From: Connor O'Brien <connoro@google.com>
Date: Wed, 12 Jan 2022 00:25:03 +0000
Subject: tools/resolve_btfids: Build with host flags
Patch-mainline: v5.18-rc1
Git-commit: 0e3a1c902ffb56e9fe4416f0cd382c97b09ecbf6
References: jsc#PED-1377
resolve_btfids is built using $(HOSTCC) and $(HOSTLD) but does not
pick up the corresponding flags. As a result, host-specific settings
(such as a sysroot specified via HOSTCFLAGS=--sysroot=..., or a linker
specified via HOSTLDFLAGS=-fuse-ld=...) will not be respected.
Fix this by setting CFLAGS to KBUILD_HOSTCFLAGS and LDFLAGS to
KBUILD_HOSTLDFLAGS.
Also pass the cflags through to libbpf via EXTRA_CFLAGS to ensure that
the host libbpf is built with flags consistent with resolve_btfids.
Signed-off-by: Connor O'Brien <connoro@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220112002503.115968-1-connoro@google.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/bpf/resolve_btfids/Makefile | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -24,6 +24,8 @@ LD = $(HOSTLD)
ARCH = $(HOSTARCH)
RM ?= rm
CROSS_COMPILE =
+CFLAGS := $(KBUILD_HOSTCFLAGS)
+LDFLAGS := $(KBUILD_HOSTLDFLAGS)
OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
@@ -51,10 +53,10 @@ $(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/l
$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUT)
$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(LIBBPF_OUT) \
- DESTDIR=$(LIBBPF_DESTDIR) prefix= \
+ DESTDIR=$(LIBBPF_DESTDIR) prefix= EXTRA_CFLAGS="$(CFLAGS)" \
$(abspath $@) install_headers
-CFLAGS := -g \
+CFLAGS += -g \
-I$(srctree)/tools/include \
-I$(srctree)/tools/include/uapi \
-I$(LIBBPF_INCLUDE) \