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V6 [PATCH 1/2] x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker [BZ #26717]

Message ID CAMe9rOrsHTaUdPGP3gSEPxDY4O3-LOZTH21W6poeRbb8c+sOOA@mail.gmail.com
State Committed
Headers show
Series V6 [PATCH 1/2] x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker [BZ #26717] | expand

Commit Message

H.J. Lu Jan. 6, 2021, 5:11 p.m. UTC
On Wed, Jan 6, 2021 at 4:01 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 06/12/2020 11:49, H.J. Lu via Libc-alpha wrote:
> > GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA
> > levels:
> >
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250
> >
> > and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with
> > GNU_PROPERTY_X86_ISA_1_V[234] marker:
> >
> > https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13
> >
> > Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by
> >
> > commit b0ab06937385e0ae25cebf1991787d64f439bf12
> > Author: H.J. Lu <hjl.tools@gmail.com>
> > Date:   Fri Oct 30 06:49:57 2020 -0700
> >
> >     x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker
> >
> > and
> >
> > commit 32930e4edbc06bc6f10c435dbcc63131715df678
> > Author: H.J. Lu <hjl.tools@gmail.com>
> > Date:   Fri Oct 9 05:05:57 2020 -0700
> >
> >     x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker
> >
> > GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the
> > micro-architecture ISA level required to execute the binary.  The marker
> > must be added by programmers explicitly in one of 3 ways:
> >
> > 1. Pass -mneeded to GCC.
> > 2. Add the marker in the linker inputs as this patch does.
> > 3. Pass -z x86-64-v[234] to the linker.
> >
> > Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > marker support to ld.so if binutils 2.32 or newer is used to build glibc:
> >
> > 1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > markers to elf.h.
> > 2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > marker to abi-note.o based on the ISA level used to compile abi-note.o,
> > assuming that the same ISA level is used to compile the whole glibc.
> > 3. Add isa_1 to cpu_features to record the supported x86 ISA level.
> > 4. Rename _dl_process_cet_property_note to _dl_process_property_note and
> > add GNU_PROPERTY_X86_ISA_1_V[234] marker detection.
> > 5. Update _rtld_main_check and _dl_open_check to check loaded objects
> > with the incompatible ISA level.
> > 6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails
> > on lesser platforms.
> > 7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c.
> >
> > Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine
> > and got:
> >
> > [hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1
> > ./elf/tst-isa-level-1: CPU ISA level is lower than required
> > [hjl@gnu-cfl-2 build-x86_64-linux]$
> > ---
> >  config.h.in                        |   3 +
> >  elf/elf.h                          |  35 ++++-----
> >  sysdeps/x86/Makefile               |  10 +++
> >  sysdeps/x86/abi-note.c             |  29 ++++++++
> >  sysdeps/x86/configure              | 101 ++++++++++++++++++++++++++
> >  sysdeps/x86/configure.ac           |  26 +++++++
> >  sysdeps/x86/cpu-features.c         |   3 +
> >  sysdeps/x86/dl-cet.c               |  12 ++-
> >  sysdeps/x86/dl-prop.h              | 113 +++++++++++++++++++++--------
> >  sysdeps/x86/get-isa-level.h        |  66 +++++++++++++++++
> >  sysdeps/x86/include/cpu-features.h |   2 +
> >  sysdeps/x86/isa-level.c            |  95 ++++++++++++++++++++++++
> >  sysdeps/x86/link_map.h             |  18 +++--
> >  sysdeps/x86/tst-isa-level-1.c      |  74 +++++++++++++++++++
> >  sysdeps/x86/tst-isa-level-mod-1.c  |  23 ++++++
> >  sysdeps/x86/tst-isa-level-mod-1a.c |   2 +
> >  sysdeps/x86/tst-isa-level-mod-1b.c |   1 +
> >  sysdeps/x86_64/dl-hwcaps-subdirs.c |  30 ++------
> >  sysdeps/x86_64/tst-glibc-hwcaps.c  |  41 +++--------
> >  19 files changed, 571 insertions(+), 113 deletions(-)
> >  create mode 100644 sysdeps/x86/abi-note.c
> >  create mode 100644 sysdeps/x86/get-isa-level.h
> >  create mode 100644 sysdeps/x86/isa-level.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-1.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1a.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1b.c
> >
> > diff --git a/config.h.in b/config.h.in
> > index b823c8e080..dc3854f4eb 100644
> > --- a/config.h.in
> > +++ b/config.h.in
> > @@ -266,4 +266,7 @@
> >  /* The default value of x86 CET control.  */
> >  #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property
> >
> > +/* Define if x86 ISA level should be included in shared libraries.  */
> > +#undef INCLUDE_X86_ISA_LEVEL
> > +
> >  #endif
> > diff --git a/elf/elf.h b/elf/elf.h
> > index bd7af7cca4..42fd697129 100644
> > --- a/elf/elf.h
> > +++ b/elf/elf.h
> > @@ -1325,31 +1325,26 @@ typedef struct
> >
> >  /* The x86 instruction sets indicated by the corresponding bits are
> >     used in program.  Their support in the hardware is optional.  */
> > -#define GNU_PROPERTY_X86_ISA_1_USED          0xc0000000
> > +#define GNU_PROPERTY_X86_ISA_1_USED          0xc0010002
> >  /* The x86 instruction sets indicated by the corresponding bits are
> >     used in program and they must be supported by the hardware.   */
> > -#define GNU_PROPERTY_X86_ISA_1_NEEDED                0xc0000001
> > +#define GNU_PROPERTY_X86_ISA_1_NEEDED                0xc0008002
> >  /* X86 processor-specific features used in program.  */
> >  #define GNU_PROPERTY_X86_FEATURE_1_AND               0xc0000002
> >
> > -#define GNU_PROPERTY_X86_ISA_1_486           (1U << 0)
> > -#define GNU_PROPERTY_X86_ISA_1_586           (1U << 1)
> > -#define GNU_PROPERTY_X86_ISA_1_686           (1U << 2)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE           (1U << 3)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE2          (1U << 4)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE3          (1U << 5)
> > -#define GNU_PROPERTY_X86_ISA_1_SSSE3         (1U << 6)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE4_1                (1U << 7)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE4_2                (1U << 8)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX           (1U << 9)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX2          (1U << 10)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512F               (1U << 11)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512CD              (1U << 12)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512ER              (1U << 13)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512PF              (1U << 14)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512VL              (1U << 15)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512DQ              (1U << 16)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512BW              (1U << 17)
> > +/* GNU_PROPERTY_X86_ISA_1_BASELINE: CMOV, CX8 (cmpxchg8b), FPU (fld),
> > +   MMX, OSFXSR (fxsave), SCE (syscall), SSE and SSE2.  */
> > +#define GNU_PROPERTY_X86_ISA_1_BASELINE              (1U << 0)
> > +/* GNU_PROPERTY_X86_ISA_1_V2: GNU_PROPERTY_X86_ISA_1_BASELINE,
> > +   CMPXCHG16B (cmpxchg16b), LAHF-SAHF (lahf), POPCNT (popcnt), SSE3,
> > +   SSSE3, SSE4.1 and SSE4.2.  */
> > +#define GNU_PROPERTY_X86_ISA_1_V2            (1U << 1)
> > +/* GNU_PROPERTY_X86_ISA_1_V3: GNU_PROPERTY_X86_ISA_1_V2, AVX, AVX2, BMI1,
> > +   BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE.  */
> > +#define GNU_PROPERTY_X86_ISA_1_V3            (1U << 2)
> > +/* GNU_PROPERTY_X86_ISA_1_V4: GNU_PROPERTY_X86_ISA_1_V3, AVX512F,
> > +   AVX512BW, AVX512CD, AVX512DQ and AVX512VL.  */
> > +#define GNU_PROPERTY_X86_ISA_1_V4            (1U << 3)
> >
> >  /* This indicates that all executable sections are compatible with
> >     IBT.  */
>
> Shouldn't it follow bintuils 32930e4edbc06 change and move current
> GNU_PROPERTY_X86_ISA_1_ definitions to GNU_PROPERTY_X86_COMPAT_2_?
> Not sure if this charecterize any exported ABI change, since the
> most possible usual consumer (bintuils) does not use glibc version.
>
> Also, maybe move this change to an specific patch.

GNU_PROPERTY_X86_COMPAT_XXX were added to binutils
consumers to support existing old binaries.  Since glibc never
supports old properties, there is no need to add them to glibc.

>
> > diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> > index 081cc72e93..109f03e9b9 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 (yesyes,$(enable-x86-isa-level)$(config-cflags-skylake-avx512))
> > +tests += tst-isa-level-1
> > +modules-names += tst-isa-level-mod-1a tst-isa-level-mod-1b
> > +
> > +CFLAGS-tst-isa-level-mod-1a.c += -march=skylake-avx512 \
> > +                             -DINCLUDE_X86_ISA_LEVEL
> > +$(objpfx)tst-isa-level-1: $(libdl)
> > +$(objpfx)tst-isa-level-1.out: $(objpfx)tst-isa-level-mod-1a.so \
> > +                           $(objpfx)tst-isa-level-mod-1b.so
> > +endif
> >  endif
> >
> >  ifeq ($(subdir),math)
>
> This will limit the test to a very narrow set of machines, couldn't
> we check only for enable-x86-isa-level and make the conditional check
> for ISA inside the test itself?

Fixed.

> What I have in mind would be something like:
>
>   1. Create onde module object for each ISA variant, by varying either
>      -march or using the specific gcc option (not sure it would clash
>      with the ABI notes isa-level.c already include).
>
>   2. On tst-isa-level-1.c check current ISA level with get_isa_level
>      and check against the ISA_BASELINE and load the modules with a
>      ISA number lower than baseline.
>
>  Something like:
>
>   const struct cpu_features *cpu_features
>     = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
>   unsigned int isa_level = get_isa_level (cpu_features);
>
>   bool check_isa_baseline = (isa_level & ISA_BASELINE) == ISA_BASELINE;
>   bool check_isa_v2       = (isa_level & ISA_V2)       == ISA_V2;
>   bool check_isa_v3       = (isa_level & ISA_V3)       == ISA_V3;
>   bool check_isa_v4       = (isa_level & ISA_V4)       == ISA_V4;
>
>   do_test_1 ("tst-isa-level-mod-1-baseline.so", true);
>   do_test_1 ("tst-isa-level-mod-1-isa_v2.so", true);
>   do_test_1 ("tst-isa-level-mod-1-isa_v3.so", true);
>   do_test_1 ("tst-isa-level-mod-1-isa_v4.so", true);

Fixed.

> You might require to just build the isa_v4 only for
> config-cflags-skylake-avx512 and conditionalize with HAVE_SKYLAKE_AVX512_SUPPORT
> (which seems to be ununsed in this patch).

Fixed.

> > diff --git a/sysdeps/x86/abi-note.c b/sysdeps/x86/abi-note.c
> > new file mode 100644
> > index 0000000000..5140e6ab47
> > --- /dev/null
> > +++ b/sysdeps/x86/abi-note.c
> > @@ -0,0 +1,29 @@
> > +/* Special .init and .fini section support.  x86-64 version.
> > +   Copyright (C) 2020 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.
> > +
> > +   In addition to the permissions in the GNU Lesser General Public
> > +   License, the Free Software Foundation gives you unlimited
> > +   permission to link the compiled version of this file with other
> > +   programs, and to distribute those programs without any restriction
> > +   coming from the use of this file.  (The Lesser General Public
> > +   License restrictions do apply in other respects; for example, they
> > +   cover modification of the file, and distribution when not linked
> > +   into another program.)
> > +
> > +   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 <isa-level.c>
> > +#include <csu/abi-note.c>
>
> Ok,
>
> > diff --git a/sysdeps/x86/configure b/sysdeps/x86/configure
> > index 81cc4e80d6..2738fe47b2 100644
> > --- a/sysdeps/x86/configure
> > +++ b/sysdeps/x86/configure
> > @@ -68,3 +68,104 @@ elif test $enable_cet = permissive; then
> >  fi
> >  config_vars="$config_vars
> >  enable-cet = $enable_cet"
> > +
> > +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for -march=skylake-avx512 support" >&5
> > +$as_echo_n "checking for -march=skylake-avx512 support... " >&6; }
> > +if ${libc_cv_cc_skylake_avx512+:} false; then :
> > +  $as_echo_n "(cached) " >&6
> > +else
> > +  if { ac_try='${CC-cc} -march=skylake-avx512 -xc /dev/null -S -o /dev/null'
> > +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> > +  (eval $ac_try) 2>&5
> > +  ac_status=$?
> > +  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> > +  test $ac_status = 0; }; }; then :
> > +  libc_cv_cc_skylake_avx512=yes
> > +else
> > +  libc_cv_cc_skylake_avx512=no
> > +fi
> > +
> > +fi
> > +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_cc_skylake_avx512" >&5
> > +$as_echo "$libc_cv_cc_skylake_avx512" >&6; }
> > +if test $libc_cv_cc_skylake_avx512 = yes; then
> > +  $as_echo "#define HAVE_SKYLAKE_AVX512_SUPPORT 1" >>confdefs.h
> > +
> > +fi
> > +config_vars="$config_vars
> > +config-cflags-skylake-avx512 = $libc_cv_cc_skylake_avx512"
> > +
> > +libc_cv_include_x86_isa_level=no
> > +if test -z "`$LD --version | sed -n 's/^GNU \(gold\).*$/\1/p'`"; then
> > +  # Check for ld 2.32 or higher.
> > +  libc_cv_include_x86_isa_level=yes
> > +  for ac_prog in $LD
> > +do
> > +  # Extract the first word of "$ac_prog", so it can be a program name with args.
> > +set dummy $ac_prog; ac_word=$2
> > +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
> > +$as_echo_n "checking for $ac_word... " >&6; }
> > +if ${ac_cv_prog_LD+:} false; then :
> > +  $as_echo_n "(cached) " >&6
> > +else
> > +  if test -n "$LD"; then
> > +  ac_cv_prog_LD="$LD" # Let the user override the test.
> > +else
> > +as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
> > +for as_dir in $PATH
> > +do
> > +  IFS=$as_save_IFS
> > +  test -z "$as_dir" && as_dir=.
> > +    for ac_exec_ext in '' $ac_executable_extensions; do
> > +  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
> > +    ac_cv_prog_LD="$ac_prog"
> > +    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
> > +    break 2
> > +  fi
> > +done
> > +  done
> > +IFS=$as_save_IFS
> > +
> > +fi
> > +fi
> > +LD=$ac_cv_prog_LD
> > +if test -n "$LD"; then
> > +  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $LD" >&5
> > +$as_echo "$LD" >&6; }
> > +else
> > +  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
> > +$as_echo "no" >&6; }
> > +fi
> > +
> > +
> > +  test -n "$LD" && break
> > +done
> > +
> > +if test -z "$LD"; then
> > +  ac_verc_fail=yes
> > +else
> > +  # Found it, now check the version.
> > +  { $as_echo "$as_me:${as_lineno-$LINENO}: checking version of $LD" >&5
> > +$as_echo_n "checking version of $LD... " >&6; }
> > +  ac_prog_version=`$LD --version 2>&1 | sed -n 's/^.*GNU ld.* \([0-9][0-9]*\.[0-9.]*\).*$/\1/p'`
> > +  case $ac_prog_version in
> > +    '') ac_prog_version="v. ?.??, bad"; ac_verc_fail=yes;;
> > +    2.3[2-9]*|2.[4-9][0-9]*|[3-9].*|[1-9][0-9]*)
> > +       ac_prog_version="$ac_prog_version, ok"; ac_verc_fail=no;;
> > +    *) ac_prog_version="$ac_prog_version, bad"; ac_verc_fail=yes;;
> > +
> > +  esac
> > +  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_prog_version" >&5
> > +$as_echo "$ac_prog_version" >&6; }
> > +fi
> > +if test $ac_verc_fail = yes; then
> > +  libc_cv_include_x86_isa_level=no
> > +fi
> > +
> > +  if test $libc_cv_include_x86_isa_level = yes; then
> > +    $as_echo "#define INCLUDE_X86_ISA_LEVEL 1" >>confdefs.h
> > +
> > +  fi
> > +fi
> > +config_vars="$config_vars
> > +enable-x86-isa-level = $libc_cv_include_x86_isa_level"
> > diff --git a/sysdeps/x86/configure.ac b/sysdeps/x86/configure.ac
> > index 8f3e1191f6..8f00b9663d 100644
> > --- a/sysdeps/x86/configure.ac
> > +++ b/sysdeps/x86/configure.ac
> > @@ -43,3 +43,29 @@ elif test $enable_cet = permissive; then
> >    AC_DEFINE(DEFAULT_DL_X86_CET_CONTROL, cet_permissive)
> >  fi
> >  LIBC_CONFIG_VAR([enable-cet], [$enable_cet])
> > +
> > +dnl Check if -march=skylake-avx512 works.
> > +AC_CACHE_CHECK(for -march=skylake-avx512 support,
> > +            libc_cv_cc_skylake_avx512, [dnl
> > +LIBC_TRY_CC_OPTION([-march=skylake-avx512],
> > +                [libc_cv_cc_skylake_avx512=yes],
> > +                [libc_cv_cc_skylake_avx512=no])
> > +])
> > +if test $libc_cv_cc_skylake_avx512 = yes; then
> > +  AC_DEFINE(HAVE_SKYLAKE_AVX512_SUPPORT)
> > +fi
>
> Where is it used specifically? There is no config.h.in tag either.

The whole check is removed.

> > +LIBC_CONFIG_VAR([config-cflags-skylake-avx512], [$libc_cv_cc_skylake_avx512])
> > +
> > +libc_cv_include_x86_isa_level=no
> > +if test -z "`$LD --version | sed -n 's/^GNU \(gold\).*$/\1/p'`"; then
> > +  # Check for ld 2.32 or higher.
> > +  libc_cv_include_x86_isa_level=yes
> > +  AC_CHECK_PROG_VER(LD, $LD, --version,
> > +                 [GNU ld.* \([0-9][0-9]*\.[0-9.]*\)],
> > +                 [2.3[2-9]*|2.[4-9][0-9]*|[3-9].*|[1-9][0-9]*],
> > +                 libc_cv_include_x86_isa_level=no)
> > +  if test $libc_cv_include_x86_isa_level = yes; then
> > +    AC_DEFINE(INCLUDE_X86_ISA_LEVEL)
> > +  fi
> > +fi
> > +LIBC_CONFIG_VAR([enable-x86-isa-level], [$libc_cv_include_x86_isa_level])
>
> Instead of version check, would it better to check if the linker actually
> build a snippet with the expected notes?

Fixed.

> > diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
> > index fe080b63b2..ec5cdafe81 100644
> > --- a/sysdeps/x86/cpu-features.c
> > +++ b/sysdeps/x86/cpu-features.c
> > @@ -19,6 +19,7 @@
> >  #include <cpuid.h>
> >  #include <dl-hwcap.h>
> >  #include <libc-pointer-arith.h>
> > +#include <get-isa-level.h>
> >  #if IS_IN (libc) && !defined SHARED
> >  # include <assert.h>
> >  # include <unistd.h>
> > @@ -290,6 +291,8 @@ update_usable (struct cpu_features *cpu_features)
> >        CPU_FEATURE_SET_USABLE (cpu_features, KL);
> >        CPU_FEATURE_SET_USABLE (cpu_features, WIDE_KL);
> >      }
> > +
> > +  cpu_features->isa_1 = get_isa_level (cpu_features);
> >  }
> >
> >  static void
>
> Ok.
>
> > diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c
> > index 5524b66038..8986c776e5 100644
> > --- a/sysdeps/x86/dl-cet.c
> > +++ b/sysdeps/x86/dl-cet.c
> > @@ -76,10 +76,12 @@ dl_cet_check (struct link_map *m, const char *program)
> >          */
> >         enable_ibt &= (HAS_CPU_FEATURE (IBT)
> >                        && (enable_ibt_type == cet_always_on
> > -                          || (m->l_cet & lc_ibt) != 0));
> > +                          || (m->l_x86_feature_1_and
> > +                              & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0));
> >         enable_shstk &= (HAS_CPU_FEATURE (SHSTK)
> >                          && (enable_shstk_type == cet_always_on
> > -                            || (m->l_cet & lc_shstk) != 0));
> > +                            || (m->l_x86_feature_1_and
> > +                                & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0));
> >       }
> >
>
> Ok.
>
> >        /* ld.so is CET-enabled by kernel.  But shared objects may not
> > @@ -111,7 +113,8 @@ dl_cet_check (struct link_map *m, const char *program)
> >             /* IBT is enabled only if it is enabled in executable as
> >                well as all shared objects.  */
> >             enable_ibt &= (enable_ibt_type == cet_always_on
> > -                          || (l->l_cet & lc_ibt) != 0);
> > +                          || (l->l_x86_feature_1_and
> > +                              & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0);
> >             if (!found_ibt_legacy && enable_ibt != ibt_enabled)
> >               {
> >                 found_ibt_legacy = true;
> > @@ -121,7 +124,8 @@ dl_cet_check (struct link_map *m, const char *program)
> >             /* SHSTK is enabled only if it is enabled in executable as
> >                well as all shared objects.  */
> >             enable_shstk &= (enable_shstk_type == cet_always_on
> > -                            || (l->l_cet & lc_shstk) != 0);
> > +                            || (l->l_x86_feature_1_and
> > +                                & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0);
> >             if (enable_shstk != shstk_enabled)
> >               {
> >                 found_shstk_legacy = true;
>
> Ok.
>
> > diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h
> > index 89911e19e2..61c0624c09 100644
> > --- a/sysdeps/x86/dl-prop.h
> > +++ b/sysdeps/x86/dl-prop.h
> > @@ -19,14 +19,54 @@
> >  #ifndef _DL_PROP_H
> >  #define _DL_PROP_H
> >
> > +#include <libintl.h>
> > +
> >  extern void _dl_cet_check (struct link_map *, const char *)
> >      attribute_hidden;
> >  extern void _dl_cet_open_check (struct link_map *)
> >      attribute_hidden;
> >
> > +static void
> > +dl_isa_level_check (struct link_map *m, const char *program)
> > +{
> > +  const struct cpu_features *cpu_features = __get_cpu_features ();
> > +  unsigned int i;
> > +  struct link_map *l;
> > +
> > +  i = m->l_searchlist.r_nlist;
> > +  while (i-- > 0)
> > +    {
> > +      /* Check each shared object to see if ISA level is compatible.  */
> > +      l = m->l_initfini[i];
> > +
> > +      /* Skip ISA level check if functions have been executed.  */
> > +      if (l->l_init_called)
> > +     continue;
> > +
> > +#ifdef SHARED
> > +      /* Skip ISA level check for ld.so since ld.so won't run if its ISA
> > +      level is higher than CPU.  */
> > +      if (l == &GL(dl_rtld_map) || l->l_real == &GL(dl_rtld_map))
> > +     continue;
> > +#endif
> > +
> > +      if ((l->l_x86_isa_1_needed & cpu_features->isa_1)
> > +       != l->l_x86_isa_1_needed)
> > +     {
> > +       if (program)
> > +         _dl_fatal_printf ("%s: CPU ISA level is lower than required\n",
> > +                           *l->l_name != '\0' ? l->l_name : program);
> > +       else
> > +         _dl_signal_error (0, l->l_name, "dlopen",
> > +                           N_("CPU ISA level is lower than required"));
> > +     }
> > +    }
> > +}
> > +
>
> Ok. Not sure if it is worth to translate the _dl_fatal_printf (it seems
> that at least one use at elf/dl-open.c does it).

I left it unchanged.

