bpf_object__find_program_by_title(), used by CO-RE relocation code, doesn't
return .text "BPF program", if it is a function storage for sub-programs.
Because of that, any CO-RE relocation in helper non-inlined functions will
fail. Fix this by searching for .text-corresponding BPF program manually.

Adjust one of bpf_iter selftest to exhibit this pattern.

Reported-by: Yonghong Song <y...@fb.com>
Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Signed-off-by: Andrii Nakryiko <andr...@fb.com>
---
 tools/lib/bpf/libbpf.c                               | 8 +++++++-
 tools/testing/selftests/bpf/progs/bpf_iter_netlink.c | 2 +-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 477c679ed945..f17151d866e6 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -4818,7 +4818,13 @@ bpf_core_reloc_fields(struct bpf_object *obj, const char 
*targ_btf_path)
                        err = -EINVAL;
                        goto out;
                }
-               prog = bpf_object__find_program_by_title(obj, sec_name);
+               prog = NULL;
+               for (i = 0; i < obj->nr_programs; i++) {
+                       if (!strcmp(obj->programs[i].section_name, sec_name)) {
+                               prog = &obj->programs[i];
+                               break;
+                       }
+               }
                if (!prog) {
                        pr_warn("failed to find program '%s' for CO-RE offset 
relocation\n",
                                sec_name);
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c 
b/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c
index e7b8753eac0b..75ecf956a2df 100644
--- a/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c
+++ b/tools/testing/selftests/bpf/progs/bpf_iter_netlink.c
@@ -25,7 +25,7 @@ struct bpf_iter__netlink {
        struct netlink_sock *sk;
 } __attribute__((preserve_access_index));
 
-static inline struct inode *SOCK_INODE(struct socket *socket)
+static __attribute__((noinline)) struct inode *SOCK_INODE(struct socket 
*socket)
 {
        return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
 }
-- 
2.24.1

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