[PATCH bpf 0/2] Two fixes for make kselftest TARGETS=bpf

[PATCH bpf 0/2] Two fixes for make kselftest TARGETS=bpf

[Ilya Leoshkevich]

While the primary documented way to run BPF tests is by invoking
make in tools/testing/selftests/bpf, kselftest documentation implies that
make kselftest TARGETS=bpf from the top directory should work as well.
This patch series contains two fixes that were neccesary to make it run:

- Patch 1: $(COMPILE.c) -> $(CC) $(CFLAGS) -c
- Patch 2: Add CXX=$(CROSS_COMPILE)g++ default value

Ilya Leoshkevich (2):
  tools/bpf: Don't use $(COMPILE.c)
  selftests/bpf: Add a default $(CXX) value

 tools/bpf/Makefile                   | 6 +++---
 tools/bpf/bpftool/Makefile           | 8 ++++----
 tools/testing/selftests/bpf/Makefile | 1 +
 3 files changed, 8 insertions(+), 7 deletions(-)

-- 
2.25.4

[PATCH bpf 1/2] tools/bpf: Don't use $(COMPILE.c)

[Ilya Leoshkevich]

When using make kselftest TARGETS=bpf, tools/bpf is built with
MAKEFLAGS=rR, which causes $(COMPILE.c) to be undefined, which in turn
causes the build to fail with

  CC       kselftest/bpf/tools/build/bpftool/map_perf_ring.o
/bin/sh: 1: -MMD: not found

Fix by using $(CC) $(CFLAGS) -c instead of $(COMPILE.c).

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/bpf/Makefile         | 6 +++---
 tools/bpf/bpftool/Makefile | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/tools/bpf/Makefile b/tools/bpf/Makefile
index f897eeeb0b4f..77472e28c8fd 100644
--- a/tools/bpf/Makefile
+++ b/tools/bpf/Makefile
@@ -64,12 +64,12 @@ $(OUTPUT)%.lex.c: $(srctree)/tools/bpf/%.l
 	$(QUIET_FLEX)$(LEX) -o $@ $<
 
 $(OUTPUT)%.o: $(srctree)/tools/bpf/%.c
-	$(QUIET_CC)$(COMPILE.c) -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
 
 $(OUTPUT)%.yacc.o: $(OUTPUT)%.yacc.c
-	$(QUIET_CC)$(COMPILE.c) -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
 $(OUTPUT)%.lex.o: $(OUTPUT)%.lex.c
-	$(QUIET_CC)$(COMPILE.c) -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -o $@ $<
 
 PROGS = $(OUTPUT)bpf_jit_disasm $(OUTPUT)bpf_dbg $(OUTPUT)bpf_asm
 
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index f584d1fdfc64..4df7ed7e47da 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -121,7 +121,7 @@ else
 endif
 
 $(OUTPUT)_prog.o: prog.c
-	$(QUIET_CC)$(COMPILE.c) -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $<
 
 $(OUTPUT)_bpftool: $(_OBJS) $(LIBBPF)
 	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(_OBJS) $(LIBS)
@@ -136,10 +136,10 @@ profiler.skel.h: $(OUTPUT)_bpftool skeleton/profiler.bpf.o
 	$(QUIET_GEN)$(OUTPUT)./_bpftool gen skeleton skeleton/profiler.bpf.o > $@
 
 $(OUTPUT)prog.o: prog.c profiler.skel.h
-	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $<
 
 $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
-	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $<
 
 $(OUTPUT)feature.o: | zdep
 
@@ -147,7 +147,7 @@ $(OUTPUT)bpftool: $(__OBJS) $(LIBBPF)
 	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(__OBJS) $(LIBS)
 
 $(OUTPUT)%.o: %.c
-	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $<
+	$(QUIET_CC)$(CC) $(CFLAGS) -c -MMD -o $@ $<
 
 clean: $(LIBBPF)-clean
 	$(call QUIET_CLEAN, bpftool)
-- 
2.25.4

[PATCH bpf 2/2] selftests/bpf: Add a default $(CXX) value

[Ilya Leoshkevich]

When using make kselftest TARGETS=bpf, tools/bpf is built with
MAKEFLAGS=rR, which causes $(CXX) to be undefined, which in turn causes
the build to fail with

  CXX      test_cpp
/bin/sh: 2: g: not found

Fix by adding a default $(CXX) value, like tools/build/feature/Makefile
already does.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/testing/selftests/bpf/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index b59cd1042f9d..03017be02fac 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -2,6 +2,7 @@
 include ../../../../scripts/Kbuild.include
 include ../../../scripts/Makefile.arch
 
+CXX ?= $(CROSS_COMPILE)g++
 CURDIR := $(abspath .)
 TOOLSDIR := $(abspath ../../..)
 LIBDIR := $(TOOLSDIR)/lib
-- 
2.25.4

Re: [PATCH bpf 0/2] Two fixes for make kselftest TARGETS=bpf

[Daniel Borkmann]

On 6/2/20 7:56 PM, Ilya Leoshkevich wrote:
> While the primary documented way to run BPF tests is by invoking
> make in tools/testing/selftests/bpf, kselftest documentation implies that
> make kselftest TARGETS=bpf from the top directory should work as well.
> This patch series contains two fixes that were neccesary to make it run:
> 
> - Patch 1: $(COMPILE.c) -> $(CC) $(CFLAGS) -c
> - Patch 2: Add CXX=$(CROSS_COMPILE)g++ default value
> 
> Ilya Leoshkevich (2):
>    tools/bpf: Don't use $(COMPILE.c)
>    selftests/bpf: Add a default $(CXX) value
> 
>   tools/bpf/Makefile                   | 6 +++---
>   tools/bpf/bpftool/Makefile           | 8 ++++----
>   tools/testing/selftests/bpf/Makefile | 1 +
>   3 files changed, 8 insertions(+), 7 deletions(-)

I've tested on x86-64 and arm64 as well, applied, thanks!