[bpf-next,8/8] samples: bpf: Makefile: base progs build on Makefile.progs

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 043f9cc14cdd..ed7131851172 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -4,55 +4,53 @@  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
-hostprogs-y += fds_example
-hostprogs-y += sockex1
-hostprogs-y += sockex2
-hostprogs-y += sockex3
-hostprogs-y += tracex1
-hostprogs-y += tracex2
-hostprogs-y += tracex3
-hostprogs-y += tracex4
-hostprogs-y += tracex5
-hostprogs-y += tracex6
-hostprogs-y += tracex7
-hostprogs-y += test_probe_write_user
-hostprogs-y += trace_output
-hostprogs-y += lathist
-hostprogs-y += offwaketime
-hostprogs-y += spintest
-hostprogs-y += map_perf_test
-hostprogs-y += test_overhead
-hostprogs-y += test_cgrp2_array_pin
-hostprogs-y += test_cgrp2_attach
-hostprogs-y += test_cgrp2_sock
-hostprogs-y += test_cgrp2_sock2
-hostprogs-y += xdp1
-hostprogs-y += xdp2
-hostprogs-y += xdp_router_ipv4
-hostprogs-y += test_current_task_under_cgroup
-hostprogs-y += trace_event
-hostprogs-y += sampleip
-hostprogs-y += tc_l2_redirect
-hostprogs-y += lwt_len_hist
-hostprogs-y += xdp_tx_iptunnel
-hostprogs-y += test_map_in_map
-hostprogs-y += per_socket_stats_example
-hostprogs-y += xdp_redirect
-hostprogs-y += xdp_redirect_map
-hostprogs-y += xdp_redirect_cpu
-hostprogs-y += xdp_monitor
-hostprogs-y += xdp_rxq_info
-hostprogs-y += syscall_tp
-hostprogs-y += cpustat
-hostprogs-y += xdp_adjust_tail
-hostprogs-y += xdpsock
-hostprogs-y += xdp_fwd
-hostprogs-y += task_fd_query
-hostprogs-y += xdp_sample_pkts
-hostprogs-y += ibumad
-hostprogs-y += hbm
+progs-y := test_lru_dist
+progs-y += sock_example
+progs-y += fds_example
+progs-y += sockex1
+progs-y += sockex2
+progs-y += sockex3
+progs-y += tracex1
+progs-y += tracex2
+progs-y += tracex3
+progs-y += tracex4
+progs-y += tracex5
+progs-y += tracex6
+progs-y += tracex7
+progs-y += test_probe_write_user
+progs-y += trace_output
+progs-y += lathist
+progs-y += offwaketime
+progs-y += spintest
+progs-y += map_perf_test
+progs-y += test_overhead
+progs-y += test_cgrp2_array_pin
+progs-y += test_cgrp2_attach
+progs-y += test_cgrp2_sock
+progs-y += test_cgrp2_sock2
+progs-y += xdp1
+progs-y += xdp2
+progs-y += xdp_router_ipv4
+progs-y += test_current_task_under_cgroup
+progs-y += trace_event
+progs-y += sampleip
+progs-y += tc_l2_redirect
+progs-y += lwt_len_hist
+progs-y += xdp_tx_iptunnel
+progs-y += test_map_in_map
+progs-y += xdp_redirect_map
+progs-y += xdp_redirect_cpu
+progs-y += xdp_monitor
+progs-y += xdp_rxq_info
+progs-y += syscall_tp
+progs-y += cpustat
+progs-y += xdp_adjust_tail
+progs-y += xdpsock
+progs-y += xdp_fwd
+progs-y += task_fd_query
+progs-y += xdp_sample_pkts
+progs-y += ibumad
+progs-y += hbm
 
 # Libbpf dependencies
 LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a
@@ -111,7 +109,7 @@  ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS)
 hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS)
 
 # Tell kbuild to always build the programs
-always := $(hostprogs-y)
+always := $(progs-y)
 always += sockex1_kern.o
 always += sockex2_kern.o
 always += sockex3_kern.o
@@ -171,26 +169,51 @@  always += ibumad_kern.o
 always += hbm_out_kern.o
 always += hbm_edt_kern.o
 
-KBUILD_HOSTCFLAGS += -I$(objtree)/usr/include
-KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/bpf/
-KBUILD_HOSTCFLAGS += -I$(srctree)/tools/testing/selftests/bpf/
-KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/ -I$(srctree)/tools/include
-KBUILD_HOSTCFLAGS += -I$(srctree)/tools/perf
-
-HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable
-
-KBUILD_HOSTLDLIBS		+= $(LIBBPF) -lelf
-HOSTLDLIBS_tracex4		+= -lrt
-HOSTLDLIBS_trace_output	+= -lrt
-HOSTLDLIBS_map_perf_test	+= -lrt
-HOSTLDLIBS_test_overhead	+= -lrt
-HOSTLDLIBS_xdpsock		+= -pthread
-
 # Strip all expet -D options needed to handle linux headers
 # for arm it's __LINUX_ARM_ARCH__ and potentially others fork vars
 D_OPTIONS = $(shell echo "$(KBUILD_CFLAGS) " | sed 's/[[:blank:]]/\n/g' | \
 	sed '/^-D/!d' | tr '\n' ' ')
 
