Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

[linux-2.6-microblaze.git] / tools / lib / bpf / libbpf.c

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 912e01b..9be88a9 100644 (file)
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -578,8 +578,6 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
                      const char *name, size_t sec_idx, const char *sec_name,
                      size_t sec_off, void *insn_data, size_t insn_data_sz)
 {
-       int i;
-
        if (insn_data_sz == 0 || insn_data_sz % BPF_INSN_SZ || sec_off % BPF_INSN_SZ) {
                pr_warn("sec '%s': corrupted program '%s', offset %zu, size %zu\n",
                        sec_name, name, sec_off, insn_data_sz);
@@ -618,13 +616,6 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog,
                goto errout;
        memcpy(prog->insns, insn_data, insn_data_sz);
 
-       for (i = 0; i < prog->insns_cnt; i++) {
-               if (insn_is_subprog_call(&prog->insns[i])) {
-                       obj->has_subcalls = true;
-                       break;
-               }
-       }
-
        return 0;
 errout:
        pr_warn("sec '%s': failed to allocate memory for prog '%s'\n", sec_name, name);
@@ -3298,7 +3289,19 @@ bpf_object__find_program_by_title(const struct bpf_object *obj,
 static bool prog_is_subprog(const struct bpf_object *obj,
                            const struct bpf_program *prog)
 {
-       return prog->sec_idx == obj->efile.text_shndx && obj->has_subcalls;
+       /* For legacy reasons, libbpf supports an entry-point BPF programs
+        * without SEC() attribute, i.e., those in the .text section. But if
+        * there are 2 or more such programs in the .text section, they all
+        * must be subprograms called from entry-point BPF programs in
+        * designated SEC()'tions, otherwise there is no way to distinguish
+        * which of those programs should be loaded vs which are a subprogram.
+        * Similarly, if there is a function/program in .text and at least one
+        * other BPF program with custom SEC() attribute, then we just assume
+        * .text programs are subprograms (even if they are not called from
+        * other programs), because libbpf never explicitly supported mixing
+        * SEC()-designated BPF programs and .text entry-point BPF programs.
+        */
+       return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1;
 }
 
 struct bpf_program *