Merge branch 'bpf: remove bpf_load loader completely'

"Daniel T. says:

====================

Numerous refactoring that rewrites BPF programs written with bpf_load
to use the libbpf loader was finally completed, resulting in BPF
programs using bpf_load within the kernel being completely no longer
present.

This patchset refactors remaining bpf programs with libbpf and
completely removes bpf_load, an outdated bpf loader that is difficult
to keep up with the latest kernel BPF and causes confusion.

Changes in v2:
 - drop 'move tracing helpers to trace_helper' patch
 - add link pinning to prevent cleaning up on process exit
 - add static at global variable and remove unused variable
 - change to destroy link even after link__pin()
 - fix return error code on exit
 - merge commit with changing Makefile

Changes in v3:
 - cleanup bpf_link, bpf_object and cgroup fd both on success and error
====================

Signed-off-by: Andrii Nakryiko <[email protected]>

samples/bpf/.gitignore

@@ -52,3 +52,6 @@ xdp_tx_iptunnel
 xdpsock
 xsk_fwd
 testfile.img
+hbm_out.log
+iperf.*
+*.out

samples/bpf/Makefile

@@ -73,16 +73,16 @@ tracex5-objs := tracex5_user.o $(TRACE_HELPERS)
 tracex6-objs := tracex6_user.o
 tracex7-objs := tracex7_user.o
 test_probe_write_user-objs := test_probe_write_user_user.o
-trace_output-objs := trace_output_user.o $(TRACE_HELPERS)
+trace_output-objs := trace_output_user.o
 lathist-objs := lathist_user.o
 offwaketime-objs := offwaketime_user.o $(TRACE_HELPERS)
 spintest-objs := spintest_user.o $(TRACE_HELPERS)
 map_perf_test-objs := map_perf_test_user.o
-test_overhead-objs := bpf_load.o test_overhead_user.o
+test_overhead-objs := test_overhead_user.o
 test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o
 test_cgrp2_attach-objs := test_cgrp2_attach.o
 test_cgrp2_sock-objs := test_cgrp2_sock.o
-test_cgrp2_sock2-objs := bpf_load.o test_cgrp2_sock2.o
+test_cgrp2_sock2-objs := test_cgrp2_sock2.o
 xdp1-objs := xdp1_user.o
 # reuse xdp1 source intentionally
 xdp2-objs := xdp1_user.o
@@ -91,8 +91,8 @@ test_current_task_under_cgroup-objs := $(CGROUP_HELPERS) \
 				       test_current_task_under_cgroup_user.o
 trace_event-objs := trace_event_user.o $(TRACE_HELPERS)
 sampleip-objs := sampleip_user.o $(TRACE_HELPERS)
-tc_l2_redirect-objs := bpf_load.o tc_l2_redirect_user.o
-lwt_len_hist-objs := bpf_load.o lwt_len_hist_user.o
+tc_l2_redirect-objs := tc_l2_redirect_user.o
+lwt_len_hist-objs := lwt_len_hist_user.o
 xdp_tx_iptunnel-objs := xdp_tx_iptunnel_user.o
 test_map_in_map-objs := test_map_in_map_user.o
 per_socket_stats_example-objs := cookie_uid_helper_example.o
@@ -107,10 +107,10 @@ xdp_adjust_tail-objs := xdp_adjust_tail_user.o
 xdpsock-objs := xdpsock_user.o
 xsk_fwd-objs := xsk_fwd.o
 xdp_fwd-objs := xdp_fwd_user.o
-task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS)
-xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS)
-ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS)
-hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS)
+task_fd_query-objs := task_fd_query_user.o $(TRACE_HELPERS)
+xdp_sample_pkts-objs := xdp_sample_pkts_user.o
+ibumad-objs := ibumad_user.o
+hbm-objs := hbm.o $(CGROUP_HELPERS)
 
 # Tell kbuild to always build the programs
 always-y := $(tprogs-y)
@@ -197,8 +197,6 @@ TPROGS_CFLAGS += --sysroot=$(SYSROOT)
 TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
 endif
 
-TPROGCFLAGS_bpf_load.o += -Wno-unused-variable
-
 TPROGS_LDLIBS			+= $(LIBBPF) -lelf -lz
 TPROGLDLIBS_tracex4		+= -lrt
 TPROGLDLIBS_trace_output	+= -lrt