[PATCH 09/10] bpf samples: Uses libbpf in tools/lib to deal with BPF operations

[Wang Nan]

Since we already have libbpf in tools/lib, there's no need to maintain
a duplicate BPF loading and operations library in samples.

This patch utilises previous introduced utils.[ch], which calls libbpf
to do these work.

The main changing in this relative large patch is very simple:

 1. Makefile modification, makes all hostprogs depend on libbpf.a.
Add include and library searching patch and rules for linker.
Remove old bpf_load.o and libbpf.o, replaces them with utils.o

 2. Make sure there are correct 'version' section so the BPF source
files can be loaded by libbpf.

 3. Uses API provided by utils.h and libbpf.

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Alex Gartrell 
Cc: Arnaldo Carvalho de Melo 
Cc: Brenden Blanco 
Cc: Daniel Borkmann 
Cc: Daniel Wagner 
Cc: David S. Miller 
Cc: Ingo Molnar 
Cc: Kaixu Xia 
Cc: Michael Holzheu 
Cc: Yang Shi 
---
 samples/bpf/Makefile| 65 ++---
 samples/bpf/fds_example.c   | 26 +++---
 samples/bpf/lathist_user.c  | 13 ---
 samples/bpf/sock_example.c  | 13 +++
 samples/bpf/sockex1_kern.c  |  2 ++
 samples/bpf/sockex1_user.c  | 27 --
 samples/bpf/sockex2_kern.c  |  2 ++
 samples/bpf/sockex2_user.c  | 26 --
 samples/bpf/sockex3_kern.c  |  2 ++
 samples/bpf/sockex3_user.c  | 23 +++-
 samples/bpf/test_maps.c | 80 -
 samples/bpf/test_verifier.c | 13 ---
 samples/bpf/trace_output_user.c | 17 +
 samples/bpf/tracex1_user.c  |  9 +++--
 samples/bpf/tracex2_user.c  | 31 +---
 samples/bpf/tracex3_user.c  | 15 
 samples/bpf/tracex4_user.c  | 15 
 samples/bpf/tracex5_user.c  |  9 +++--
 samples/bpf/tracex6_user.c  | 16 -
 19 files changed, 221 insertions(+), 183 deletions(-)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index edd638b..edb7c04 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -1,6 +1,20 @@
 # kbuild trick to avoid linker error. Can be omitted if a module is built.
 obj- := dummy.o
 
+INC_DIR = $(src)/include
+TOOLS_DIR = $(realpath $(srctree))/tools
+TOOLS_LIB_DIR = $(TOOLS_DIR)/lib
+LIBBPF_DIR = $(TOOLS_LIB_DIR)/bpf
+
+$(obj)/libbpf/libbpf.a:
+   $(Q)mkdir -p $(obj)/libbpf
+   $(MAKE) -C $(LIBBPF_DIR) O=$(realpath $(obj))/libbpf CFLAGS= LDFLAGS= 
V=1 $(realpath $(obj))/libbpf/libbpf.a
+
+HOSTCFLAGS += -I$(TOOLS_LIB_DIR) -I$(INC_DIR)
+HOSTLDFLAGS += -L$(obj)/libbpf
+HOSTCFLAGS += -I$(INC_DIR) -I$(TOOLS_LIB_DIR)
+HOST_LOADLIBES += -lelf -lbpf
+
 # List of programs to build
 hostprogs-y := test_verifier test_maps
 hostprogs-y += sock_example
@@ -17,21 +31,27 @@ hostprogs-y += tracex6
 hostprogs-y += trace_output
 hostprogs-y += lathist
 
