Merge branch 'fix-samples'

Jakub Kicinski says:

====================
Following patches address build issues after recent move to libbpf.
For out-of-tree builds we would see the following error:

gcc: error: samples/bpf/../../tools/lib/bpf/libbpf.a: No such file or directory

libbpf build system is now always invoked explicitly rather than
relying on building single objects most of the time.  We need to
resolve the friction between Kbuild and tools/ build system.

Mini-library called libbpf.h in samples is renamed to bpf_insn.h,
using linux/filter.h seems not completely trivial since some samples
get upset when order on include search path in changed.  We do have
to rename libbpf.h, however, because otherwise it's hard to reliably
get to libbpf's header in out-of-tree builds.

v2:
 - fix the build error harder (patch 3);
 - add patch 5 (make clang less noisy).
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

samples/bpf/Makefile

@@ -1,4 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
+
+BPF_SAMPLES_PATH ?= $(abspath $(srctree)/$(src))
+TOOLS_PATH := $(BPF_SAMPLES_PATH)/../../tools
+
 # List of programs to build
 hostprogs-y := test_lru_dist
 hostprogs-y += sock_example
@@ -49,59 +53,58 @@ hostprogs-y += xdpsock
 hostprogs-y += xdp_fwd
 
 # Libbpf dependencies
-LIBBPF := ../../tools/lib/bpf/libbpf.a
+LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a
+
 CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
 TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
 
