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-rw-r--r--tools/lib/bpf/libbpf.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 313034117070..28baee7ba1ca 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -560,8 +560,6 @@ 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);
@@ -600,13 +598,6 @@ 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);
@@ -3280,7 +3271,19 @@ 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 *