[bpf] libbpf: Fix build on read-only filesystems
diff mbox series

Message ID 20191223030530.725937-1-namhyung@kernel.org
State New
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Series
  • [bpf] libbpf: Fix build on read-only filesystems
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Commit Message

Namhyung Kim Dec. 23, 2019, 3:05 a.m. UTC
I got the following error when I tried to build perf on a read-only
filesystem with O=dir option.

  $ cd /some/where/ro/linux/tools/perf
  $ make O=$HOME/build/perf
  ...
    CC       /home/namhyung/build/perf/lib.o
  /bin/sh: bpf_helper_defs.h: Read-only file system
  make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1
  make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2
  make[2]: *** Waiting for unfinished jobs....
    LD       /home/namhyung/build/perf/libperf-in.o
    AR       /home/namhyung/build/perf/libperf.a
    PERF_VERSION = 5.4.0
  make[1]: *** [Makefile.perf:225: sub-make] Error 2
  make: *** [Makefile:70: all] Error 2

It was becaused bpf_helper_defs.h was generated in current directory.
Move it to OUTPUT directory.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/lib/bpf/Makefile               | 15 ++++++++-------
 tools/testing/selftests/bpf/Makefile |  6 +++---
 2 files changed, 11 insertions(+), 10 deletions(-)

Comments

Andrii Nakryiko Dec. 23, 2019, 5:45 a.m. UTC | #1
On Sun, Dec 22, 2019 at 7:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> I got the following error when I tried to build perf on a read-only
> filesystem with O=dir option.
>
>   $ cd /some/where/ro/linux/tools/perf
>   $ make O=$HOME/build/perf
>   ...
>     CC       /home/namhyung/build/perf/lib.o
>   /bin/sh: bpf_helper_defs.h: Read-only file system
>   make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1
>   make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2
>   make[2]: *** Waiting for unfinished jobs....
>     LD       /home/namhyung/build/perf/libperf-in.o
>     AR       /home/namhyung/build/perf/libperf.a
>     PERF_VERSION = 5.4.0
>   make[1]: *** [Makefile.perf:225: sub-make] Error 2
>   make: *** [Makefile:70: all] Error 2
>
> It was becaused bpf_helper_defs.h was generated in current directory.
> Move it to OUTPUT directory.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---

Looks good, thanks!

Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>

>  tools/lib/bpf/Makefile               | 15 ++++++++-------
>  tools/testing/selftests/bpf/Makefile |  6 +++---
>  2 files changed, 11 insertions(+), 10 deletions(-)
>

[...]
Andrii Nakryiko Dec. 23, 2019, 5:54 a.m. UTC | #2
On Sun, Dec 22, 2019 at 9:45 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Sun, Dec 22, 2019 at 7:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > I got the following error when I tried to build perf on a read-only
> > filesystem with O=dir option.
> >
> >   $ cd /some/where/ro/linux/tools/perf
> >   $ make O=$HOME/build/perf
> >   ...
> >     CC       /home/namhyung/build/perf/lib.o
> >   /bin/sh: bpf_helper_defs.h: Read-only file system
> >   make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1
> >   make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2
> >   make[2]: *** Waiting for unfinished jobs....
> >     LD       /home/namhyung/build/perf/libperf-in.o
> >     AR       /home/namhyung/build/perf/libperf.a
> >     PERF_VERSION = 5.4.0
> >   make[1]: *** [Makefile.perf:225: sub-make] Error 2
> >   make: *** [Makefile:70: all] Error 2
> >
> > It was becaused bpf_helper_defs.h was generated in current directory.
> > Move it to OUTPUT directory.
> >
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
>
> Looks good, thanks!

just one minor thing: bpf_helper_defs.h has to be added to .gitignore
under selftests/bpf now

>
> Tested-by: Andrii Nakryiko <andriin@fb.com>
> Acked-by: Andrii Nakryiko <andriin@fb.com>
>
> >  tools/lib/bpf/Makefile               | 15 ++++++++-------
> >  tools/testing/selftests/bpf/Makefile |  6 +++---
> >  2 files changed, 11 insertions(+), 10 deletions(-)
> >
>
> [...]
Namhyung Kim Dec. 23, 2019, 6:09 a.m. UTC | #3
Hello,

On Mon, Dec 23, 2019 at 2:55 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Sun, Dec 22, 2019 at 9:45 PM Andrii Nakryiko
> <andrii.nakryiko@gmail.com> wrote:
> >
> > On Sun, Dec 22, 2019 at 7:05 PM Namhyung Kim <namhyung@kernel.org> wrote:
> > >
> > > I got the following error when I tried to build perf on a read-only
> > > filesystem with O=dir option.
> > >
> > >   $ cd /some/where/ro/linux/tools/perf
> > >   $ make O=$HOME/build/perf
> > >   ...
> > >     CC       /home/namhyung/build/perf/lib.o
> > >   /bin/sh: bpf_helper_defs.h: Read-only file system
> > >   make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1
> > >   make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2
> > >   make[2]: *** Waiting for unfinished jobs....
> > >     LD       /home/namhyung/build/perf/libperf-in.o
> > >     AR       /home/namhyung/build/perf/libperf.a
> > >     PERF_VERSION = 5.4.0
> > >   make[1]: *** [Makefile.perf:225: sub-make] Error 2
> > >   make: *** [Makefile:70: all] Error 2
> > >
> > > It was becaused bpf_helper_defs.h was generated in current directory.
> > > Move it to OUTPUT directory.
> > >
> > > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > > ---
> >
> > Looks good, thanks!
>
> just one minor thing: bpf_helper_defs.h has to be added to .gitignore
> under selftests/bpf now
>
> >
> > Tested-by: Andrii Nakryiko <andriin@fb.com>
> > Acked-by: Andrii Nakryiko <andriin@fb.com>