>
> >  static inline void __attribute__ ((always_inline))
> >  _rtld_main_check (struct link_map *m, const char *program)
> >  {
> > +  dl_isa_level_check (m, program);
> >  #if CET_ENABLED
> >    _dl_cet_check (m, program);
> >  #endif
> > @@ -35,20 +75,18 @@ _rtld_main_check (struct link_map *m, const char *program)
> >  static inline void __attribute__ ((always_inline))
> >  _dl_open_check (struct link_map *m)
> >  {
> > +  dl_isa_level_check (m, NULL);
> >  #if CET_ENABLED
> >    _dl_cet_open_check (m);
> >  #endif
> >  }
> >
>
> Ok.
>
> >  static inline void __attribute__ ((unused))
> > -_dl_process_cet_property_note (struct link_map *l,
> > -                           const ElfW(Nhdr) *note,
> > -                           const ElfW(Addr) size,
> > -                           const ElfW(Addr) align)
> > +_dl_process_property_note (struct link_map *l, const ElfW(Nhdr) *note,
> > +                        const ElfW(Addr) size, const ElfW(Addr) align)
> >  {
> > -#if CET_ENABLED
> >    /* Skip if we have seen a NT_GNU_PROPERTY_TYPE_0 note before.  */
> > -  if (l->l_cet != lc_unknown)
> > +  if (l->l_property != lc_property_unknown)
> >      return;
> >
> >    /* The NT_GNU_PROPERTY_TYPE_0 note must be aliged to 4 bytes in
>
> Ok.
>
> > @@ -59,7 +97,8 @@ _dl_process_cet_property_note (struct link_map *l,
> >
> >    const ElfW(Addr) start = (ElfW(Addr)) note;
> >
> > -  unsigned int feature_1 = 0;
> > +  unsigned int feature_1_and = 0;
> > +  unsigned int isa_1_needed = 0;
> >    unsigned int last_type = 0;
> >
> >    while ((ElfW(Addr)) (note + 1) - start < size)
> > @@ -71,11 +110,11 @@ _dl_process_cet_property_note (struct link_map *l,
> >       {
> >         /* Stop if we see more than one GNU property note which may
> >            be generated by the older linker.  */
> > -       if (l->l_cet != lc_unknown)
> > +       if (l->l_property != lc_property_unknown)
> >           return;
> >
> > -       /* Check CET status now.  */
> > -       l->l_cet = lc_none;
> > +       /* Check CET status and ISA levels now.  */
> > +       l->l_property = lc_property_none;
> >
> >         /* Check for invalid property.  */
> >         if (note->n_descsz < 8
>
> Ok.
>
> > @@ -101,26 +140,37 @@ _dl_process_cet_property_note (struct link_map *l,
> >
> >             last_type = type;
> >
> > -           if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
> > +           if (type == GNU_PROPERTY_X86_FEATURE_1_AND
> > +               || type == GNU_PROPERTY_X86_ISA_1_NEEDED)
> >               {
> > -               /* The size of GNU_PROPERTY_X86_FEATURE_1_AND is 4
> > -                  bytes.  When seeing GNU_PROPERTY_X86_FEATURE_1_AND,
> > -                  we stop the search regardless if its size is correct
> > -                  or not.  There is no point to continue if this note
> > -                  is ill-formed.  */
> > +               /* The sizes of types which we are searching for are
> > +                  4 bytes.  There is no point to continue if this
> > +                  note is ill-formed.  */
> >                 if (datasz != 4)
> >                   return;
> >
>
> Ok.
>
> > -               feature_1 = *(unsigned int *) ptr;
> > -
> > -               /* Keep searching for the next GNU property note
> > -                  generated by the older linker.  */
> > -               break;
> > +               /* NB: Stop the scan only after seeing all types which
> > +                  we are searching for.  */
> > +               _Static_assert ((GNU_PROPERTY_X86_ISA_1_NEEDED >
> > +                                GNU_PROPERTY_X86_FEATURE_1_AND),
> > +                               "GNU_PROPERTY_X86_ISA_1_NEEDED > "
> > +                               "GNU_PROPERTY_X86_FEATURE_1_AND");
>
> Ok.
>
> > +               if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
> > +                 feature_1_and = *(unsigned int *) ptr;
> > +               else
> > +                 {
> > +                   isa_1_needed = *(unsigned int *) ptr;
> > +
> > +                   /* Keep searching for the next GNU property note
> > +                      generated by the older linker.  */
> > +                   break;
> > +                 }
> >               }
> > -           else if (type > GNU_PROPERTY_X86_FEATURE_1_AND)
> > +           else if (type > GNU_PROPERTY_X86_ISA_1_NEEDED)
> >               {
> > -               /* Stop since property type is in ascending order.  */
> > -               return;
> > +               /* Stop the scan since property type is in ascending
> > +                  order.  */
> > +               break;
> >               }
> >
> >             /* Check the next property item.  */
>
> Ok.
>
> > @@ -137,18 +187,21 @@ _dl_process_cet_property_note (struct link_map *l,
> >      }
> >
> >    /* We get here only if there is one or no GNU property note.  */
> > -  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_IBT))
> > -    l->l_cet |= lc_ibt;
> > -  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
> > -    l->l_cet |= lc_shstk;
> > -#endif
> > +  if (isa_1_needed || feature_1_and)
>
> No implicit checks.

Fixed.

> > +    {
> > +      l->l_property = lc_property_valid;
> > +      l->l_x86_isa_1_needed = isa_1_needed;
> > +      l->l_x86_feature_1_and = feature_1_and;
> > +    }
> > +  else
> > +    l->l_property = lc_property_none;
> >  }
> >
> >  static inline void __attribute__ ((unused))
> >  _dl_process_pt_note (struct link_map *l, const ElfW(Phdr) *ph)
> >  {
> >    const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
> > -  _dl_process_cet_property_note (l, note, ph->p_memsz, ph->p_align);
> > +  _dl_process_property_note (l, note, ph->p_memsz, ph->p_align);
> >  }
> >
> >  static inline int __attribute__ ((always_inline))
>
> Ok.
>
> > diff --git a/sysdeps/x86/get-isa-level.h b/sysdeps/x86/get-isa-level.h
> > new file mode 100644
> > index 0000000000..166dd5df01
> > --- /dev/null
> > +++ b/sysdeps/x86/get-isa-level.h
> > @@ -0,0 +1,66 @@
> > +/* Get x86 ISA level.
> > +   This file is part of the GNU C Library.
> > +   Copyright (C) 2020 Free Software Foundation, Inc.
> > +
> > +   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>
> > +
> > +/* Get GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > +   ISA level.  */
> > +
> > +static unsigned int
> > +get_isa_level (const struct cpu_features *cpu_features)
> > +{
> > +  unsigned isa_level = 0;
>
> s/unsigned/unsigned int/

Fixed.

> > +
> > +  if (CPU_FEATURE_USABLE_P (cpu_features, CMOV)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, CX8)
> > +      && CPU_FEATURE_CPU_P (cpu_features, FPU)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, FXSR)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, MMX)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, SSE)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, SSE2))
> > +    {
> > +      isa_level = GNU_PROPERTY_X86_ISA_1_BASELINE;
> > +      if (CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
> > +     {
> > +       isa_level |= GNU_PROPERTY_X86_ISA_1_V2;
> > +       if (CPU_FEATURE_USABLE_P (cpu_features, AVX)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, F16C)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, FMA)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, MOVBE))
> > +         {
> > +           isa_level |= GNU_PROPERTY_X86_ISA_1_V3;
> > +           if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
> > +             isa_level |= GNU_PROPERTY_X86_ISA_1_V4;
> > +         }
> > +     }
> > +    }
> > +
> > +  return isa_level;
> > +}
>
> Do we actually support a isa level lower than baseline?

Yes.  In 32-bit, we require i486 or above.

> > diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
> > index f62be0b9b3..ef0c6b4fbc 100644
> > --- a/sysdeps/x86/include/cpu-features.h
> > +++ b/sysdeps/x86/include/cpu-features.h
> > @@ -129,6 +129,8 @@ struct cpu_features
> >    struct cpu_features_basic basic;
> >    struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
> >    unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
> > +  /* X86 micro-architecture ISA levels.  */
> > +  unsigned int isa_1;
> >    /* The state size for XSAVEC or XSAVE.  The type must be unsigned long
> >       int so that we use
> >
>
> Ok.
>
> > diff --git a/sysdeps/x86/isa-level.c b/sysdeps/x86/isa-level.c
> > new file mode 100644
> > index 0000000000..0751e86f27
> > --- /dev/null
> > +++ b/sysdeps/x86/isa-level.c
> > @@ -0,0 +1,95 @@
> > +/* ELF program property for x86 ISA level.
> > +   Copyright (C) 2020 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.
> > +
> > +   In addition to the permissions in the GNU Lesser General Public
> > +   License, the Free Software Foundation gives you unlimited
> > +   permission to link the compiled version of this file with other
> > +   programs, and to distribute those programs without any restriction
> > +   coming from the use of this file.  (The Lesser General Public
> > +   License restrictions do apply in other respects; for example, they
> > +   cover modification of the file, and distribution when not linked
> > +   into another program.)
> > +
> > +   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 <elf.h>
> > +
> > +/* ELF program property for x86 ISA level.  */
> > +#ifdef INCLUDE_X86_ISA_LEVEL
> > +# if defined __x86_64__ || defined __FXSR__ || !defined _SOFT_FLOAT \
> > +     || defined  __MMX__ || defined __SSE__ || defined __SSE2__
> > +#  define ISA_BASELINE       GNU_PROPERTY_X86_ISA_1_BASELINE
> > +# else
> > +#  define ISA_BASELINE       0
> > +# endif
> > +
> > +# if defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
> > +     || (defined __x86_64__ && defined __LAHF_SAHF__) \
> > +     || defined __POPCNT__ || defined __SSE3__ \
> > +     || defined __SSSE3__ || defined __SSE4_1__ || defined __SSE4_2__
> > +#  define ISA_V2     GNU_PROPERTY_X86_ISA_1_V2
> > +# else
> > +#  define ISA_V2     0
> > +# endif
> > +
> > +# if defined __AVX__ || defined __AVX2__ || defined __F16C__ \
> > +     || defined __FMA__ || defined __LZCNT__ || defined __MOVBE__ \
> > +     || defined __XSAVE__
> > +#  define ISA_V3     GNU_PROPERTY_X86_ISA_1_V3
> > +# else
> > +#  define ISA_V3     0
> > +# endif
> > +
> > +# if defined __AVX512F__ || defined __AVX512BW__ || defined __AVX512CD__ \
> > +     || defined __AVX512DQ__ || defined __AVX512VL__
> > +#  define ISA_V4     GNU_PROPERTY_X86_ISA_1_V4
> > +# else
> > +#  define ISA_V4     0
> > +# endif
> > +
> > +# define ISA_LEVEL (ISA_BASELINE | ISA_V2 | ISA_V3 | ISA_V4)
> > +
> > +# if ISA_LEVEL
> > +#  ifdef __LP64__
> > +#   define PROPERTY_ALIGN 3
> > +#  else
> > +#   define PROPERTY_ALIGN 2
> > +#  endif
> > +
> > +#  define note_stringify(arg) note_stringify_1(arg)
> > +#  define note_stringify_1(arg) #arg
> > +
> > +asm(".pushsection \".note.gnu.property\",\"a\",@note\n"
> > +"    .p2align " note_stringify (PROPERTY_ALIGN)
> > +     /* name length.  */
> > +"\n  .long 1f - 0f\n"
> > +     /* data length.  */
> > +"    .long 4f - 1f\n"
> > +     /* note type: NT_GNU_PROPERTY_TYPE_0.  */
> > +"    .long " note_stringify (NT_GNU_PROPERTY_TYPE_0)
> > +     /* vendor name.  */
> > +"\n0:        .asciz \"GNU\"\n"
> > +"1:  .p2align " note_stringify (PROPERTY_ALIGN)
> > +     /* pr_type: GNU_PROPERTY_X86_ISA_1_NEEDED.  */
> > +"\n  .long " note_stringify (GNU_PROPERTY_X86_ISA_1_NEEDED)
> > +     /* pr_datasz.  */
> > +"\n  .long 3f - 2f\n"
> > +     /* GNU_PROPERTY_X86_ISA_1_V[234].  */
> > +"2:\n         .long " note_stringify (ISA_LEVEL)
> > +"\n3:\n      .p2align " note_stringify (PROPERTY_ALIGN)
> > +"\n4:\n .popsection");
> > +# endif /* ISA_LEVEL */
> > +#endif /* INCLUDE_X86_ISA_LEVEL */
>
> Ok.
>
> > diff --git a/sysdeps/x86/link_map.h b/sysdeps/x86/link_map.h
> > index 2e4f8850f9..3c550e529a 100644
> > --- a/sysdeps/x86/link_map.h
> > +++ b/sysdeps/x86/link_map.h
> > @@ -16,12 +16,16 @@
> >     License along with the GNU C Library; if not, see
> >     <https://www.gnu.org/licenses/>.  */
> >
> > -/* If this object is enabled with CET.  */
> > +/* if this object has GNU property.  */
> >  enum
> >    {
> > -    lc_unknown = 0,                   /* Unknown CET status.  */
> > -    lc_none = 1 << 0,                         /* Not enabled with CET.  */
> > -    lc_ibt = 1 << 1,                  /* Enabled with IBT.  */
> > -    lc_shstk = 1 << 2,                        /* Enabled with STSHK.  */
> > -    lc_ibt_and_shstk = lc_ibt | lc_shstk /* Enabled with both.  */
> > -  } l_cet:3;
> > +    lc_property_unknown = 0,         /* Unknown property status.  */
> > +    lc_property_none = 1 << 0,               /* No property.  */
> > +    lc_property_valid = 1 << 1               /* Has valid property.  */
> > +  } l_property:2;
> > +
>
> Ok.
>
> > +/* GNU_PROPERTY_X86_FEATURE_1_AND of this object.  */
> > +unsigned int l_x86_feature_1_and;
> > +
> > +/* GNU_PROPERTY_X86_ISA_1_NEEDED of this object.  */
> > +unsigned int l_x86_isa_1_needed;
>
> Ok.
>
> > diff --git a/sysdeps/x86/tst-isa-level-1.c b/sysdeps/x86/tst-isa-level-1.c
> > new file mode 100644
> > index 0000000000..c263157c8c
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-1.c
> > @@ -0,0 +1,74 @@
> > +/* Check ISA level on dlopened shared object.
> > +   Copyright (C) 2020 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 <stdbool.h>
> > +#include <string.h>
> > +#include <elf.h>
> > +#include <get-isa-level.h>
> > +#include <support/xdlfcn.h>
> > +#include <support/check.h>
> > +#include <support/test-driver.h>
> > +
> > +static void
> > +do_test_1 (const char *modname, bool fail)
> > +{
> > +  int (*fp) (void);
> > +  void *h;
> > +
> > +  h = dlopen (modname, RTLD_LAZY);
> > +  if (h == NULL)
> > +    {
> > +      const char *err = dlerror ();
> > +      if (fail)
> > +     {
> > +       if (strstr (err, "CPU ISA level is lower than required") == NULL)
> > +         FAIL_EXIT1 ("incorrect dlopen '%s' error: %s\n", modname, err);
> > +
> > +       return;
> > +     }
> > +
> > +      FAIL_EXIT1 ("cannot open '%s': %s\n", modname, err);
> > +    }
> > +
> > +  if (fail)
> > +    FAIL_EXIT1 ("dlopen '%s' should have failed\n", modname);
> > +
> > +  fp = xdlsym (h, "test");
> > +
> > +  if (fp () != 0)
> > +    FAIL_EXIT1 ("test () != 0\n");
> > +
> > +  dlclose (h);
> > +}
> > +
>
> Ok.
>
> > +static int
> > +do_test (void)
> > +{
> > +  const struct cpu_features *cpu_features
> > +    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> > +  unsigned int isa_level = get_isa_level (cpu_features);
> > +  /* Skip on x86-64-v4 platforms since dlopen always works.  */
> > +  if ((isa_level & GNU_PROPERTY_X86_ISA_1_V4) != 0)
> > +    return EXIT_UNSUPPORTED;
> > +  do_test_1 ("tst-isa-level-mod-1a.so", true);
> > +  do_test_1 ("tst-isa-level-mod-1b.so", false);
> > +  return EXIT_SUCCESS;
> > +}
> > +
> > +#include <support/test-driver.c>
>
> Maybe use my suggestion to improve test coverage.

Fixed.

> > diff --git a/sysdeps/x86/tst-isa-level-mod-1.c b/sysdeps/x86/tst-isa-level-mod-1.c
> > new file mode 100644
> > index 0000000000..3816536428
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1.c
> > @@ -0,0 +1,23 @@
> > +/* Check ISA level on dlopened shared object.
> > +   Copyright (C) 2019-2020 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/>.  */
> > +
> > +int
> > +test (void)
> > +{
> > +  return 0;
> > +}
>
> Ok.
>
> > diff --git a/sysdeps/x86/tst-isa-level-mod-1a.c b/sysdeps/x86/tst-isa-level-mod-1a.c
> > new file mode 100644
> > index 0000000000..4f026dd915
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1a.c
> > @@ -0,0 +1,2 @@
> > +#include <isa-level.c>
> > +#include "tst-isa-level-mod-1.c"
> > diff --git a/sysdeps/x86/tst-isa-level-mod-1b.c b/sysdeps/x86/tst-isa-level-mod-1b.c
> > new file mode 100644
> > index 0000000000..d6fe0685a4
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1b.c
> > @@ -0,0 +1 @@
> > +#include "tst-isa-level-mod-1.c"
>
> Ok.
>
> > diff --git a/sysdeps/x86_64/dl-hwcaps-subdirs.c b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> > index 8810a822ef..e5640303f9 100644
> > --- a/sysdeps/x86_64/dl-hwcaps-subdirs.c
> > +++ b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> > @@ -18,6 +18,7 @@
> >
> >  #include <dl-hwcaps.h>
> >  #include <cpu-features.h>
> > +#include <get-isa-level.h>
> >
> >  const char _dl_hwcaps_subdirs[] = "x86-64-v4:x86-64-v3:x86-64-v2";
> >  enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
> > @@ -25,40 +26,25 @@ enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
> >  uint32_t
> >  _dl_hwcaps_subdirs_active (void)
> >  {
> > +  const struct cpu_features *cpu_features
> > +    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> > +  unsigned int isa_level = get_isa_level (cpu_features);
> >    int active = 0;
> >
> >    /* Test in reverse preference order.  */
> >
> >    /* x86-64-v2.  */
> > -  if (!(CPU_FEATURE_USABLE (CMPXCHG16B)
> > -        && CPU_FEATURE_USABLE (LAHF64_SAHF64)
> > -        && CPU_FEATURE_USABLE (POPCNT)
> > -        && CPU_FEATURE_USABLE (SSE3)
> > -        && CPU_FEATURE_USABLE (SSE4_1)
> > -        && CPU_FEATURE_USABLE (SSE4_2)
> > -        && CPU_FEATURE_USABLE (SSSE3)))
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
> >      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> >    ++active;
> >
> >    /* x86-64-v3.  */
> > -  if (!(CPU_FEATURE_USABLE (AVX)
> > -        && CPU_FEATURE_USABLE (AVX2)
> > -        && CPU_FEATURE_USABLE (BMI1)
> > -        && CPU_FEATURE_USABLE (BMI2)
> > -        && CPU_FEATURE_USABLE (F16C)
> > -        && CPU_FEATURE_USABLE (FMA)
> > -        && CPU_FEATURE_USABLE (LZCNT)
> > -        && CPU_FEATURE_USABLE (MOVBE)
> > -        && CPU_FEATURE_USABLE (OSXSAVE)))
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
> >      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> >    ++active;
> >
> > - /* x86-64-v4.  */
> > -  if (!(CPU_FEATURE_USABLE (AVX512F)
> > -        && CPU_FEATURE_USABLE (AVX512BW)
> > -        && CPU_FEATURE_USABLE (AVX512CD)
> > -        && CPU_FEATURE_USABLE (AVX512DQ)
> > -        && CPU_FEATURE_USABLE (AVX512VL)))
> > +  /* x86-64-v4.  */
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
> >      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> >    ++active;
> >
>
> Ok.
>
> > diff --git a/sysdeps/x86_64/tst-glibc-hwcaps.c b/sysdeps/x86_64/tst-glibc-hwcaps.c
> > index 3075a8286d..a041a9047d 100644
> > --- a/sysdeps/x86_64/tst-glibc-hwcaps.c
> > +++ b/sysdeps/x86_64/tst-glibc-hwcaps.c
> > @@ -19,7 +19,8 @@
> >  #include <stdio.h>
> >  #include <support/check.h>
> >  #include <sys/param.h>
> > -#include <sys/platform/x86.h>
> > +#include <elf.h>
> > +#include <get-isa-level.h>
> >
> >  extern int marker2 (void);
> >  extern int marker3 (void);
> > @@ -31,35 +32,15 @@ compute_level (void)
> >  {
> >    const struct cpu_features *cpu_features
> >      = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> > -
> > - if (!(CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, MMX)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE2)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)))
> > -   return 1;
> > - if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, BMI1)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, F16C)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, FMA)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, OSXSAVE)))
> > -   return 2;
> > - if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)))
> > -   return 3;
> > - return 4;
> > +  unsigned int isa_level = get_isa_level (cpu_features);
> > +
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
> > +    return 1;
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
> > +    return 2;
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
> > +    return 3;
> > +  return 4;
> >  }
> >
> >  static int
> >
>
> Ok.

Here is the updated patch.  Tested under i686, x32 and x86-64 modes
on x86-64-v2, x86-64-v3 and x86-64-v4 machines.

OK for master?

Thanks.

Comments

Adhemerval Zanella Jan. 7, 2021, 8:09 p.m. UTC | #1
On 06/01/2021 14:11, H.J. Lu wrote:
> Here is the updated patch.  Tested under i686, x32 and x86-64 modes
> on x86-64-v2, x86-64-v3 and x86-64-v4 machines.
> 
> OK for master?
> 
> Thanks.
> 

LGTM with just two clarification below.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> From 6630e06f9bcb361177d46c277cf8e67cbd722429 Mon Sep 17 00:00:00 2001
> From: "H.J. Lu" <hjl.tools@gmail.com>
> Date: Fri, 9 Oct 2020 06:06:56 -0700
> Subject: [PATCH] x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker [BZ #26717]
> 
> GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA
> levels:
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250
> 
> and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with
> GNU_PROPERTY_X86_ISA_1_V[234] marker:
> 
> https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13
> 
> Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by
> 
> commit b0ab06937385e0ae25cebf1991787d64f439bf12
> Author: H.J. Lu <hjl.tools@gmail.com>
> Date:   Fri Oct 30 06:49:57 2020 -0700
> 
>     x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker
> 
> and
> 
> commit 32930e4edbc06bc6f10c435dbcc63131715df678
> Author: H.J. Lu <hjl.tools@gmail.com>
> Date:   Fri Oct 9 05:05:57 2020 -0700
> 
>     x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker
> 
> GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the
> micro-architecture ISA level required to execute the binary.  The marker
> must be added by programmers explicitly in one of 3 ways:
> 
> 1. Pass -mneeded to GCC.
> 2. Add the marker in the linker inputs as this patch does.
> 3. Pass -z x86-64-v[234] to the linker.
> 
> Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> marker support to ld.so if binutils 2.32 or newer is used to build glibc:
> 
> 1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> markers to elf.h.
> 2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> marker to abi-note.o based on the ISA level used to compile abi-note.o,
> assuming that the same ISA level is used to compile the whole glibc.
> 3. Add isa_1 to cpu_features to record the supported x86 ISA level.
> 4. Rename _dl_process_cet_property_note to _dl_process_property_note and
> add GNU_PROPERTY_X86_ISA_1_V[234] marker detection.
> 5. Update _rtld_main_check and _dl_open_check to check loaded objects
> with the incompatible ISA level.
> 6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails
> on lesser platforms.
> 7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c.
> 
> Tested under i686, x32 and x86-64 modes on x86-64-v2, x86-64-v3 and
> x86-64-v4 machines.
> 
> Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine
> and got:
> 
> [hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1
> ./elf/tst-isa-level-1: CPU ISA level is lower than required
> [hjl@gnu-cfl-2 build-x86_64-linux]$
> ---
>  config.h.in                                |   3 +
>  elf/elf.h                                  |  35 +++----
>  sysdeps/x86/Makefile                       |  30 ++++++
>  sysdeps/x86/abi-note.c                     |  29 ++++++
>  sysdeps/x86/configure                      |  79 ++++++++++++++
>  sysdeps/x86/configure.ac                   |  66 ++++++++++++
>  sysdeps/x86/cpu-features.c                 |   3 +
>  sysdeps/x86/dl-cet.c                       |  12 ++-
>  sysdeps/x86/dl-prop.h                      | 113 +++++++++++++++------
>  sysdeps/x86/get-isa-level.h                |  66 ++++++++++++
>  sysdeps/x86/include/cpu-features.h         |   2 +
>  sysdeps/x86/isa-level.c                    |  97 ++++++++++++++++++
>  sysdeps/x86/link_map.h                     |  18 ++--
>  sysdeps/x86/tst-isa-level-1.c              | 104 +++++++++++++++++++
>  sysdeps/x86/tst-isa-level-mod-1-baseline.c |   1 +
>  sysdeps/x86/tst-isa-level-mod-1-v2.c       |   1 +
>  sysdeps/x86/tst-isa-level-mod-1-v3.c       |   1 +
>  sysdeps/x86/tst-isa-level-mod-1-v4.c       |   1 +
>  sysdeps/x86/tst-isa-level-mod-1.c          |  25 +++++
>  sysdeps/x86_64/dl-hwcaps-subdirs.c         |  30 ++----
>  sysdeps/x86_64/tst-glibc-hwcaps.c          |  41 ++------
>  21 files changed, 644 insertions(+), 113 deletions(-)
>  create mode 100644 sysdeps/x86/abi-note.c
>  create mode 100644 sysdeps/x86/get-isa-level.h
>  create mode 100644 sysdeps/x86/isa-level.c
>  create mode 100644 sysdeps/x86/tst-isa-level-1.c
>  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-baseline.c
>  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v2.c
>  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v3.c
>  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v4.c
>  create mode 100644 sysdeps/x86/tst-isa-level-mod-1.c
> 
> diff --git a/config.h.in b/config.h.in
> index eca2d66a2c..947feeff36 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -269,4 +269,7 @@
>  /* The default value of x86 CET control.  */
>  #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property
>  
> +/* Define if x86 ISA level should be included in shared libraries.  */
> +#undef INCLUDE_X86_ISA_LEVEL
> +
>  #endif
> diff --git a/elf/elf.h b/elf/elf.h

Ok.

