[PATCH bpf-next 11/16] libbpf: add multi-prog section support for struct_ops
From: Andrii Nakryiko <hidden>
Date: 2020-08-20 23:13:33
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Adjust struct_ops handling code to work with multi-program ELF sections properly. Signed-off-by: Andrii Nakryiko <redacted> --- tools/lib/bpf/libbpf.c | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 2151bb0ecfb8..c6edd8eb614b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c@@ -73,8 +73,6 @@ #define __printf(a, b) __attribute__((format(printf, a, b))) static struct bpf_map *bpf_object__add_map(struct bpf_object *obj); -static struct bpf_program *bpf_object__find_prog_by_idx(struct bpf_object *obj, - int idx); static const struct btf_type * skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);
@@ -3247,20 +3245,6 @@ static int bpf_object__collect_externs(struct bpf_object *obj) return 0; } -static struct bpf_program * -bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx) -{ - struct bpf_program *prog; - size_t i; - - for (i = 0; i < obj->nr_programs; i++) { - prog = &obj->programs[i]; - if (prog->sec_idx == idx) - return prog; - } - return NULL; -} - struct bpf_program * bpf_object__find_program_by_title(const struct bpf_object *obj, const char *title)
@@ -8084,7 +8068,7 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, const struct btf *btf; struct bpf_map *map; Elf_Data *symbols; - unsigned int moff; + unsigned int moff, insn_idx; const char *name; __u32 member_idx; GElf_Sym sym;
@@ -8129,6 +8113,12 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, map->name, (size_t)rel.r_offset, shdr_idx); return -LIBBPF_ERRNO__RELOC; } + if (sym.st_value % BPF_INSN_SZ) { + pr_warn("struct_ops reloc %s: invalid target program offset %llu\n", + map->name, (__u64)sym.st_value); + return -LIBBPF_ERRNO__FORMAT; + } + insn_idx = sym.st_value / BPF_INSN_SZ; member = find_member_by_offset(st_ops->type, moff * 8); if (!member) {
@@ -8145,7 +8135,7 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj, return -EINVAL; } - prog = bpf_object__find_prog_by_idx(obj, shdr_idx); + prog = find_prog_by_sec_insn(obj, shdr_idx, insn_idx); if (!prog) { pr_warn("struct_ops reloc %s: cannot find prog at shdr_idx %u to relocate func ptr %s\n", map->name, shdr_idx, name);
--
2.24.1