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.
Signed-off-by: Akihiko Odaki <[email protected]>
---
tools/testing/selftests/bpf/Makefile | 3 ++-
tools/testing/selftests/bpf/README.rst | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index caede9b574cb..833134aa2eda 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -4,6 +4,7 @@ include ../../../scripts/Makefile.arch
include ../../../scripts/Makefile.include
CXX ?= $(CROSS_COMPILE)g++
+PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
CURDIR := $(abspath .)
TOOLSDIR := $(abspath ../../..)
@@ -31,7 +32,7 @@ CFLAGS += -g -O0 -rdynamic -Wall -Werror $(GENFLAGS) $(SAN_CFLAGS) \
-I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \
-I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT)
LDFLAGS += $(SAN_LDFLAGS)
-LDLIBS += -lelf -lz -lrt -lpthread
+LDLIBS += $(shell $(PKG_CONFIG) --libs libelf zlib) -lrt -lpthread
ifneq ($(LLVM),)
# Silence some warnings when compiled with clang
diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst
index cb9b95702ac6..9af79c7a9b58 100644
--- a/tools/testing/selftests/bpf/README.rst
+++ b/tools/testing/selftests/bpf/README.rst
@@ -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.
--
2.42.0
On 10/15/23 3:39 PM, Akihiko Odaki wrote:
> 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.
Is this not covered via -lz or is it that the name differs?
Anyway, this change breaks selftest build for BPF CI (see below), could this
either be made optional or detected differently?
https://github.com/kernel-patches/bpf/actions/runs/6524480596/job/17716170021
[...]
make: pkg-config: Command not found
CC bench.o
make: pkg-config: Command not found
make: pkg-config: Command not found
CC bench_count.o
make: pkg-config: Command not found
BINARY xdp_redirect_multi
HOSTLD /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/fixdep-in.o
LINK /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/fixdep
CC veristat.o
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/exec-cmd.h
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/exec-cmd.o
make: pkg-config: Command not found
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/help.h
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/help.o
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/pager.h
make: pkg-config: Command not found
BINARY test_verifier
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/pager.o
BINARY test_tag
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/parse-options.o
make: pkg-config: Command not found
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/run-command.o
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/parse-options.h
make: pkg-config: Command not found
INSTALL /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd//include/subcmd/run-command.h
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/sigchain.o
BINARY flow_dissector_load
CC /tmp/work/bpf/bpf/tools/testing/selftests/bpf/tools/build/resolve_btfids/libsubcmd/subcmd-config.o
make: pkg-config: Command not found
BINARY test_lirc_mode2_user
INSTALL libsubcmd_headers
BINARY xdping
make: pkg-config: Command not found
> tools/testing/selftests/bpf/Makefile | 3 ++-
> tools/testing/selftests/bpf/README.rst | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index caede9b574cb..833134aa2eda 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -4,6 +4,7 @@ include ../../../scripts/Makefile.arch
> include ../../../scripts/Makefile.include
>
> CXX ?= $(CROSS_COMPILE)g++
> +PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
>
> CURDIR := $(abspath .)
> TOOLSDIR := $(abspath ../../..)
> @@ -31,7 +32,7 @@ CFLAGS += -g -O0 -rdynamic -Wall -Werror $(GENFLAGS) $(SAN_CFLAGS) \
> -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \
> -I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT)
> LDFLAGS += $(SAN_LDFLAGS)
> -LDLIBS += -lelf -lz -lrt -lpthread
> +LDLIBS += $(shell $(PKG_CONFIG) --libs libelf zlib) -lrt -lpthread
>
> ifneq ($(LLVM),)
> # Silence some warnings when compiled with clang
> diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst
> index cb9b95702ac6..9af79c7a9b58 100644
> --- a/tools/testing/selftests/bpf/README.rst
> +++ b/tools/testing/selftests/bpf/README.rst
> @@ -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.
>
>
On 2023/10/16 20:39, Daniel Borkmann wrote:
> On 10/15/23 3:39 PM, Akihiko Odaki wrote:
>> 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.
>
> Is this not covered via -lz or is it that the name differs?
libelf may not only be linked with zlib but also with zstandard.
>
> Anyway, this change breaks selftest build for BPF CI (see below), could
> this
> either be made optional or detected differently?
>
> https://github.com/kernel-patches/bpf/actions/runs/6524480596/job/17716170021
I sent v2 (I forgot to add bpf-next to the subject for this).
This version implements a fallback just in the same way done for
HOSTPKG_CONFIG.