> index 4a9ae97dfc..9ebd052c8a 100644
> --- a/elf/elf.h
> +++ b/elf/elf.h
> @@ -1324,31 +1324,26 @@ typedef struct
>  
>  /* The x86 instruction sets indicated by the corresponding bits are
>     used in program.  Their support in the hardware is optional.  */
> -#define GNU_PROPERTY_X86_ISA_1_USED		0xc0000000
> +#define GNU_PROPERTY_X86_ISA_1_USED		0xc0010002
>  /* The x86 instruction sets indicated by the corresponding bits are
>     used in program and they must be supported by the hardware.   */
> -#define GNU_PROPERTY_X86_ISA_1_NEEDED		0xc0000001
> +#define GNU_PROPERTY_X86_ISA_1_NEEDED		0xc0008002
>  /* X86 processor-specific features used in program.  */
>  #define GNU_PROPERTY_X86_FEATURE_1_AND		0xc0000002
>  
> -#define GNU_PROPERTY_X86_ISA_1_486		(1U << 0)
> -#define GNU_PROPERTY_X86_ISA_1_586		(1U << 1)
> -#define GNU_PROPERTY_X86_ISA_1_686		(1U << 2)
> -#define GNU_PROPERTY_X86_ISA_1_SSE		(1U << 3)
> -#define GNU_PROPERTY_X86_ISA_1_SSE2		(1U << 4)
> -#define GNU_PROPERTY_X86_ISA_1_SSE3		(1U << 5)
> -#define GNU_PROPERTY_X86_ISA_1_SSSE3		(1U << 6)
> -#define GNU_PROPERTY_X86_ISA_1_SSE4_1		(1U << 7)
> -#define GNU_PROPERTY_X86_ISA_1_SSE4_2		(1U << 8)
> -#define GNU_PROPERTY_X86_ISA_1_AVX		(1U << 9)
> -#define GNU_PROPERTY_X86_ISA_1_AVX2		(1U << 10)
> -#define GNU_PROPERTY_X86_ISA_1_AVX512F		(1U << 11)
> -#define GNU_PROPERTY_X86_ISA_1_AVX512CD		(1U << 12)
> -#define GNU_PROPERTY_X86_ISA_1_AVX512ER		(1U << 13)
> -#define GNU_PROPERTY_X86_ISA_1_AVX512PF		(1U << 14)
> -#define GNU_PROPERTY_X86_ISA_1_AVX512VL		(1U << 15)
> -#define GNU_PROPERTY_X86_ISA_1_AVX512DQ		(1U << 16)
> -#define GNU_PROPERTY_X86_ISA_1_AVX512BW		(1U << 17)
> +/* GNU_PROPERTY_X86_ISA_1_BASELINE: CMOV, CX8 (cmpxchg8b), FPU (fld),
> +   MMX, OSFXSR (fxsave), SCE (syscall), SSE and SSE2.  */
> +#define GNU_PROPERTY_X86_ISA_1_BASELINE		(1U << 0)
> +/* GNU_PROPERTY_X86_ISA_1_V2: GNU_PROPERTY_X86_ISA_1_BASELINE,
> +   CMPXCHG16B (cmpxchg16b), LAHF-SAHF (lahf), POPCNT (popcnt), SSE3,
> +   SSSE3, SSE4.1 and SSE4.2.  */
> +#define GNU_PROPERTY_X86_ISA_1_V2		(1U << 1)
> +/* GNU_PROPERTY_X86_ISA_1_V3: GNU_PROPERTY_X86_ISA_1_V2, AVX, AVX2, BMI1,
> +   BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE.  */
> +#define GNU_PROPERTY_X86_ISA_1_V3		(1U << 2)
> +/* GNU_PROPERTY_X86_ISA_1_V4: GNU_PROPERTY_X86_ISA_1_V3, AVX512F,
> +   AVX512BW, AVX512CD, AVX512DQ and AVX512VL.  */
> +#define GNU_PROPERTY_X86_ISA_1_V4		(1U << 3)
>  
>  /* This indicates that all executable sections are compatible with
>     IBT.  */

Ok.

> diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> index 081cc72e93..c814d5a195 100644
> --- a/sysdeps/x86/Makefile
> +++ b/sysdeps/x86/Makefile
> @@ -9,6 +9,36 @@ 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,$(enable-x86-isa-level))
> +tests += tst-isa-level-1
> +modules-names += tst-isa-level-mod-1-baseline \
> +		 tst-isa-level-mod-1-v2 \
> +		 tst-isa-level-mod-1-v3 \
> +		 tst-isa-level-mod-1-v4 \
> +
> +# X86 ISA level baseline
> +CFLAGS-tst-isa-level-mod-1-baseline.c += -DINCLUDE_X86_ISA_LEVEL \
> +					 -DISA_LEVEL=0x1 \
> +					 -march=x86-64
> +# X86 ISA level v2
> +CFLAGS-tst-isa-level-mod-1-v2.c += -DINCLUDE_X86_ISA_LEVEL \
> +				   -DISA_LEVEL=0x3 \
> +				   -march=x86-64
> +# X86 ISA level v3
> +CFLAGS-tst-isa-level-mod-1-v3.c += -DINCLUDE_X86_ISA_LEVEL \
> +				   -DISA_LEVEL=0x7 \
> +				   -march=x86-64
> +# X86 ISA level v4
> +CFLAGS-tst-isa-level-mod-1-v4.c += -DINCLUDE_X86_ISA_LEVEL \
> +				   -DISA_LEVEL=0xf \
> +				   -march=x86-64
> +
> +$(objpfx)tst-isa-level-1: $(libdl)
> +$(objpfx)tst-isa-level-1.out: $(objpfx)tst-isa-level-mod-1-baseline.so \
> +			      $(objpfx)tst-isa-level-mod-1-v2.so \
> +			      $(objpfx)tst-isa-level-mod-1-v3.so \
> +			      $(objpfx)tst-isa-level-mod-1-v4.so
> +endif
>  endif
>  
>  ifeq ($(subdir),math)

Ok.

> diff --git a/sysdeps/x86/abi-note.c b/sysdeps/x86/abi-note.c
> new file mode 100644
> index 0000000000..5140e6ab47
> --- /dev/null
> +++ b/sysdeps/x86/abi-note.c
> @@ -0,0 +1,29 @@
> +/* Special .init and .fini section support.  x86-64 version.
> +   Copyright (C) 2020 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.
> +
> +   In addition to the permissions in the GNU Lesser General Public
> +   License, the Free Software Foundation gives you unlimited
> +   permission to link the compiled version of this file with other
> +   programs, and to distribute those programs without any restriction
> +   coming from the use of this file.  (The Lesser General Public
> +   License restrictions do apply in other respects; for example, they
> +   cover modification of the file, and distribution when not linked
> +   into another program.)
> +
> +   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 <isa-level.c>
> +#include <csu/abi-note.c>

Ok.

> diff --git a/sysdeps/x86/configure b/sysdeps/x86/configure
> index 81cc4e80d6..5e32dc62b3 100644
> --- a/sysdeps/x86/configure
> +++ b/sysdeps/x86/configure
> @@ -68,3 +68,82 @@ elif test $enable_cet = permissive; then
>  fi
>  config_vars="$config_vars
>  enable-cet = $enable_cet"
> +
> +# Check if linker supports x86 ISA level.
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker x86 ISA level support" >&5
> +$as_echo_n "checking for linker x86 ISA level support... " >&6; }
> +if ${libc_cv_include_x86_isa_level+:} false; then :
> +  $as_echo_n "(cached) " >&6
> +else
> +  cat > conftest1.S <<EOF
> +#ifdef __LP64__
> +# define P2ALIGN 3
> +#else
> +# define P2ALIGN 2
> +#endif
> +	.section ".note.gnu.property", "a"
> +	.p2align P2ALIGN
> +	.long 1f - 0f		/* name length.  */
> +	.long 4f - 1f		/* data length.  */
> +	/* NT_GNU_PROPERTY_TYPE_0 */
> +	.long 5			/* note type.  */
> +0:
> +	.asciz "GNU"		/* vendor name.  */
> +1:
> +	.p2align P2ALIGN
> +	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
> +	.long 0xc0008002	/* pr_type.  */
> +	.long 3f - 2f		/* pr_datasz.  */
> +2:
> +	.long 0x1
> +3:
> +	.p2align P2ALIGN
> +4:
> +EOF
> +cat > conftest2.S <<EOF
> +#ifdef __LP64__
> +# define P2ALIGN 3
> +#else
> +# define P2ALIGN 2
> +#endif
> +	.section ".note.gnu.property", "a"
> +	.p2align P2ALIGN
> +	.long 1f - 0f		/* name length.  */
> +	.long 4f - 1f		/* data length.  */
> +	/* NT_GNU_PROPERTY_TYPE_0 */
> +	.long 5			/* note type.  */
> +0:
> +	.asciz "GNU"		/* vendor name.  */
> +1:
> +	.p2align P2ALIGN
> +	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
> +	.long 0xc0008002	/* pr_type.  */
> +	.long 3f - 2f		/* pr_datasz.  */
> +2:
> +	.long 0x2
> +3:
> +	.p2align P2ALIGN
> +4:
> +EOF
> +libc_cv_include_x86_isa_level=no
> +if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S'
> +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> +  (eval $ac_try) 2>&5
> +  ac_status=$?
> +  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> +  test $ac_status = 0; }; }; then
> +  count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
> +  if test "$count" = 1; then
> +    libc_cv_include_x86_isa_level=yes
> +  fi
> +fi
> +rm -f conftest*
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_include_x86_isa_level" >&5
> +$as_echo "$libc_cv_include_x86_isa_level" >&6; }
> +if test $libc_cv_include_x86_isa_level = yes; then
> +  $as_echo "#define INCLUDE_X86_ISA_LEVEL 1" >>confdefs.h
> +
> +fi
> +config_vars="$config_vars
> +enable-x86-isa-level = $libc_cv_include_x86_isa_level"
> diff --git a/sysdeps/x86/configure.ac b/sysdeps/x86/configure.ac
> index 8f3e1191f6..f94088f377 100644
> --- a/sysdeps/x86/configure.ac
> +++ b/sysdeps/x86/configure.ac
> @@ -43,3 +43,69 @@ elif test $enable_cet = permissive; then
>    AC_DEFINE(DEFAULT_DL_X86_CET_CONTROL, cet_permissive)
>  fi
>  LIBC_CONFIG_VAR([enable-cet], [$enable_cet])
> +
> +# Check if linker supports x86 ISA level.
> +AC_CACHE_CHECK([for linker x86 ISA level support],
> +	       libc_cv_include_x86_isa_level, [dnl
> +cat > conftest1.S <<EOF
> +#ifdef __LP64__
> +# define P2ALIGN 3
> +#else
> +# define P2ALIGN 2
> +#endif
> +	.section ".note.gnu.property", "a"
> +	.p2align P2ALIGN
> +	.long 1f - 0f		/* name length.  */
> +	.long 4f - 1f		/* data length.  */
> +	/* NT_GNU_PROPERTY_TYPE_0 */
> +	.long 5			/* note type.  */
> +0:
> +	.asciz "GNU"		/* vendor name.  */
> +1:
> +	.p2align P2ALIGN
> +	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
> +	.long 0xc0008002	/* pr_type.  */
> +	.long 3f - 2f		/* pr_datasz.  */
> +2:
> +	.long 0x1
> +3:
> +	.p2align P2ALIGN
> +4:
> +EOF
> +cat > conftest2.S <<EOF
> +#ifdef __LP64__
> +# define P2ALIGN 3
> +#else
> +# define P2ALIGN 2
> +#endif
> +	.section ".note.gnu.property", "a"
> +	.p2align P2ALIGN
> +	.long 1f - 0f		/* name length.  */
> +	.long 4f - 1f		/* data length.  */
> +	/* NT_GNU_PROPERTY_TYPE_0 */
> +	.long 5			/* note type.  */
> +0:
> +	.asciz "GNU"		/* vendor name.  */
> +1:
> +	.p2align P2ALIGN
> +	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
> +	.long 0xc0008002	/* pr_type.  */
> +	.long 3f - 2f		/* pr_datasz.  */
> +2:
> +	.long 0x2
> +3:
> +	.p2align P2ALIGN
> +4:
> +EOF
> +libc_cv_include_x86_isa_level=no
> +if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S); then
> +  count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
> +  if test "$count" = 1; then
> +    libc_cv_include_x86_isa_level=yes
> +  fi
> +fi
> +rm -f conftest*])
> +if test $libc_cv_include_x86_isa_level = yes; then
> +  AC_DEFINE(INCLUDE_X86_ISA_LEVEL)
> +fi
> +LIBC_CONFIG_VAR([enable-x86-isa-level], [$libc_cv_include_x86_isa_level])

Skipping autogenerated file.

> diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
> index 529c586193..e7da682a2e 100644
> --- a/sysdeps/x86/cpu-features.c
> +++ b/sysdeps/x86/cpu-features.c
> @@ -19,6 +19,7 @@
>  #include <cpuid.h>
>  #include <dl-hwcap.h>
>  #include <libc-pointer-arith.h>
> +#include <get-isa-level.h>
>  #if IS_IN (libc) && !defined SHARED
>  # include <assert.h>
>  # include <unistd.h>
> @@ -290,6 +291,8 @@ update_usable (struct cpu_features *cpu_features)
>        CPU_FEATURE_SET_USABLE (cpu_features, KL);
>        CPU_FEATURE_SET_USABLE (cpu_features, WIDE_KL);
>      }
> +
> +  cpu_features->isa_1 = get_isa_level (cpu_features);
>  }
>  
>  static void

Ok.

> diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c
> index b4910f7634..ed7fd6d10d 100644
> --- a/sysdeps/x86/dl-cet.c
> +++ b/sysdeps/x86/dl-cet.c
> @@ -76,10 +76,12 @@ dl_cet_check (struct link_map *m, const char *program)
>  	   */
>  	  enable_ibt &= (HAS_CPU_FEATURE (IBT)
>  			 && (enable_ibt_type == cet_always_on
> -			     || (m->l_cet & lc_ibt) != 0));
> +			     || (m->l_x86_feature_1_and
> +				 & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0));
>  	  enable_shstk &= (HAS_CPU_FEATURE (SHSTK)
>  			   && (enable_shstk_type == cet_always_on
> -			       || (m->l_cet & lc_shstk) != 0));
> +			       || (m->l_x86_feature_1_and
> +				   & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0));
>  	}
>  
>        /* ld.so is CET-enabled by kernel.  But shared objects may not

Ok.

> @@ -111,7 +113,8 @@ dl_cet_check (struct link_map *m, const char *program)
>  	      /* IBT is enabled only if it is enabled in executable as
>  		 well as all shared objects.  */
>  	      enable_ibt &= (enable_ibt_type == cet_always_on
> -			     || (l->l_cet & lc_ibt) != 0);
> +			     || (l->l_x86_feature_1_and
> +				 & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0);
>  	      if (!found_ibt_legacy && enable_ibt != ibt_enabled)
>  		{
>  		  found_ibt_legacy = true;
> @@ -121,7 +124,8 @@ dl_cet_check (struct link_map *m, const char *program)
>  	      /* SHSTK is enabled only if it is enabled in executable as
>  		 well as all shared objects.  */
>  	      enable_shstk &= (enable_shstk_type == cet_always_on
> -			       || (l->l_cet & lc_shstk) != 0);
> +			       || (l->l_x86_feature_1_and
> +				   & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0);
>  	      if (enable_shstk != shstk_enabled)
>  		{
>  		  found_shstk_legacy = true;

Ok.

> diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h
> index ce1667dc7a..56bd020b3c 100644
> --- a/sysdeps/x86/dl-prop.h
> +++ b/sysdeps/x86/dl-prop.h
> @@ -19,14 +19,54 @@
>  #ifndef _DL_PROP_H
>  #define _DL_PROP_H
>  
> +#include <libintl.h>
> +
>  extern void _dl_cet_check (struct link_map *, const char *)
>      attribute_hidden;
>  extern void _dl_cet_open_check (struct link_map *)
>      attribute_hidden;
>  
> +static void
> +dl_isa_level_check (struct link_map *m, const char *program)
> +{
> +  const struct cpu_features *cpu_features = __get_cpu_features ();
> +  unsigned int i;
> +  struct link_map *l;
> +
> +  i = m->l_searchlist.r_nlist;
> +  while (i-- > 0)
> +    {
> +      /* Check each shared object to see if ISA level is compatible.  */
> +      l = m->l_initfini[i];
> +
> +      /* Skip ISA level check if functions have been executed.  */
> +      if (l->l_init_called)
> +	continue;
> +
> +#ifdef SHARED
> +      /* Skip ISA level check for ld.so since ld.so won't run if its ISA
> +	 level is higher than CPU.  */
> +      if (l == &GL(dl_rtld_map) || l->l_real == &GL(dl_rtld_map))
> +	continue;
> +#endif
> +
> +      if ((l->l_x86_isa_1_needed & cpu_features->isa_1)
> +	  != l->l_x86_isa_1_needed)
> +	{
> +	  if (program)
> +	    _dl_fatal_printf ("%s: CPU ISA level is lower than required\n",
> +			      *l->l_name != '\0' ? l->l_name : program);
> +	  else
> +	    _dl_signal_error (0, l->l_name, "dlopen",
> +			      N_("CPU ISA level is lower than required"));
> +	}
> +    }
> +}
> +

Ok.

>  static inline void __attribute__ ((always_inline))
>  _rtld_main_check (struct link_map *m, const char *program)
>  {
> +  dl_isa_level_check (m, program);
>  #if CET_ENABLED
>    _dl_cet_check (m, program);
>  #endif
> @@ -35,20 +75,18 @@ _rtld_main_check (struct link_map *m, const char *program)
>  static inline void __attribute__ ((always_inline))
>  _dl_open_check (struct link_map *m)
>  {
> +  dl_isa_level_check (m, NULL);
>  #if CET_ENABLED
>    _dl_cet_open_check (m);
>  #endif
>  }
>  
>  static inline void __attribute__ ((unused))
> -_dl_process_cet_property_note (struct link_map *l,
> -			      const ElfW(Nhdr) *note,
> -			      const ElfW(Addr) size,
> -			      const ElfW(Addr) align)
> +_dl_process_property_note (struct link_map *l, const ElfW(Nhdr) *note,
> +			   const ElfW(Addr) size, const ElfW(Addr) align)
>  {
> -#if CET_ENABLED
>    /* Skip if we have seen a NT_GNU_PROPERTY_TYPE_0 note before.  */
> -  if (l->l_cet != lc_unknown)
> +  if (l->l_property != lc_property_unknown)
>      return;
>  
>    /* The NT_GNU_PROPERTY_TYPE_0 note must be aliged to 4 bytes in

Ok.

> @@ -59,7 +97,8 @@ _dl_process_cet_property_note (struct link_map *l,
>  
>    const ElfW(Addr) start = (ElfW(Addr)) note;
>  
> -  unsigned int feature_1 = 0;
> +  unsigned int feature_1_and = 0;
> +  unsigned int isa_1_needed = 0;
>    unsigned int last_type = 0;
>  
>    while ((ElfW(Addr)) (note + 1) - start < size)
> @@ -71,11 +110,11 @@ _dl_process_cet_property_note (struct link_map *l,
>  	{
>  	  /* Stop if we see more than one GNU property note which may
>  	     be generated by the older linker.  */
> -	  if (l->l_cet != lc_unknown)
> +	  if (l->l_property != lc_property_unknown)
>  	    return;
>  
> -	  /* Check CET status now.  */
> -	  l->l_cet = lc_none;
> +	  /* Check CET status and ISA levels now.  */
> +	  l->l_property = lc_property_none;
>  
>  	  /* Check for invalid property.  */
>  	  if (note->n_descsz < 8
> @@ -101,26 +140,37 @@ _dl_process_cet_property_note (struct link_map *l,
>  
>  	      last_type = type;
>  
> -	      if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
> +	      if (type == GNU_PROPERTY_X86_FEATURE_1_AND
> +		  || type == GNU_PROPERTY_X86_ISA_1_NEEDED)
>  		{
> -		  /* The size of GNU_PROPERTY_X86_FEATURE_1_AND is 4
> -		     bytes.  When seeing GNU_PROPERTY_X86_FEATURE_1_AND,
> -		     we stop the search regardless if its size is correct
> -		     or not.  There is no point to continue if this note
> -		     is ill-formed.  */
> +		  /* The sizes of types which we are searching for are
> +		     4 bytes.  There is no point to continue if this
> +		     note is ill-formed.  */
>  		  if (datasz != 4)
>  		    return;
>  
> -		  feature_1 = *(unsigned int *) ptr;
> -
> -		  /* Keep searching for the next GNU property note
> -		     generated by the older linker.  */
> -		  break;
> +		  /* NB: Stop the scan only after seeing all types which
> +		     we are searching for.  */
> +		  _Static_assert ((GNU_PROPERTY_X86_ISA_1_NEEDED >
> +				   GNU_PROPERTY_X86_FEATURE_1_AND),
> +				  "GNU_PROPERTY_X86_ISA_1_NEEDED > "
> +				  "GNU_PROPERTY_X86_FEATURE_1_AND");
> +		  if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
> +		    feature_1_and = *(unsigned int *) ptr;
> +		  else
> +		    {
> +		      isa_1_needed = *(unsigned int *) ptr;
> +
> +		      /* Keep searching for the next GNU property note
> +			 generated by the older linker.  */
> +		      break;
> +		    }
>  		}
> -	      else if (type > GNU_PROPERTY_X86_FEATURE_1_AND)
> +	      else if (type > GNU_PROPERTY_X86_ISA_1_NEEDED)
>  		{
> -		  /* Stop since property type is in ascending order.  */
> -		  return;
> +		  /* Stop the scan since property type is in ascending
> +		     order.  */
> +		  break;
>  		}
>  
>  	      /* Check the next property item.  */

Ok.

