libbpf: Refactor bpf_object__reloc_code

Refactor bpf_object__append_subprog_code out of bpf_object__reloc_code
to be able to reuse it to append subprog related code for the exception
callback to the main program.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-15-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 96ff1aa..afc07a8 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6234,6 +6234,38 @@ static int append_subprog_relos(struct bpf_program *main_prog, struct bpf_progra
        return 0;
 }
 
+static int
+bpf_object__append_subprog_code(struct bpf_object *obj, struct bpf_program *main_prog,
+                               struct bpf_program *subprog)
+{
+       struct bpf_insn *insns;
+       size_t new_cnt;
+       int err;
+
+       subprog->sub_insn_off = main_prog->insns_cnt;
+
+       new_cnt = main_prog->insns_cnt + subprog->insns_cnt;
+       insns = libbpf_reallocarray(main_prog->insns, new_cnt, sizeof(*insns));
+       if (!insns) {
+               pr_warn("prog '%s': failed to realloc prog code\n", main_prog->name);
+               return -ENOMEM;
+       }
+       main_prog->insns = insns;
+       main_prog->insns_cnt = new_cnt;
+
+       memcpy(main_prog->insns + subprog->sub_insn_off, subprog->insns,
+              subprog->insns_cnt * sizeof(*insns));
+
+       pr_debug("prog '%s': added %zu insns from sub-prog '%s'\n",
+                main_prog->name, subprog->insns_cnt, subprog->name);
+
+       /* The subprog insns are now appended. Append its relos too. */
+       err = append_subprog_relos(main_prog, subprog);
+       if (err)
+               return err;
+       return 0;
+}
+
 static int
 bpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog,
                       struct bpf_program *prog)
@@ -6316,25 +6348,7 @@ bpf_object__reloc_code(struct bpf_object *obj, struct bpf_program *main_prog,
                 *   and relocate.
                 */
                if (subprog->sub_insn_off == 0) {
-                       subprog->sub_insn_off = main_prog->insns_cnt;
-
-                       new_cnt = main_prog->insns_cnt + subprog->insns_cnt;
-                       insns = libbpf_reallocarray(main_prog->insns, new_cnt, sizeof(*insns));
-                       if (!insns) {
-                               pr_warn("prog '%s': failed to realloc prog code\n", main_prog->name);
-                               return -ENOMEM;
-                       }
-                       main_prog->insns = insns;
-                       main_prog->insns_cnt = new_cnt;
-
-                       memcpy(main_prog->insns + subprog->sub_insn_off, subprog->insns,
-                              subprog->insns_cnt * sizeof(*insns));
-
-                       pr_debug("prog '%s': added %zu insns from sub-prog '%s'\n",
-                                main_prog->name, subprog->insns_cnt, subprog->name);
-
-                       /* The subprog insns are now appended. Append its relos too. */
-                       err = append_subprog_relos(main_prog, subprog);
+                       err = bpf_object__append_subprog_code(obj, main_prog, subprog);
                        if (err)
                                return err;
                        err = bpf_object__reloc_code(obj, main_prog, subprog);