-test_lru_dist-objs := test_lru_dist.o $(LIBBPF)
-sock_example-objs := sock_example.o $(LIBBPF)
-fds_example-objs := bpf_load.o $(LIBBPF) fds_example.o
-sockex1-objs := bpf_load.o $(LIBBPF) sockex1_user.o
-sockex2-objs := bpf_load.o $(LIBBPF) sockex2_user.o
-sockex3-objs := bpf_load.o $(LIBBPF) sockex3_user.o
-tracex1-objs := bpf_load.o $(LIBBPF) tracex1_user.o
-tracex2-objs := bpf_load.o $(LIBBPF) tracex2_user.o
-tracex3-objs := bpf_load.o $(LIBBPF) tracex3_user.o
-tracex4-objs := bpf_load.o $(LIBBPF) tracex4_user.o
-tracex5-objs := bpf_load.o $(LIBBPF) tracex5_user.o
-tracex6-objs := bpf_load.o $(LIBBPF) tracex6_user.o
-tracex7-objs := bpf_load.o $(LIBBPF) tracex7_user.o
-load_sock_ops-objs := bpf_load.o $(LIBBPF) load_sock_ops.o
-test_probe_write_user-objs := bpf_load.o $(LIBBPF) test_probe_write_user_user.o
-trace_output-objs := bpf_load.o $(LIBBPF) trace_output_user.o $(TRACE_HELPERS)
-lathist-objs := bpf_load.o $(LIBBPF) lathist_user.o
-offwaketime-objs := bpf_load.o $(LIBBPF) offwaketime_user.o $(TRACE_HELPERS)
-spintest-objs := bpf_load.o $(LIBBPF) spintest_user.o $(TRACE_HELPERS)
-map_perf_test-objs := bpf_load.o $(LIBBPF) map_perf_test_user.o
-test_overhead-objs := bpf_load.o $(LIBBPF) test_overhead_user.o
-test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o $(LIBBPF)
-test_cgrp2_attach-objs := test_cgrp2_attach.o $(LIBBPF)
-test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(LIBBPF) $(CGROUP_HELPERS)
-test_cgrp2_sock-objs := test_cgrp2_sock.o $(LIBBPF)
-test_cgrp2_sock2-objs := bpf_load.o $(LIBBPF) test_cgrp2_sock2.o
-xdp1-objs := xdp1_user.o $(LIBBPF)
+fds_example-objs := bpf_load.o fds_example.o
+sockex1-objs := bpf_load.o sockex1_user.o
+sockex2-objs := bpf_load.o sockex2_user.o
+sockex3-objs := bpf_load.o sockex3_user.o
+tracex1-objs := bpf_load.o tracex1_user.o
+tracex2-objs := bpf_load.o tracex2_user.o
+tracex3-objs := bpf_load.o tracex3_user.o
+tracex4-objs := bpf_load.o tracex4_user.o
+tracex5-objs := bpf_load.o tracex5_user.o
+tracex6-objs := bpf_load.o tracex6_user.o
+tracex7-objs := bpf_load.o tracex7_user.o
+load_sock_ops-objs := bpf_load.o load_sock_ops.o
+test_probe_write_user-objs := bpf_load.o test_probe_write_user_user.o
+trace_output-objs := bpf_load.o trace_output_user.o $(TRACE_HELPERS)
+lathist-objs := bpf_load.o lathist_user.o
+offwaketime-objs := bpf_load.o offwaketime_user.o $(TRACE_HELPERS)
+spintest-objs := bpf_load.o spintest_user.o $(TRACE_HELPERS)
+map_perf_test-objs := bpf_load.o map_perf_test_user.o
+test_overhead-objs := bpf_load.o test_overhead_user.o
+test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o
+test_cgrp2_attach-objs := test_cgrp2_attach.o
+test_cgrp2_attach2-objs := test_cgrp2_attach2.o $(CGROUP_HELPERS)
+test_cgrp2_sock-objs := test_cgrp2_sock.o
+test_cgrp2_sock2-objs := bpf_load.o test_cgrp2_sock2.o
+xdp1-objs := xdp1_user.o
 # reuse xdp1 source intentionally
-xdp2-objs := xdp1_user.o $(LIBBPF)
-xdp_router_ipv4-objs := bpf_load.o $(LIBBPF) xdp_router_ipv4_user.o
-test_current_task_under_cgroup-objs := bpf_load.o $(LIBBPF) $(CGROUP_HELPERS) \
+xdp2-objs := xdp1_user.o
+xdp_router_ipv4-objs := bpf_load.o xdp_router_ipv4_user.o
+test_current_task_under_cgroup-objs := bpf_load.o $(CGROUP_HELPERS) \
 				       test_current_task_under_cgroup_user.o
-trace_event-objs := bpf_load.o $(LIBBPF) trace_event_user.o $(TRACE_HELPERS)
-sampleip-objs := bpf_load.o $(LIBBPF) sampleip_user.o $(TRACE_HELPERS)
-tc_l2_redirect-objs := bpf_load.o $(LIBBPF) tc_l2_redirect_user.o
-lwt_len_hist-objs := bpf_load.o $(LIBBPF) lwt_len_hist_user.o
-xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o
-test_map_in_map-objs := bpf_load.o $(LIBBPF) test_map_in_map_user.o
-per_socket_stats_example-objs := cookie_uid_helper_example.o $(LIBBPF)
-xdp_redirect-objs := bpf_load.o $(LIBBPF) xdp_redirect_user.o
-xdp_redirect_map-objs := bpf_load.o $(LIBBPF) xdp_redirect_map_user.o
-xdp_redirect_cpu-objs := bpf_load.o $(LIBBPF) xdp_redirect_cpu_user.o
-xdp_monitor-objs := bpf_load.o $(LIBBPF) xdp_monitor_user.o
-xdp_rxq_info-objs := xdp_rxq_info_user.o $(LIBBPF)
-syscall_tp-objs := bpf_load.o $(LIBBPF) syscall_tp_user.o
-cpustat-objs := bpf_load.o $(LIBBPF) cpustat_user.o
-xdp_adjust_tail-objs := xdp_adjust_tail_user.o $(LIBBPF)
-xdpsock-objs := bpf_load.o $(LIBBPF) xdpsock_user.o
-xdp_fwd-objs := bpf_load.o $(LIBBPF) xdp_fwd_user.o
+trace_event-objs := bpf_load.o trace_event_user.o $(TRACE_HELPERS)
+sampleip-objs := bpf_load.o 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
+xdp_tx_iptunnel-objs := bpf_load.o xdp_tx_iptunnel_user.o
+test_map_in_map-objs := bpf_load.o test_map_in_map_user.o
+per_socket_stats_example-objs := cookie_uid_helper_example.o
+xdp_redirect-objs := bpf_load.o xdp_redirect_user.o
+xdp_redirect_map-objs := bpf_load.o xdp_redirect_map_user.o
+xdp_redirect_cpu-objs := bpf_load.o xdp_redirect_cpu_user.o
+xdp_monitor-objs := bpf_load.o xdp_monitor_user.o
+xdp_rxq_info-objs := xdp_rxq_info_user.o
+syscall_tp-objs := bpf_load.o syscall_tp_user.o
+cpustat-objs := bpf_load.o cpustat_user.o
+xdp_adjust_tail-objs := xdp_adjust_tail_user.o
+xdpsock-objs := bpf_load.o xdpsock_user.o
+xdp_fwd-objs := bpf_load.o xdp_fwd_user.o
 
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
@@ -173,53 +176,12 @@ HOSTCFLAGS_spintest_user.o += -I$(srctree)/tools/lib/bpf/
 HOSTCFLAGS_trace_event_user.o += -I$(srctree)/tools/lib/bpf/
 HOSTCFLAGS_sampleip_user.o += -I$(srctree)/tools/lib/bpf/
 