> @@ -137,18 +187,21 @@ _dl_process_cet_property_note (struct link_map *l,
>      }
>  
>    /* We get here only if there is one or no GNU property note.  */
> -  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_IBT))
> -    l->l_cet |= lc_ibt;
> -  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
> -    l->l_cet |= lc_shstk;
> -#endif
> +  if (isa_1_needed != 0 || feature_1_and != 0)
> +    {
> +      l->l_property = lc_property_valid;
> +      l->l_x86_isa_1_needed = isa_1_needed;
> +      l->l_x86_feature_1_and = feature_1_and;
> +    }
> +  else
> +    l->l_property = lc_property_none;
>  }
>  
>  static inline void __attribute__ ((unused))
>  _dl_process_pt_note (struct link_map *l, int fd, const ElfW(Phdr) *ph)
>  {
>    const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
> -  _dl_process_cet_property_note (l, note, ph->p_memsz, ph->p_align);
> +  _dl_process_property_note (l, note, ph->p_memsz, ph->p_align);
>  }
>  
>  static inline int __attribute__ ((always_inline))

Ok.

> diff --git a/sysdeps/x86/get-isa-level.h b/sysdeps/x86/get-isa-level.h
> new file mode 100644
> index 0000000000..a86e1e8941
> --- /dev/null
> +++ b/sysdeps/x86/get-isa-level.h
> @@ -0,0 +1,66 @@
> +/* Get x86 ISA level.
> +   This file is part of the GNU C Library.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +
> +   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>
> +
> +/* Get GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> +   ISA level.  */
> +
> +static unsigned int
> +get_isa_level (const struct cpu_features *cpu_features)
> +{
> +  unsigned int isa_level = 0;
> +
> +  if (CPU_FEATURE_USABLE_P (cpu_features, CMOV)
> +      && CPU_FEATURE_USABLE_P (cpu_features, CX8)
> +      && CPU_FEATURE_CPU_P (cpu_features, FPU)
> +      && CPU_FEATURE_USABLE_P (cpu_features, FXSR)
> +      && CPU_FEATURE_USABLE_P (cpu_features, MMX)
> +      && CPU_FEATURE_USABLE_P (cpu_features, SSE)
> +      && CPU_FEATURE_USABLE_P (cpu_features, SSE2))
> +    {
> +      isa_level = GNU_PROPERTY_X86_ISA_1_BASELINE;
> +      if (CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
> +	  && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
> +	  && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
> +	  && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
> +	  && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
> +	  && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
> +	  && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
> +	{
> +	  isa_level |= GNU_PROPERTY_X86_ISA_1_V2;
> +	  if (CPU_FEATURE_USABLE_P (cpu_features, AVX)
> +	      && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> +	      && CPU_FEATURE_USABLE_P (cpu_features, F16C)
> +	      && CPU_FEATURE_USABLE_P (cpu_features, FMA)
> +	      && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
> +	      && CPU_FEATURE_USABLE_P (cpu_features, MOVBE))
> +	    {
> +	      isa_level |= GNU_PROPERTY_X86_ISA_1_V3;
> +	      if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> +		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> +		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
> +		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
> +		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
> +		isa_level |= GNU_PROPERTY_X86_ISA_1_V4;
> +	    }
> +	}
> +    }
> +
> +  return isa_level;
> +}

Ok, is there any plan to add the gcc ISA_1_VX for 32-bit ABI as well? I am
asking because if there is no upcoming plan maybe an option is just to 
return 0 for !__X86_64__.

> diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
> index ffe300c931..99e7ee08cf 100644
> --- a/sysdeps/x86/include/cpu-features.h
> +++ b/sysdeps/x86/include/cpu-features.h
> @@ -123,6 +123,8 @@ struct cpu_features
>    struct cpu_features_basic basic;
>    struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
>    unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
> +  /* X86 micro-architecture ISA levels.  */
> +  unsigned int isa_1;
>    /* The state size for XSAVEC or XSAVE.  The type must be unsigned long
>       int so that we use
>  

Ok.

> diff --git a/sysdeps/x86/isa-level.c b/sysdeps/x86/isa-level.c
> new file mode 100644
> index 0000000000..aaf524cb56
> --- /dev/null
> +++ b/sysdeps/x86/isa-level.c
> @@ -0,0 +1,97 @@
> +/* ELF program property for x86 ISA level.
> +   Copyright (C) 2020 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.
> +
> +   In addition to the permissions in the GNU Lesser General Public
> +   License, the Free Software Foundation gives you unlimited
> +   permission to link the compiled version of this file with other
> +   programs, and to distribute those programs without any restriction
> +   coming from the use of this file.  (The Lesser General Public
> +   License restrictions do apply in other respects; for example, they
> +   cover modification of the file, and distribution when not linked
> +   into another program.)
> +
> +   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 <elf.h>
> +
> +/* ELF program property for x86 ISA level.  */
> +#ifdef INCLUDE_X86_ISA_LEVEL
> +# if defined __x86_64__ || defined __FXSR__ || !defined _SOFT_FLOAT \
> +     || defined  __MMX__ || defined __SSE__ || defined __SSE2__
> +#  define ISA_BASELINE	GNU_PROPERTY_X86_ISA_1_BASELINE
> +# else
> +#  define ISA_BASELINE	0
> +# endif
> +
> +# if defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
> +     || (defined __x86_64__ && defined __LAHF_SAHF__) \
> +     || defined __POPCNT__ || defined __SSE3__ \
> +     || defined __SSSE3__ || defined __SSE4_1__ || defined __SSE4_2__
> +#  define ISA_V2	GNU_PROPERTY_X86_ISA_1_V2
> +# else
> +#  define ISA_V2	0
> +# endif
> +
> +# if defined __AVX__ || defined __AVX2__ || defined __F16C__ \
> +     || defined __FMA__ || defined __LZCNT__ || defined __MOVBE__ \
> +     || defined __XSAVE__
> +#  define ISA_V3	GNU_PROPERTY_X86_ISA_1_V3
> +# else
> +#  define ISA_V3	0
> +# endif
> +
> +# if defined __AVX512F__ || defined __AVX512BW__ || defined __AVX512CD__ \
> +     || defined __AVX512DQ__ || defined __AVX512VL__
> +#  define ISA_V4	GNU_PROPERTY_X86_ISA_1_V4
> +# else
> +#  define ISA_V4	0
> +# endif
> +
> +# ifndef ISA_LEVEL
> +#  define ISA_LEVEL (ISA_BASELINE | ISA_V2 | ISA_V3 | ISA_V4)
> +# endif
> +
> +# if ISA_LEVEL
> +#  ifdef __LP64__
> +#   define PROPERTY_ALIGN 3
> +#  else
> +#   define PROPERTY_ALIGN 2
> +#  endif
> +
> +#  define note_stringify(arg) note_stringify_1(arg)
> +#  define note_stringify_1(arg) #arg
> +
> +asm(".pushsection \".note.gnu.property\",\"a\",@note\n"
> +"	.p2align " note_stringify (PROPERTY_ALIGN)
> +	/* name length.  */
> +"\n	.long 1f - 0f\n"
> +	/* data length.  */
> +"	.long 4f - 1f\n"
> +	/* note type: NT_GNU_PROPERTY_TYPE_0.  */
> +"	.long " note_stringify (NT_GNU_PROPERTY_TYPE_0)
> +	/* vendor name.  */
> +"\n0:	.asciz \"GNU\"\n"
> +"1:	.p2align " note_stringify (PROPERTY_ALIGN)
> +	/* pr_type: GNU_PROPERTY_X86_ISA_1_NEEDED.  */
> +"\n	.long " note_stringify (GNU_PROPERTY_X86_ISA_1_NEEDED)
> +	/* pr_datasz.  */
> +"\n	.long 3f - 2f\n"
> +	/* GNU_PROPERTY_X86_ISA_1_V[234].  */
> +"2:\n	 .long " note_stringify (ISA_LEVEL)
> +"\n3:\n	.p2align " note_stringify (PROPERTY_ALIGN)
> +"\n4:\n .popsection");
> +# endif /* ISA_LEVEL */
> +#endif /* INCLUDE_X86_ISA_LEVEL */

Ok.

> diff --git a/sysdeps/x86/link_map.h b/sysdeps/x86/link_map.h
> index 8074739b47..4c46a25f83 100644
> --- a/sysdeps/x86/link_map.h
> +++ b/sysdeps/x86/link_map.h
> @@ -16,12 +16,16 @@
>     License along with the GNU C Library; if not, see
>     <https://www.gnu.org/licenses/>.  */
>  
> -/* If this object is enabled with CET.  */
> +/* if this object has GNU property.  */
>  enum
>    {
> -    lc_unknown = 0,			 /* Unknown CET status.  */
> -    lc_none = 1 << 0,			 /* Not enabled with CET.  */
> -    lc_ibt = 1 << 1,			 /* Enabled with IBT.  */
> -    lc_shstk = 1 << 2,			 /* Enabled with STSHK.  */
> -    lc_ibt_and_shstk = lc_ibt | lc_shstk /* Enabled with both.  */
> -  } l_cet:3;
> +    lc_property_unknown = 0,		/* Unknown property status.  */
> +    lc_property_none = 1 << 0,		/* No property.  */
> +    lc_property_valid = 1 << 1		/* Has valid property.  */
> +  } l_property:2;
> +
> +/* GNU_PROPERTY_X86_FEATURE_1_AND of this object.  */
> +unsigned int l_x86_feature_1_and;
> +
> +/* GNU_PROPERTY_X86_ISA_1_NEEDED of this object.  */
> +unsigned int l_x86_isa_1_needed;

Ok.

> diff --git a/sysdeps/x86/tst-isa-level-1.c b/sysdeps/x86/tst-isa-level-1.c
> new file mode 100644
> index 0000000000..dc31d71ad2
> --- /dev/null
> +++ b/sysdeps/x86/tst-isa-level-1.c
> @@ -0,0 +1,104 @@
> +/* Check ISA level on dlopened shared object.
> +   Copyright (C) 2020 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 <stdbool.h>
> +#include <string.h>
> +#include <elf.h>
> +#include <get-isa-level.h>
> +#include <support/xdlfcn.h>
> +#include <support/check.h>
> +#include <support/test-driver.h>
> +
> +static void
> +do_test_1 (const char *modname, bool fail)
> +{
> +  int (*fp) (void);
> +  void *h;
> +
> +  h = dlopen (modname, RTLD_LAZY);
> +  if (h == NULL)
> +    {
> +      const char *err = dlerror ();
> +      if (fail)
> +	{
> +	  if (strstr (err, "CPU ISA level is lower than required") == NULL)
> +	    FAIL_EXIT1 ("incorrect dlopen '%s' error: %s\n", modname, err);
> +
> +	  return;
> +	}
> +
> +      FAIL_EXIT1 ("cannot open '%s': %s\n", modname, err);
> +    }
> +
> +  if (fail)
> +    FAIL_EXIT1 ("dlopen '%s' should have failed\n", modname);
> +
> +  fp = xdlsym (h, "test");
> +
> +  if (fp () != 0)
> +    FAIL_EXIT1 ("test () != 0\n");
> +
> +  dlclose (h);
> +}
> +
> +static int
> +do_test (void)
> +{
> +  const struct cpu_features *cpu_features
> +    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> +  unsigned int isa_level = get_isa_level (cpu_features);
> +  bool has_isa_baseline = ((isa_level & GNU_PROPERTY_X86_ISA_1_BASELINE)
> +			   == GNU_PROPERTY_X86_ISA_1_BASELINE);
> +  bool has_isa_v2 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V2)
> +			   == GNU_PROPERTY_X86_ISA_1_V2);
> +  bool has_isa_v3 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V3)
> +			   == GNU_PROPERTY_X86_ISA_1_V3);
> +  bool has_isa_v4 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V4)
> +			   == GNU_PROPERTY_X86_ISA_1_V4);
> +
> +  if (!has_isa_baseline)
> +    {
> +      do_test_1 ("tst-isa-level-mod-1-baseline.so", true);
> +      return EXIT_SUCCESS;
> +    }
> +
> +  do_test_1 ("tst-isa-level-mod-1-baseline.so", false);
> +
> +  /* Skip on x86-64-v4 platforms since dlopen v4 module always works.  */
> +  if (has_isa_v4)
> +    return EXIT_UNSUPPORTED;

Not sure if unsupported is the right error code here, since the isa
selection is just ignored (not really not supported).

> +
> +  do_test_1 ("tst-isa-level-mod-1-v4.so", true);
> +
> +  /* Skip on x86-64-v3 platforms since dlopen v3 module always works.  */
> +  if (has_isa_v3)
> +    return EXIT_SUCCESS;
> +
> +  do_test_1 ("tst-isa-level-mod-1-v3.so", true);
> +
> +  /* Skip on x86-64-v2 platforms since dlopen v2 module always works.  */
> +  if (has_isa_v2)
> +    return EXIT_SUCCESS;
> +
> +  do_test_1 ("tst-isa-level-mod-1-v2.so", true);
> +
> +  return EXIT_SUCCESS;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/sysdeps/x86/tst-isa-level-mod-1-baseline.c b/sysdeps/x86/tst-isa-level-mod-1-baseline.c
> new file mode 100644
> index 0000000000..d6fe0685a4
> --- /dev/null
> +++ b/sysdeps/x86/tst-isa-level-mod-1-baseline.c
> @@ -0,0 +1 @@
> +#include "tst-isa-level-mod-1.c"
> diff --git a/sysdeps/x86/tst-isa-level-mod-1-v2.c b/sysdeps/x86/tst-isa-level-mod-1-v2.c
> new file mode 100644
> index 0000000000..d6fe0685a4
> --- /dev/null
> +++ b/sysdeps/x86/tst-isa-level-mod-1-v2.c
> @@ -0,0 +1 @@
> +#include "tst-isa-level-mod-1.c"
> diff --git a/sysdeps/x86/tst-isa-level-mod-1-v3.c b/sysdeps/x86/tst-isa-level-mod-1-v3.c
> new file mode 100644
> index 0000000000..d6fe0685a4
> --- /dev/null
> +++ b/sysdeps/x86/tst-isa-level-mod-1-v3.c
> @@ -0,0 +1 @@
> +#include "tst-isa-level-mod-1.c"
> diff --git a/sysdeps/x86/tst-isa-level-mod-1-v4.c b/sysdeps/x86/tst-isa-level-mod-1-v4.c
> new file mode 100644
> index 0000000000..d6fe0685a4
> --- /dev/null
> +++ b/sysdeps/x86/tst-isa-level-mod-1-v4.c
> @@ -0,0 +1 @@
> +#include "tst-isa-level-mod-1.c"

Ok.

> diff --git a/sysdeps/x86/tst-isa-level-mod-1.c b/sysdeps/x86/tst-isa-level-mod-1.c
> new file mode 100644
> index 0000000000..40a2e1d99f
> --- /dev/null
> +++ b/sysdeps/x86/tst-isa-level-mod-1.c
> @@ -0,0 +1,25 @@
> +/* Check ISA level on dlopened shared object.
> +   Copyright (C) 2019-2020 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 <isa-level.c>
> +
> +int
> +test (void)
> +{
> +  return 0;
> +}

Ok.

> diff --git a/sysdeps/x86_64/dl-hwcaps-subdirs.c b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> index 0aaa635a00..e030534f1b 100644
> --- a/sysdeps/x86_64/dl-hwcaps-subdirs.c
> +++ b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> @@ -18,6 +18,7 @@
>  
>  #include <dl-hwcaps.h>
>  #include <cpu-features.h>
> +#include <get-isa-level.h>
>  
>  const char _dl_hwcaps_subdirs[] = "x86-64-v4:x86-64-v3:x86-64-v2";
>  enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
> @@ -25,40 +26,25 @@ enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
>  uint32_t
>  _dl_hwcaps_subdirs_active (void)
>  {
> +  const struct cpu_features *cpu_features
> +    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> +  unsigned int isa_level = get_isa_level (cpu_features);
>    int active = 0;
>  
>    /* Test in reverse preference order.  */
>  
>    /* x86-64-v2.  */
> -  if (!(CPU_FEATURE_USABLE (CMPXCHG16B)
> -        && CPU_FEATURE_USABLE (LAHF64_SAHF64)
> -        && CPU_FEATURE_USABLE (POPCNT)
> -        && CPU_FEATURE_USABLE (SSE3)
> -        && CPU_FEATURE_USABLE (SSE4_1)
> -        && CPU_FEATURE_USABLE (SSE4_2)
> -        && CPU_FEATURE_USABLE (SSSE3)))
> +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
>      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
>    ++active;
>  
>    /* x86-64-v3.  */
> -  if (!(CPU_FEATURE_USABLE (AVX)
> -        && CPU_FEATURE_USABLE (AVX2)
> -        && CPU_FEATURE_USABLE (BMI1)
> -        && CPU_FEATURE_USABLE (BMI2)
> -        && CPU_FEATURE_USABLE (F16C)
> -        && CPU_FEATURE_USABLE (FMA)
> -        && CPU_FEATURE_USABLE (LZCNT)
> -        && CPU_FEATURE_USABLE (MOVBE)
> -        && CPU_FEATURE_USABLE (OSXSAVE)))
> +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
>      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
>    ++active;
>  
> - /* x86-64-v4.  */
> -  if (!(CPU_FEATURE_USABLE (AVX512F)
> -        && CPU_FEATURE_USABLE (AVX512BW)
> -        && CPU_FEATURE_USABLE (AVX512CD)
> -        && CPU_FEATURE_USABLE (AVX512DQ)
> -        && CPU_FEATURE_USABLE (AVX512VL)))
> +  /* x86-64-v4.  */
> +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
>      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
>    ++active;
>  
> diff --git a/sysdeps/x86_64/tst-glibc-hwcaps.c b/sysdeps/x86_64/tst-glibc-hwcaps.c
> index 8bdcb91db0..37b61d3c84 100644
> --- a/sysdeps/x86_64/tst-glibc-hwcaps.c
> +++ b/sysdeps/x86_64/tst-glibc-hwcaps.c
> @@ -19,7 +19,8 @@
>  #include <stdio.h>
>  #include <support/check.h>
>  #include <sys/param.h>
> -#include <sys/platform/x86.h>
> +#include <elf.h>
> +#include <get-isa-level.h>
>  
>  extern int marker2 (void);
>  extern int marker3 (void);
> @@ -31,35 +32,15 @@ compute_level (void)
>  {
>    const struct cpu_features *cpu_features
>      = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> -
> - if (!(CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
> -       && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
> -       && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
> -       && CPU_FEATURE_USABLE_P (cpu_features, MMX)
> -       && CPU_FEATURE_USABLE_P (cpu_features, SSE)
> -       && CPU_FEATURE_USABLE_P (cpu_features, SSE2)
> -       && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
> -       && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
> -       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
> -       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)))
> -   return 1;
> - if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX)
> -       && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> -       && CPU_FEATURE_USABLE_P (cpu_features, BMI1)
> -       && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
> -       && CPU_FEATURE_USABLE_P (cpu_features, F16C)
> -       && CPU_FEATURE_USABLE_P (cpu_features, FMA)
> -       && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
> -       && CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
> -       && CPU_FEATURE_USABLE_P (cpu_features, OSXSAVE)))
> -   return 2;
> - if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
> -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
> -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)))
> -   return 3;
> - return 4;
> +  unsigned int isa_level = get_isa_level (cpu_features);
> +
> +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
> +    return 1;
> +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
> +    return 2;
> +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
> +    return 3;
> +  return 4;
>  }
>  
>  static int
> -- 
> 2.29.2