-test_verifier-objs := test_verifier.o libbpf.o
-test_maps-objs := test_maps.o libbpf.o
-sock_example-objs := sock_example.o libbpf.o
-fds_example-objs := bpf_load.o libbpf.o fds_example.o
-sockex1-objs := bpf_load.o libbpf.o sockex1_user.o
-sockex2-objs := bpf_load.o libbpf.o sockex2_user.o
-sockex3-objs := bpf_load.o libbpf.o sockex3_user.o
-tracex1-objs := bpf_load.o libbpf.o tracex1_user.o
-tracex2-objs := bpf_load.o libbpf.o tracex2_user.o
-tracex3-objs := bpf_load.o libbpf.o tracex3_user.o
-tracex4-objs := bpf_load.o libbpf.o tracex4_user.o
-tracex5-objs := bpf_load.o libbpf.o tracex5_user.o
-tracex6-objs := bpf_load.o libbpf.o tracex6_user.o
-trace_output-objs := bpf_load.o libbpf.o trace_output_user.o
-lathist-objs := bpf_load.o libbpf.o lathist_user.o
+test_verifier-objs := test_verifier.o
+test_maps-objs := test_maps.o
+sock_example-objs := sock_example.o utils.o
+fds_example-objs := utils.o fds_example.o
+sockex1-objs := utils.o sockex1_user.o
+sockex2-objs := utils.o sockex2_user.o
+sockex3-objs := utils.o sockex3_user.o
+tracex1-objs := utils.o tracex1_user.o
+tracex2-objs := utils.o tracex2_user.o
+tracex3-objs := utils.o tracex3_user.o
+tracex4-objs := utils.o tracex4_user.o
+tracex5-objs := utils.o tracex5_user.o
+tracex6-objs := utils.o tracex6_user.o
+trace_output-objs := utils.o trace_output_user.o
+lathist-objs := utils.o lathist_user.o
+
+define add_depend
+$(foreach m, $(notdir $1), \
+   $(eval $(obj)/$m: $(obj)/libbpf/libbpf.a))
+endef
+$(call add_depend, $(hostprogs-y))
 
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
@@ -50,19 +70,8 @@ always += lathist_kern.o
 
 HOSTCFLAGS += -I$(objtree)/usr/include
 
-HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable
-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_trace_output += -lelf -lrt
-HOSTLOADLIBES_lathist += -lelf

[PATCH 09/10] bpf samples: Uses libbpf in tools/lib to deal with BPF operations

[Wang Nan]

Since we already have libbpf in tools/lib, there's no need to maintain
a duplicate BPF loading and operations library in samples.

This patch utilises previous introduced utils.[ch], which calls libbpf
to do these work.

The main changing in this relative large patch is very simple:

 1. Makefile modification, makes all hostprogs depend on libbpf.a.
Add include and library searching patch and rules for linker.
Remove old bpf_load.o and libbpf.o, replaces them with utils.o

 2. Make sure there are correct 'version' section so the BPF source
files can be loaded by libbpf.

 3. Uses API provided by utils.h and libbpf.

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Alex Gartrell 
Cc: Arnaldo Carvalho de Melo 
Cc: Brenden Blanco 
Cc: Daniel Borkmann 
Cc: Daniel Wagner 
Cc: David S. Miller 
Cc: Ingo Molnar 
Cc: Kaixu Xia 
Cc: Michael Holzheu 
Cc: Yang Shi 
---
 samples/bpf/Makefile| 65 ++---
 samples/bpf/fds_example.c   | 26 +++---
 samples/bpf/lathist_user.c  | 13 ---
 samples/bpf/sock_example.c  | 13 +++
 samples/bpf/sockex1_kern.c  |  2 ++
 samples/bpf/sockex1_user.c  | 27 --
 samples/bpf/sockex2_kern.c  |  2 ++
 samples/bpf/sockex2_user.c  | 26 --
 samples/bpf/sockex3_kern.c  |  2 ++
 samples/bpf/sockex3_user.c  | 23 +++-
 samples/bpf/test_maps.c | 80 -
 samples/bpf/test_verifier.c | 13 ---
 samples/bpf/trace_output_user.c | 17 +
 samples/bpf/tracex1_user.c  |  9 +++--
 samples/bpf/tracex2_user.c  | 31 +---
 samples/bpf/tracex3_user.c  | 15 
 samples/bpf/tracex4_user.c  | 15 
 samples/bpf/tracex5_user.c  |  9 +++--
 samples/bpf/tracex6_user.c  | 16 -
 19 files changed, 221 insertions(+), 183 deletions(-)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index edd638b..edb7c04 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -1,6 +1,20 @@
 # kbuild trick to avoid linker error. Can be omitted if a module is built.
 obj- := dummy.o
 
