Re: V2 [PATCH v4 09/10] x86: Check ifunc resolver with CPU_FEATURE_USABLE [BZ #27072]

["H.J. Lu via Libc-alpha" <libc-alpha@sourceware.org>]

On Tue, Jan 19, 2021 at 6:37 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Tue, Jan 19, 2021 at 6:12 AM Adhemerval Zanella via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
> >
> >
> >
> > On 18/01/2021 13:25, Szabolcs Nagy via Libc-alpha wrote:
> > > From: "H.J. Lu" <hjl.tools@gmail.com>
> > >
> > > Check ifunc resolver with CPU_FEATURE_USABLE and tunables in dynamic and
> > > static executables to verify that CPUID features are initialized early in
> > > static PIE.
> >
> > LGTM, thanks.  Maybe refactor the tests to use a common file with the
> > ifunc definitions, since both a copying and pasting similar code.
> >
> > Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> >
> > > ---
> > >  sysdeps/x86/Makefile                 |  14 ++++
> > >  sysdeps/x86/tst-ifunc-isa-1-static.c |   1 +
> > >  sysdeps/x86/tst-ifunc-isa-1.c        | 115 ++++++++++++++++++++++++++
> > >  sysdeps/x86/tst-ifunc-isa-2-static.c |   1 +
> > >  sysdeps/x86/tst-ifunc-isa-2.c        | 119 +++++++++++++++++++++++++++
> > >  5 files changed, 250 insertions(+)
> > >  create mode 100644 sysdeps/x86/tst-ifunc-isa-1-static.c
> > >  create mode 100644 sysdeps/x86/tst-ifunc-isa-1.c
> > >  create mode 100644 sysdeps/x86/tst-ifunc-isa-2-static.c
> > >  create mode 100644 sysdeps/x86/tst-ifunc-isa-2.c
> > >
> > > diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> > > index adaa2a92cd..f7969309bc 100644
> > > --- a/sysdeps/x86/Makefile
> > > +++ b/sysdeps/x86/Makefile
> > > @@ -9,6 +9,16 @@ sysdep_headers += sys/platform/x86.h
> > >  tests += tst-get-cpu-features tst-get-cpu-features-static \
> > >        tst-cpu-features-cpuinfo tst-cpu-features-supports
> > >  tests-static += tst-get-cpu-features-static
> > > +ifeq (yes,$(have-ifunc))
> > > +tests += \
> > > +  tst-ifunc-isa-1 \
> > > +  tst-ifunc-isa-1-static \
> > > +  tst-ifunc-isa-2 \
> > > +  tst-ifunc-isa-2-static
> > > +tests-static += \
> > > +  tst-ifunc-isa-1-static \
> > > +  tst-ifunc-isa-2-static
> > > +endif
> > >  ifeq (yes,$(enable-x86-isa-level))
> > >  tests += tst-isa-level-1
> > >  modules-names += tst-isa-level-mod-1-baseline \
> > > @@ -39,6 +49,10 @@ $(objpfx)tst-isa-level-1.out: $(objpfx)tst-isa-level-mod-1-baseline.so \
> > >                             $(objpfx)tst-isa-level-mod-1-v3.so \
> > >                             $(objpfx)tst-isa-level-mod-1-v4.so
> > >  endif
> > > +ifneq ($(have-tunables),no)
> > > +tst-ifunc-isa-2-ENV = GLIBC_TUNABLES=glibc.cpu.hwcaps=-SSE4_2,-AVX,-AVX2,-AVX512F
> > > +tst-ifunc-isa-2-static-ENV = $(tst-ifunc-isa-2-ENV)
> > > +endif
> > >  endif
> > >
> > >  ifeq ($(subdir),math)
> >
> > Ok.
> >
> > > diff --git a/sysdeps/x86/tst-ifunc-isa-1-static.c b/sysdeps/x86/tst-ifunc-isa-1-static.c
> > > new file mode 100644
> > > index 0000000000..0e94f6119b
> > > --- /dev/null
> > > +++ b/sysdeps/x86/tst-ifunc-isa-1-static.c
> > > @@ -0,0 +1 @@
> > > +#include "tst-ifunc-isa-1.c"
> >
> > Ok.
