Commit e2fa0156 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

libbpf: Preliminary support for fd_idx 



Prep libbpf to use FD_IDX kernel feature when generating loader program.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-14-alexei.starovoitov@gmail.com
parent 9ca1f56a

tools/lib/bpf/libbpf.c

+25 −6
Original line number Diff line number Diff line
@@ -412,6 +412,8 @@ struct module_btf { 
	int fd;

};



struct bpf_gen;



struct bpf_object {

	char name[BPF_OBJ_NAME_LEN];

	char license[64];
@@ -432,6 +434,8 @@ struct bpf_object { 
	bool loaded;

	bool has_subcalls;



	struct bpf_gen *gen_loader;



	/*

	 * Information when doing elf related work. Only valid if fd

	 * is valid.
@@ -6388,19 +6392,34 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog) 


		switch (relo->type) {

		case RELO_LD64:

			if (obj->gen_loader) {

				insn[0].src_reg = BPF_PSEUDO_MAP_IDX;

				insn[0].imm = relo->map_idx;

			} else {

				insn[0].src_reg = BPF_PSEUDO_MAP_FD;

				insn[0].imm = obj->maps[relo->map_idx].fd;

			}

			break;

		case RELO_DATA:

			insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;

			insn[1].imm = insn[0].imm + relo->sym_off;

			if (obj->gen_loader) {

				insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE;

				insn[0].imm = relo->map_idx;

			} else {

				insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;

				insn[0].imm = obj->maps[relo->map_idx].fd;

			}

			break;

		case RELO_EXTERN_VAR:

			ext = &obj->externs[relo->sym_off];

			if (ext->type == EXT_KCFG) {

				if (obj->gen_loader) {

					insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE;

					insn[0].imm = obj->kconfig_map_idx;

				} else {

					insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;

					insn[0].imm = obj->maps[obj->kconfig_map_idx].fd;

				}

				insn[1].imm = ext->kcfg.data_off;

			} else /* EXT_KSYM */ {

				if (ext->ksym.type_id) { /* typed ksyms */