Re: Problems when trying to build tools/testing/selftests

[Shuah Khan <skhan@linuxfoundation.org>]

On 12/3/25 14:01, Guenter Roeck wrote:
> On 12/3/25 09:55, Randy Dunlap wrote:
>>
>>
>> On 12/3/25 9:25 AM, Shuah wrote:
>>> On 12/2/25 22:20, Guenter Roeck wrote:
>>>> Hi,
>>>>
>>>> when trying to build tools/testing/selftests, I get a lot of warnings such as
>>>>
>>>> mount-notify_test.c: In function ‘fanotify_fsmount’:
>>>> mount-notify_test.c:360:14: warning: implicit declaration of function ‘fsopen’; did you mean ‘fdopen’?
>>>>
>>>> and subsequent build errors.
>>>>
>>>> testing/selftests/filesystems/mount-notify/mount-notify_test.c:360: undefined reference to `fsopen'
>>>> /usr/bin/ld: tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c:363: undefined reference to `fsconfig'
>>>> /usr/bin/ld:tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c:366: undefined reference to `fsmount'
>>>> /usr/bin/ld: tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c:371: undefined reference to `move_mount'

This usually indicates missing libraries or header path
issues.

>>>>
>>>> This does not just affect a single file, but several of them.
>>>>
>>>> What am I missing ? Is there some magic needed to build the selftests ?
>>>
>>> Not sure. It built fine for me on Linux 6.18 latest. Are you missing
>>> a library possibly?
>>
>> Guenter, did you follow Documentation/dev-tools/kselftest.rst?
>>
> 
> The document says
> 
> To build the tests::
> 
>    $ make headers
>    $ make -C tools/testing/selftests
> 
> which is what I did.
> 
> I did run
> 
> kselftest_deps.sh gcc
> 
> which tells me
> 
> FAIL: net/tcp_ao/Makefile dependency check: $(LIB)
> FAIL: bpf/Makefile dependency check: $(LIBELF_LIBS)
> FAIL: bpf/Makefile dependency check: $(PCAP_LIBS)
> FAIL: net/netfilter/Makefile dependency check: $(MNL_LDLIBS)
> FAIL: net/netfilter/Makefile dependency check: $(MNL_LDLIBS)
> --------------------------------------------------------
> Targets failed build dependency check on system:
> bpf net
> --------------------------------------------------------
> Missing libraries system
> $(LIB) $(LIBELF_LIBS) $(MNL_LDLIBS) $(PCAP_LIBS)
> 
> which doeesn't really help. For example, PCAP_LIBS seems to refer to libpcap,
> and I have libpcap-dev installed on my system.
> 
> Unless I am missing something that doesn't explain the build failures.
> 

I ran "make kselftest-all" - mount-notify/mount-notify_test.c built
fine on Linux 6.18 - which repo are you trying on?

Can you try "make kselftest-all" and tell me what happens?

I also tried

make -C tools/testing/selftests

and

make -C tools/testing/selftests TARGETS="filesystems/mount-notify"

Which repo are you trying on?

thanks,
-- Shuah