diff options
| author | Ihor Solodrai <ihor.solodrai@linux.dev> | 2026-03-04 17:47:30 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-03-07 08:51:51 -0800 |
| commit | b0dcdcb9ae757c8a8ba2fb24d34f8d147bae707b (patch) | |
| tree | d9a12fe3b9f35ec21c296342fcfdc94c1da4cca4 | |
| parent | 325d1ba3cac4a1c0bf981f73f4edbb7411f0e4dc (diff) | |
resolve_btfids: Fix linker flags detection
The "|| echo -lzstd" default makes zstd an unconditional link
dependency of resolve_btfids. On systems where libzstd-dev is not
installed and pkg-config fails, the linker fails:
ld: cannot find -lzstd: No such file or directory
libzstd is a transitive dependency of libelf, so the -lzstd flag is
strictly necessary only for static builds [1].
Remove ZSTD_LIBS variable, and instead set LIBELF_LIBS depending on
whether the build is static or not. Use $(HOSTPKG_CONFIG) as primary
source of the flags list.
Also add a default value for HOSTPKG_CONFIG in case it's not built via
the toplevel Makefile. Pass it from selftests/bpf too.
[1] https://lore.kernel.org/bpf/4ff82800-2daa-4b9f-95a9-6f512859ee70@linux.dev/
Reported-by: BPF CI Bot (Claude Opus 4.6) <bot+bpf-ci@kernel.org>
Reported-by: Vitaly Chikunov <vt@altlinux.org>
Closes: https://lore.kernel.org/bpf/aaWqMcK-2AQw5dx8@altlinux.org/
Fixes: 4021848a903e ("selftests/bpf: Pass through build flags to bpftool and resolve_btfids")
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Reviewed-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260305014730.3123382-1-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/bpf/resolve_btfids/Makefile | 9 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/Makefile | 1 |
2 files changed, 8 insertions, 2 deletions
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile index ef083602b73a..7672208f65e4 100644 --- a/tools/bpf/resolve_btfids/Makefile +++ b/tools/bpf/resolve_btfids/Makefile @@ -23,6 +23,7 @@ RM ?= rm HOSTCC ?= gcc HOSTLD ?= ld HOSTAR ?= ar +HOSTPKG_CONFIG ?= pkg-config CROSS_COMPILE = OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/ @@ -63,10 +64,14 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OU $(abspath $@) install_headers LIBELF_FLAGS := $(shell $(HOSTPKG_CONFIG) libelf --cflags 2>/dev/null) + +ifneq ($(filter -static,$(EXTRA_LDFLAGS)),) +LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs --static 2>/dev/null || echo -lelf -lzstd) +else LIBELF_LIBS := $(shell $(HOSTPKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf) +endif ZLIB_LIBS := $(shell $(HOSTPKG_CONFIG) zlib --libs 2>/dev/null || echo -lz) -ZSTD_LIBS := $(shell $(HOSTPKG_CONFIG) libzstd --libs 2>/dev/null || echo -lzstd) HOSTCFLAGS_resolve_btfids += -g \ -I$(srctree)/tools/include \ @@ -76,7 +81,7 @@ HOSTCFLAGS_resolve_btfids += -g \ $(LIBELF_FLAGS) \ -Wall -Werror -LIBS = $(LIBELF_LIBS) $(ZLIB_LIBS) $(ZSTD_LIBS) +LIBS = $(LIBELF_LIBS) $(ZLIB_LIBS) export srctree OUTPUT HOSTCFLAGS_resolve_btfids Q HOSTCC HOSTLD HOSTAR include $(srctree)/tools/build/Makefile.include diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 72a9ba41f95e..d5acbeba0383 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -409,6 +409,7 @@ $(RESOLVE_BTFIDS): $(HOST_BPFOBJ) | $(HOST_BUILD_DIR)/resolve_btfids \ CC="$(HOSTCC)" LD="$(HOSTLD)" AR="$(HOSTAR)" \ LIBBPF_INCLUDE=$(HOST_INCLUDE_DIR) \ EXTRA_LDFLAGS='$(SAN_LDFLAGS) $(EXTRA_LDFLAGS)' \ + HOSTPKG_CONFIG=$(PKG_CONFIG) \ OUTPUT=$(HOST_BUILD_DIR)/resolve_btfids/ BPFOBJ=$(HOST_BPFOBJ) # Get Clang's default includes on this system, as opposed to those seen by |