On 2/4/22 5:11 PM, Reinette Chatre wrote:
Hi Shuah,
On 2/4/2022 3:39 PM, Shuah Khan wrote:
On 2/4/22 12:17 PM, Reinette Chatre wrote:
A few tests that require running CPUID do so with a private
implementation of a wrapper for CPUID. This duplication of
the CPUID wrapper should be avoided but having one is also
unnecessary because of the existence of a macro that can
be used instead.
This series replaces private CPUID wrappers with calls
to the __cpuid_count() macro from cpuid.h as made available
by gcc and clang/llvm.
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Ram Pai <linuxram@xxxxxxxxxx>
Cc: Sandipan Das <sandipan@xxxxxxxxxxxxx>
Cc: Florian Weimer <fweimer@xxxxxxxxxx>
Cc: "Desnes A. Nunes do Rosario" <desnesn@xxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Michal Suchanek <msuchanek@xxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Reinette Chatre (3):
selftests/vm/pkeys: Use existing __cpuid_count() macro
selftests/x86/amx: Use existing __cpuid_count() macro
selftests/x86/corrupt_xstate_header: Use existing __cpuid_count()
macro
tools/testing/selftests/vm/pkey-x86.h | 22 +++---------------
tools/testing/selftests/x86/amx.c | 23 +++++--------------
.../selftests/x86/corrupt_xstate_header.c | 17 ++------------
3 files changed, 11 insertions(+), 51 deletions(-)
I am all for this cleanup. However, I am not finding __cpuid_count()
marco on my system with gcc:
gcc --version
gcc (Ubuntu 11.2.0-7ubuntu2) 11.2.0
My concern is regression on older gcc versions.
Please see this message from our earlier thread where you were able
to find it on your system:
https://lore.kernel.org/linux-kselftest/63293c72-55ca-9446-35eb-74aff4c8ba5d@xxxxxxxxxxxxxxxxxxx/
Right. After I sent off the response, I was thinking we discussed
this before. Thanks for the refresh.
As mentioned in that thread, on my system it arrived via user space's
libgcc-dev package. This does not seem to be the first time including
files from this source - I did a quick check and from what I can tell
existing kselftest includes like stdarg.h, stdbool.h, stdatomic.h,
unwind.h, x86intrin.h ... arrive via libgcc-dev.
This will work fine on newer versions of gcc/clang. However this could
fail when mainline kselftest is used on stable releases on test rings
and so on, especially if they have older versions of gcc/clang.
We will have to find a solution for this. Instead of deleting the local
define, let's keep it under ifndef __cpuid_count
/usr/lib/gcc/x86_64-linux-gnu/11/include/cpuid.h
#define __cpuid_count(level, count, a, b, c, d) \
__asm__ __volatile__ ("cpuid\n\t" \
: "=a" (a), "=b" (b), "=c" (c), "=d" (d) \
: "0" (level), "2" (count))
thanks,
-- Shuah