-HOSTLOADLIBES_test_lru_dist += -lelf
-HOSTLOADLIBES_sock_example += -lelf
-HOSTLOADLIBES_fds_example += -lelf
-HOSTLOADLIBES_sockex1 += -lelf
-HOSTLOADLIBES_sockex2 += -lelf
-HOSTLOADLIBES_sockex3 += -lelf
-HOSTLOADLIBES_tracex1 += -lelf
-HOSTLOADLIBES_tracex2 += -lelf
-HOSTLOADLIBES_tracex3 += -lelf
-HOSTLOADLIBES_tracex4 += -lelf -lrt
-HOSTLOADLIBES_tracex5 += -lelf
-HOSTLOADLIBES_tracex6 += -lelf
-HOSTLOADLIBES_tracex7 += -lelf
-HOSTLOADLIBES_test_cgrp2_array_pin += -lelf
-HOSTLOADLIBES_test_cgrp2_attach += -lelf
-HOSTLOADLIBES_test_cgrp2_attach2 += -lelf
-HOSTLOADLIBES_test_cgrp2_sock += -lelf
-HOSTLOADLIBES_test_cgrp2_sock2 += -lelf
-HOSTLOADLIBES_load_sock_ops += -lelf
-HOSTLOADLIBES_test_probe_write_user += -lelf
-HOSTLOADLIBES_trace_output += -lelf -lrt
-HOSTLOADLIBES_lathist += -lelf
-HOSTLOADLIBES_offwaketime += -lelf
-HOSTLOADLIBES_spintest += -lelf
-HOSTLOADLIBES_map_perf_test += -lelf -lrt
-HOSTLOADLIBES_test_overhead += -lelf -lrt
-HOSTLOADLIBES_xdp1 += -lelf
-HOSTLOADLIBES_xdp2 += -lelf
-HOSTLOADLIBES_xdp_router_ipv4 += -lelf
-HOSTLOADLIBES_test_current_task_under_cgroup += -lelf
-HOSTLOADLIBES_trace_event += -lelf
-HOSTLOADLIBES_sampleip += -lelf
-HOSTLOADLIBES_tc_l2_redirect += -l elf
-HOSTLOADLIBES_lwt_len_hist += -l elf
-HOSTLOADLIBES_xdp_tx_iptunnel += -lelf
-HOSTLOADLIBES_test_map_in_map += -lelf
-HOSTLOADLIBES_per_socket_stats_example += -lelf
-HOSTLOADLIBES_xdp_redirect += -lelf
-HOSTLOADLIBES_xdp_redirect_map += -lelf
-HOSTLOADLIBES_xdp_redirect_cpu += -lelf
-HOSTLOADLIBES_xdp_monitor += -lelf
-HOSTLOADLIBES_xdp_rxq_info += -lelf
-HOSTLOADLIBES_syscall_tp += -lelf
-HOSTLOADLIBES_cpustat += -lelf
-HOSTLOADLIBES_xdp_adjust_tail += -lelf
-HOSTLOADLIBES_xdpsock += -lelf -pthread
-HOSTLOADLIBES_xdp_fwd += -lelf
+HOST_LOADLIBES		+= $(LIBBPF) -lelf
+HOSTLOADLIBES_tracex4		+= -lrt
+HOSTLOADLIBES_trace_output	+= -lrt
+HOSTLOADLIBES_map_perf_test	+= -lrt
+HOSTLOADLIBES_test_overhead	+= -lrt
+HOSTLOADLIBES_xdpsock		+= -pthread
 
 # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
 #  make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
@@ -233,15 +195,16 @@ CLANG_ARCH_ARGS = -target $(ARCH)
 endif
 
 # Trick to allow make to be run from this directory
-all: $(LIBBPF)
-	$(MAKE) -C ../../ $(CURDIR)/
+all:
+	$(MAKE) -C ../../ $(CURDIR)/ BPF_SAMPLES_PATH=$(CURDIR)
 
 clean:
 	$(MAKE) -C ../../ M=$(CURDIR) clean
 	@rm -f *~
 
 $(LIBBPF): FORCE
-	$(MAKE) -C $(dir $@)
+# Fix up variables inherited from Kbuild that tools/ build system won't like
+	$(MAKE) -C $(dir $@) RM='rm -rf' LDFLAGS= srctree=$(BPF_SAMPLES_PATH)/../../ O=
 
 $(obj)/syscall_nrs.s:	$(src)/syscall_nrs.c
 	$(call if_changed_dep,cc_s_c)
@@ -272,15 +235,17 @@ verify_target_bpf: verify_cmds
 		exit 2; \
 	else true; fi
 
-$(src)/*.c: verify_target_bpf
+$(BPF_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
+$(src)/*.c: verify_target_bpf $(LIBBPF)
 
