_cands() and bpf_core_free_cands to handle
> candidates list.
> - Expose bpf_core_calc_relo_insn() to bpftool.
>
> Signed-off-by: Mauricio Vásquez <mauricio@xxxxxxxxxx>
> Signed-off-by: Rafael David Tinoco <rafael.tinoco@xxxxxxxxxxx>
> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@xxxxxxxxxx>
> Signed-off-by: Leonardo Di Donato <leonardo.didonato@xxxxxxxxxx>
> ---
> tools/lib/bpf/Makefile | 2 +-
> tools/lib/bpf/libbpf.c | 43 +++++++++++++++++++++------------
> tools/lib/bpf/libbpf_internal.h | 12 +++++++++
> 3 files changed, 41 insertions(+), 16 deletions(-)
>
> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> index f947b61b2107..dba019ee2832 100644
> --- a/tools/lib/bpf/Makefile
> +++ b/tools/lib/bpf/Makefile
> @@ -239,7 +239,7 @@ install_lib: all_cmd
>
> SRC_HDRS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h \
> bpf_helpers.h bpf_tracing.h bpf_endian.h bpf_core_read.h \
> - skel_internal.h libbpf_version.h
> + skel_internal.h libbpf_version.h relo_core.h libbpf_internal.h
this is the list of public API headers, this is not the right place,
as Quentin pointed out
> GEN_HDRS := $(BPF_GENERATED)
>
> INSTALL_PFX := $(DESTDIR)$(prefix)/include/bpf
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 4959c03a46f4..344b8b8e8a50 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -5185,18 +5185,18 @@ size_t bpf_core_essential_name_len(const char *name)
> return n;
> }
>
> -static void bpf_core_free_cands(struct bpf_core_cand_list *cands)
> +void bpf_core_free_cands(struct bpf_core_cand_list *cands)
> {
> free(cands->cands);
> free(cands);
> }
>
> -static int bpf_core_add_cands(struct bpf_core_cand *local_cand,
> - size_t local_essent_len,
> - const struct btf *targ_btf,
> - const char *targ_btf_name,
> - int targ_start_id,
> - struct bpf_core_cand_list *cands)
> +int bpf_core_add_cands(struct bpf_core_cand *local_cand,
> + size_t local_essent_len,
> + const struct btf *targ_btf,
> + const char *targ_btf_name,
> + int targ_start_id,
> + struct bpf_core_cand_list *cands)
> {
> struct bpf_core_cand *new_cands, *cand;
> const struct btf_type *t, *local_t;
> @@ -5567,6 +5567,24 @@ static int bpf_core_resolve_relo(struct bpf_program *prog,
> targ_res);
> }
>
> +struct hashmap *bpf_core_create_cand_cache(void)
> +{
> + return hashmap__new(bpf_core_hash_fn, bpf_core_equal_fn, NULL);
> +}
> +
> +void bpf_core_free_cand_cache(struct hashmap *cand_cache)
> +{
> + struct hashmap_entry *entry;
> + int i;
> +
> + if (!IS_ERR_OR_NULL(cand_cache)) {
with separate function for clean up, it's nicer to invert the if
condition and exit early to reduce nesting
> + hashmap__for_each_entry(cand_cache, entry, i) {
> + bpf_core_free_cands(entry->value);
> + }
> + hashmap__free(cand_cache);
> + }
> +}
> +
[...]