+ifdef SYSROOT
+ccflags-y += --sysroot=${SYSROOT}
+ccflags-y += -I${SYSROOT}/usr/include
+CLANG_EXTRA_CFLAGS := $(ccflags-y)
+PROGS_LDFLAGS := -L${SYSROOT}/usr/lib
+endif
+
+ccflags-y += -I$(srctree)/tools/lib/bpf/
+ccflags-y += -I$(srctree)/tools/testing/selftests/bpf/
+ccflags-y += -I$(srctree)/tools/lib/
+ccflags-y += -I$(srctree)/tools/perf
+
+ccflags-y += $(D_OPTIONS)
+ccflags-y += -Wall
+ccflags-y += -Wmissing-prototypes
+ccflags-y += -Wstrict-prototypes
+ccflags-y += -fomit-frame-pointer
+
+PROGS_CFLAGS := $(ccflags-y)
+
+ccflags-y += -I$(objtree)/usr/include
+ccflags-y += -I$(srctree)/tools/include
+
+PROGCFLAGS_bpf_load.o += -I$(objtree)/usr/include -I$(srctree)/tools/include \
+			 -Wno-unused-variable
+PROGCFLAGS_sampleip_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_task_fd_query_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_trace_event_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_trace_output_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_tracex6_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_xdp_sample_pkts_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_xdpsock_user.o += -I$(srctree)/tools/include
+
+PROGS_LDLIBS			:= $(LIBBPF) -lelf
+PROGLDLIBS_tracex4		+= -lrt
+PROGLDLIBS_trace_output		+= -lrt
+PROGLDLIBS_map_perf_test	+= -lrt
+PROGLDLIBS_test_overhead	+= -lrt
+PROGLDLIBS_xdpsock		+= -pthread
+
 CLANG_EXTRA_CFLAGS += $(D_OPTIONS)
 
 # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
@@ -202,15 +225,14 @@  BTF_PAHOLE ?= pahole
 
 # Detect that we're cross compiling and use the cross compiler
 ifdef CROSS_COMPILE
-HOSTCC = $(CROSS_COMPILE)gcc
 CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
 endif
 
 # Don't evaluate probes and warnings if we need to run make recursively
 ifneq ($(src),)
 HDR_PROBE := $(shell printf "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
-	$(HOSTCC) $(KBUILD_HOSTCFLAGS) -x c - -o /dev/null 2>/dev/null && \
-	echo okay)
+	$(CC) $(PROGS_CFLAGS) $(PROGS_LDFLAGS) -x c - -o /dev/null \
+	2>/dev/null && echo okay)
 
 ifeq ($(HDR_PROBE),)
 $(warning WARNING: Detected possible issues with include path.)
@@ -246,7 +268,9 @@  clean:
 
 $(LIBBPF): FORCE
 # 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=
+	$(MAKE) -C $(dir $@) RM='rm -rf' EXTRA_CFLAGS="$(ccflags-y)" \
+		EXTRA_CXXFLAGS="$(ccflags-y)" LDFLAGS=$(PROGS_LDFLAGS) \
+		srctree=$(BPF_SAMPLES_PATH)/../../ O=
 
 $(obj)/syscall_nrs.h:	$(obj)/syscall_nrs.s FORCE
 	$(call filechk,offsets,__SYSCALL_NRS_H__)
@@ -283,6 +307,8 @@  $(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
 $(obj)/hbm.o: $(src)/hbm.h
 $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
 
+-include $(BPF_SAMPLES_PATH)/Makefile.prog
+
 # 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.
diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
index 5f27e4faca50..6b5e4eace977 100644
--- a/samples/bpf/README.rst
+++ b/samples/bpf/README.rst
@@ -74,3 +74,10 @@  samples for the cross target.
 export ARCH=arm64
 export CROSS_COMPILE="aarch64-linux-gnu-"
 make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
+
+If need to use environment of target board, the SYSROOT also can be set,
+pointing on FS of target board:
+
+make samples/bpf/ LLC=~/git/llvm/build/bin/llc \
+     CLANG=~/git/llvm/build/bin/clang \
+     SYSROOT=~/some_sdk/linux-devkit/sysroots/aarch64-linux-gnu