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

Message ID CAMe9rOqC+stavFXCaC8JmvgeL3bb+R4qFX-VwhxqMmPhXGLW5g@mail.gmail.com
State Committed
Headers
Series V2 [PATCH v4 09/10] x86: Check ifunc resolver with CPU_FEATURE_USABLE [BZ #27072] |

Commit Message

H.J. Lu Jan. 19, 2021, 2:37 p.m. UTC
  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.
  

Comments

H.J. Lu Jan. 21, 2021, 4:33 p.m. UTC | #1
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.
  

Patch

From f311b138e90a77f5a1153093a0496884bcb8c7e4 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 12 Jan 2021 14:41:10 -0800
Subject: [PATCH] x86: Check ifunc resolver with CPU_FEATURE_USABLE [BZ #27072]

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.
---
 sysdeps/x86/Makefile                 |  14 ++++
 sysdeps/x86/tst-ifunc-isa-1-static.c |   1 +
 sysdeps/x86/tst-ifunc-isa-1.c        |  30 ++++++++
 sysdeps/x86/tst-ifunc-isa-2-static.c |   1 +
 sysdeps/x86/tst-ifunc-isa-2.c        |  34 +++++++++
 sysdeps/x86/tst-ifunc-isa.h          | 104 +++++++++++++++++++++++++++
 6 files changed, 184 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
 create mode 100644 sysdeps/x86/tst-ifunc-isa.h

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)
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"
diff --git a/sysdeps/x86/tst-ifunc-isa-1.c b/sysdeps/x86/tst-ifunc-isa-1.c
new file mode 100644
index 0000000000..37d599210c
--- /dev/null
+++ b/sysdeps/x86/tst-ifunc-isa-1.c
@@ -0,0 +1,30 @@ 
+/* Check IFUNC resolver 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 "tst-ifunc-isa.h"
+
+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>
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"
diff --git a/sysdeps/x86/tst-ifunc-isa-2.c b/sysdeps/x86/tst-ifunc-isa-2.c
new file mode 100644
index 0000000000..0bdf7176fa
--- /dev/null
+++ b/sysdeps/x86/tst-ifunc-isa-2.c
@@ -0,0 +1,34 @@ 
+/* Check IFUNC resolver 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 "tst-ifunc-isa.h"
+#include <support/test-driver.h>
+
+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>
diff --git a/sysdeps/x86/tst-ifunc-isa.h b/sysdeps/x86/tst-ifunc-isa.h
new file mode 100644
index 0000000000..60aa1cea6a
--- /dev/null
+++ b/sysdeps/x86/tst-ifunc-isa.h
@@ -0,0 +1,104 @@ 
+/* IFUNC resolver 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 <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;
+}
-- 
2.29.2