diff mbox series

[bpf-next,v3] selftests/bpf: Use pkg-config to determine ld flags

Message ID 20231016124313.60220-1-akihiko.odaki@daynix.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series [bpf-next,v3] selftests/bpf: Use pkg-config to determine ld flags | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-VM_Test-5 fail Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-2 fail Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-3 fail Logs for build for s390x with gcc
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-4 fail Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-7 success Logs for veristat
bpf/vmtest-bpf-next-VM_Test-0 success Logs for ShellCheck
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 9 this patch: 9
netdev/cc_maintainers success CCed 16 of 16 maintainers
netdev/build_clang success Errors and warnings before: 9 this patch: 9
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 9 this patch: 9
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 24 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Akihiko Odaki Oct. 16, 2023, 12:43 p.m. UTC
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 <akihiko.odaki@daynix.com>
---
V2 -> V3: Added missing "echo".
V1 -> V2: Implemented fallback, referring to HOSTPKG_CONFIG.

 tools/testing/selftests/bpf/Makefile   | 4 +++-
 tools/testing/selftests/bpf/README.rst | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

Comments

Akihiko Odaki Oct. 16, 2023, 1:08 p.m. UTC | #1
On 2023/10/16 21:52, Daniel Borkmann wrote:
> On 10/16/23 2:43 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.
>>
>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
>> ---
>> V2 -> V3: Added missing "echo".
>> V1 -> V2: Implemented fallback, referring to HOSTPKG_CONFIG.
> 
> Same issue in v3. Please don't resend your patches too quickly, but 
> properly set up an
> environment where you can test that this fallback works first :
> 
> https://github.com/kernel-patches/bpf/actions/runs/6533309175/job/17738285759

I think you are looking at a wrong run. The run checks out:
https://github.com/kernel-patches/bpf/commit/0c184cb0b561d2fb60b2dc79c2917cd7ff8cd8a2

This is v2. I think the correct one is:
https://github.com/kernel-patches/bpf/actions/runs/6533797864

That said, I found spurious error messages with the run. I tested it by 
setting PKG_CONFIG=false, but I should have tested it with 
PKG_CONFIG=a-command-that-does-not-exist. Now I sent v4, which does no 
longer emit noisy error messages and is properly tested.
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index caede9b574cb..0b4ce6266bfc 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 +32,8 @@  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 || echo -lelf -lz)	\
+	  -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.