 $(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h
 
 # asm/sysreg.h - inline assembly used by it is incompatible with llvm.
 # But, there is no easy way to fix it, so just exclude it since it is
 # useless for BPF samples.
 $(obj)/%.o: $(src)/%.c
-	$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \
+	@echo "  CLANG-bpf " $@
+	$(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \
 		-I$(srctree)/tools/testing/selftests/bpf/ \
 		-D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \
 		-D__TARGET_ARCH_$(ARCH) -Wno-compare-distinct-pointer-types \

samples/bpf/libbpf.h → samples/bpf/bpf_insn.h

@@ -1,9 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-/* eBPF mini library */
-#ifndef __LIBBPF_H
-#define __LIBBPF_H
-
-#include <bpf/bpf.h>
+/* eBPF instruction mini library */
+#ifndef __BPF_INSN_H
+#define __BPF_INSN_H
 
 struct bpf_insn;
 

samples/bpf/bpf_load.c

@@ -24,7 +24,7 @@
 #include <poll.h>
 #include <ctype.h>
 #include <assert.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 #include "perf-sys.h"
 

samples/bpf/bpf_load.h

@@ -2,7 +2,7 @@
 #ifndef __BPF_LOAD_H
 #define __BPF_LOAD_H
 
-#include "libbpf.h"
+#include <bpf/bpf.h>
 
 #define MAX_MAPS 32
 #define MAX_PROGS 32

samples/bpf/cookie_uid_helper_example.c

@@ -51,7 +51,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <bpf/bpf.h>
-#include "libbpf.h"
+#include "bpf_insn.h"
 
 #define PORT 8888
 

samples/bpf/cpustat_user.c

@@ -17,7 +17,7 @@
 #include <sys/resource.h>
 #include <sys/wait.h>
 
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 
 #define MAX_CPU			8

samples/bpf/fds_example.c

@@ -12,8 +12,10 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 
+#include <bpf/bpf.h>
+
+#include "bpf_insn.h"
 #include "bpf_load.h"
-#include "libbpf.h"
 #include "sock_example.h"
 
 #define BPF_F_PIN	(1 << 0)

samples/bpf/lathist_user.c

@@ -10,7 +10,7 @@
 #include <stdlib.h>
 #include <signal.h>
 #include <linux/bpf.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 
 #define MAX_ENTRIES	20

samples/bpf/load_sock_ops.c

@@ -8,7 +8,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <linux/bpf.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 #include <unistd.h>
 #include <errno.h>

samples/bpf/lwt_len_hist_user.c

@@ -9,7 +9,7 @@
 #include <errno.h>
 #include <arpa/inet.h>
 
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_util.h"
 
 #define MAX_INDEX 64

samples/bpf/map_perf_test_user.c

@@ -21,7 +21,7 @@
 #include <arpa/inet.h>
 #include <errno.h>
 
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 
 #define TEST_BIT(t) (1U << (t))

samples/bpf/sock_example.c

@@ -26,7 +26,8 @@
 #include <linux/if_ether.h>
 #include <linux/ip.h>
 #include <stddef.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
+#include "bpf_insn.h"
 #include "sock_example.h"
 
 char bpf_log_buf[BPF_LOG_BUF_SIZE];

samples/bpf/sock_example.h

@@ -9,7 +9,6 @@
 #include <net/if.h>
 #include <linux/if_packet.h>
 #include <arpa/inet.h>
-#include "libbpf.h"
 
 static inline int open_raw_sock(const char *name)
 {

samples/bpf/sockex1_user.c

@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <assert.h>
 #include <linux/bpf.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 #include "sock_example.h"
 #include <unistd.h>

samples/bpf/sockex2_user.c

@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <assert.h>
 #include <linux/bpf.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 #include "sock_example.h"
 #include <unistd.h>

samples/bpf/sockex3_user.c

@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <assert.h>
 #include <linux/bpf.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 #include "sock_example.h"
 #include <unistd.h>

samples/bpf/syscall_tp_user.c

@@ -16,7 +16,7 @@
 #include <assert.h>
 #include <stdbool.h>
 #include <sys/resource.h>
-#include "libbpf.h"
+#include <bpf/bpf.h>
 #include "bpf_load.h"
 
 /* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*.

samples/bpf/tc_l2_redirect_user.c

@@ -13,7 +13,7 @@
 #include <string.h>
 #include <errno.h>
 
-#include "libbpf.h"
+#include <bpf/bpf.h>
 
 static void usage(void)
 {

samples/bpf/test_cgrp2_array_pin.c

@@ -14,7 +14,7 @@
 #include <errno.h>
 #include <fcntl.h>
 
-#include "libbpf.h"
+#include <bpf/bpf.h>
 
 static void usage(void)
 {

samples/bpf/test_cgrp2_attach.c

@@ -28,8 +28,9 @@
 #include <fcntl.h>
 
 #include <linux/bpf.h>
+#include <bpf/bpf.h>
 
-#include "libbpf.h"
+#include "bpf_insn.h"
 
 enum {
 	MAP_KEY_PACKETS,