* [PATCH v2] tools/resolve_btfids: Tidy host CFLAGS forcing
@ 2023-02-01 21:37 Ian Rogers
2023-02-01 23:31 ` Nathan Chancellor
0 siblings, 1 reply; 2+ messages in thread
From: Ian Rogers @ 2023-02-01 21:37 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend,
KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, Connor OBrien,
Nathan Chancellor, Ian Rogers, Kumar Kartikeya Dwivedi, bpf,
linux-kernel
Avoid passing CROSS_COMPILE to submakes and ensure CFLAGS is forced to
HOSTCFLAGS for submake builds. This fixes problems with cross
compilation.
Tidy to not unnecessarily modify/export CFLAGS, make the override for
prepare and build clearer.
Fixes: 13e07691a16f ("tools/resolve_btfids: Alter how HOSTCC is forced")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/bpf/resolve_btfids/Makefile | 49 ++++++++++++++++---------------
1 file changed, 26 insertions(+), 23 deletions(-)
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
index daed388aa5d7..3ed4e3be4e06 100644
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -17,12 +17,7 @@ else
MAKEFLAGS=--no-print-directory
endif
-# always use the host compiler
-HOST_OVERRIDES := AR="$(HOSTAR)" CC="$(HOSTCC)" LD="$(HOSTLD)" ARCH="$(HOSTARCH)" \
- EXTRA_CFLAGS="$(HOSTCFLAGS) $(KBUILD_HOSTCFLAGS)"
-
RM ?= rm
-CROSS_COMPILE =
OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
@@ -43,8 +38,31 @@ SUBCMD_INCLUDE := $(SUBCMD_DESTDIR)include
BINARY := $(OUTPUT)/resolve_btfids
BINARY_IN := $(BINARY)-in.o
+LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null)
+LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
+
+RESOLVE_BTFIDS_CFLAGS = -g \
+ -I$(srctree)/tools/include \
+ -I$(srctree)/tools/include/uapi \
+ -I$(LIBBPF_INCLUDE) \
+ -I$(SUBCMD_INCLUDE) \
+ $(LIBELF_FLAGS)
+
+# Overrides for the prepare step libraries.
+HOST_OVERRIDES_PREPARE := AR="$(HOSTAR)" CC="$(HOSTCC)" LD="$(HOSTLD)" \
+ ARCH="$(HOSTARCH)" CROSS_COMPILE=""
+
+# Overrides for Makefile.build C targets.
+HOST_OVERRIDES_BUILD := $(HOST_OVERRIDES_PREPARE) \
+ CFLAGS="$(HOSTCFLAGS) $(KBUILD_HOSTCFLAGS) $(RESOLVE_BTFIDS_CFLAGS)" \
+
+LIBS = $(LIBELF_LIBS) -lz
+
all: $(BINARY)
+export srctree OUTPUT Q
+include $(srctree)/tools/build/Makefile.include
+
prepare: $(BPFOBJ) $(SUBCMDOBJ)
$(OUTPUT) $(OUTPUT)/libsubcmd $(LIBBPF_OUT):
@@ -53,31 +71,16 @@ $(OUTPUT) $(OUTPUT)/libsubcmd $(LIBBPF_OUT):
$(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/libsubcmd
$(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(SUBCMD_OUT) \
- DESTDIR=$(SUBCMD_DESTDIR) $(HOST_OVERRIDES) prefix= subdir= \
+ DESTDIR=$(SUBCMD_DESTDIR) $(HOST_OVERRIDES_PREPARE) prefix= subdir= \
$(abspath $@) install_headers
$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUT)
$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(LIBBPF_OUT) \
- DESTDIR=$(LIBBPF_DESTDIR) $(HOST_OVERRIDES) prefix= subdir= \
+ DESTDIR=$(LIBBPF_DESTDIR) $(HOST_OVERRIDES_PREPARE) prefix= subdir= \
$(abspath $@) install_headers
-LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null)
-LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
-
-CFLAGS += -g \
- -I$(srctree)/tools/include \
- -I$(srctree)/tools/include/uapi \
- -I$(LIBBPF_INCLUDE) \
- -I$(SUBCMD_INCLUDE) \
- $(LIBELF_FLAGS)
-
-LIBS = $(LIBELF_LIBS) -lz
-
-export srctree OUTPUT CFLAGS Q
-include $(srctree)/tools/build/Makefile.include
-
$(BINARY_IN): fixdep FORCE prepare | $(OUTPUT)
- $(Q)$(MAKE) $(build)=resolve_btfids $(HOST_OVERRIDES)
+ $(Q)$(MAKE) $(build)=resolve_btfids $(HOST_OVERRIDES_BUILD)
$(BINARY): $(BPFOBJ) $(SUBCMDOBJ) $(BINARY_IN)
$(call msg,LINK,$@)
--
2.39.1.519.gcb327c4b5f-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] tools/resolve_btfids: Tidy host CFLAGS forcing
2023-02-01 21:37 [PATCH v2] tools/resolve_btfids: Tidy host CFLAGS forcing Ian Rogers
@ 2023-02-01 23:31 ` Nathan Chancellor
0 siblings, 0 replies; 2+ messages in thread
From: Nathan Chancellor @ 2023-02-01 23:31 UTC (permalink / raw)
To: Ian Rogers
Cc: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
Martin KaFai Lau, Song Liu, Yonghong Song, John Fastabend,
KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa, Connor OBrien,
Kumar Kartikeya Dwivedi, bpf, linux-kernel
On Wed, Feb 01, 2023 at 01:37:43PM -0800, Ian Rogers wrote:
> Avoid passing CROSS_COMPILE to submakes and ensure CFLAGS is forced to
> HOSTCFLAGS for submake builds. This fixes problems with cross
> compilation.
