[PATCH v2 5/6] x86: Add x86-64-vN check to early startup

[Florian Weimer <fweimer@redhat.com>]

This ISA level covers the glibc build itself.  <dl-hwcap-check.h>
cannot be used because this check (by design) happens before
DL_PLATFORM_INIT and the x86 CPU flags initialization.
---
v2: Reflect renamed Makefile variable.
 sysdeps/x86/Makefile              |  1 +
 sysdeps/x86/dl-get-cpu-features.c | 31 ++++++++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/sysdeps/x86/Makefile b/sysdeps/x86/Makefile
index 402986ff68..6cf708335c 100644
--- a/sysdeps/x86/Makefile
+++ b/sysdeps/x86/Makefile
@@ -7,6 +7,7 @@ sysdep_routines += get-cpuid-feature-leaf
 sysdep-dl-routines += dl-get-cpu-features
 sysdep_headers += sys/platform/x86.h bits/platform/x86.h
 
+CFLAGS-dl-get-cpu-features.os += $(rtld-early-cflags)
 CFLAGS-get-cpuid-feature-leaf.o += $(no-stack-protector)
 
 tests += tst-get-cpu-features tst-get-cpu-features-static \
diff --git a/sysdeps/x86/dl-get-cpu-features.c b/sysdeps/x86/dl-get-cpu-features.c
index 6339c9df4e..4ec0e5d2af 100644
--- a/sysdeps/x86/dl-get-cpu-features.c
+++ b/sysdeps/x86/dl-get-cpu-features.c
@@ -20,6 +20,7 @@
 
 #ifdef SHARED
 # include <cpu-features.c>
+# include <gcc-macros.h>
 
 /* NB: Normally, DL_PLATFORM_INIT calls init_cpu_features to initialize
    CPU features in dynamic executable.  But when loading ld.so inside of
@@ -36,7 +37,35 @@ _dl_x86_init_cpu_features (void)
 {
   struct cpu_features *cpu_features = __get_cpu_features ();
   if (cpu_features->basic.kind == arch_kind_unknown)
-    init_cpu_features (cpu_features);
+    {
+      init_cpu_features (cpu_features);
+
+# if IS_IN (rtld)
+      /* See isa-level.c.  */
+#  if defined GCCMACRO__GCC_HAVE_SYNC_COMPARE_AND_SWAP_16		\
+  && defined HAVE_X86_LAHF_SAHF && defined GCCMACRO__POPCNT__		\
+  && defined GCCMACRO__SSE3__ && defined GCCMACRO__SSSE3__		\
+  && defined GCCMACRO__SSE4_1__ && defined GCCMACRO__SSE4_2__
+      if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V2))
+	_dl_fatal_printf ("\
+Fatal glibc error: CPU does not support x86-64-v%d\n", 2);
+#   if defined GCCMACRO__AVX__ && defined GCCMACRO__AVX2__ \
+  && defined GCCMACRO__F16C__ && defined GCCMACRO__FMA__   \
+  && defined GCCMACRO__LZCNT__ && defined HAVE_X86_MOVBE
+      if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V3))
+	_dl_fatal_printf ("\
+Fatal glibc error: CPU does not support x86-64-v%d\n", 3);
+#    if defined GCCMACRO__AVX512F__ && defined GCCMACRO__AVX512BW__ \
+     && defined GCCMACRO__AVX512CD__ && defined GCCMACRO__AVX512DQ__ \
+     && defined GCCMACRO__AVX512VL__
+      if (!(cpu_features->isa_1 & GNU_PROPERTY_X86_ISA_1_V4))
+	_dl_fatal_printf ("\
+Fatal glibc error: CPU does not support x86-64-v%d\n", 4);
+#    endif /* ISA level 4 */
+#   endif /* ISA level 3 */
+#  endif /* ISA level 2 */
+# endif /* IS_IN (rtld) */
+    }
 }
 
 __ifunc (__x86_cpu_features, __x86_cpu_features, NULL, void,
-- 
2.34.1