From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Tue, 2 Jun 2020 19:56:48 +0200
Subject: tools/bpf: Don't use $(COMPILE.c)
Patch-mainline: v5.8-rc1
Git-commit: d70a6be1e2ab98f13688e4a529b326e8e11230d0
References: bsc#1177028

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>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200602175649.2501580-2-iii@linux.ibm.com
Acked-by: Gary Lin <glin@suse.com>
---
 tools/bpf/Makefile         |    6 +++---
 tools/bpf/bpftool/Makefile |    8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

--- a/tools/bpf/Makefile
+++ b/tools/bpf/Makefile
@@ -64,12 +64,12 @@ $(OUTPUT)%.lex.c: $(srctree)/tools/bpf/%
 	$(QUIET_FLEX)$(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
 
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -126,7 +126,7 @@ 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)
@@ -141,10 +141,10 @@ profiler.skel.h: $(OUTPUT)_bpftool skele
 	$(QUIET_GEN)$(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
 
@@ -152,7 +152,7 @@ $(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)