Hi Shuah,

CC kbuild, gpio

On Thu, Sep 14, 2017 at 5:34 PM Shuah Khan shuah@kernel.org wrote:

bpf test depends on clang and fails to compile when

---

make -C tools/testing/selftests/bpf run_tests

make: clang: Command not found Makefile:39: recipe for target '.linux-kselftest/tools/testing/selftests/bpf/test_pkt_access.o' failed make: *** [./linux-kselftest/tools/testing/selftests/bpf/test_pkt_access.o] Error 127 make: Leaving directory '.linux-kselftest/tools/testing/selftests/bpf'

The above failure is indeed due to missing clang.

With "make TARGETS=bpf kselftest" it fails earlier:

make[3]: Entering directory './linux-kselftest/tools/lib/bpf' Makefile:40: tools/scripts/Makefile.arch: No such file or directory Makefile:84: tools/build/Makefile.feature: No such file or directory Makefile:143: tools/build/Makefile.include: No such file or directory

This is due to srctree being "." instead of the actual source tree, when invoked as "make kselftest". When using "make -C tools/testing/selftests", srctree is correct.

tools/testing/selftests/bpf/Makefile has:

$(BPFOBJ): force $(MAKE) -C $(BPFDIR) OUTPUT=$(OUTPUT)/

to enter the tools/lib/bpf directory to force a build of libbpf.a

Note that tools/gpio has the same issue.

There seem to be _four_ different ways to build kselftests (Documentation/dev-tools/kselftest.rst):

make kselftest make O=/path/to/output kselftest make -C tools/testing/selftests make O=/path/to/output -C tools/testing/selftests

I'm not so fond of the latter two, as they basically run make from somewhere inside the tree, which complicates things. I believe we don't support this anywhere else.

Each of the four seem to have (different) issues. Especially when you throw cross-compiling into the mix. And care about where installed headers end up (yes, kselftest calls headers_install internally).

I'm working on fixes for some of them, but I don't know how to fix the srctree issue.

Anyone with a suggestion?

Thanks!

make[3]: *** No rule to make target 'tools/build/Makefile.include'. Stop. make[3]: Leaving directory '.linux-kselftest/tools/lib/bpf' Makefile:34: recipe for target './linux-kselftest/tools/testing/selftests/bpf/libbpf.a' failed make[2]: *** [./linux-kselftest/tools/testing/selftests/bpf/libbpf.a] Error 2 make[2]: Leaving directory './linux-kselftest/tools/testing/selftests/bpf' Makefile:69: recipe for target 'all' failed make[1]: *** [all] Error 2 Makefile:1190: recipe for target 'kselftest' failed make: *** [kselftest] Error 2

Gr{oetje,eeting}s,

Geert