[PATCH] tools/perf: Fix bpf-script-test-prologue test compile issue with clang

[Athira Rajeev]

> On 05-Jan-2023, at 6:23 PM, Arnaldo Carvalho de Melo <acme at kernel.org> wrote:
> 
> Em Thu, Jan 05, 2023 at 05:34:36PM +0530, Athira Rajeev escreveu:
>> While running perf test for bpf, observed that "BPF prologue
>> generation" test case fails to compile with clang. Logs below
>> from powerpc:
>> 
>> <stdin>:33:2: error: use of undeclared identifier 'fmode_t'
>>        fmode_t f_mode = (fmode_t)_f_mode;
>>        ^
>> <stdin>:37:6: error: use of undeclared identifier 'f_mode'; did you mean '_f_mode'?
>>        if (f_mode & FMODE_WRITE)
>>            ^~~~~~
>>            _f_mode
>> <stdin>:30:60: note: '_f_mode' declared here
>> int bpf_func__null_lseek(void *ctx, int err, unsigned long _f_mode,
>>                                                           ^
>> 2 errors generated.
> 
> Thanks for fixing this, I noticed the problem but didn't got around to
> investigate it.
> 
> Tested and applied.

Thanks Arnaldo for checking the patch.

Athira
> 
> - Arnaldo
> 
>> The test code tests/bpf-script-test-prologue.c uses fmode_t.
>> And the error above is for "fmode_t" which is defined in
>> include/linux/types.h as part of kernel build directory:
>> "/lib/modules/<kernel_version>/build" that comes from
>> kernel devel [ soft link to /usr/src/<kernel_version> ].
>> Clang picks this header file from "-working-directory" build
>> option that specifies this build folder.
>> 
>> But the 'commit 14e4b9f4289a ("perf trace: Raw augmented
>> syscalls fix libbpf 1.0+ compatibility")', changed the
>> include directory to use: "/usr/include".  Post this change,
>> types.h from /usr/include/ is getting picked upwhich doesn’t
>> contain definition of "fmode_t" and hence fails to compile.
>> 
>> Compilation command before this commit:
>> /usr/bin/clang -D__KERNEL__ -D__NR_CPUS__=72 -DLINUX_VERSION_CODE=0x50e00 -xc  -I/root/lib/perf/include/bpf -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h  -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/<ver>/build -c - -target bpf  -g -O2 -o -
>> 
>> Compilation command after this commit:
>> /usr/bin/clang -D__KERNEL__ -D__NR_CPUS__=72 -DLINUX_VERSION_CODE=0x50e00 -xc  -I/usr/include/ -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h  -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/<ver>/build -c - -target bpf  -g -O2 -o -
>> 
>> The difference is addition of -I/usr/include/  in the first line
>> which is causing the error. Fix this by adding typedef for "fmode_t"
>> in the testcase to solve the compile issue.
>> 
>> Fixes: 14e4b9f4289a ("perf trace: Raw augmented syscalls fix libbpf 1.0+ compatibility")
>> Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
>> ---
>> tools/perf/tests/bpf-script-test-prologue.c | 2 ++
>> 1 file changed, 2 insertions(+)
>> 
>> diff --git a/tools/perf/tests/bpf-script-test-prologue.c b/tools/perf/tests/bpf-script-test-prologue.c
>> index bd83d364cf30..91778b5c6125 100644
>> --- a/tools/perf/tests/bpf-script-test-prologue.c
>> +++ b/tools/perf/tests/bpf-script-test-prologue.c
>> @@ -20,6 +20,8 @@
>> # undef if
>> #endif
>> 
>> +typedef unsigned int __bitwise fmode_t;
>> +
>> #define FMODE_READ		0x1
>> #define FMODE_WRITE		0x2
>> 
>> -- 
>> 2.31.1
> 
> -- 
> 
> - Arnaldo