Re: [PATCH] selftests: bpf: fix urandom_read build issue

[Anders Roxell]

On 8 June 2018 at 07:08, Y Song <ys114321@xxxxxxxxx> wrote:
> On Thu, Jun 7, 2018 at 2:43 PM, Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
>> On 7 June 2018 at 23:17, Y Song <ys114321@xxxxxxxxx> wrote:
>>> On Thu, Jun 7, 2018 at 12:07 PM, Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
>>>> On 7 June 2018 at 19:52, Y Song <ys114321@xxxxxxxxx> wrote:
>>>>> On Thu, Jun 7, 2018 at 3:57 AM, Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
>>>>>> gcc complains that urandom_read gets built twice.
>>>>>>
>>>>>> gcc -o tools/testing/selftests/bpf/urandom_read
>>>>>> -static urandom_read.c -Wl,--build-id
>>>>>> gcc -Wall -O2 -I../../../include/uapi -I../../../lib -I../../../lib/bpf
>>>>>> -I../../../../include/generated  -I../../../include    urandom_read.c
>>>>>> urandom_read -lcap -lelf -lrt -lpthread -o
>>>>>> tools/testing/selftests/bpf/urandom_read
>>>>>> gcc: fatal error: input file
>>>>>> âtools/testing/selftests/bpf/urandom_readâ is the
>>>>>> same as output file
>>>>>> compilation terminated.
>>>>>> ../lib.mk:110: recipe for target
>>>>>> 'tools/testing/selftests/bpf/urandom_read' failed
>>>>>
>>>>> What is the build/make command to reproduce the above failure?
>>>>
>>>> make -C tools/testing/selftests
>>>
>>> Thanks. The patch will break
>>>    make -C tools/testing/selftests/bpf
>>>
>>> [yhs@localhost bpf-next]$ make -C tools/testing/selftests/bpf
>>> make: Entering directory '/home/yhs/work/bpf-next/tools/testing/selftests/bpf'
>>> gcc -o /urandom_read -static urandom_read.c -Wl,--build-id
>>> /usr/bin/ld: cannot open output file /urandom_read: Permission denied
>>> collect2: error: ld returned 1 exit status
>>> make: *** [Makefile:20: /urandom_read] Error 1
>>> make: Leaving directory '/home/yhs/work/bpf-next/tools/testing/selftests/bpf'
>>> [yhs@localhost bpf-next]$
>>
>> urgh, I'm sorry, missed that.
>>
>>>
>>> Could you still make the above command work?
>>
>> $(TEST_CUSTOM_PROGS): $(OUTPUT)/%: %.c
>>         $(CC) -o $(TEST_CUSTOM_PROGS) -static $< -Wl,--build-id
>>
>> That worked both with:
>> make -C tools/testing/selftests
>> and
>> make -C tools/testing/selftests/bpf
>>
>> for me.
>>
>> what do you think?
>
> This indeed works. You can submit a revised patch and add my Ack.
> Acked-by: Yonghong Song <yhs@xxxxxx>

Thank you for your time reviewing this.
I will send that out shortly.


Cheers,
Anders