On Wed, Jan 10, 2024 at 06:14:25PM -0700, Daniel Xu wrote:
SNIP
> +
> +static int btf_encoder__tag_kfuncs(struct btf_encoder *encoder)
> +{
> + const char *filename = encoder->filename;
> + Elf_Scn *symscn = NULL;
> + int symbols_shndx = -1;
> + int fd = -1, err = -1;
> + int idlist_shndx = -1;
> + Elf_Scn *scn = NULL;
> + size_t idlist_addr;
> + Elf_Data *symbols;
> + Elf_Data *idlist;
> + size_t strtabidx;
> + Elf *elf = NULL;
> + int set_cnt = 0;
> + GElf_Shdr shdr;
> + size_t strndx;
> + char *secname;
> + int nr_syms;
> + int i = 0;
smooth ;-)
SNIP
> +
> + nr_syms = shdr.sh_size / shdr.sh_entsize;
> + for (i = 0; i < nr_syms; i++) {
> + char *kfunc, *name;
> + int new_set_cnt;
> + GElf_Sym sym;
> + int err;
> +
> + if (!gelf_getsym(symbols, i, &sym)) {
> + elf_error("Failed to get ELF symbol(%d)", i);
> + goto out;
> + }
> +
> + if (sym.st_shndx != idlist_shndx)
> + continue;
> +
> + name = elf_strptr(elf, strtabidx, sym.st_name);
> + new_set_cnt = get_kfunc_set_cnt(&sym, name, idlist, idlist_addr);
> + if (new_set_cnt < 0) {
> + err = new_set_cnt;
> + goto out;
> + } else if (new_set_cnt) {
> + if (set_cnt)
> + fprintf(stderr, "%s: warning: overlapping set8 '%s'\n",
> + __func__, name);
> + set_cnt = new_set_cnt;
> + continue;
> + }
> +
> + if (!set_cnt)
> + continue;
> + set_cnt--;
> +
> + kfunc = get_kfunc_name(name);
> + if (!kfunc)
> + continue;
> +
> + err = btf_encoder__tag_kfunc(encoder, kfunc);
are .BTF_ids records guaranteed to be sorted by address? so we are
sure that the set will be followed by its records?
I thought we'd need to find size for each set and then check each
.BTF_ids record if it belongs to the set
jirka
> + if (err) {
> + fprintf(stderr, "%s: failed to tag kfunc '%s'\n", __func__, kfunc);
> + free(kfunc);
> + goto out;
> + }
> + free(kfunc);
> + }
> +
> + err = 0;
> +out:
> + if (elf)
> + elf_end(elf);
> + if (fd != -1)
> + close(fd);
> + return err;
> +}
> +
> int btf_encoder__encode(struct btf_encoder *encoder)
> {
> int err;
> @@ -1366,6 +1681,14 @@ int btf_encoder__encode(struct btf_encoder *encoder)
> if (btf__type_cnt(encoder->btf) == 1)
> return 0;
>
> + /* Note vmlinux may already contain btf_decl_tag's for kfuncs. So
> + * take care to call this before btf_dedup().
> + */
> + if (btf_encoder__tag_kfuncs(encoder)) {
> + fprintf(stderr, "%s: failed to tag kfuncs!\n", __func__);
> + return -1;
> + }
> +
> if (btf__dedup(encoder->btf, NULL)) {
> fprintf(stderr, "%s: btf__dedup failed!\n", __func__);
> return -1;
> @@ -1712,6 +2035,7 @@ void btf_encoder__delete(struct btf_encoder *encoder)
>
> btf_encoders__delete(encoder);
> __gobuffer__delete(&encoder->percpu_secinfo);
> + __gobuffer__delete(&encoder->btf_funcs);
> zfree(&encoder->filename);
> btf__free(encoder->btf);
> encoder->btf = NULL;
> --
> 2.42.1
>
