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

[Reinette Chatre <reinette.chatre@intel.com>]

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/