+INC_DIR = $(src)/include
+TOOLS_DIR = $(realpath $(srctree))/tools
+TOOLS_LIB_DIR = $(TOOLS_DIR)/lib
+LIBBPF_DIR = $(TOOLS_LIB_DIR)/bpf
+
+$(obj)/libbpf/libbpf.a:
+   $(Q)mkdir -p $(obj)/libbpf
+   $(MAKE) -C $(LIBBPF_DIR) O=$(realpath $(obj))/libbpf CFLAGS= LDFLAGS= 
V=1 $(realpath $(obj))/libbpf/libbpf.a
+
+HOSTCFLAGS += -I$(TOOLS_LIB_DIR) -I$(INC_DIR)
+HOSTLDFLAGS += -L$(obj)/libbpf
+HOSTCFLAGS += -I$(INC_DIR) -I$(TOOLS_LIB_DIR)
+HOST_LOADLIBES += -lelf -lbpf
+
 # List of programs to build
 hostprogs-y := test_verifier test_maps
 hostprogs-y += sock_example
@@ -17,21 +31,27 @@ hostprogs-y += tracex6
 hostprogs-y += trace_output
 hostprogs-y += lathist
 
-test_verifier-objs := test_verifier.o libbpf.o
-test_maps-objs := test_maps.o libbpf.o
-sock_example-objs := sock_example.o libbpf.o
-fds_example-objs := bpf_load.o libbpf.o fds_example.o
-sockex1-objs := bpf_load.o libbpf.o sockex1_user.o
-sockex2-objs := bpf_load.o libbpf.o sockex2_user.o
-sockex3-objs := bpf_load.o libbpf.o sockex3_user.o
-tracex1-objs := bpf_load.o libbpf.o tracex1_user.o
-tracex2-objs := bpf_load.o libbpf.o tracex2_user.o
-tracex3-objs := bpf_load.o libbpf.o tracex3_user.o
-tracex4-objs := bpf_load.o libbpf.o tracex4_user.o
-tracex5-objs := bpf_load.o libbpf.o tracex5_user.o
-tracex6-objs := bpf_load.o libbpf.o tracex6_user.o
-trace_output-objs := bpf_load.o libbpf.o trace_output_user.o
-lathist-objs := bpf_load.o libbpf.o lathist_user.o
+test_verifier-objs := test_verifier.o
+test_maps-objs := test_maps.o
+sock_example-objs := sock_example.o utils.o
+fds_example-objs := utils.o fds_example.o
+sockex1-objs := utils.o sockex1_user.o
+sockex2-objs := utils.o sockex2_user.o
+sockex3-objs := utils.o sockex3_user.o
+tracex1-objs := utils.o tracex1_user.o
+tracex2-objs := utils.o tracex2_user.o
+tracex3-objs := utils.o tracex3_user.o
+tracex4-objs := utils.o tracex4_user.o
+tracex5-objs := utils.o tracex5_user.o
+tracex6-objs := utils.o tracex6_user.o
+trace_output-objs := utils.o trace_output_user.o
+lathist-objs := utils.o lathist_user.o
+
+define add_depend
+$(foreach m, $(notdir $1), \
+   $(eval $(obj)/$m: $(obj)/libbpf/libbpf.a))
+endef
+$(call add_depend, $(hostprogs-y))
 
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
@@ -50,19 +70,8 @@ always += lathist_kern.o
 
 HOSTCFLAGS += -I$(objtree)/usr/include
 
-HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable
-HOSTLOADLIBES_fds_example += -lelf
-HOSTLOADLIBES_sockex1 += -lelf
-HOSTLOADLIBES_sockex2 += -lelf
-HOSTLOADLIBES_sockex3 += -lelf
-HOSTLOADLIBES_tracex1 += -lelf