On Sun, Dec 22, 2019 at 10:14 PM Namhyung Kim <namhyung@xxxxxxxxxx> 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. > > Tested-by: Andrii Nakryiko <andriin@xxxxxx> > Acked-by: Andrii Nakryiko <andriin@xxxxxx> > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> > --- > tools/lib/bpf/Makefile | 15 ++++++++------- > tools/testing/selftests/bpf/.gitignore | 1 + > tools/testing/selftests/bpf/Makefile | 6 +++--- > 3 files changed, 12 insertions(+), 10 deletions(-) > [...] > diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore > index 419652458da4..1ff0a9f49c01 100644 > --- a/tools/testing/selftests/bpf/.gitignore > +++ b/tools/testing/selftests/bpf/.gitignore > @@ -40,3 +40,4 @@ xdping > test_cpp > /no_alu32 > /bpf_gcc > +bpf_helper_defs.h looks good, thanks! [...]
