On Sun, Dec 22, 2019 at 10:14 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.
Tested-by: Andrii Nakryiko andriin@fb.com Acked-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Namhyung Kim namhyung@kernel.org
tools/lib/bpf/Makefile | 15 ++++++++------- tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 6 +++--- 3 files changed, 12 insertions(+), 10 deletions(-)
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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!
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