From 7e06aad52929d17610f28acd40dd10ed62295f85 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 3 Sep 2020 13:35:34 -0700 Subject: [PATCH] libbpf: Add multi-prog section support for struct_ops Adjust struct_ops handling code to work with multi-program ELF sections properly. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200903203542.15944-7-andriin@fb.com --- 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 ca2b5c91..2d6bf0a 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); @@ -3249,20 +3247,6 @@ 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) @@ -8198,7 +8182,7 @@ 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; @@ -8243,6 +8227,12 @@ 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) { @@ -8259,7 +8249,7 @@ 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); -- 2.7.4