Re: [PATCH] selftests/sgx: Fix corrupted cpuid macro invocation

[Jarkko Sakkinen <jarkko@kernel.org>]

On Tue, Dec 14, 2021 at 04:19:24PM -0800, Reinette Chatre wrote:
> Hi Dave and Jarkko,
> 
> On 12/4/2021 12:23 PM, Jarkko Sakkinen wrote:
> > Compilation results:
> > 
> > $ make -C tools/testing/selftests/sgx/
> > make: Entering directory '/home/jarkko/Projects/linux-sgx/tools/testing/selftests/sgx'
> > gcc -Wall -Werror -g -I../../../../tools/include -fPIC -z noexecstack -c main.c -o /home/jarkko/Projects/linux-sgx/tools/testing/selftests/sgx/main.o
> > main.c: In function ‘get_total_epc_mem’:
> > main.c:296:17: error: implicit declaration of function ‘__cpuid’ [-Werror=implicit-function-declaration]
> >    296 |                 __cpuid(&eax, &ebx, &ecx, &edx);
> >        |                 ^~~~~~~
> > cc1: all warnings being treated as errors
> > make: *** [Makefile:33: /home/jarkko/Projects/linux-sgx/tools/testing/selftests/sgx/main.o] Error 1
> > make: Leaving directory '/home/jarkko/Projects/linux-sgx/tools/testing/selftests/sgx'
> > 
> > Include to cpuid.h is missing and the macro usage is incorrect.
> > 
> > Include cpuid.h and use __cpuid_count() macro in order to fix the
> > compilation issue.
> > 
> > Fixes: f0ff2447b861 ("selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed")
> > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
> > ---
> >   tools/testing/selftests/sgx/main.c | 5 ++---
> >   1 file changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
> > index 7e912db4c6c5..370c4995f7c4 100644
> > --- a/tools/testing/selftests/sgx/main.c
> > +++ b/tools/testing/selftests/sgx/main.c
> > @@ -1,6 +1,7 @@
> >   // SPDX-License-Identifier: GPL-2.0
> >   /*  Copyright(c) 2016-20 Intel Corporation. */
> > +#include <cpuid.h>
> >   #include <elf.h>
> >   #include <errno.h>
> >   #include <fcntl.h>
> > @@ -291,9 +292,7 @@ static unsigned long get_total_epc_mem(void)
> >   	int section = 0;
> >   	while (true) {
> > -		eax = SGX_CPUID;
> > -		ecx = section + SGX_CPUID_EPC;
> > -		__cpuid(&eax, &ebx, &ecx, &edx);
> > +		__cpuid_count(SGX_CPUID, section + SGX_CPUID_EPC, eax, ebx, ecx, edx);
> >   		type = eax & SGX_CPUID_EPC_MASK;
> >   		if (type == SGX_CPUID_EPC_INVALID)
> 
> 
> Shuah confirmed ([1]) that there is no problem including cpuid.h and that
> this is the preferred fix.
> 
> Thank you very much Jarkko.
> 
> Acked-by: Reinette Chatre <reinette.chatre@intel.com>
> 
> Reinette
> 
> [1] https://lore.kernel.org/linux-kselftest/63293c72-55ca-9446-35eb-74aff4c8ba5d@linuxfoundation.org/

OK, cool, thanks!

/Jarkko