Commit 40d0eb02 authored by Andrii Nakryiko's avatar Andrii Nakryiko
Browse files

Merge branch 'selftests-bpf-use-pkg-config-to-determine-ld-flags' 

Akihiko Odaki says:

====================
selftests/bpf: Use pkg-config to determine ld flags

When linking statically, libraries may require other dependencies to be
included to ld flags. In particular, libelf may require libzstd. Use
pkg-config to determine such dependencies.

V4 -> V5: Introduced variables LIBELF_CFLAGS and LIBELF_LIBS.
          (Daniel Borkmann)
          Added patch "selftests/bpf: Choose pkg-config for the target".
V3 -> V4: Added "2> /dev/null".
V2 -> V3: Added missing "echo".
V1 -> V2: Implemented fallback, referring to HOSTPKG_CONFIG.
====================

Link: https://lore.kernel.org/r/20231125084253.85025-1-akihiko.odaki@daynix.com


Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
parents d4e7dd48 8998a479

tools/testing/selftests/bpf/Makefile

+9 −5
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ else 
GENDIR := $(abspath ../../../../include/generated)

endif

GENHDR := $(GENDIR)/autoconf.h

HOSTPKG_CONFIG := pkg-config

PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config



ifneq ($(wildcard $(GENHDR)),)

  GENFLAGS := -DHAVE_GENHDR
@@ -29,13 +29,17 @@ SAN_CFLAGS ?= 
SAN_LDFLAGS	?= $(SAN_CFLAGS)

RELEASE		?=

OPT_FLAGS	?= $(if $(RELEASE),-O2,-O0)



LIBELF_CFLAGS	:= $(shell $(PKG_CONFIG) libelf --cflags 2>/dev/null)

LIBELF_LIBS	:= $(shell $(PKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)



CFLAGS += -g $(OPT_FLAGS) -rdynamic					\

	  -Wall -Werror 						\

	  $(GENFLAGS) $(SAN_CFLAGS)					\

	  $(GENFLAGS) $(SAN_CFLAGS) $(LIBELF_CFLAGS)			\

	  -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR)		\

	  -I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT)

LDFLAGS += $(SAN_LDFLAGS)

LDLIBS += -lelf -lz -lrt -lpthread

LDLIBS += $(LIBELF_LIBS) -lz -lrt -lpthread



ifneq ($(LLVM),)

# Silence some warnings when compiled with clang
@@ -219,9 +223,9 @@ $(OUTPUT)/urandom_read: urandom_read.c urandom_read_aux.c $(OUTPUT)/liburandom_r 


$(OUTPUT)/sign-file: ../../../../scripts/sign-file.c

	$(call msg,SIGN-FILE,,$@)

	$(Q)$(CC) $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null) \

	$(Q)$(CC) $(shell $(PKG_CONFIG) --cflags libcrypto 2> /dev/null) \

		  $< -o $@ \

		  $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)

		  $(shell $(PKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)



$(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(RESOLVE_BTFIDS) $(wildcard bpf_testmod/Makefile bpf_testmod/*.[ch])

	$(call msg,MOD,,$@)

tools/testing/selftests/bpf/README.rst

+1 −1
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ In case of linker errors when running selftests, try using static linking: 


.. code-block:: console



  $ LDLIBS=-static vmtest.sh

  $ LDLIBS=-static PKG_CONFIG='pkg-config --static' vmtest.sh



.. note:: Some distros may not support static linking.