mainline inclusion
from mainline-5.15-rc1
commit 1373ff59
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1373ff59955621b7e71e7a1152036c93a5780c11

-------------------------------------------------

btf_custom_path allows developers to load custom BTF which libbpf will
subsequently use for CO-RE relocation instead of vmlinux BTF.

Having btf_custom_path in bpf_object_open_opts one can directly use the
skeleton's <objname>_bpf__open_opts() API to pass in the btf_custom_path
parameter, as opposed to using bpf_object__load_xattr() which is slated to be
deprecated ([0]).

This work continues previous work started by another developer ([1]).

  [0] https://lore.kernel.org/bpf/CAEf4BzbJZLjNoiK8_VfeVg_Vrg=9iYFv+po-38SMe=UzwDKJ=Q@mail.gmail.com/#t
  [1] https://yhbt.net/lore/all/CAEf4Bzbgw49w2PtowsrzKQNcxD4fZRE6AKByX-5-dMo-+oWHHA@mail.gmail.com/Signed-off-by: NShuyi Cheng <chengshuyi@linux.alibaba.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1626180159-112996-2-git-send-email-chengshuyi@linux.alibaba.com
(cherry picked from commit 1373ff59)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>