>
> Tidy to not unnecessarily modify/export CFLAGS, make the override for
> prepare and build clearer.
>
> Fixes: 13e07691a16f ("tools/resolve_btfids: Alter how HOSTCC is forced")
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
I can test alternative solutions as well.
> ---
> tools/bpf/resolve_btfids/Makefile | 49 ++++++++++++++++---------------
> 1 file changed, 26 insertions(+), 23 deletions(-)
>
> diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
> index daed388aa5d7..3ed4e3be4e06 100644
> --- a/tools/bpf/resolve_btfids/Makefile
> +++ b/tools/bpf/resolve_btfids/Makefile
> @@ -17,12 +17,7 @@ else
> MAKEFLAGS=--no-print-directory
> endif
>
> -# always use the host compiler
> -HOST_OVERRIDES := AR="$(HOSTAR)" CC="$(HOSTCC)" LD="$(HOSTLD)" ARCH="$(HOSTARCH)" \
> - EXTRA_CFLAGS="$(HOSTCFLAGS) $(KBUILD_HOSTCFLAGS)"
> -
> RM ?= rm
> -CROSS_COMPILE =
>
> OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
>
> @@ -43,8 +38,31 @@ SUBCMD_INCLUDE := $(SUBCMD_DESTDIR)include
> BINARY := $(OUTPUT)/resolve_btfids
> BINARY_IN := $(BINARY)-in.o
>
> +LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null)
> +LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
> +
> +RESOLVE_BTFIDS_CFLAGS = -g \
> + -I$(srctree)/tools/include \
> + -I$(srctree)/tools/include/uapi \
> + -I$(LIBBPF_INCLUDE) \
> + -I$(SUBCMD_INCLUDE) \
> + $(LIBELF_FLAGS)
> +
> +# Overrides for the prepare step libraries.
> +HOST_OVERRIDES_PREPARE := AR="$(HOSTAR)" CC="$(HOSTCC)" LD="$(HOSTLD)" \
> + ARCH="$(HOSTARCH)" CROSS_COMPILE=""
> +
> +# Overrides for Makefile.build C targets.
> +HOST_OVERRIDES_BUILD := $(HOST_OVERRIDES_PREPARE) \
> + CFLAGS="$(HOSTCFLAGS) $(KBUILD_HOSTCFLAGS) $(RESOLVE_BTFIDS_CFLAGS)" \
> +
> +LIBS = $(LIBELF_LIBS) -lz
> +
> all: $(BINARY)
>
> +export srctree OUTPUT Q
> +include $(srctree)/tools/build/Makefile.include
> +
> prepare: $(BPFOBJ) $(SUBCMDOBJ)
>
> $(OUTPUT) $(OUTPUT)/libsubcmd $(LIBBPF_OUT):
> @@ -53,31 +71,16 @@ $(OUTPUT) $(OUTPUT)/libsubcmd $(LIBBPF_OUT):
>
> $(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/libsubcmd
> $(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(SUBCMD_OUT) \
> - DESTDIR=$(SUBCMD_DESTDIR) $(HOST_OVERRIDES) prefix= subdir= \
> + DESTDIR=$(SUBCMD_DESTDIR) $(HOST_OVERRIDES_PREPARE) prefix= subdir= \
> $(abspath $@) install_headers
>
> $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUT)
> $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(LIBBPF_OUT) \
> - DESTDIR=$(LIBBPF_DESTDIR) $(HOST_OVERRIDES) prefix= subdir= \
> + DESTDIR=$(LIBBPF_DESTDIR) $(HOST_OVERRIDES_PREPARE) prefix= subdir= \
> $(abspath $@) install_headers
>
> -LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null)
> -LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
> -
> -CFLAGS += -g \
> - -I$(srctree)/tools/include \
> - -I$(srctree)/tools/include/uapi \
> - -I$(LIBBPF_INCLUDE) \
> - -I$(SUBCMD_INCLUDE) \
> - $(LIBELF_FLAGS)
> -
> -LIBS = $(LIBELF_LIBS) -lz
> -
> -export srctree OUTPUT CFLAGS Q
> -include $(srctree)/tools/build/Makefile.include
> -
> $(BINARY_IN): fixdep FORCE prepare | $(OUTPUT)
> - $(Q)$(MAKE) $(build)=resolve_btfids $(HOST_OVERRIDES)
> + $(Q)$(MAKE) $(build)=resolve_btfids $(HOST_OVERRIDES_BUILD)
>
> $(BINARY): $(BPFOBJ) $(SUBCMDOBJ) $(BINARY_IN)
> $(call msg,LINK,$@)
> --
> 2.39.1.519.gcb327c4b5f-goog
>
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