> >
> > > diff --git a/sysdeps/x86/tst-ifunc-isa-1.c b/sysdeps/x86/tst-ifunc-isa-1.c
> > > new file mode 100644
> > > index 0000000000..b3bc2a55a2
> > > --- /dev/null
> > > +++ b/sysdeps/x86/tst-ifunc-isa-1.c
> > > @@ -0,0 +1,115 @@
> > > +/* Check ifunc with CPU_FEATURE_USABLE.
> > > +   Copyright (C) 2021 Free Software Foundation, Inc.
> > > +   This file is part of the GNU C Library.
> > > +
> > > +   The GNU C Library is free software; you can redistribute it and/or
> > > +   modify it under the terms of the GNU Lesser General Public
> > > +   License as published by the Free Software Foundation; either
> > > +   version 2.1 of the License, or (at your option) any later version.
> > > +
> > > +   The GNU C Library is distributed in the hope that it will be useful,
> > > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > > +   Lesser General Public License for more details.
> > > +
> > > +   You should have received a copy of the GNU Lesser General Public
> > > +   License along with the GNU C Library; if not, see
> > > +   <https://www.gnu.org/licenses/>.  */
> > > +
> > > +#include <stdlib.h>
> > > +#include <sys/platform/x86.h>
> > > +
> > > +enum isa
> > > +{
> > > +  none,
> > > +  sse2,
> > > +  sse4_2,
> > > +  avx,
> > > +  avx2,
> > > +  avx512f
> > > +};
> > > +
> > > +enum isa
> > > +get_isa (void)
> > > +{
> > > +  if (CPU_FEATURE_USABLE (AVX512F))
> > > +    return avx512f;
> > > +  if (CPU_FEATURE_USABLE (AVX2))
> > > +    return avx2;
> > > +  if (CPU_FEATURE_USABLE (AVX))
> > > +    return avx;
> > > +  if (CPU_FEATURE_USABLE (SSE4_2))
> > > +    return sse4_2;
> > > +  if (CPU_FEATURE_USABLE (SSE2))
> > > +    return sse2;
> > > +  return none;
> > > +}
> > > +
> > > +static int
> > > +isa_sse2 (void)
> > > +{
> > > +  return sse2;
> > > +}
> > > +
> > > +static int
> > > +isa_sse4_2 (void)
> > > +{
> > > +  return sse4_2;
> > > +}
> > > +
> > > +static int
> > > +isa_avx (void)
> > > +{
> > > +  return avx;
> > > +}
> > > +
> > > +static int
> > > +isa_avx2 (void)
> > > +{
> > > +  return avx2;
> > > +}
> > > +
> > > +static int
> > > +isa_avx512f (void)
> > > +{
> > > +  return avx512f;
> > > +}
> > > +
> > > +static int
> > > +isa_none (void)
> > > +{
> > > +  return none;
> > > +}
> > > +
> > > +int foo (void) __attribute__ ((ifunc ("foo_ifunc")));
> > > +
> > > +void *
> > > +foo_ifunc (void)
> > > +{
> > > +  switch (get_isa ())
> > > +    {
> > > +    case avx512f:
> > > +      return isa_avx512f;
> > > +    case avx2:
> > > +      return isa_avx2;
> > > +    case avx:
> > > +      return isa_avx;
> > > +    case sse4_2:
> > > +      return isa_sse4_2;
> > > +    case sse2:
> > > +      return isa_sse2;
> > > +    default:
> > > +      break;
> > > +    }
> > > +  return isa_none;
> > > +}
> > > +
> > > +static int
> > > +do_test (void)
> > > +{
> > > +  enum isa value = foo ();
> > > +  enum isa expected = get_isa ();
> > > +  return value == expected ? EXIT_SUCCESS : EXIT_FAILURE;
> > > +}
> > > +
> > > +#include <support/test-driver.c>
> >
> > Ok.
> >
> > > diff --git a/sysdeps/x86/tst-ifunc-isa-2-static.c b/sysdeps/x86/tst-ifunc-isa-2-static.c
> > > new file mode 100644
> > > index 0000000000..4a5af9a270
> > > --- /dev/null
> > > +++ b/sysdeps/x86/tst-ifunc-isa-2-static.c
> > > @@ -0,0 +1 @@
> > > +#include "tst-ifunc-isa-2.c"
> >
> > Ok.
