Commit f8c7a4d4 authored by Joe Stringer's avatar Joe Stringer Committed by Alexei Starovoitov
Browse files

bpf, libbpf: refactor relocation handling 



Adjust the code for relocations slightly with no functional changes,
so that upcoming patches that will introduce support for relocations
into the .data, .rodata and .bss sections can be added independent
of these changes.

Signed-off-by: default avatarJoe Stringer <joe@wand.net.nz>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent c83fef6b

tools/lib/bpf/libbpf.c

+32 −30
Original line number Diff line number Diff line
@@ -871,9 +871,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) 
				obj->efile.symbols = data;

				obj->efile.strtabidx = sh.sh_link;

			}

		} else if ((sh.sh_type == SHT_PROGBITS) &&

			   (sh.sh_flags & SHF_EXECINSTR) &&

			   (data->d_size > 0)) {

		} else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {

			if (sh.sh_flags & SHF_EXECINSTR) {

				if (strcmp(name, ".text") == 0)

					obj->efile.text_shndx = idx;

				err = bpf_object__add_program(obj, data->d_buf,
@@ -886,6 +885,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) 
					pr_warning("failed to alloc program %s (%s): %s",

						   name, obj->path, cp);

				}

			}

		} else if (sh.sh_type == SHT_REL) {

			void *reloc = obj->efile.reloc;

			int nr_reloc = obj->efile.nr_reloc + 1;
@@ -1046,6 +1046,7 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, 
			return -LIBBPF_ERRNO__RELOC;

		}



		if (sym.st_shndx == maps_shndx) {

			/* TODO: 'maps' is sorted. We can use bsearch to make it faster. */

			for (map_idx = 0; map_idx < nr_maps; map_idx++) {

				if (maps[map_idx].offset == sym.st_value) {
@@ -1065,6 +1066,7 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, 
			prog->reloc_desc[i].insn_idx = insn_idx;

			prog->reloc_desc[i].map_idx = map_idx;

		}

	}

	return 0;

}
@@ -1425,7 +1427,7 @@ bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) 
			}

			insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;

			insns[insn_idx].imm = obj->maps[map_idx].fd;

		} else {

		} else if (prog->reloc_desc[i].type == RELO_CALL) {

			err = bpf_program__reloc_text(prog, obj,

						      &prog->reloc_desc[i]);

			if (err)

CRA Git | Maintained and supported by SUSTech CRA and CCSE