Ok.
H.J. Lu Jan. 7, 2021, 8:58 p.m. UTC | #2
On Thu, Jan 7, 2021 at 12:09 PM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 06/01/2021 14:11, H.J. Lu wrote:
> > Here is the updated patch.  Tested under i686, x32 and x86-64 modes
> > on x86-64-v2, x86-64-v3 and x86-64-v4 machines.
> >
> > OK for master?
> >
> > Thanks.
> >
>
> LGTM with just two clarification below.
>
> Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
>
> > From 6630e06f9bcb361177d46c277cf8e67cbd722429 Mon Sep 17 00:00:00 2001
> > From: "H.J. Lu" <hjl.tools@gmail.com>
> > Date: Fri, 9 Oct 2020 06:06:56 -0700
> > Subject: [PATCH] x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker [BZ #26717]
> >
> > GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA
> > levels:
> >
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250
> >
> > and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with
> > GNU_PROPERTY_X86_ISA_1_V[234] marker:
> >
> > https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13
> >
> > Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by
> >
> > commit b0ab06937385e0ae25cebf1991787d64f439bf12
> > Author: H.J. Lu <hjl.tools@gmail.com>
> > Date:   Fri Oct 30 06:49:57 2020 -0700
> >
> >     x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker
> >
> > and
> >
> > commit 32930e4edbc06bc6f10c435dbcc63131715df678
> > Author: H.J. Lu <hjl.tools@gmail.com>
> > Date:   Fri Oct 9 05:05:57 2020 -0700
> >
> >     x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker
> >
> > GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the
> > micro-architecture ISA level required to execute the binary.  The marker
> > must be added by programmers explicitly in one of 3 ways:
> >
> > 1. Pass -mneeded to GCC.
> > 2. Add the marker in the linker inputs as this patch does.
> > 3. Pass -z x86-64-v[234] to the linker.
> >
> > Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > marker support to ld.so if binutils 2.32 or newer is used to build glibc:
> >
> > 1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > markers to elf.h.
> > 2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > marker to abi-note.o based on the ISA level used to compile abi-note.o,
> > assuming that the same ISA level is used to compile the whole glibc.
> > 3. Add isa_1 to cpu_features to record the supported x86 ISA level.
> > 4. Rename _dl_process_cet_property_note to _dl_process_property_note and
> > add GNU_PROPERTY_X86_ISA_1_V[234] marker detection.
> > 5. Update _rtld_main_check and _dl_open_check to check loaded objects
> > with the incompatible ISA level.
> > 6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails
> > on lesser platforms.
> > 7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c.
> >
> > Tested under i686, x32 and x86-64 modes on x86-64-v2, x86-64-v3 and
> > x86-64-v4 machines.
> >
> > Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine
> > and got:
> >
> > [hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1
> > ./elf/tst-isa-level-1: CPU ISA level is lower than required
> > [hjl@gnu-cfl-2 build-x86_64-linux]$
> > ---
> >  config.h.in                                |   3 +
> >  elf/elf.h                                  |  35 +++----
> >  sysdeps/x86/Makefile                       |  30 ++++++
> >  sysdeps/x86/abi-note.c                     |  29 ++++++
> >  sysdeps/x86/configure                      |  79 ++++++++++++++
> >  sysdeps/x86/configure.ac                   |  66 ++++++++++++
> >  sysdeps/x86/cpu-features.c                 |   3 +
> >  sysdeps/x86/dl-cet.c                       |  12 ++-
> >  sysdeps/x86/dl-prop.h                      | 113 +++++++++++++++------
> >  sysdeps/x86/get-isa-level.h                |  66 ++++++++++++
> >  sysdeps/x86/include/cpu-features.h         |   2 +
> >  sysdeps/x86/isa-level.c                    |  97 ++++++++++++++++++
> >  sysdeps/x86/link_map.h                     |  18 ++--
> >  sysdeps/x86/tst-isa-level-1.c              | 104 +++++++++++++++++++
> >  sysdeps/x86/tst-isa-level-mod-1-baseline.c |   1 +
> >  sysdeps/x86/tst-isa-level-mod-1-v2.c       |   1 +
> >  sysdeps/x86/tst-isa-level-mod-1-v3.c       |   1 +
> >  sysdeps/x86/tst-isa-level-mod-1-v4.c       |   1 +
> >  sysdeps/x86/tst-isa-level-mod-1.c          |  25 +++++
> >  sysdeps/x86_64/dl-hwcaps-subdirs.c         |  30 ++----
> >  sysdeps/x86_64/tst-glibc-hwcaps.c          |  41 ++------
> >  21 files changed, 644 insertions(+), 113 deletions(-)
> >  create mode 100644 sysdeps/x86/abi-note.c
> >  create mode 100644 sysdeps/x86/get-isa-level.h
> >  create mode 100644 sysdeps/x86/isa-level.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-1.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-baseline.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v2.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v3.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v4.c
> >  create mode 100644 sysdeps/x86/tst-isa-level-mod-1.c
> >
> > diff --git a/config.h.in b/config.h.in
> > index eca2d66a2c..947feeff36 100644
> > --- a/config.h.in
> > +++ b/config.h.in
> > @@ -269,4 +269,7 @@
> >  /* The default value of x86 CET control.  */
> >  #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property
> >
> > +/* Define if x86 ISA level should be included in shared libraries.  */
> > +#undef INCLUDE_X86_ISA_LEVEL
> > +
> >  #endif
> > diff --git a/elf/elf.h b/elf/elf.h
>
> Ok.
>
> > index 4a9ae97dfc..9ebd052c8a 100644
> > --- a/elf/elf.h
> > +++ b/elf/elf.h
> > @@ -1324,31 +1324,26 @@ typedef struct
> >
> >  /* The x86 instruction sets indicated by the corresponding bits are
> >     used in program.  Their support in the hardware is optional.  */
> > -#define GNU_PROPERTY_X86_ISA_1_USED          0xc0000000
> > +#define GNU_PROPERTY_X86_ISA_1_USED          0xc0010002
> >  /* The x86 instruction sets indicated by the corresponding bits are
> >     used in program and they must be supported by the hardware.   */
> > -#define GNU_PROPERTY_X86_ISA_1_NEEDED                0xc0000001
> > +#define GNU_PROPERTY_X86_ISA_1_NEEDED                0xc0008002
> >  /* X86 processor-specific features used in program.  */
> >  #define GNU_PROPERTY_X86_FEATURE_1_AND               0xc0000002
> >
> > -#define GNU_PROPERTY_X86_ISA_1_486           (1U << 0)
> > -#define GNU_PROPERTY_X86_ISA_1_586           (1U << 1)
> > -#define GNU_PROPERTY_X86_ISA_1_686           (1U << 2)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE           (1U << 3)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE2          (1U << 4)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE3          (1U << 5)
> > -#define GNU_PROPERTY_X86_ISA_1_SSSE3         (1U << 6)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE4_1                (1U << 7)
> > -#define GNU_PROPERTY_X86_ISA_1_SSE4_2                (1U << 8)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX           (1U << 9)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX2          (1U << 10)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512F               (1U << 11)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512CD              (1U << 12)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512ER              (1U << 13)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512PF              (1U << 14)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512VL              (1U << 15)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512DQ              (1U << 16)
> > -#define GNU_PROPERTY_X86_ISA_1_AVX512BW              (1U << 17)
> > +/* GNU_PROPERTY_X86_ISA_1_BASELINE: CMOV, CX8 (cmpxchg8b), FPU (fld),
> > +   MMX, OSFXSR (fxsave), SCE (syscall), SSE and SSE2.  */
> > +#define GNU_PROPERTY_X86_ISA_1_BASELINE              (1U << 0)
> > +/* GNU_PROPERTY_X86_ISA_1_V2: GNU_PROPERTY_X86_ISA_1_BASELINE,
> > +   CMPXCHG16B (cmpxchg16b), LAHF-SAHF (lahf), POPCNT (popcnt), SSE3,
> > +   SSSE3, SSE4.1 and SSE4.2.  */
> > +#define GNU_PROPERTY_X86_ISA_1_V2            (1U << 1)
> > +/* GNU_PROPERTY_X86_ISA_1_V3: GNU_PROPERTY_X86_ISA_1_V2, AVX, AVX2, BMI1,
> > +   BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE.  */
> > +#define GNU_PROPERTY_X86_ISA_1_V3            (1U << 2)
> > +/* GNU_PROPERTY_X86_ISA_1_V4: GNU_PROPERTY_X86_ISA_1_V3, AVX512F,
> > +   AVX512BW, AVX512CD, AVX512DQ and AVX512VL.  */
> > +#define GNU_PROPERTY_X86_ISA_1_V4            (1U << 3)
> >
> >  /* This indicates that all executable sections are compatible with
> >     IBT.  */
>
> Ok.
>
> > diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
> > index 081cc72e93..c814d5a195 100644
> > --- a/sysdeps/x86/Makefile
> > +++ b/sysdeps/x86/Makefile
> > @@ -9,6 +9,36 @@ 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,$(enable-x86-isa-level))
> > +tests += tst-isa-level-1
> > +modules-names += tst-isa-level-mod-1-baseline \
> > +              tst-isa-level-mod-1-v2 \
> > +              tst-isa-level-mod-1-v3 \
> > +              tst-isa-level-mod-1-v4 \
> > +
> > +# X86 ISA level baseline
> > +CFLAGS-tst-isa-level-mod-1-baseline.c += -DINCLUDE_X86_ISA_LEVEL \
> > +                                      -DISA_LEVEL=0x1 \
> > +                                      -march=x86-64
> > +# X86 ISA level v2
> > +CFLAGS-tst-isa-level-mod-1-v2.c += -DINCLUDE_X86_ISA_LEVEL \
> > +                                -DISA_LEVEL=0x3 \
> > +                                -march=x86-64
> > +# X86 ISA level v3
> > +CFLAGS-tst-isa-level-mod-1-v3.c += -DINCLUDE_X86_ISA_LEVEL \
> > +                                -DISA_LEVEL=0x7 \
> > +                                -march=x86-64
> > +# X86 ISA level v4
> > +CFLAGS-tst-isa-level-mod-1-v4.c += -DINCLUDE_X86_ISA_LEVEL \
> > +                                -DISA_LEVEL=0xf \
> > +                                -march=x86-64
> > +
> > +$(objpfx)tst-isa-level-1: $(libdl)
> > +$(objpfx)tst-isa-level-1.out: $(objpfx)tst-isa-level-mod-1-baseline.so \
> > +                           $(objpfx)tst-isa-level-mod-1-v2.so \
> > +                           $(objpfx)tst-isa-level-mod-1-v3.so \
> > +                           $(objpfx)tst-isa-level-mod-1-v4.so
> > +endif
> >  endif
> >
> >  ifeq ($(subdir),math)
>
> Ok.
>
> > diff --git a/sysdeps/x86/abi-note.c b/sysdeps/x86/abi-note.c
> > new file mode 100644
> > index 0000000000..5140e6ab47
> > --- /dev/null
> > +++ b/sysdeps/x86/abi-note.c
> > @@ -0,0 +1,29 @@
> > +/* Special .init and .fini section support.  x86-64 version.
> > +   Copyright (C) 2020 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.
> > +
> > +   In addition to the permissions in the GNU Lesser General Public
> > +   License, the Free Software Foundation gives you unlimited
> > +   permission to link the compiled version of this file with other
> > +   programs, and to distribute those programs without any restriction
> > +   coming from the use of this file.  (The Lesser General Public
> > +   License restrictions do apply in other respects; for example, they
> > +   cover modification of the file, and distribution when not linked
> > +   into another program.)
> > +
> > +   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 <isa-level.c>
> > +#include <csu/abi-note.c>
>
> Ok.
>
> > diff --git a/sysdeps/x86/configure b/sysdeps/x86/configure
> > index 81cc4e80d6..5e32dc62b3 100644
> > --- a/sysdeps/x86/configure
> > +++ b/sysdeps/x86/configure
> > @@ -68,3 +68,82 @@ elif test $enable_cet = permissive; then
> >  fi
> >  config_vars="$config_vars
> >  enable-cet = $enable_cet"
> > +
> > +# Check if linker supports x86 ISA level.
> > +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker x86 ISA level support" >&5
> > +$as_echo_n "checking for linker x86 ISA level support... " >&6; }
> > +if ${libc_cv_include_x86_isa_level+:} false; then :
> > +  $as_echo_n "(cached) " >&6
> > +else
> > +  cat > conftest1.S <<EOF
> > +#ifdef __LP64__
> > +# define P2ALIGN 3
> > +#else
> > +# define P2ALIGN 2
> > +#endif
> > +     .section ".note.gnu.property", "a"
> > +     .p2align P2ALIGN
> > +     .long 1f - 0f           /* name length.  */
> > +     .long 4f - 1f           /* data length.  */
> > +     /* NT_GNU_PROPERTY_TYPE_0 */
> > +     .long 5                 /* note type.  */
> > +0:
> > +     .asciz "GNU"            /* vendor name.  */
> > +1:
> > +     .p2align P2ALIGN
> > +     /* GNU_PROPERTY_X86_ISA_1_NEEDED */
> > +     .long 0xc0008002        /* pr_type.  */
> > +     .long 3f - 2f           /* pr_datasz.  */
> > +2:
> > +     .long 0x1
> > +3:
> > +     .p2align P2ALIGN
> > +4:
> > +EOF
> > +cat > conftest2.S <<EOF
> > +#ifdef __LP64__
> > +# define P2ALIGN 3
> > +#else
> > +# define P2ALIGN 2
> > +#endif
> > +     .section ".note.gnu.property", "a"
> > +     .p2align P2ALIGN
> > +     .long 1f - 0f           /* name length.  */
> > +     .long 4f - 1f           /* data length.  */
> > +     /* NT_GNU_PROPERTY_TYPE_0 */
> > +     .long 5                 /* note type.  */
> > +0:
> > +     .asciz "GNU"            /* vendor name.  */
> > +1:
> > +     .p2align P2ALIGN
> > +     /* GNU_PROPERTY_X86_ISA_1_NEEDED */
> > +     .long 0xc0008002        /* pr_type.  */
> > +     .long 3f - 2f           /* pr_datasz.  */
> > +2:
> > +     .long 0x2
> > +3:
> > +     .p2align P2ALIGN
> > +4:
> > +EOF
> > +libc_cv_include_x86_isa_level=no
> > +if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S'
> > +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> > +  (eval $ac_try) 2>&5
> > +  ac_status=$?
> > +  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> > +  test $ac_status = 0; }; }; then
> > +  count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
> > +  if test "$count" = 1; then
> > +    libc_cv_include_x86_isa_level=yes
> > +  fi
> > +fi
> > +rm -f conftest*
> > +fi
> > +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_include_x86_isa_level" >&5
> > +$as_echo "$libc_cv_include_x86_isa_level" >&6; }
> > +if test $libc_cv_include_x86_isa_level = yes; then
> > +  $as_echo "#define INCLUDE_X86_ISA_LEVEL 1" >>confdefs.h
> > +
> > +fi
> > +config_vars="$config_vars
> > +enable-x86-isa-level = $libc_cv_include_x86_isa_level"
> > diff --git a/sysdeps/x86/configure.ac b/sysdeps/x86/configure.ac
> > index 8f3e1191f6..f94088f377 100644
> > --- a/sysdeps/x86/configure.ac
> > +++ b/sysdeps/x86/configure.ac
> > @@ -43,3 +43,69 @@ elif test $enable_cet = permissive; then
> >    AC_DEFINE(DEFAULT_DL_X86_CET_CONTROL, cet_permissive)
> >  fi
> >  LIBC_CONFIG_VAR([enable-cet], [$enable_cet])
> > +
> > +# Check if linker supports x86 ISA level.
> > +AC_CACHE_CHECK([for linker x86 ISA level support],
> > +            libc_cv_include_x86_isa_level, [dnl
> > +cat > conftest1.S <<EOF
> > +#ifdef __LP64__
> > +# define P2ALIGN 3
> > +#else
> > +# define P2ALIGN 2
> > +#endif
> > +     .section ".note.gnu.property", "a"
> > +     .p2align P2ALIGN
> > +     .long 1f - 0f           /* name length.  */
> > +     .long 4f - 1f           /* data length.  */
> > +     /* NT_GNU_PROPERTY_TYPE_0 */
> > +     .long 5                 /* note type.  */
> > +0:
> > +     .asciz "GNU"            /* vendor name.  */
> > +1:
> > +     .p2align P2ALIGN
> > +     /* GNU_PROPERTY_X86_ISA_1_NEEDED */
> > +     .long 0xc0008002        /* pr_type.  */
> > +     .long 3f - 2f           /* pr_datasz.  */
> > +2:
> > +     .long 0x1
> > +3:
> > +     .p2align P2ALIGN
> > +4:
> > +EOF
> > +cat > conftest2.S <<EOF
> > +#ifdef __LP64__
> > +# define P2ALIGN 3
> > +#else
> > +# define P2ALIGN 2
> > +#endif
> > +     .section ".note.gnu.property", "a"
> > +     .p2align P2ALIGN
> > +     .long 1f - 0f           /* name length.  */
> > +     .long 4f - 1f           /* data length.  */
> > +     /* NT_GNU_PROPERTY_TYPE_0 */
> > +     .long 5                 /* note type.  */
> > +0:
> > +     .asciz "GNU"            /* vendor name.  */
> > +1:
> > +     .p2align P2ALIGN
> > +     /* GNU_PROPERTY_X86_ISA_1_NEEDED */
> > +     .long 0xc0008002        /* pr_type.  */
> > +     .long 3f - 2f           /* pr_datasz.  */
> > +2:
> > +     .long 0x2
> > +3:
> > +     .p2align P2ALIGN
> > +4:
> > +EOF
> > +libc_cv_include_x86_isa_level=no
> > +if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S); then
> > +  count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
> > +  if test "$count" = 1; then
> > +    libc_cv_include_x86_isa_level=yes
> > +  fi
> > +fi
> > +rm -f conftest*])
> > +if test $libc_cv_include_x86_isa_level = yes; then
> > +  AC_DEFINE(INCLUDE_X86_ISA_LEVEL)
> > +fi
> > +LIBC_CONFIG_VAR([enable-x86-isa-level], [$libc_cv_include_x86_isa_level])
>
> Skipping autogenerated file.
>
> > diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
> > index 529c586193..e7da682a2e 100644
> > --- a/sysdeps/x86/cpu-features.c
> > +++ b/sysdeps/x86/cpu-features.c
> > @@ -19,6 +19,7 @@
> >  #include <cpuid.h>
> >  #include <dl-hwcap.h>
> >  #include <libc-pointer-arith.h>
> > +#include <get-isa-level.h>
> >  #if IS_IN (libc) && !defined SHARED
> >  # include <assert.h>
> >  # include <unistd.h>
> > @@ -290,6 +291,8 @@ update_usable (struct cpu_features *cpu_features)
> >        CPU_FEATURE_SET_USABLE (cpu_features, KL);
> >        CPU_FEATURE_SET_USABLE (cpu_features, WIDE_KL);
> >      }
> > +
> > +  cpu_features->isa_1 = get_isa_level (cpu_features);
> >  }
> >
> >  static void
>
> Ok.
>
> > diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c
> > index b4910f7634..ed7fd6d10d 100644
> > --- a/sysdeps/x86/dl-cet.c
> > +++ b/sysdeps/x86/dl-cet.c
> > @@ -76,10 +76,12 @@ dl_cet_check (struct link_map *m, const char *program)
> >          */
> >         enable_ibt &= (HAS_CPU_FEATURE (IBT)
> >                        && (enable_ibt_type == cet_always_on
> > -                          || (m->l_cet & lc_ibt) != 0));
> > +                          || (m->l_x86_feature_1_and
> > +                              & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0));
> >         enable_shstk &= (HAS_CPU_FEATURE (SHSTK)
> >                          && (enable_shstk_type == cet_always_on
> > -                            || (m->l_cet & lc_shstk) != 0));
> > +                            || (m->l_x86_feature_1_and
> > +                                & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0));
> >       }
> >
> >        /* ld.so is CET-enabled by kernel.  But shared objects may not
>
> Ok.
>
> > @@ -111,7 +113,8 @@ dl_cet_check (struct link_map *m, const char *program)
> >             /* IBT is enabled only if it is enabled in executable as
> >                well as all shared objects.  */
> >             enable_ibt &= (enable_ibt_type == cet_always_on
> > -                          || (l->l_cet & lc_ibt) != 0);
> > +                          || (l->l_x86_feature_1_and
> > +                              & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0);
> >             if (!found_ibt_legacy && enable_ibt != ibt_enabled)
> >               {
> >                 found_ibt_legacy = true;
> > @@ -121,7 +124,8 @@ dl_cet_check (struct link_map *m, const char *program)
> >             /* SHSTK is enabled only if it is enabled in executable as
> >                well as all shared objects.  */
> >             enable_shstk &= (enable_shstk_type == cet_always_on
> > -                            || (l->l_cet & lc_shstk) != 0);
> > +                            || (l->l_x86_feature_1_and
> > +                                & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0);
> >             if (enable_shstk != shstk_enabled)
> >               {
> >                 found_shstk_legacy = true;
>
> Ok.
>
> > diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h
> > index ce1667dc7a..56bd020b3c 100644
> > --- a/sysdeps/x86/dl-prop.h
> > +++ b/sysdeps/x86/dl-prop.h
> > @@ -19,14 +19,54 @@
> >  #ifndef _DL_PROP_H
> >  #define _DL_PROP_H
> >
> > +#include <libintl.h>
> > +
> >  extern void _dl_cet_check (struct link_map *, const char *)
> >      attribute_hidden;
> >  extern void _dl_cet_open_check (struct link_map *)
> >      attribute_hidden;
> >
> > +static void
> > +dl_isa_level_check (struct link_map *m, const char *program)
> > +{
> > +  const struct cpu_features *cpu_features = __get_cpu_features ();
> > +  unsigned int i;
> > +  struct link_map *l;
> > +
> > +  i = m->l_searchlist.r_nlist;
> > +  while (i-- > 0)
> > +    {
> > +      /* Check each shared object to see if ISA level is compatible.  */
> > +      l = m->l_initfini[i];
> > +
> > +      /* Skip ISA level check if functions have been executed.  */
> > +      if (l->l_init_called)
> > +     continue;
> > +
> > +#ifdef SHARED
> > +      /* Skip ISA level check for ld.so since ld.so won't run if its ISA
> > +      level is higher than CPU.  */
> > +      if (l == &GL(dl_rtld_map) || l->l_real == &GL(dl_rtld_map))
> > +     continue;
> > +#endif
> > +
> > +      if ((l->l_x86_isa_1_needed & cpu_features->isa_1)
> > +       != l->l_x86_isa_1_needed)
> > +     {
> > +       if (program)
> > +         _dl_fatal_printf ("%s: CPU ISA level is lower than required\n",
> > +                           *l->l_name != '\0' ? l->l_name : program);
> > +       else
> > +         _dl_signal_error (0, l->l_name, "dlopen",
> > +                           N_("CPU ISA level is lower than required"));
> > +     }
> > +    }
> > +}
> > +
>
> Ok.
>
> >  static inline void __attribute__ ((always_inline))
> >  _rtld_main_check (struct link_map *m, const char *program)
> >  {
> > +  dl_isa_level_check (m, program);
> >  #if CET_ENABLED
> >    _dl_cet_check (m, program);
> >  #endif
> > @@ -35,20 +75,18 @@ _rtld_main_check (struct link_map *m, const char *program)
> >  static inline void __attribute__ ((always_inline))
> >  _dl_open_check (struct link_map *m)
> >  {
> > +  dl_isa_level_check (m, NULL);
> >  #if CET_ENABLED
> >    _dl_cet_open_check (m);
> >  #endif
> >  }
> >
> >  static inline void __attribute__ ((unused))
> > -_dl_process_cet_property_note (struct link_map *l,
> > -                           const ElfW(Nhdr) *note,
> > -                           const ElfW(Addr) size,
> > -                           const ElfW(Addr) align)
> > +_dl_process_property_note (struct link_map *l, const ElfW(Nhdr) *note,
> > +                        const ElfW(Addr) size, const ElfW(Addr) align)
> >  {
> > -#if CET_ENABLED
> >    /* Skip if we have seen a NT_GNU_PROPERTY_TYPE_0 note before.  */
> > -  if (l->l_cet != lc_unknown)
> > +  if (l->l_property != lc_property_unknown)
> >      return;
> >
> >    /* The NT_GNU_PROPERTY_TYPE_0 note must be aliged to 4 bytes in
>
> Ok.
>
> > @@ -59,7 +97,8 @@ _dl_process_cet_property_note (struct link_map *l,
> >
> >    const ElfW(Addr) start = (ElfW(Addr)) note;
> >
> > -  unsigned int feature_1 = 0;
> > +  unsigned int feature_1_and = 0;
> > +  unsigned int isa_1_needed = 0;
> >    unsigned int last_type = 0;
> >
> >    while ((ElfW(Addr)) (note + 1) - start < size)
> > @@ -71,11 +110,11 @@ _dl_process_cet_property_note (struct link_map *l,
> >       {
> >         /* Stop if we see more than one GNU property note which may
> >            be generated by the older linker.  */
> > -       if (l->l_cet != lc_unknown)
> > +       if (l->l_property != lc_property_unknown)
> >           return;
> >
> > -       /* Check CET status now.  */
> > -       l->l_cet = lc_none;
> > +       /* Check CET status and ISA levels now.  */
> > +       l->l_property = lc_property_none;
> >
> >         /* Check for invalid property.  */
> >         if (note->n_descsz < 8
> > @@ -101,26 +140,37 @@ _dl_process_cet_property_note (struct link_map *l,
> >
> >             last_type = type;
> >
> > -           if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
> > +           if (type == GNU_PROPERTY_X86_FEATURE_1_AND
> > +               || type == GNU_PROPERTY_X86_ISA_1_NEEDED)
> >               {
> > -               /* The size of GNU_PROPERTY_X86_FEATURE_1_AND is 4
> > -                  bytes.  When seeing GNU_PROPERTY_X86_FEATURE_1_AND,
> > -                  we stop the search regardless if its size is correct
> > -                  or not.  There is no point to continue if this note
> > -                  is ill-formed.  */
> > +               /* The sizes of types which we are searching for are
> > +                  4 bytes.  There is no point to continue if this
> > +                  note is ill-formed.  */
> >                 if (datasz != 4)
> >                   return;
> >
> > -               feature_1 = *(unsigned int *) ptr;
> > -
> > -               /* Keep searching for the next GNU property note
> > -                  generated by the older linker.  */
> > -               break;
> > +               /* NB: Stop the scan only after seeing all types which
> > +                  we are searching for.  */
> > +               _Static_assert ((GNU_PROPERTY_X86_ISA_1_NEEDED >
> > +                                GNU_PROPERTY_X86_FEATURE_1_AND),
> > +                               "GNU_PROPERTY_X86_ISA_1_NEEDED > "
> > +                               "GNU_PROPERTY_X86_FEATURE_1_AND");
> > +               if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
> > +                 feature_1_and = *(unsigned int *) ptr;
> > +               else
> > +                 {
> > +                   isa_1_needed = *(unsigned int *) ptr;
> > +
> > +                   /* Keep searching for the next GNU property note
> > +                      generated by the older linker.  */
> > +                   break;
> > +                 }
> >               }
> > -           else if (type > GNU_PROPERTY_X86_FEATURE_1_AND)
> > +           else if (type > GNU_PROPERTY_X86_ISA_1_NEEDED)
> >               {
> > -               /* Stop since property type is in ascending order.  */
> > -               return;
> > +               /* Stop the scan since property type is in ascending
> > +                  order.  */
> > +               break;
> >               }
> >
> >             /* Check the next property item.  */
>
> Ok.
>
> > @@ -137,18 +187,21 @@ _dl_process_cet_property_note (struct link_map *l,
> >      }
> >
> >    /* We get here only if there is one or no GNU property note.  */
> > -  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_IBT))
> > -    l->l_cet |= lc_ibt;
> > -  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
> > -    l->l_cet |= lc_shstk;
> > -#endif
> > +  if (isa_1_needed != 0 || feature_1_and != 0)
> > +    {
> > +      l->l_property = lc_property_valid;
> > +      l->l_x86_isa_1_needed = isa_1_needed;
> > +      l->l_x86_feature_1_and = feature_1_and;
> > +    }
> > +  else
> > +    l->l_property = lc_property_none;
> >  }
> >
> >  static inline void __attribute__ ((unused))
> >  _dl_process_pt_note (struct link_map *l, int fd, const ElfW(Phdr) *ph)
> >  {
> >    const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
> > -  _dl_process_cet_property_note (l, note, ph->p_memsz, ph->p_align);
> > +  _dl_process_property_note (l, note, ph->p_memsz, ph->p_align);
> >  }
> >
> >  static inline int __attribute__ ((always_inline))
>
> Ok.
>
> > diff --git a/sysdeps/x86/get-isa-level.h b/sysdeps/x86/get-isa-level.h
> > new file mode 100644
> > index 0000000000..a86e1e8941
> > --- /dev/null
> > +++ b/sysdeps/x86/get-isa-level.h
> > @@ -0,0 +1,66 @@
> > +/* Get x86 ISA level.
> > +   This file is part of the GNU C Library.
> > +   Copyright (C) 2020 Free Software Foundation, Inc.
> > +
> > +   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>
> > +
> > +/* Get GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
> > +   ISA level.  */
> > +
> > +static unsigned int
> > +get_isa_level (const struct cpu_features *cpu_features)
> > +{
> > +  unsigned int isa_level = 0;
> > +
> > +  if (CPU_FEATURE_USABLE_P (cpu_features, CMOV)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, CX8)
> > +      && CPU_FEATURE_CPU_P (cpu_features, FPU)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, FXSR)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, MMX)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, SSE)
> > +      && CPU_FEATURE_USABLE_P (cpu_features, SSE2))
> > +    {
> > +      isa_level = GNU_PROPERTY_X86_ISA_1_BASELINE;
> > +      if (CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
> > +       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
> > +     {
> > +       isa_level |= GNU_PROPERTY_X86_ISA_1_V2;
> > +       if (CPU_FEATURE_USABLE_P (cpu_features, AVX)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, F16C)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, FMA)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
> > +           && CPU_FEATURE_USABLE_P (cpu_features, MOVBE))
> > +         {
> > +           isa_level |= GNU_PROPERTY_X86_ISA_1_V3;
> > +           if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
> > +               && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
> > +             isa_level |= GNU_PROPERTY_X86_ISA_1_V4;
> > +         }
> > +     }
> > +    }
> > +
> > +  return isa_level;
> > +}
>
> Ok, is there any plan to add the gcc ISA_1_VX for 32-bit ABI as well? I am
> asking because if there is no upcoming plan maybe an option is just to
> return 0 for !__X86_64__.

