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

[Anders Roxell]

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

Cheers,
Anders

>
>> To fix this issue remove the urandom_read target and so target
>> TEST_CUSTOM_PROGS gets used.
>>
>> Fixes: 81f77fd0deeb ("bpf: add selftest for stackmap with BPF_F_STACK_BUILD_ID")
>> Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
>> ---
>>  tools/testing/selftests/bpf/Makefile | 6 ++----
>>  1 file changed, 2 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
>> index 607ed8729c06..67285591ffd7 100644
>> --- a/tools/testing/selftests/bpf/Makefile
>> +++ b/tools/testing/selftests/bpf/Makefile
>> @@ -16,10 +16,8 @@ LDLIBS += -lcap -lelf -lrt -lpthread
>>  TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read
>>  all: $(TEST_CUSTOM_PROGS)
>>
>> -$(TEST_CUSTOM_PROGS): urandom_read
>> -
>> -urandom_read: urandom_read.c
>> -       $(CC) -o $(TEST_CUSTOM_PROGS) -static $< -Wl,--build-id
>> +$(TEST_CUSTOM_PROGS): $(OUTPUT)/%: %.c
>> +       $(CC) -o $@ -static $< -Wl,--build-id
>>
>>  # Order correspond to 'make run_tests' order
>>  TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \
>> --
>> 2.17.1
>>