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| author | Brian Norris <briannorris@chromium.org> | 2024-07-15 13:32:44 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-08-05 12:19:48 -0300 |
| commit | dbb2a7a986971ef43d5a60d235c05491647e16f4 (patch) | |
| tree | 07a926eb50058e2bef10955cc9be64c26bcf7715 /tools/lib/bpf/Makefile | |
| parent | ea974028a049f2cea4bb6be963ee3e3844a03f6d (diff) | |
| download | lwn-dbb2a7a986971ef43d5a60d235c05491647e16f4.tar.gz lwn-dbb2a7a986971ef43d5a60d235c05491647e16f4.zip | |
tools build: Correct bpf fixdep dependencies
The dependencies in tools/lib/bpf/Makefile are incorrect. Before we
recurse to build $(BPF_IN_STATIC), we need to build its 'fixdep'
executable.
I can't use the usual shortcut from Makefile.include:
<target>: <sources> fixdep
because its 'fixdep' target relies on $(OUTPUT), and $(OUTPUT) differs
in the parent 'make' versus the child 'make' -- so I imitate it via
open-coding.
I tweak a few $(MAKE) invocations while I'm at it, because
1. I'm adding a new recursive make; and
2. these recursive 'make's print spurious lines about files that are "up
to date" (which isn't normally a feature in Kbuild subtargets) or
"jobserver not available" (see [1])
I also need to tweak the assignment of the OUTPUT variable, so that
relative path builds work. For example, for 'make tools/lib/bpf', OUTPUT
is unset, and is usually treated as "cwd" -- but recursive make will
change cwd and so OUTPUT has a new meaning. For consistency, I ensure
OUTPUT is always an absolute path.
And $(Q) gets a backup definition in tools/build/Makefile.include,
because Makefile.include is sometimes included without
tools/build/Makefile, so the "quiet command" stuff doesn't actually work
consistently without it.
After this change, top-level builds result in an empty grep result from:
$ grep 'cannot find fixdep' $(find tools/ -name '*.cmd')
[1] https://www.gnu.org/software/make/manual/html_node/MAKE-Variable.html
If we're not using $(MAKE) directly, then we need to use more '+'.
Signed-off-by: Brian Norris <briannorris@chromium.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20240715203325.3832977-4-briannorris@chromium.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib/bpf/Makefile')
| -rw-r--r-- | tools/lib/bpf/Makefile | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 2cf892774346..1b22f0f37288 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -108,6 +108,8 @@ MAKEOVERRIDES= all: +OUTPUT ?= ./ +OUTPUT := $(abspath $(OUTPUT))/ export srctree OUTPUT CC LD CFLAGS V include $(srctree)/tools/build/Makefile.include @@ -141,7 +143,10 @@ all: fixdep all_cmd: $(CMD_TARGETS) check -$(BPF_IN_SHARED): force $(BPF_GENERATED) +$(SHARED_OBJDIR) $(STATIC_OBJDIR): + $(Q)mkdir -p $@ + +$(BPF_IN_SHARED): force $(BPF_GENERATED) | $(SHARED_OBJDIR) @(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \ (diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) || \ echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true @@ -151,9 +156,11 @@ $(BPF_IN_SHARED): force $(BPF_GENERATED) @(test -f ../../include/uapi/linux/if_xdp.h -a -f ../../../include/uapi/linux/if_xdp.h && ( \ (diff -B ../../include/uapi/linux/if_xdp.h ../../../include/uapi/linux/if_xdp.h >/dev/null) || \ echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true + $(SILENT_MAKE) -C $(srctree)/tools/build CFLAGS= LDFLAGS= OUTPUT=$(SHARED_OBJDIR) $(SHARED_OBJDIR)fixdep $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)" -$(BPF_IN_STATIC): force $(BPF_GENERATED) +$(BPF_IN_STATIC): force $(BPF_GENERATED) | $(STATIC_OBJDIR) + $(SILENT_MAKE) -C $(srctree)/tools/build CFLAGS= LDFLAGS= OUTPUT=$(STATIC_OBJDIR) $(STATIC_OBJDIR)fixdep $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR) $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h @@ -263,7 +270,7 @@ install_pkgconfig: $(PC_FILE) install: install_lib install_pkgconfig install_headers -clean: +clean: fixdep-clean $(call QUIET_CLEAN, libbpf) $(RM) -rf $(CMD_TARGETS) \ *~ .*.d .*.cmd LIBBPF-CFLAGS $(BPF_GENERATED) \ $(SHARED_OBJDIR) $(STATIC_OBJDIR) \ |