Thanks a lot for the review, I'll send v3 soon

Thanks
Namhyung

Patch
diff mbox series

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index defae23a0169..97830e46d1a0 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -138,6 +138,7 @@  STATIC_OBJDIR	:= $(OUTPUT)staticobjs/
 BPF_IN_SHARED	:= $(SHARED_OBJDIR)libbpf-in.o
 BPF_IN_STATIC	:= $(STATIC_OBJDIR)libbpf-in.o
 VERSION_SCRIPT	:= libbpf.map
+BPF_HELPER_DEFS	:= $(OUTPUT)bpf_helper_defs.h
 
 LIB_TARGET	:= $(addprefix $(OUTPUT),$(LIB_TARGET))
 LIB_FILE	:= $(addprefix $(OUTPUT),$(LIB_FILE))
@@ -159,7 +160,7 @@  all: fixdep
 
 all_cmd: $(CMD_TARGETS) check
 
-$(BPF_IN_SHARED): force elfdep bpfdep bpf_helper_defs.h
+$(BPF_IN_SHARED): force elfdep bpfdep $(BPF_HELPER_DEFS)
 	@(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
@@ -177,12 +178,12 @@  $(BPF_IN_SHARED): force elfdep bpfdep bpf_helper_defs.h
 	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
 	$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)"
 
-$(BPF_IN_STATIC): force elfdep bpfdep bpf_helper_defs.h
+$(BPF_IN_STATIC): force elfdep bpfdep $(BPF_HELPER_DEFS)
 	$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)
 
-bpf_helper_defs.h: $(srctree)/tools/include/uapi/linux/bpf.h
+$(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h
 	$(Q)$(srctree)/scripts/bpf_helpers_doc.py --header 		\
-		--file $(srctree)/tools/include/uapi/linux/bpf.h > bpf_helper_defs.h
+		--file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS)
 
 $(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION)
 
@@ -243,7 +244,7 @@  install_lib: all_cmd
 		$(call do_install_mkdir,$(libdir_SQ)); \
 		cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)
 
-install_headers: bpf_helper_defs.h
+install_headers: $(BPF_HELPER_DEFS)
 	$(call QUIET_INSTALL, headers) \
 		$(call do_install,bpf.h,$(prefix)/include/bpf,644); \
 		$(call do_install,libbpf.h,$(prefix)/include/bpf,644); \
@@ -251,7 +252,7 @@  install_headers: bpf_helper_defs.h
 		$(call do_install,libbpf_util.h,$(prefix)/include/bpf,644); \
 		$(call do_install,xsk.h,$(prefix)/include/bpf,644); \
 		$(call do_install,bpf_helpers.h,$(prefix)/include/bpf,644); \
-		$(call do_install,bpf_helper_defs.h,$(prefix)/include/bpf,644); \
+		$(call do_install,$(BPF_HELPER_DEFS),$(prefix)/include/bpf,644); \
 		$(call do_install,bpf_tracing.h,$(prefix)/include/bpf,644); \
 		$(call do_install,bpf_endian.h,$(prefix)/include/bpf,644); \
 		$(call do_install,bpf_core_read.h,$(prefix)/include/bpf,644);
@@ -271,7 +272,7 @@  install: install_lib install_pkgconfig
 clean:
 	$(call QUIET_CLEAN, libbpf) $(RM) -rf $(CMD_TARGETS) \
 		*.o *~ *.a *.so *.so.$(LIBBPF_MAJOR_VERSION) .*.d .*.cmd \
-		*.pc LIBBPF-CFLAGS bpf_helper_defs.h \
+		*.pc LIBBPF-CFLAGS $(BPF_HELPER_DEFS) \
 		$(SHARED_OBJDIR) $(STATIC_OBJDIR)
 	$(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf
 
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index e0fe01d9ec33..e2fd6f8d579c 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -120,9 +120,9 @@  $(OUTPUT)/test_cgroup_attach: cgroup_helpers.c
 $(BPFOBJ): force
 	$(MAKE) -C $(BPFDIR) OUTPUT=$(OUTPUT)/
 
-BPF_HELPERS := $(BPFDIR)/bpf_helper_defs.h $(wildcard $(BPFDIR)/bpf_*.h)
-$(BPFDIR)/bpf_helper_defs.h:
-	$(MAKE) -C $(BPFDIR) OUTPUT=$(OUTPUT)/ bpf_helper_defs.h
+BPF_HELPERS := $(OUTPUT)/bpf_helper_defs.h $(wildcard $(BPFDIR)/bpf_*.h)
+$(OUTPUT)/bpf_helper_defs.h:
+	$(MAKE) -C $(BPFDIR) OUTPUT=$(OUTPUT)/ $(OUTPUT)/bpf_helper_defs.h
 
 # Get Clang's default includes on this system, as opposed to those seen by
 # '-target bpf'. This fixes "missing" files on some architectures/distros,