Although there is no official plan to support it in 32-bit,  since the ISA level
support implemented in GCC and binutils is independent of 32-bit or 64-bit,
32-bit also get the same feature:

[hjl@gnu-cfl-2 tmp]$ touch x.c
[hjl@gnu-cfl-2 tmp]$ /usr/gcc-11.0.0-x32/bin/gcc -c -mneeded x.c -mavx2
[hjl@gnu-cfl-2 tmp]$ readelf -n x.o

Displaying notes found in: .note.gnu.property
  Owner                Data size Description
  GNU                  0x00000010 NT_GNU_PROPERTY_TYPE_0
      Properties: x86 ISA needed: x86-64-baseline, x86-64-v2, x86-64-v3
  GNU                  0x00000020 NT_GNU_PROPERTY_TYPE_0
      Properties: x86 ISA used:
x86 feature used: x86
[hjl@gnu-cfl-2 tmp]$ /usr/gcc-11.0.0-x32/bin/gcc -c -mneeded x.c -mavx2 -m32
[hjl@gnu-cfl-2 tmp]$ readelf -n x.o

Displaying notes found in: .note.gnu.property
  Owner                Data size Description
  GNU                  0x0000000c NT_GNU_PROPERTY_TYPE_0
      Properties: x86 ISA needed: x86-64-baseline, x86-64-v2, x86-64-v3
  GNU                  0x00000018 NT_GNU_PROPERTY_TYPE_0
      Properties: x86 ISA used:
x86 feature used: x86
[hjl@gnu-cfl-2 tmp]$

The glibc implementation also works on 32-bit.

> > diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
> > index ffe300c931..99e7ee08cf 100644
> > --- a/sysdeps/x86/include/cpu-features.h
> > +++ b/sysdeps/x86/include/cpu-features.h
> > @@ -123,6 +123,8 @@ struct cpu_features
> >    struct cpu_features_basic basic;
> >    struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
> >    unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
> > +  /* X86 micro-architecture ISA levels.  */
> > +  unsigned int isa_1;
> >    /* The state size for XSAVEC or XSAVE.  The type must be unsigned long
> >       int so that we use
> >
>
> Ok.
>
> > diff --git a/sysdeps/x86/isa-level.c b/sysdeps/x86/isa-level.c
> > new file mode 100644
> > index 0000000000..aaf524cb56
> > --- /dev/null
> > +++ b/sysdeps/x86/isa-level.c
> > @@ -0,0 +1,97 @@
> > +/* ELF program property for x86 ISA level.
> > +   Copyright (C) 2020 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.
> > +
> > +   In addition to the permissions in the GNU Lesser General Public
> > +   License, the Free Software Foundation gives you unlimited
> > +   permission to link the compiled version of this file with other
> > +   programs, and to distribute those programs without any restriction
> > +   coming from the use of this file.  (The Lesser General Public
> > +   License restrictions do apply in other respects; for example, they
> > +   cover modification of the file, and distribution when not linked
> > +   into another program.)
> > +
> > +   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 <elf.h>
> > +
> > +/* ELF program property for x86 ISA level.  */
> > +#ifdef INCLUDE_X86_ISA_LEVEL
> > +# if defined __x86_64__ || defined __FXSR__ || !defined _SOFT_FLOAT \
> > +     || defined  __MMX__ || defined __SSE__ || defined __SSE2__
> > +#  define ISA_BASELINE       GNU_PROPERTY_X86_ISA_1_BASELINE
> > +# else
> > +#  define ISA_BASELINE       0
> > +# endif
> > +
> > +# if defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
> > +     || (defined __x86_64__ && defined __LAHF_SAHF__) \
> > +     || defined __POPCNT__ || defined __SSE3__ \
> > +     || defined __SSSE3__ || defined __SSE4_1__ || defined __SSE4_2__
> > +#  define ISA_V2     GNU_PROPERTY_X86_ISA_1_V2
> > +# else
> > +#  define ISA_V2     0
> > +# endif
> > +
> > +# if defined __AVX__ || defined __AVX2__ || defined __F16C__ \
> > +     || defined __FMA__ || defined __LZCNT__ || defined __MOVBE__ \
> > +     || defined __XSAVE__
> > +#  define ISA_V3     GNU_PROPERTY_X86_ISA_1_V3
> > +# else
> > +#  define ISA_V3     0
> > +# endif
> > +
> > +# if defined __AVX512F__ || defined __AVX512BW__ || defined __AVX512CD__ \
> > +     || defined __AVX512DQ__ || defined __AVX512VL__
> > +#  define ISA_V4     GNU_PROPERTY_X86_ISA_1_V4
> > +# else
> > +#  define ISA_V4     0
> > +# endif
> > +
> > +# ifndef ISA_LEVEL
> > +#  define ISA_LEVEL (ISA_BASELINE | ISA_V2 | ISA_V3 | ISA_V4)
> > +# endif
> > +
> > +# if ISA_LEVEL
> > +#  ifdef __LP64__
> > +#   define PROPERTY_ALIGN 3
> > +#  else
> > +#   define PROPERTY_ALIGN 2
> > +#  endif
> > +
> > +#  define note_stringify(arg) note_stringify_1(arg)
> > +#  define note_stringify_1(arg) #arg
> > +
> > +asm(".pushsection \".note.gnu.property\",\"a\",@note\n"
> > +"    .p2align " note_stringify (PROPERTY_ALIGN)
> > +     /* name length.  */
> > +"\n  .long 1f - 0f\n"
> > +     /* data length.  */
> > +"    .long 4f - 1f\n"
> > +     /* note type: NT_GNU_PROPERTY_TYPE_0.  */
> > +"    .long " note_stringify (NT_GNU_PROPERTY_TYPE_0)
> > +     /* vendor name.  */
> > +"\n0:        .asciz \"GNU\"\n"
> > +"1:  .p2align " note_stringify (PROPERTY_ALIGN)
> > +     /* pr_type: GNU_PROPERTY_X86_ISA_1_NEEDED.  */
> > +"\n  .long " note_stringify (GNU_PROPERTY_X86_ISA_1_NEEDED)
> > +     /* pr_datasz.  */
> > +"\n  .long 3f - 2f\n"
> > +     /* GNU_PROPERTY_X86_ISA_1_V[234].  */
> > +"2:\n         .long " note_stringify (ISA_LEVEL)
> > +"\n3:\n      .p2align " note_stringify (PROPERTY_ALIGN)
> > +"\n4:\n .popsection");
> > +# endif /* ISA_LEVEL */
> > +#endif /* INCLUDE_X86_ISA_LEVEL */
>
> Ok.
>
> > diff --git a/sysdeps/x86/link_map.h b/sysdeps/x86/link_map.h
> > index 8074739b47..4c46a25f83 100644
> > --- a/sysdeps/x86/link_map.h
> > +++ b/sysdeps/x86/link_map.h
> > @@ -16,12 +16,16 @@
> >     License along with the GNU C Library; if not, see
> >     <https://www.gnu.org/licenses/>.  */
> >
> > -/* If this object is enabled with CET.  */
> > +/* if this object has GNU property.  */
> >  enum
> >    {
> > -    lc_unknown = 0,                   /* Unknown CET status.  */
> > -    lc_none = 1 << 0,                         /* Not enabled with CET.  */
> > -    lc_ibt = 1 << 1,                  /* Enabled with IBT.  */
> > -    lc_shstk = 1 << 2,                        /* Enabled with STSHK.  */
> > -    lc_ibt_and_shstk = lc_ibt | lc_shstk /* Enabled with both.  */
> > -  } l_cet:3;
> > +    lc_property_unknown = 0,         /* Unknown property status.  */
> > +    lc_property_none = 1 << 0,               /* No property.  */
> > +    lc_property_valid = 1 << 1               /* Has valid property.  */
> > +  } l_property:2;
> > +
> > +/* GNU_PROPERTY_X86_FEATURE_1_AND of this object.  */
> > +unsigned int l_x86_feature_1_and;
> > +
> > +/* GNU_PROPERTY_X86_ISA_1_NEEDED of this object.  */
> > +unsigned int l_x86_isa_1_needed;
>
> Ok.
>
> > diff --git a/sysdeps/x86/tst-isa-level-1.c b/sysdeps/x86/tst-isa-level-1.c
> > new file mode 100644
> > index 0000000000..dc31d71ad2
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-1.c
> > @@ -0,0 +1,104 @@
> > +/* Check ISA level on dlopened shared object.
> > +   Copyright (C) 2020 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 <stdbool.h>
> > +#include <string.h>
> > +#include <elf.h>
> > +#include <get-isa-level.h>
> > +#include <support/xdlfcn.h>
> > +#include <support/check.h>
> > +#include <support/test-driver.h>
> > +
> > +static void
> > +do_test_1 (const char *modname, bool fail)
> > +{
> > +  int (*fp) (void);
> > +  void *h;
> > +
> > +  h = dlopen (modname, RTLD_LAZY);
> > +  if (h == NULL)
> > +    {
> > +      const char *err = dlerror ();
> > +      if (fail)
> > +     {
> > +       if (strstr (err, "CPU ISA level is lower than required") == NULL)
> > +         FAIL_EXIT1 ("incorrect dlopen '%s' error: %s\n", modname, err);
> > +
> > +       return;
> > +     }
> > +
> > +      FAIL_EXIT1 ("cannot open '%s': %s\n", modname, err);
> > +    }
> > +
> > +  if (fail)
> > +    FAIL_EXIT1 ("dlopen '%s' should have failed\n", modname);
> > +
> > +  fp = xdlsym (h, "test");
> > +
> > +  if (fp () != 0)
> > +    FAIL_EXIT1 ("test () != 0\n");
> > +
> > +  dlclose (h);
> > +}
> > +
> > +static int
> > +do_test (void)
> > +{
> > +  const struct cpu_features *cpu_features
> > +    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> > +  unsigned int isa_level = get_isa_level (cpu_features);
> > +  bool has_isa_baseline = ((isa_level & GNU_PROPERTY_X86_ISA_1_BASELINE)
> > +                        == GNU_PROPERTY_X86_ISA_1_BASELINE);
> > +  bool has_isa_v2 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V2)
> > +                        == GNU_PROPERTY_X86_ISA_1_V2);
> > +  bool has_isa_v3 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V3)
> > +                        == GNU_PROPERTY_X86_ISA_1_V3);
> > +  bool has_isa_v4 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V4)
> > +                        == GNU_PROPERTY_X86_ISA_1_V4);
> > +
> > +  if (!has_isa_baseline)
> > +    {
> > +      do_test_1 ("tst-isa-level-mod-1-baseline.so", true);
> > +      return EXIT_SUCCESS;
> > +    }
> > +
> > +  do_test_1 ("tst-isa-level-mod-1-baseline.so", false);
> > +
> > +  /* Skip on x86-64-v4 platforms since dlopen v4 module always works.  */
> > +  if (has_isa_v4)
> > +    return EXIT_UNSUPPORTED;
>
> Not sure if unsupported is the right error code here, since the isa
> selection is just ignored (not really not supported).

I will change it to EXIT_SUCCESS.

> > +
> > +  do_test_1 ("tst-isa-level-mod-1-v4.so", true);
> > +
> > +  /* Skip on x86-64-v3 platforms since dlopen v3 module always works.  */
> > +  if (has_isa_v3)
> > +    return EXIT_SUCCESS;
> > +
> > +  do_test_1 ("tst-isa-level-mod-1-v3.so", true);
> > +
> > +  /* Skip on x86-64-v2 platforms since dlopen v2 module always works.  */
> > +  if (has_isa_v2)
> > +    return EXIT_SUCCESS;
> > +
> > +  do_test_1 ("tst-isa-level-mod-1-v2.so", true);
> > +
> > +  return EXIT_SUCCESS;
> > +}
> > +
> > +#include <support/test-driver.c>
> > diff --git a/sysdeps/x86/tst-isa-level-mod-1-baseline.c b/sysdeps/x86/tst-isa-level-mod-1-baseline.c
> > new file mode 100644
> > index 0000000000..d6fe0685a4
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1-baseline.c
> > @@ -0,0 +1 @@
> > +#include "tst-isa-level-mod-1.c"
> > diff --git a/sysdeps/x86/tst-isa-level-mod-1-v2.c b/sysdeps/x86/tst-isa-level-mod-1-v2.c
> > new file mode 100644
> > index 0000000000..d6fe0685a4
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1-v2.c
> > @@ -0,0 +1 @@
> > +#include "tst-isa-level-mod-1.c"
> > diff --git a/sysdeps/x86/tst-isa-level-mod-1-v3.c b/sysdeps/x86/tst-isa-level-mod-1-v3.c
> > new file mode 100644
> > index 0000000000..d6fe0685a4
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1-v3.c
> > @@ -0,0 +1 @@
> > +#include "tst-isa-level-mod-1.c"
> > diff --git a/sysdeps/x86/tst-isa-level-mod-1-v4.c b/sysdeps/x86/tst-isa-level-mod-1-v4.c
> > new file mode 100644
> > index 0000000000..d6fe0685a4
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1-v4.c
> > @@ -0,0 +1 @@
> > +#include "tst-isa-level-mod-1.c"
>
> Ok.
>
> > diff --git a/sysdeps/x86/tst-isa-level-mod-1.c b/sysdeps/x86/tst-isa-level-mod-1.c
> > new file mode 100644
> > index 0000000000..40a2e1d99f
> > --- /dev/null
> > +++ b/sysdeps/x86/tst-isa-level-mod-1.c
> > @@ -0,0 +1,25 @@
> > +/* Check ISA level on dlopened shared object.
> > +   Copyright (C) 2019-2020 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 <isa-level.c>
> > +
> > +int
> > +test (void)
> > +{
> > +  return 0;
> > +}
>
> Ok.
>
> > diff --git a/sysdeps/x86_64/dl-hwcaps-subdirs.c b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> > index 0aaa635a00..e030534f1b 100644
> > --- a/sysdeps/x86_64/dl-hwcaps-subdirs.c
> > +++ b/sysdeps/x86_64/dl-hwcaps-subdirs.c
> > @@ -18,6 +18,7 @@
> >
> >  #include <dl-hwcaps.h>
> >  #include <cpu-features.h>
> > +#include <get-isa-level.h>
> >
> >  const char _dl_hwcaps_subdirs[] = "x86-64-v4:x86-64-v3:x86-64-v2";
> >  enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
> > @@ -25,40 +26,25 @@ enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
> >  uint32_t
> >  _dl_hwcaps_subdirs_active (void)
> >  {
> > +  const struct cpu_features *cpu_features
> > +    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> > +  unsigned int isa_level = get_isa_level (cpu_features);
> >    int active = 0;
> >
> >    /* Test in reverse preference order.  */
> >
> >    /* x86-64-v2.  */
> > -  if (!(CPU_FEATURE_USABLE (CMPXCHG16B)
> > -        && CPU_FEATURE_USABLE (LAHF64_SAHF64)
> > -        && CPU_FEATURE_USABLE (POPCNT)
> > -        && CPU_FEATURE_USABLE (SSE3)
> > -        && CPU_FEATURE_USABLE (SSE4_1)
> > -        && CPU_FEATURE_USABLE (SSE4_2)
> > -        && CPU_FEATURE_USABLE (SSSE3)))
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
> >      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> >    ++active;
> >
> >    /* x86-64-v3.  */
> > -  if (!(CPU_FEATURE_USABLE (AVX)
> > -        && CPU_FEATURE_USABLE (AVX2)
> > -        && CPU_FEATURE_USABLE (BMI1)
> > -        && CPU_FEATURE_USABLE (BMI2)
> > -        && CPU_FEATURE_USABLE (F16C)
> > -        && CPU_FEATURE_USABLE (FMA)
> > -        && CPU_FEATURE_USABLE (LZCNT)
> > -        && CPU_FEATURE_USABLE (MOVBE)
> > -        && CPU_FEATURE_USABLE (OSXSAVE)))
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
> >      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> >    ++active;
> >
> > - /* x86-64-v4.  */
> > -  if (!(CPU_FEATURE_USABLE (AVX512F)
> > -        && CPU_FEATURE_USABLE (AVX512BW)
> > -        && CPU_FEATURE_USABLE (AVX512CD)
> > -        && CPU_FEATURE_USABLE (AVX512DQ)
> > -        && CPU_FEATURE_USABLE (AVX512VL)))
> > +  /* x86-64-v4.  */
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
> >      return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
> >    ++active;
> >
> > diff --git a/sysdeps/x86_64/tst-glibc-hwcaps.c b/sysdeps/x86_64/tst-glibc-hwcaps.c
> > index 8bdcb91db0..37b61d3c84 100644
> > --- a/sysdeps/x86_64/tst-glibc-hwcaps.c
> > +++ b/sysdeps/x86_64/tst-glibc-hwcaps.c
> > @@ -19,7 +19,8 @@
> >  #include <stdio.h>
> >  #include <support/check.h>
> >  #include <sys/param.h>
> > -#include <sys/platform/x86.h>
> > +#include <elf.h>
> > +#include <get-isa-level.h>
> >
> >  extern int marker2 (void);
> >  extern int marker3 (void);
> > @@ -31,35 +32,15 @@ compute_level (void)
> >  {
> >    const struct cpu_features *cpu_features
> >      = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
> > -
> > - if (!(CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, MMX)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE2)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)))
> > -   return 1;
> > - if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, BMI1)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, F16C)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, FMA)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, OSXSAVE)))
> > -   return 2;
> > - if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
> > -       && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)))
> > -   return 3;
> > - return 4;
> > +  unsigned int isa_level = get_isa_level (cpu_features);
> > +
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
> > +    return 1;
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
> > +    return 2;
> > +  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
> > +    return 3;
> > +  return 4;
> >  }
> >
> >  static int
> > --
> > 2.29.2
>
> Ok.

This is the patch I am checking in.

Thanks.
Florian Weimer Jan. 18, 2021, 11:17 a.m. UTC | #3
* H. J. Lu via Libc-alpha:

> +static void
> +dl_isa_level_check (struct link_map *m, const char *program)
> +{
> +  const struct cpu_features *cpu_features = __get_cpu_features ();
> +  unsigned int i;
> +  struct link_map *l;
> +
> +  i = m->l_searchlist.r_nlist;
> +  while (i-- > 0)
> +    {
> +      /* Check each shared object to see if ISA level is compatible.  */
> +      l = m->l_initfini[i];
> +
> +      /* Skip ISA level check if functions have been executed.  */
> +      if (l->l_init_called)
> +	continue;
> +
> +#ifdef SHARED
> +      /* Skip ISA level check for ld.so since ld.so won't run if its ISA
> +	 level is higher than CPU.  */
> +      if (l == &GL(dl_rtld_map) || l->l_real == &GL(dl_rtld_map))
> +	continue;
> +#endif
> +
> +      if ((l->l_x86_isa_1_needed & cpu_features->isa_1)
> +	  != l->l_x86_isa_1_needed)
> +	{
> +	  if (program)
> +	    _dl_fatal_printf ("%s: CPU ISA level is lower than required\n",
> +			      *l->l_name != '\0' ? l->l_name : program);
> +	  else
> +	    _dl_signal_error (0, l->l_name, "dlopen",
> +			      N_("CPU ISA level is lower than required"));
> +	}
> +    }
> +}

We may have hit an integration issue with this check.

It turns out that libvirt defaults to the qemu64 model.  It masks most
of the feature bits required by x86-64-v2.  Libvirt developers have
previously told me that nothing should be using the qemu64 model, but
it's still the default for API stability reasons (in the same way SSL 3
and DES used to be the default in crypto libraries, under the assumption
that if you negotiatied a particular protocol and set of algorithms in
1998, you'd still want the exact same choice fifteen years later).

But of course, despite no one should be using the qemu64 model, they
still do.  Here's an example:

  Guest: fix to always use host-passthrough CPU for all arches
  <https://github.com/clalancette/oz/pull/283>

One pecularity about x86-64-v2 is that under KVM virtualization, the new
structions added over the baseline do not actually trap (assuming the
host supports them).  So we could paper over this integration issue by
doing the check for x86-64-v3 and later only.  (Although it might not
work there—I looked at printing a nice error message for the same
situation when we transitioned to z13, but it it turned to be quite
difficult.)

Downstream, this would likely buy us about three years, in which we
could fix qemu64-type problems.  But maybe we should tackle this now.

I also hope to have a conversation about the libvirt developers
regarding defaults, but I'm still trying to figure out the appropriate
forum.

