From: Stanislav Fomichev sdf@google.com
[ Upstream commit 8e2688876c7f7073d925e1f150e86b8ed3338f52 ]
libbpf targets don't explicitly depend on fixdep target, so when we do 'make -j$(nproc)', there is a high probability, that some objects will be built before fixdep binary is available.
Fix this by running sub-make; this makes sure that fixdep dependency is properly accounted for.
For the same issue in perf, see commit abb26210a395 ("perf tools: Force fixdep compilation at the start of the build").
Before:
$ rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld -C tools/lib/bpf/
Auto-detecting system features: ... libelf: [ on ] ... bpf: [ on ]
HOSTCC /tmp/bld/fixdep.o CC /tmp/bld/libbpf.o CC /tmp/bld/bpf.o CC /tmp/bld/btf.o CC /tmp/bld/nlattr.o CC /tmp/bld/libbpf_errno.o CC /tmp/bld/str_error.o CC /tmp/bld/netlink.o CC /tmp/bld/bpf_prog_linfo.o CC /tmp/bld/libbpf_probes.o CC /tmp/bld/xsk.o HOSTLD /tmp/bld/fixdep-in.o LINK /tmp/bld/fixdep LD /tmp/bld/libbpf-in.o LINK /tmp/bld/libbpf.a LINK /tmp/bld/libbpf.so LINK /tmp/bld/test_libbpf
$ head /tmp/bld/.libbpf.o.cmd # cannot find fixdep (/usr/local/google/home/sdf/src/linux/xxx//fixdep) # using basic dep data
/tmp/bld/libbpf.o: libbpf.c /usr/include/stdc-predef.h \ /usr/include/stdlib.h /usr/include/features.h \ /usr/include/x86_64-linux-gnu/sys/cdefs.h \ /usr/include/x86_64-linux-gnu/bits/wordsize.h \ /usr/include/x86_64-linux-gnu/gnu/stubs.h \ /usr/include/x86_64-linux-gnu/gnu/stubs-64.h \ /usr/lib/gcc/x86_64-linux-gnu/7/include/stddef.h \
After:
$ rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld -C tools/lib/bpf/
Auto-detecting system features: ... libelf: [ on ] ... bpf: [ on ]
HOSTCC /tmp/bld/fixdep.o HOSTLD /tmp/bld/fixdep-in.o LINK /tmp/bld/fixdep CC /tmp/bld/libbpf.o CC /tmp/bld/bpf.o CC /tmp/bld/nlattr.o CC /tmp/bld/btf.o CC /tmp/bld/libbpf_errno.o CC /tmp/bld/str_error.o CC /tmp/bld/netlink.o CC /tmp/bld/bpf_prog_linfo.o CC /tmp/bld/libbpf_probes.o CC /tmp/bld/xsk.o LD /tmp/bld/libbpf-in.o LINK /tmp/bld/libbpf.a LINK /tmp/bld/libbpf.so LINK /tmp/bld/test_libbpf
$ head /tmp/bld/.libbpf.o.cmd cmd_/tmp/bld/libbpf.o := gcc -Wp,-MD,/tmp/bld/.libbpf.o.d -Wp,-MT,/tmp/bld/libbpf.o -g -Wall -DHAVE_LIBELF_MMAP_SUPPORT -DCOMPAT_NEED_REALLOCARRAY -Wbad-function-cast -Wdeclaration-after-statement -Wformat-security -Wformat-y2k -Winit-self -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wno-system-headers -Wold-style-definition -Wpacked -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wundef -Wwrite-strings -Wformat -Wstrict-aliasing=3 -Werror -Wall -fPIC -I. -I/usr/local/google/home/sdf/src/linux/tools/include -I/usr/local/google/home/sdf/src/linux/tools/arch/x86/include/uapi -I/usr/local/google/home/sdf/src/linux/tools/include/uapi -fvisibility=hidden -D"BUILD_STR(s)=$(pound)s" -c -o /tmp/bld/libbpf.o libbpf.c
source_/tmp/bld/libbpf.o := libbpf.c
deps_/tmp/bld/libbpf.o := \ /usr/include/stdc-predef.h \ /usr/include/stdlib.h \ /usr/include/features.h \ /usr/include/x86_64-linux-gnu/sys/cdefs.h \ /usr/include/x86_64-linux-gnu/bits/wordsize.h \
Fixes: 7c422f557266 ("tools build: Build fixdep helper from perf and basic libs") Reported-by: Eric Dumazet edumazet@google.com Signed-off-by: Stanislav Fomichev sdf@google.com Acked-by: Yonghong Song yhs@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 34d9c3619c96..78fd86b85087 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -162,7 +162,8 @@ endif
TARGETS = $(CMD_TARGETS)
-all: fixdep all_cmd +all: fixdep + $(Q)$(MAKE) all_cmd
all_cmd: $(CMD_TARGETS) check