> >
> > > diff --git a/sysdeps/x86/tst-ifunc-isa-2.c b/sysdeps/x86/tst-ifunc-isa-2.c
> > > new file mode 100644
> > > index 0000000000..bb0f76c3e4
> > > --- /dev/null
> > > +++ b/sysdeps/x86/tst-ifunc-isa-2.c
> > > @@ -0,0 +1,119 @@
> > > +/* Check ifunc with CPU_FEATURE_USABLE and tunables.
> > > +   Copyright (C) 2021 Free Software Foundation, Inc.
> > > +   This file is part of the GNU C Library.
> > > +
> > > +   The GNU C Library is free software; you can redistribute it and/or
> > > +   modify it under the terms of the GNU Lesser General Public
> > > +   License as published by the Free Software Foundation; either
> > > +   version 2.1 of the License, or (at your option) any later version.
> > > +
> > > +   The GNU C Library is distributed in the hope that it will be useful,
> > > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > > +   Lesser General Public License for more details.
> > > +
> > > +   You should have received a copy of the GNU Lesser General Public
> > > +   License along with the GNU C Library; if not, see
> > > +   <https://www.gnu.org/licenses/>.  */
> > > +
> > > +#include <stdlib.h>
> > > +#include <sys/platform/x86.h>
> > > +#include <support/test-driver.h>
> > > +
> > > +enum isa
> > > +{
> > > +  none,
> > > +  sse2,
> > > +  sse4_2,
> > > +  avx,
> > > +  avx2,
> > > +  avx512f
> > > +};
> > > +
> > > +enum isa
> > > +get_isa (void)
> > > +{
> > > +  if (CPU_FEATURE_USABLE (AVX512F))
> > > +    return avx512f;
> > > +  if (CPU_FEATURE_USABLE (AVX2))
> > > +    return avx2;
> > > +  if (CPU_FEATURE_USABLE (AVX))
> > > +    return avx;
> > > +  if (CPU_FEATURE_USABLE (SSE4_2))
> > > +    return sse4_2;
> > > +  if (CPU_FEATURE_USABLE (SSE2))
> > > +    return sse2;
> > > +  return none;
> > > +}
> > > +
> > > +static int
> > > +isa_sse2 (void)
> > > +{
> > > +  return sse2;
> > > +}
> > > +
> > > +static int
> > > +isa_sse4_2 (void)
> > > +{
> > > +  return sse4_2;
> > > +}
> > > +
> > > +static int
> > > +isa_avx (void)
> > > +{
> > > +  return avx;
> > > +}
> > > +
> > > +static int
> > > +isa_avx2 (void)
> > > +{
> > > +  return avx2;
> > > +}
> > > +
> > > +static int
> > > +isa_avx512f (void)
> > > +{
> > > +  return avx512f;
> > > +}
> > > +
> > > +static int
> > > +isa_none (void)
> > > +{
> > > +  return none;
> > > +}
> > > +
> > > +int foo (void) __attribute__ ((ifunc ("foo_ifunc")));
> > > +
> > > +void *
> > > +foo_ifunc (void)
> > > +{
> > > +  switch (get_isa ())
> > > +    {
> > > +    case avx512f:
> > > +      return isa_avx512f;
> > > +    case avx2:
> > > +      return isa_avx2;
> > > +    case avx:
> > > +      return isa_avx;
> > > +    case sse4_2:
> > > +      return isa_sse4_2;
> > > +    case sse2:
> > > +      return isa_sse2;
> > > +    default:
> > > +      break;
> > > +    }
> > > +  return isa_none;
> > > +}
> > > +
> >
> > Maybe move this part to a common file?
>
> Fixed.
>
> > > +static int
> > > +do_test (void)
> > > +{
> > > +  /* CPU must support SSE2.  */
> > > +  if (!__builtin_cpu_supports ("sse2"))
> > > +    return EXIT_UNSUPPORTED;
> > > +  enum isa value = foo ();
> > > +  /* All ISAs, but SSE2, are disabled by tunables.  */
> > > +  return value == sse2 ? EXIT_SUCCESS : EXIT_FAILURE;
> > > +}
> > > +
> > > +#include <support/test-driver.c>
> > >
> >
> > Ok.
>
> Here is the updated patch.  OK for master?
>
> Thanks.
>

Static PIE changes have been checked in.  I am checking this in.

-- 
H.J.