Thanks,
Florian
H.J. Lu Jan. 18, 2021, 1:49 p.m. UTC | #4
On Mon, Jan 18, 2021 at 3:17 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> * H. J. Lu via Libc-alpha:
>
> > +static void
> > +dl_isa_level_check (struct link_map *m, const char *program)
> > +{
> > +  const struct cpu_features *cpu_features = __get_cpu_features ();
> > +  unsigned int i;
> > +  struct link_map *l;
> > +
> > +  i = m->l_searchlist.r_nlist;
> > +  while (i-- > 0)
> > +    {
> > +      /* Check each shared object to see if ISA level is compatible.  */
> > +      l = m->l_initfini[i];
> > +
> > +      /* Skip ISA level check if functions have been executed.  */
> > +      if (l->l_init_called)
> > +     continue;
> > +
> > +#ifdef SHARED
> > +      /* Skip ISA level check for ld.so since ld.so won't run if its ISA
> > +      level is higher than CPU.  */
> > +      if (l == &GL(dl_rtld_map) || l->l_real == &GL(dl_rtld_map))
> > +     continue;
> > +#endif
> > +
> > +      if ((l->l_x86_isa_1_needed & cpu_features->isa_1)
> > +       != l->l_x86_isa_1_needed)
> > +     {
> > +       if (program)
> > +         _dl_fatal_printf ("%s: CPU ISA level is lower than required\n",
> > +                           *l->l_name != '\0' ? l->l_name : program);
> > +       else
> > +         _dl_signal_error (0, l->l_name, "dlopen",
> > +                           N_("CPU ISA level is lower than required"));
> > +     }
> > +    }
> > +}
>
> We may have hit an integration issue with this check.
>
> It turns out that libvirt defaults to the qemu64 model.  It masks most
> of the feature bits required by x86-64-v2.  Libvirt developers have
> previously told me that nothing should be using the qemu64 model, but
> it's still the default for API stability reasons (in the same way SSL 3
> and DES used to be the default in crypto libraries, under the assumption
> that if you negotiatied a particular protocol and set of algorithms in
> 1998, you'd still want the exact same choice fifteen years later).
>
> But of course, despite no one should be using the qemu64 model, they
> still do.  Here's an example:
>
>   Guest: fix to always use host-passthrough CPU for all arches
>   <https://github.com/clalancette/oz/pull/283>
>
> One pecularity about x86-64-v2 is that under KVM virtualization, the new
> structions added over the baseline do not actually trap (assuming the
> host supports them).  So we could paper over this integration issue by
> doing the check for x86-64-v3 and later only.  (Although it might not
> work there—I looked at printing a nice error message for the same
> situation when we transitioned to z13, but it it turned to be quite
> difficult.)
>
> Downstream, this would likely buy us about three years, in which we
> could fix qemu64-type problems.  But maybe we should tackle this now.
>
> I also hope to have a conversation about the libvirt developers
> regarding defaults, but I'm still trying to figure out the appropriate
> forum.
>

If we are considering a possible glibc solution, can you open a glibc bug
to track it?

Thanks.
Florian Weimer Jan. 18, 2021, 3:15 p.m. UTC | #5
* H. J. Lu:

> If we are considering a possible glibc solution, can you open a glibc bug
> to track it?

Done: <https://sourceware.org/bugzilla/show_bug.cgi?id=27201>

Florian
diff mbox series

Patch

From 6630e06f9bcb361177d46c277cf8e67cbd722429 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 9 Oct 2020 06:06:56 -0700
Subject: [PATCH] x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker [BZ #26717]

GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA
levels:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250

and -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property with
GNU_PROPERTY_X86_ISA_1_V[234] marker:

https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13

Binutils support for GNU_PROPERTY_X86_ISA_1_V[234] marker were added by

commit b0ab06937385e0ae25cebf1991787d64f439bf12
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Oct 30 06:49:57 2020 -0700

    x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker

and

commit 32930e4edbc06bc6f10c435dbcc63131715df678
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Fri Oct 9 05:05:57 2020 -0700

    x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker

GNU_PROPERTY_X86_ISA_1_NEEDED property in x86 ELF binaries indicate the
micro-architecture ISA level required to execute the binary.  The marker
must be added by programmers explicitly in one of 3 ways:

1. Pass -mneeded to GCC.
2. Add the marker in the linker inputs as this patch does.
3. Pass -z x86-64-v[234] to the linker.

Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker support to ld.so if binutils 2.32 or newer is used to build glibc:

1. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
markers to elf.h.
2. Add GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
marker to abi-note.o based on the ISA level used to compile abi-note.o,
assuming that the same ISA level is used to compile the whole glibc.
3. Add isa_1 to cpu_features to record the supported x86 ISA level.
4. Rename _dl_process_cet_property_note to _dl_process_property_note and
add GNU_PROPERTY_X86_ISA_1_V[234] marker detection.
5. Update _rtld_main_check and _dl_open_check to check loaded objects
with the incompatible ISA level.
6. Add a testcase to verify that dlopen an x86-64-v4 shared object fails
on lesser platforms.
7. Use <get-isa-level.h> in dl-hwcaps-subdirs.c and tst-glibc-hwcaps.c.

Tested under i686, x32 and x86-64 modes on x86-64-v2, x86-64-v3 and
x86-64-v4 machines.

Marked elf/tst-isa-level-1 with x86-64-v4, ran it on x86-64-v3 machine
and got:

[hjl@gnu-cfl-2 build-x86_64-linux]$ ./elf/tst-isa-level-1
./elf/tst-isa-level-1: CPU ISA level is lower than required
[hjl@gnu-cfl-2 build-x86_64-linux]$
---
 config.h.in                                |   3 +
 elf/elf.h                                  |  35 +++----
 sysdeps/x86/Makefile                       |  30 ++++++
 sysdeps/x86/abi-note.c                     |  29 ++++++
 sysdeps/x86/configure                      |  79 ++++++++++++++
 sysdeps/x86/configure.ac                   |  66 ++++++++++++
 sysdeps/x86/cpu-features.c                 |   3 +
 sysdeps/x86/dl-cet.c                       |  12 ++-
 sysdeps/x86/dl-prop.h                      | 113 +++++++++++++++------
 sysdeps/x86/get-isa-level.h                |  66 ++++++++++++
 sysdeps/x86/include/cpu-features.h         |   2 +
 sysdeps/x86/isa-level.c                    |  97 ++++++++++++++++++
 sysdeps/x86/link_map.h                     |  18 ++--
 sysdeps/x86/tst-isa-level-1.c              | 104 +++++++++++++++++++
 sysdeps/x86/tst-isa-level-mod-1-baseline.c |   1 +
 sysdeps/x86/tst-isa-level-mod-1-v2.c       |   1 +
 sysdeps/x86/tst-isa-level-mod-1-v3.c       |   1 +
 sysdeps/x86/tst-isa-level-mod-1-v4.c       |   1 +
 sysdeps/x86/tst-isa-level-mod-1.c          |  25 +++++
 sysdeps/x86_64/dl-hwcaps-subdirs.c         |  30 ++----
 sysdeps/x86_64/tst-glibc-hwcaps.c          |  41 ++------
 21 files changed, 644 insertions(+), 113 deletions(-)
 create mode 100644 sysdeps/x86/abi-note.c
 create mode 100644 sysdeps/x86/get-isa-level.h
 create mode 100644 sysdeps/x86/isa-level.c
 create mode 100644 sysdeps/x86/tst-isa-level-1.c
 create mode 100644 sysdeps/x86/tst-isa-level-mod-1-baseline.c
 create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v2.c
 create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v3.c
 create mode 100644 sysdeps/x86/tst-isa-level-mod-1-v4.c
 create mode 100644 sysdeps/x86/tst-isa-level-mod-1.c

diff --git a/config.h.in b/config.h.in
index eca2d66a2c..947feeff36 100644
--- a/config.h.in
+++ b/config.h.in
@@ -269,4 +269,7 @@ 
 /* The default value of x86 CET control.  */
 #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property
 
+/* Define if x86 ISA level should be included in shared libraries.  */
+#undef INCLUDE_X86_ISA_LEVEL
+
 #endif
diff --git a/elf/elf.h b/elf/elf.h
index 4a9ae97dfc..9ebd052c8a 100644
--- a/elf/elf.h
+++ b/elf/elf.h
@@ -1324,31 +1324,26 @@  typedef struct
 
 /* The x86 instruction sets indicated by the corresponding bits are
    used in program.  Their support in the hardware is optional.  */
-#define GNU_PROPERTY_X86_ISA_1_USED		0xc0000000
+#define GNU_PROPERTY_X86_ISA_1_USED		0xc0010002
 /* The x86 instruction sets indicated by the corresponding bits are
    used in program and they must be supported by the hardware.   */
-#define GNU_PROPERTY_X86_ISA_1_NEEDED		0xc0000001
+#define GNU_PROPERTY_X86_ISA_1_NEEDED		0xc0008002
 /* X86 processor-specific features used in program.  */
 #define GNU_PROPERTY_X86_FEATURE_1_AND		0xc0000002
 
-#define GNU_PROPERTY_X86_ISA_1_486		(1U << 0)
-#define GNU_PROPERTY_X86_ISA_1_586		(1U << 1)
-#define GNU_PROPERTY_X86_ISA_1_686		(1U << 2)
-#define GNU_PROPERTY_X86_ISA_1_SSE		(1U << 3)
-#define GNU_PROPERTY_X86_ISA_1_SSE2		(1U << 4)
-#define GNU_PROPERTY_X86_ISA_1_SSE3		(1U << 5)
-#define GNU_PROPERTY_X86_ISA_1_SSSE3		(1U << 6)
-#define GNU_PROPERTY_X86_ISA_1_SSE4_1		(1U << 7)
-#define GNU_PROPERTY_X86_ISA_1_SSE4_2		(1U << 8)
-#define GNU_PROPERTY_X86_ISA_1_AVX		(1U << 9)
-#define GNU_PROPERTY_X86_ISA_1_AVX2		(1U << 10)
-#define GNU_PROPERTY_X86_ISA_1_AVX512F		(1U << 11)
-#define GNU_PROPERTY_X86_ISA_1_AVX512CD		(1U << 12)
-#define GNU_PROPERTY_X86_ISA_1_AVX512ER		(1U << 13)
-#define GNU_PROPERTY_X86_ISA_1_AVX512PF		(1U << 14)
-#define GNU_PROPERTY_X86_ISA_1_AVX512VL		(1U << 15)
-#define GNU_PROPERTY_X86_ISA_1_AVX512DQ		(1U << 16)
-#define GNU_PROPERTY_X86_ISA_1_AVX512BW		(1U << 17)
+/* GNU_PROPERTY_X86_ISA_1_BASELINE: CMOV, CX8 (cmpxchg8b), FPU (fld),
+   MMX, OSFXSR (fxsave), SCE (syscall), SSE and SSE2.  */
+#define GNU_PROPERTY_X86_ISA_1_BASELINE		(1U << 0)
+/* GNU_PROPERTY_X86_ISA_1_V2: GNU_PROPERTY_X86_ISA_1_BASELINE,
+   CMPXCHG16B (cmpxchg16b), LAHF-SAHF (lahf), POPCNT (popcnt), SSE3,
+   SSSE3, SSE4.1 and SSE4.2.  */
+#define GNU_PROPERTY_X86_ISA_1_V2		(1U << 1)
+/* GNU_PROPERTY_X86_ISA_1_V3: GNU_PROPERTY_X86_ISA_1_V2, AVX, AVX2, BMI1,
+   BMI2, F16C, FMA, LZCNT, MOVBE, XSAVE.  */
+#define GNU_PROPERTY_X86_ISA_1_V3		(1U << 2)
+/* GNU_PROPERTY_X86_ISA_1_V4: GNU_PROPERTY_X86_ISA_1_V3, AVX512F,
+   AVX512BW, AVX512CD, AVX512DQ and AVX512VL.  */
+#define GNU_PROPERTY_X86_ISA_1_V4		(1U << 3)
 
 /* This indicates that all executable sections are compatible with
    IBT.  */
diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index 081cc72e93..c814d5a195 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -9,6 +9,36 @@  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,$(enable-x86-isa-level))
+tests += tst-isa-level-1
+modules-names += tst-isa-level-mod-1-baseline \
+		 tst-isa-level-mod-1-v2 \
+		 tst-isa-level-mod-1-v3 \
+		 tst-isa-level-mod-1-v4 \
+
+# X86 ISA level baseline
+CFLAGS-tst-isa-level-mod-1-baseline.c += -DINCLUDE_X86_ISA_LEVEL \
+					 -DISA_LEVEL=0x1 \
+					 -march=x86-64
+# X86 ISA level v2
+CFLAGS-tst-isa-level-mod-1-v2.c += -DINCLUDE_X86_ISA_LEVEL \
+				   -DISA_LEVEL=0x3 \
+				   -march=x86-64
+# X86 ISA level v3
+CFLAGS-tst-isa-level-mod-1-v3.c += -DINCLUDE_X86_ISA_LEVEL \
+				   -DISA_LEVEL=0x7 \
+				   -march=x86-64
+# X86 ISA level v4
+CFLAGS-tst-isa-level-mod-1-v4.c += -DINCLUDE_X86_ISA_LEVEL \
+				   -DISA_LEVEL=0xf \
+				   -march=x86-64
+
+$(objpfx)tst-isa-level-1: $(libdl)
+$(objpfx)tst-isa-level-1.out: $(objpfx)tst-isa-level-mod-1-baseline.so \
+			      $(objpfx)tst-isa-level-mod-1-v2.so \
+			      $(objpfx)tst-isa-level-mod-1-v3.so \
+			      $(objpfx)tst-isa-level-mod-1-v4.so
+endif
 endif
 
 ifeq ($(subdir),math)
diff --git a/sysdeps/x86/abi-note.c b/sysdeps/x86/abi-note.c
new file mode 100644
index 0000000000..5140e6ab47
--- /dev/null
+++ b/sysdeps/x86/abi-note.c
@@ -0,0 +1,29 @@ 
+/* Special .init and .fini section support.  x86-64 version.
+   Copyright (C) 2020 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.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file with other
+   programs, and to distribute those programs without any restriction
+   coming from the use of this file.  (The Lesser General Public
+   License restrictions do apply in other respects; for example, they
+   cover modification of the file, and distribution when not linked
+   into another program.)
+
+   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 <isa-level.c>
+#include <csu/abi-note.c>
diff --git a/sysdeps/x86/configure b/sysdeps/x86/configure
index 81cc4e80d6..5e32dc62b3 100644
--- a/sysdeps/x86/configure
+++ b/sysdeps/x86/configure
@@ -68,3 +68,82 @@  elif test $enable_cet = permissive; then
 fi
 config_vars="$config_vars
 enable-cet = $enable_cet"
+
+# Check if linker supports x86 ISA level.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for linker x86 ISA level support" >&5
+$as_echo_n "checking for linker x86 ISA level support... " >&6; }
+if ${libc_cv_include_x86_isa_level+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat > conftest1.S <<EOF
+#ifdef __LP64__
+# define P2ALIGN 3
+#else
+# define P2ALIGN 2
+#endif
+	.section ".note.gnu.property", "a"
+	.p2align P2ALIGN
+	.long 1f - 0f		/* name length.  */
+	.long 4f - 1f		/* data length.  */
+	/* NT_GNU_PROPERTY_TYPE_0 */
+	.long 5			/* note type.  */
+0:
+	.asciz "GNU"		/* vendor name.  */
+1:
+	.p2align P2ALIGN
+	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
+	.long 0xc0008002	/* pr_type.  */
+	.long 3f - 2f		/* pr_datasz.  */
+2:
+	.long 0x1
+3:
+	.p2align P2ALIGN
+4:
+EOF
+cat > conftest2.S <<EOF
+#ifdef __LP64__
+# define P2ALIGN 3
+#else
+# define P2ALIGN 2
+#endif
+	.section ".note.gnu.property", "a"
+	.p2align P2ALIGN
+	.long 1f - 0f		/* name length.  */
+	.long 4f - 1f		/* data length.  */
+	/* NT_GNU_PROPERTY_TYPE_0 */
+	.long 5			/* note type.  */
+0:
+	.asciz "GNU"		/* vendor name.  */
+1:
+	.p2align P2ALIGN
+	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
+	.long 0xc0008002	/* pr_type.  */
+	.long 3f - 2f		/* pr_datasz.  */
+2:
+	.long 0x2
+3:
+	.p2align P2ALIGN
+4:
+EOF
+libc_cv_include_x86_isa_level=no
+if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }; then
+  count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
+  if test "$count" = 1; then
+    libc_cv_include_x86_isa_level=yes
+  fi
+fi
+rm -f conftest*
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_include_x86_isa_level" >&5
+$as_echo "$libc_cv_include_x86_isa_level" >&6; }
+if test $libc_cv_include_x86_isa_level = yes; then
+  $as_echo "#define INCLUDE_X86_ISA_LEVEL 1" >>confdefs.h
+
+fi
+config_vars="$config_vars
+enable-x86-isa-level = $libc_cv_include_x86_isa_level"
diff --git a/sysdeps/x86/configure.ac b/sysdeps/x86/configure.ac
index 8f3e1191f6..f94088f377 100644
--- a/sysdeps/x86/configure.ac
+++ b/sysdeps/x86/configure.ac
@@ -43,3 +43,69 @@  elif test $enable_cet = permissive; then
   AC_DEFINE(DEFAULT_DL_X86_CET_CONTROL, cet_permissive)
 fi
 LIBC_CONFIG_VAR([enable-cet], [$enable_cet])
+
+# Check if linker supports x86 ISA level.
+AC_CACHE_CHECK([for linker x86 ISA level support],
+	       libc_cv_include_x86_isa_level, [dnl
+cat > conftest1.S <<EOF
+#ifdef __LP64__
+# define P2ALIGN 3
+#else
+# define P2ALIGN 2
+#endif
+	.section ".note.gnu.property", "a"
+	.p2align P2ALIGN
+	.long 1f - 0f		/* name length.  */
+	.long 4f - 1f		/* data length.  */
+	/* NT_GNU_PROPERTY_TYPE_0 */
+	.long 5			/* note type.  */
+0:
+	.asciz "GNU"		/* vendor name.  */
+1:
+	.p2align P2ALIGN
+	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
+	.long 0xc0008002	/* pr_type.  */
+	.long 3f - 2f		/* pr_datasz.  */
+2:
+	.long 0x1
+3:
+	.p2align P2ALIGN
+4:
+EOF
+cat > conftest2.S <<EOF
+#ifdef __LP64__
+# define P2ALIGN 3
+#else
+# define P2ALIGN 2
+#endif
+	.section ".note.gnu.property", "a"
+	.p2align P2ALIGN
+	.long 1f - 0f		/* name length.  */
+	.long 4f - 1f		/* data length.  */
+	/* NT_GNU_PROPERTY_TYPE_0 */
+	.long 5			/* note type.  */
+0:
+	.asciz "GNU"		/* vendor name.  */
+1:
+	.p2align P2ALIGN
+	/* GNU_PROPERTY_X86_ISA_1_NEEDED */
+	.long 0xc0008002	/* pr_type.  */
+	.long 3f - 2f		/* pr_datasz.  */
+2:
+	.long 0x2
+3:
+	.p2align P2ALIGN
+4:
+EOF
+libc_cv_include_x86_isa_level=no
+if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS -nostartfiles -nostdlib -r -o conftest conftest1.S conftest2.S); then
+  count=`LC_ALL=C $READELF -n conftest | grep NT_GNU_PROPERTY_TYPE_0 | wc -l`
+  if test "$count" = 1; then
+    libc_cv_include_x86_isa_level=yes
+  fi
+fi
+rm -f conftest*])
+if test $libc_cv_include_x86_isa_level = yes; then
+  AC_DEFINE(INCLUDE_X86_ISA_LEVEL)
+fi
+LIBC_CONFIG_VAR([enable-x86-isa-level], [$libc_cv_include_x86_isa_level])
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 529c586193..e7da682a2e 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -19,6 +19,7 @@ 
 #include <cpuid.h>
 #include <dl-hwcap.h>
 #include <libc-pointer-arith.h>
+#include <get-isa-level.h>
 #if IS_IN (libc) && !defined SHARED
 # include <assert.h>
 # include <unistd.h>
@@ -290,6 +291,8 @@  update_usable (struct cpu_features *cpu_features)
       CPU_FEATURE_SET_USABLE (cpu_features, KL);
       CPU_FEATURE_SET_USABLE (cpu_features, WIDE_KL);
     }
+
+  cpu_features->isa_1 = get_isa_level (cpu_features);
 }
 
 static void
diff --git a/sysdeps/x86/dl-cet.c b/sysdeps/x86/dl-cet.c
index b4910f7634..ed7fd6d10d 100644
--- a/sysdeps/x86/dl-cet.c
+++ b/sysdeps/x86/dl-cet.c
@@ -76,10 +76,12 @@  dl_cet_check (struct link_map *m, const char *program)
 	   */
 	  enable_ibt &= (HAS_CPU_FEATURE (IBT)
 			 && (enable_ibt_type == cet_always_on
-			     || (m->l_cet & lc_ibt) != 0));
+			     || (m->l_x86_feature_1_and
+				 & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0));
 	  enable_shstk &= (HAS_CPU_FEATURE (SHSTK)
 			   && (enable_shstk_type == cet_always_on
-			       || (m->l_cet & lc_shstk) != 0));
+			       || (m->l_x86_feature_1_and
+				   & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0));
 	}
 
       /* ld.so is CET-enabled by kernel.  But shared objects may not
@@ -111,7 +113,8 @@  dl_cet_check (struct link_map *m, const char *program)
 	      /* IBT is enabled only if it is enabled in executable as
 		 well as all shared objects.  */
 	      enable_ibt &= (enable_ibt_type == cet_always_on
-			     || (l->l_cet & lc_ibt) != 0);
+			     || (l->l_x86_feature_1_and
+				 & GNU_PROPERTY_X86_FEATURE_1_IBT) != 0);
 	      if (!found_ibt_legacy && enable_ibt != ibt_enabled)
 		{
 		  found_ibt_legacy = true;
@@ -121,7 +124,8 @@  dl_cet_check (struct link_map *m, const char *program)
 	      /* SHSTK is enabled only if it is enabled in executable as
 		 well as all shared objects.  */
 	      enable_shstk &= (enable_shstk_type == cet_always_on
-			       || (l->l_cet & lc_shstk) != 0);
+			       || (l->l_x86_feature_1_and
+				   & GNU_PROPERTY_X86_FEATURE_1_SHSTK) != 0);
 	      if (enable_shstk != shstk_enabled)
 		{
 		  found_shstk_legacy = true;
diff --git a/sysdeps/x86/dl-prop.h b/sysdeps/x86/dl-prop.h
index ce1667dc7a..56bd020b3c 100644
--- a/sysdeps/x86/dl-prop.h
+++ b/sysdeps/x86/dl-prop.h
@@ -19,14 +19,54 @@ 
 #ifndef _DL_PROP_H
 #define _DL_PROP_H
 
+#include <libintl.h>
+
 extern void _dl_cet_check (struct link_map *, const char *)
     attribute_hidden;
 extern void _dl_cet_open_check (struct link_map *)
     attribute_hidden;
 
+static void
+dl_isa_level_check (struct link_map *m, const char *program)
+{
+  const struct cpu_features *cpu_features = __get_cpu_features ();
+  unsigned int i;
+  struct link_map *l;
+
+  i = m->l_searchlist.r_nlist;
+  while (i-- > 0)
+    {
+      /* Check each shared object to see if ISA level is compatible.  */
+      l = m->l_initfini[i];
+
+      /* Skip ISA level check if functions have been executed.  */
+      if (l->l_init_called)
+	continue;
+
+#ifdef SHARED
+      /* Skip ISA level check for ld.so since ld.so won't run if its ISA
+	 level is higher than CPU.  */
+      if (l == &GL(dl_rtld_map) || l->l_real == &GL(dl_rtld_map))
+	continue;
+#endif
+
+      if ((l->l_x86_isa_1_needed & cpu_features->isa_1)
+	  != l->l_x86_isa_1_needed)
+	{
+	  if (program)
+	    _dl_fatal_printf ("%s: CPU ISA level is lower than required\n",
+			      *l->l_name != '\0' ? l->l_name : program);
+	  else
+	    _dl_signal_error (0, l->l_name, "dlopen",
+			      N_("CPU ISA level is lower than required"));
+	}
+    }
+}
+
 static inline void __attribute__ ((always_inline))
 _rtld_main_check (struct link_map *m, const char *program)
 {
+  dl_isa_level_check (m, program);
 #if CET_ENABLED
   _dl_cet_check (m, program);
 #endif
@@ -35,20 +75,18 @@  _rtld_main_check (struct link_map *m, const char *program)
 static inline void __attribute__ ((always_inline))
 _dl_open_check (struct link_map *m)
 {
+  dl_isa_level_check (m, NULL);
 #if CET_ENABLED
   _dl_cet_open_check (m);
 #endif
 }
 
 static inline void __attribute__ ((unused))
-_dl_process_cet_property_note (struct link_map *l,
-			      const ElfW(Nhdr) *note,
-			      const ElfW(Addr) size,
-			      const ElfW(Addr) align)
+_dl_process_property_note (struct link_map *l, const ElfW(Nhdr) *note,
+			   const ElfW(Addr) size, const ElfW(Addr) align)
 {
-#if CET_ENABLED
   /* Skip if we have seen a NT_GNU_PROPERTY_TYPE_0 note before.  */
-  if (l->l_cet != lc_unknown)
+  if (l->l_property != lc_property_unknown)
     return;
 
   /* The NT_GNU_PROPERTY_TYPE_0 note must be aliged to 4 bytes in
@@ -59,7 +97,8 @@  _dl_process_cet_property_note (struct link_map *l,
 
   const ElfW(Addr) start = (ElfW(Addr)) note;
 
-  unsigned int feature_1 = 0;
+  unsigned int feature_1_and = 0;
+  unsigned int isa_1_needed = 0;
   unsigned int last_type = 0;
 
   while ((ElfW(Addr)) (note + 1) - start < size)
@@ -71,11 +110,11 @@  _dl_process_cet_property_note (struct link_map *l,
 	{
 	  /* Stop if we see more than one GNU property note which may
 	     be generated by the older linker.  */
-	  if (l->l_cet != lc_unknown)
+	  if (l->l_property != lc_property_unknown)
 	    return;
 
-	  /* Check CET status now.  */
-	  l->l_cet = lc_none;
+	  /* Check CET status and ISA levels now.  */
+	  l->l_property = lc_property_none;
 
 	  /* Check for invalid property.  */
 	  if (note->n_descsz < 8
@@ -101,26 +140,37 @@  _dl_process_cet_property_note (struct link_map *l,
 
 	      last_type = type;
 
-	      if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
+	      if (type == GNU_PROPERTY_X86_FEATURE_1_AND
+		  || type == GNU_PROPERTY_X86_ISA_1_NEEDED)
 		{
-		  /* The size of GNU_PROPERTY_X86_FEATURE_1_AND is 4
-		     bytes.  When seeing GNU_PROPERTY_X86_FEATURE_1_AND,
-		     we stop the search regardless if its size is correct
-		     or not.  There is no point to continue if this note
-		     is ill-formed.  */
+		  /* The sizes of types which we are searching for are
+		     4 bytes.  There is no point to continue if this
+		     note is ill-formed.  */
 		  if (datasz != 4)
 		    return;
 
-		  feature_1 = *(unsigned int *) ptr;
-
-		  /* Keep searching for the next GNU property note
-		     generated by the older linker.  */
-		  break;
+		  /* NB: Stop the scan only after seeing all types which
+		     we are searching for.  */
+		  _Static_assert ((GNU_PROPERTY_X86_ISA_1_NEEDED >
+				   GNU_PROPERTY_X86_FEATURE_1_AND),
+				  "GNU_PROPERTY_X86_ISA_1_NEEDED > "
+				  "GNU_PROPERTY_X86_FEATURE_1_AND");
+		  if (type == GNU_PROPERTY_X86_FEATURE_1_AND)
+		    feature_1_and = *(unsigned int *) ptr;
+		  else
+		    {
+		      isa_1_needed = *(unsigned int *) ptr;
+
+		      /* Keep searching for the next GNU property note
+			 generated by the older linker.  */
+		      break;
+		    }
 		}
-	      else if (type > GNU_PROPERTY_X86_FEATURE_1_AND)
+	      else if (type > GNU_PROPERTY_X86_ISA_1_NEEDED)
 		{
-		  /* Stop since property type is in ascending order.  */
-		  return;
+		  /* Stop the scan since property type is in ascending
+		     order.  */
+		  break;
 		}
 
 	      /* Check the next property item.  */
@@ -137,18 +187,21 @@  _dl_process_cet_property_note (struct link_map *l,
     }
 
   /* We get here only if there is one or no GNU property note.  */
-  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_IBT))
-    l->l_cet |= lc_ibt;
-  if ((feature_1 & GNU_PROPERTY_X86_FEATURE_1_SHSTK))
-    l->l_cet |= lc_shstk;
-#endif
+  if (isa_1_needed != 0 || feature_1_and != 0)
+    {
+      l->l_property = lc_property_valid;
+      l->l_x86_isa_1_needed = isa_1_needed;
+      l->l_x86_feature_1_and = feature_1_and;
+    }
+  else
+    l->l_property = lc_property_none;
 }
 
 static inline void __attribute__ ((unused))
 _dl_process_pt_note (struct link_map *l, int fd, const ElfW(Phdr) *ph)
 {
   const ElfW(Nhdr) *note = (const void *) (ph->p_vaddr + l->l_addr);
-  _dl_process_cet_property_note (l, note, ph->p_memsz, ph->p_align);
+  _dl_process_property_note (l, note, ph->p_memsz, ph->p_align);
 }
 
 static inline int __attribute__ ((always_inline))
diff --git a/sysdeps/x86/get-isa-level.h b/sysdeps/x86/get-isa-level.h
new file mode 100644
index 0000000000..a86e1e8941
--- /dev/null
+++ b/sysdeps/x86/get-isa-level.h
@@ -0,0 +1,66 @@ 
+/* Get x86 ISA level.
+   This file is part of the GNU C Library.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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>
+
+/* Get GNU_PROPERTY_X86_ISA_1_BASELINE and GNU_PROPERTY_X86_ISA_1_V[234]
+   ISA level.  */
+
+static unsigned int
+get_isa_level (const struct cpu_features *cpu_features)
+{
+  unsigned int isa_level = 0;
+
+  if (CPU_FEATURE_USABLE_P (cpu_features, CMOV)
+      && CPU_FEATURE_USABLE_P (cpu_features, CX8)
+      && CPU_FEATURE_CPU_P (cpu_features, FPU)
+      && CPU_FEATURE_USABLE_P (cpu_features, FXSR)
+      && CPU_FEATURE_USABLE_P (cpu_features, MMX)
+      && CPU_FEATURE_USABLE_P (cpu_features, SSE)
+      && CPU_FEATURE_USABLE_P (cpu_features, SSE2))
+    {
+      isa_level = GNU_PROPERTY_X86_ISA_1_BASELINE;
+      if (CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
+	  && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
+	  && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
+	  && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
+	  && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
+	  && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
+	  && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2))
+	{
+	  isa_level |= GNU_PROPERTY_X86_ISA_1_V2;
+	  if (CPU_FEATURE_USABLE_P (cpu_features, AVX)
+	      && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
+	      && CPU_FEATURE_USABLE_P (cpu_features, F16C)
+	      && CPU_FEATURE_USABLE_P (cpu_features, FMA)
+	      && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
+	      && CPU_FEATURE_USABLE_P (cpu_features, MOVBE))
+	    {
+	      isa_level |= GNU_PROPERTY_X86_ISA_1_V3;
+	      if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
+		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
+		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
+		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
+		  && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL))
+		isa_level |= GNU_PROPERTY_X86_ISA_1_V4;
+	    }
+	}
+    }
+
+  return isa_level;
+}
diff --git a/sysdeps/x86/include/cpu-features.h b/sysdeps/x86/include/cpu-features.h
index ffe300c931..99e7ee08cf 100644
--- a/sysdeps/x86/include/cpu-features.h
+++ b/sysdeps/x86/include/cpu-features.h
@@ -123,6 +123,8 @@  struct cpu_features
   struct cpu_features_basic basic;
   struct cpuid_features features[COMMON_CPUID_INDEX_MAX];
   unsigned int preferred[PREFERRED_FEATURE_INDEX_MAX];
+  /* X86 micro-architecture ISA levels.  */
+  unsigned int isa_1;
   /* The state size for XSAVEC or XSAVE.  The type must be unsigned long
      int so that we use
 
diff --git a/sysdeps/x86/isa-level.c b/sysdeps/x86/isa-level.c
new file mode 100644
index 0000000000..aaf524cb56
--- /dev/null
+++ b/sysdeps/x86/isa-level.c
@@ -0,0 +1,97 @@ 
+/* ELF program property for x86 ISA level.
+   Copyright (C) 2020 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.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file with other
+   programs, and to distribute those programs without any restriction
+   coming from the use of this file.  (The Lesser General Public
+   License restrictions do apply in other respects; for example, they
+   cover modification of the file, and distribution when not linked
+   into another program.)
+
+   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 <elf.h>
+
+/* ELF program property for x86 ISA level.  */
+#ifdef INCLUDE_X86_ISA_LEVEL
+# if defined __x86_64__ || defined __FXSR__ || !defined _SOFT_FLOAT \
+     || defined  __MMX__ || defined __SSE__ || defined __SSE2__
+#  define ISA_BASELINE	GNU_PROPERTY_X86_ISA_1_BASELINE
+# else
+#  define ISA_BASELINE	0
+# endif
+
+# if defined __GCC_HAVE_SYNC_COMPARE_AND_SWAP_16 \
+     || (defined __x86_64__ && defined __LAHF_SAHF__) \
+     || defined __POPCNT__ || defined __SSE3__ \
+     || defined __SSSE3__ || defined __SSE4_1__ || defined __SSE4_2__
+#  define ISA_V2	GNU_PROPERTY_X86_ISA_1_V2
+# else
+#  define ISA_V2	0
+# endif
+
+# if defined __AVX__ || defined __AVX2__ || defined __F16C__ \
+     || defined __FMA__ || defined __LZCNT__ || defined __MOVBE__ \
+     || defined __XSAVE__
+#  define ISA_V3	GNU_PROPERTY_X86_ISA_1_V3
+# else
+#  define ISA_V3	0
+# endif
+
+# if defined __AVX512F__ || defined __AVX512BW__ || defined __AVX512CD__ \
+     || defined __AVX512DQ__ || defined __AVX512VL__
+#  define ISA_V4	GNU_PROPERTY_X86_ISA_1_V4
+# else
+#  define ISA_V4	0
+# endif
+
+# ifndef ISA_LEVEL
+#  define ISA_LEVEL (ISA_BASELINE | ISA_V2 | ISA_V3 | ISA_V4)
+# endif
+
+# if ISA_LEVEL
+#  ifdef __LP64__
+#   define PROPERTY_ALIGN 3
+#  else
+#   define PROPERTY_ALIGN 2
+#  endif
+
+#  define note_stringify(arg) note_stringify_1(arg)
+#  define note_stringify_1(arg) #arg
+
+asm(".pushsection \".note.gnu.property\",\"a\",@note\n"
+"	.p2align " note_stringify (PROPERTY_ALIGN)
+	/* name length.  */
+"\n	.long 1f - 0f\n"
+	/* data length.  */
+"	.long 4f - 1f\n"
+	/* note type: NT_GNU_PROPERTY_TYPE_0.  */
+"	.long " note_stringify (NT_GNU_PROPERTY_TYPE_0)
+	/* vendor name.  */
+"\n0:	.asciz \"GNU\"\n"
+"1:	.p2align " note_stringify (PROPERTY_ALIGN)
+	/* pr_type: GNU_PROPERTY_X86_ISA_1_NEEDED.  */
+"\n	.long " note_stringify (GNU_PROPERTY_X86_ISA_1_NEEDED)
+	/* pr_datasz.  */
+"\n	.long 3f - 2f\n"
+	/* GNU_PROPERTY_X86_ISA_1_V[234].  */
+"2:\n	 .long " note_stringify (ISA_LEVEL)
+"\n3:\n	.p2align " note_stringify (PROPERTY_ALIGN)
+"\n4:\n .popsection");
+# endif /* ISA_LEVEL */
+#endif /* INCLUDE_X86_ISA_LEVEL */
diff --git a/sysdeps/x86/link_map.h b/sysdeps/x86/link_map.h
index 8074739b47..4c46a25f83 100644
--- a/sysdeps/x86/link_map.h
+++ b/sysdeps/x86/link_map.h
@@ -16,12 +16,16 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-/* If this object is enabled with CET.  */
+/* if this object has GNU property.  */
 enum
   {
-    lc_unknown = 0,			 /* Unknown CET status.  */
-    lc_none = 1 << 0,			 /* Not enabled with CET.  */
-    lc_ibt = 1 << 1,			 /* Enabled with IBT.  */
-    lc_shstk = 1 << 2,			 /* Enabled with STSHK.  */
-    lc_ibt_and_shstk = lc_ibt | lc_shstk /* Enabled with both.  */
-  } l_cet:3;
+    lc_property_unknown = 0,		/* Unknown property status.  */
+    lc_property_none = 1 << 0,		/* No property.  */
+    lc_property_valid = 1 << 1		/* Has valid property.  */
+  } l_property:2;
+
+/* GNU_PROPERTY_X86_FEATURE_1_AND of this object.  */
+unsigned int l_x86_feature_1_and;
+
+/* GNU_PROPERTY_X86_ISA_1_NEEDED of this object.  */
+unsigned int l_x86_isa_1_needed;
diff --git a/sysdeps/x86/tst-isa-level-1.c b/sysdeps/x86/tst-isa-level-1.c
new file mode 100644
index 0000000000..dc31d71ad2
--- /dev/null
+++ b/sysdeps/x86/tst-isa-level-1.c
@@ -0,0 +1,104 @@ 
+/* Check ISA level on dlopened shared object.
+   Copyright (C) 2020 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 <stdbool.h>
+#include <string.h>
+#include <elf.h>
+#include <get-isa-level.h>
+#include <support/xdlfcn.h>
+#include <support/check.h>
+#include <support/test-driver.h>
+
+static void
+do_test_1 (const char *modname, bool fail)
+{
+  int (*fp) (void);
+  void *h;
+
+  h = dlopen (modname, RTLD_LAZY);
+  if (h == NULL)
+    {
+      const char *err = dlerror ();
+      if (fail)
+	{
+	  if (strstr (err, "CPU ISA level is lower than required") == NULL)
+	    FAIL_EXIT1 ("incorrect dlopen '%s' error: %s\n", modname, err);
+
+	  return;
+	}
+
+      FAIL_EXIT1 ("cannot open '%s': %s\n", modname, err);
+    }
+
+  if (fail)
+    FAIL_EXIT1 ("dlopen '%s' should have failed\n", modname);
+
+  fp = xdlsym (h, "test");
+
+  if (fp () != 0)
+    FAIL_EXIT1 ("test () != 0\n");
+
+  dlclose (h);
+}
+
+static int
+do_test (void)
+{
+  const struct cpu_features *cpu_features
+    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
+  unsigned int isa_level = get_isa_level (cpu_features);
+  bool has_isa_baseline = ((isa_level & GNU_PROPERTY_X86_ISA_1_BASELINE)
+			   == GNU_PROPERTY_X86_ISA_1_BASELINE);
+  bool has_isa_v2 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V2)
+			   == GNU_PROPERTY_X86_ISA_1_V2);
+  bool has_isa_v3 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V3)
+			   == GNU_PROPERTY_X86_ISA_1_V3);
+  bool has_isa_v4 = ((isa_level & GNU_PROPERTY_X86_ISA_1_V4)
+			   == GNU_PROPERTY_X86_ISA_1_V4);
+
+  if (!has_isa_baseline)
+    {
+      do_test_1 ("tst-isa-level-mod-1-baseline.so", true);
+      return EXIT_SUCCESS;
+    }
+
+  do_test_1 ("tst-isa-level-mod-1-baseline.so", false);
+
+  /* Skip on x86-64-v4 platforms since dlopen v4 module always works.  */
+  if (has_isa_v4)
+    return EXIT_UNSUPPORTED;
+
+  do_test_1 ("tst-isa-level-mod-1-v4.so", true);
+
+  /* Skip on x86-64-v3 platforms since dlopen v3 module always works.  */
+  if (has_isa_v3)
+    return EXIT_SUCCESS;
+
+  do_test_1 ("tst-isa-level-mod-1-v3.so", true);
+
+  /* Skip on x86-64-v2 platforms since dlopen v2 module always works.  */
+  if (has_isa_v2)
+    return EXIT_SUCCESS;
+
+  do_test_1 ("tst-isa-level-mod-1-v2.so", true);
+
+  return EXIT_SUCCESS;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/x86/tst-isa-level-mod-1-baseline.c b/sysdeps/x86/tst-isa-level-mod-1-baseline.c
new file mode 100644
index 0000000000..d6fe0685a4
--- /dev/null
+++ b/sysdeps/x86/tst-isa-level-mod-1-baseline.c
@@ -0,0 +1 @@ 
+#include "tst-isa-level-mod-1.c"
diff --git a/sysdeps/x86/tst-isa-level-mod-1-v2.c b/sysdeps/x86/tst-isa-level-mod-1-v2.c
new file mode 100644
index 0000000000..d6fe0685a4
--- /dev/null
+++ b/sysdeps/x86/tst-isa-level-mod-1-v2.c
@@ -0,0 +1 @@ 
+#include "tst-isa-level-mod-1.c"
diff --git a/sysdeps/x86/tst-isa-level-mod-1-v3.c b/sysdeps/x86/tst-isa-level-mod-1-v3.c
new file mode 100644
index 0000000000..d6fe0685a4
--- /dev/null
+++ b/sysdeps/x86/tst-isa-level-mod-1-v3.c
@@ -0,0 +1 @@ 
+#include "tst-isa-level-mod-1.c"
diff --git a/sysdeps/x86/tst-isa-level-mod-1-v4.c b/sysdeps/x86/tst-isa-level-mod-1-v4.c
new file mode 100644
index 0000000000..d6fe0685a4
--- /dev/null
+++ b/sysdeps/x86/tst-isa-level-mod-1-v4.c
@@ -0,0 +1 @@ 
+#include "tst-isa-level-mod-1.c"
diff --git a/sysdeps/x86/tst-isa-level-mod-1.c b/sysdeps/x86/tst-isa-level-mod-1.c
new file mode 100644
index 0000000000..40a2e1d99f
--- /dev/null
+++ b/sysdeps/x86/tst-isa-level-mod-1.c
@@ -0,0 +1,25 @@ 
+/* Check ISA level on dlopened shared object.
+   Copyright (C) 2019-2020 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 <isa-level.c>
+
+int
+test (void)
+{
+  return 0;
+}
diff --git a/sysdeps/x86_64/dl-hwcaps-subdirs.c b/sysdeps/x86_64/dl-hwcaps-subdirs.c
index 0aaa635a00..e030534f1b 100644
--- a/sysdeps/x86_64/dl-hwcaps-subdirs.c
+++ b/sysdeps/x86_64/dl-hwcaps-subdirs.c
@@ -18,6 +18,7 @@ 
 
 #include <dl-hwcaps.h>
 #include <cpu-features.h>
+#include <get-isa-level.h>
 
 const char _dl_hwcaps_subdirs[] = "x86-64-v4:x86-64-v3:x86-64-v2";
 enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
@@ -25,40 +26,25 @@  enum { subdirs_count = 3 }; /* Number of components in _dl_hwcaps_subdirs.  */
 uint32_t
 _dl_hwcaps_subdirs_active (void)
 {
+  const struct cpu_features *cpu_features
+    = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
+  unsigned int isa_level = get_isa_level (cpu_features);
   int active = 0;
 
   /* Test in reverse preference order.  */
 
   /* x86-64-v2.  */
-  if (!(CPU_FEATURE_USABLE (CMPXCHG16B)
-        && CPU_FEATURE_USABLE (LAHF64_SAHF64)
-        && CPU_FEATURE_USABLE (POPCNT)
-        && CPU_FEATURE_USABLE (SSE3)
-        && CPU_FEATURE_USABLE (SSE4_1)
-        && CPU_FEATURE_USABLE (SSE4_2)
-        && CPU_FEATURE_USABLE (SSSE3)))
+  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
     return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
   ++active;
 
   /* x86-64-v3.  */
-  if (!(CPU_FEATURE_USABLE (AVX)
-        && CPU_FEATURE_USABLE (AVX2)
-        && CPU_FEATURE_USABLE (BMI1)
-        && CPU_FEATURE_USABLE (BMI2)
-        && CPU_FEATURE_USABLE (F16C)
-        && CPU_FEATURE_USABLE (FMA)
-        && CPU_FEATURE_USABLE (LZCNT)
-        && CPU_FEATURE_USABLE (MOVBE)
-        && CPU_FEATURE_USABLE (OSXSAVE)))
+  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
     return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
   ++active;
 
- /* x86-64-v4.  */
-  if (!(CPU_FEATURE_USABLE (AVX512F)
-        && CPU_FEATURE_USABLE (AVX512BW)
-        && CPU_FEATURE_USABLE (AVX512CD)
-        && CPU_FEATURE_USABLE (AVX512DQ)
-        && CPU_FEATURE_USABLE (AVX512VL)))
+  /* x86-64-v4.  */
+  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
     return _dl_hwcaps_subdirs_build_bitmask (subdirs_count, active);
   ++active;
 
diff --git a/sysdeps/x86_64/tst-glibc-hwcaps.c b/sysdeps/x86_64/tst-glibc-hwcaps.c
index 8bdcb91db0..37b61d3c84 100644
--- a/sysdeps/x86_64/tst-glibc-hwcaps.c
+++ b/sysdeps/x86_64/tst-glibc-hwcaps.c
@@ -19,7 +19,8 @@ 
 #include <stdio.h>
 #include <support/check.h>
 #include <sys/param.h>
-#include <sys/platform/x86.h>
+#include <elf.h>
+#include <get-isa-level.h>
 
 extern int marker2 (void);
 extern int marker3 (void);
@@ -31,35 +32,15 @@  compute_level (void)
 {
   const struct cpu_features *cpu_features
     = __x86_get_cpu_features (COMMON_CPUID_INDEX_MAX);
-
- if (!(CPU_FEATURE_USABLE_P (cpu_features, CMPXCHG16B)
-       && CPU_FEATURE_USABLE_P (cpu_features, LAHF64_SAHF64)
-       && CPU_FEATURE_USABLE_P (cpu_features, POPCNT)
-       && CPU_FEATURE_USABLE_P (cpu_features, MMX)
-       && CPU_FEATURE_USABLE_P (cpu_features, SSE)
-       && CPU_FEATURE_USABLE_P (cpu_features, SSE2)
-       && CPU_FEATURE_USABLE_P (cpu_features, SSE3)
-       && CPU_FEATURE_USABLE_P (cpu_features, SSSE3)
-       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_1)
-       && CPU_FEATURE_USABLE_P (cpu_features, SSE4_2)))
-   return 1;
- if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX)
-       && CPU_FEATURE_USABLE_P (cpu_features, AVX2)
-       && CPU_FEATURE_USABLE_P (cpu_features, BMI1)
-       && CPU_FEATURE_USABLE_P (cpu_features, BMI2)
-       && CPU_FEATURE_USABLE_P (cpu_features, F16C)
-       && CPU_FEATURE_USABLE_P (cpu_features, FMA)
-       && CPU_FEATURE_USABLE_P (cpu_features, LZCNT)
-       && CPU_FEATURE_USABLE_P (cpu_features, MOVBE)
-       && CPU_FEATURE_USABLE_P (cpu_features, OSXSAVE)))
-   return 2;
- if (!(CPU_FEATURE_USABLE_P (cpu_features, AVX512F)
-       && CPU_FEATURE_USABLE_P (cpu_features, AVX512BW)
-       && CPU_FEATURE_USABLE_P (cpu_features, AVX512CD)
-       && CPU_FEATURE_USABLE_P (cpu_features, AVX512DQ)
-       && CPU_FEATURE_USABLE_P (cpu_features, AVX512VL)))
-   return 3;
- return 4;
+  unsigned int isa_level = get_isa_level (cpu_features);
+
+  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V2))
+    return 1;
+  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V3))
+    return 2;
+  if (!(isa_level & GNU_PROPERTY_X86_ISA_1_V4))
+    return 3;
+  return 4;
 }
 
 static int
-- 
2.29.2