x86: Define MINIMUM_X86_ISA_LEVEL in config.h [BZ #31676]

Define MINIMUM_X86_ISA_LEVEL at configure time to avoid

/usr/bin/ld: …/build/elf/librtld.os: in function `init_cpu_features':
…/git/elf/../sysdeps/x86/cpu-features.c:1202: undefined reference to `_dl_runtime_resolve_fxsave'
/usr/bin/ld: …/build/elf/librtld.os: relocation R_X86_64_PC32 against undefined hidden symbol `_dl_runtime_resolve_fxsave' can not be used when making a shared object
/usr/bin/ld: final link failed: bad value
collect2: error: ld returned 1 exit status

when glibc is built with -march=x86-64-v3 and configured with
--with-rtld-early-cflags=-march=x86-64, which is used to allow ld.so to
print an error message on unsupported CPUs:

Fatal glibc error: CPU does not support x86-64-v3

This fixes BZ #31676.
Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>

diff --git a/config.h.in b/config.h.in
index 69ac450356b954424f20aef24a653d02736cd33c..c4cc7d3b9aebc71c9f9ee45bf50c2042bb0e68d3 100644 (file)
--- a/config.h.in
+++ b/config.h.in
@@ -285,6 +285,9 @@
 /* Define if x86 ISA level should be included in shared libraries.  */
 #undef INCLUDE_X86_ISA_LEVEL
 
+/* The x86 ISA level.  1 for baseline.  Undefined on non-x86.  */
+#undef MINIMUM_X86_ISA_LEVEL
+
 /* Define if -msahf is enabled by default on x86.  */
 #undef HAVE_X86_LAHF_SAHF
 

diff --git a/sysdeps/x86/configure b/sysdeps/x86/configure
index 2a5421bb31e9efe47117d70ae2a323bd2a57dca8..d28d9bcb296c63805f6bdc4c3201ef50978366fe 100644 (file)
--- a/sysdeps/x86/configure
+++ b/sysdeps/x86/configure
@@ -151,6 +151,13 @@ printf "%s\n" "$libc_cv_have_x86_isa_level" >&6; }
 else
   libc_cv_have_x86_isa_level=baseline
 fi
+if test $libc_cv_have_x86_isa_level = baseline; then
+  printf "%s\n" "#define MINIMUM_X86_ISA_LEVEL 1" >>confdefs.h
+
+else
+  printf "%s\n" "#define MINIMUM_X86_ISA_LEVEL $libc_cv_have_x86_isa_level" >>confdefs.h
+
+fi
 config_vars="$config_vars
 have-x86-isa-level = $libc_cv_have_x86_isa_level"
 config_vars="$config_vars

diff --git a/sysdeps/x86/configure.ac b/sysdeps/x86/configure.ac
index 78ff7c8f41c552bc757ec655b8959367b3ad02a7..5b0acd03d2a30c9b3073c93f5524c810215adaf9 100644 (file)
--- a/sysdeps/x86/configure.ac
+++ b/sysdeps/x86/configure.ac
@@ -105,6 +105,11 @@ EOF
 else
   libc_cv_have_x86_isa_level=baseline
 fi
+if test $libc_cv_have_x86_isa_level = baseline; then
+  AC_DEFINE_UNQUOTED(MINIMUM_X86_ISA_LEVEL, 1)
+else
+  AC_DEFINE_UNQUOTED(MINIMUM_X86_ISA_LEVEL, $libc_cv_have_x86_isa_level)
+fi
 LIBC_CONFIG_VAR([have-x86-isa-level], [$libc_cv_have_x86_isa_level])
 LIBC_CONFIG_VAR([x86-isa-level-3-or-above], [3 4])
 LIBC_CONFIG_VAR([enable-x86-isa-level], [$libc_cv_include_x86_isa_level])

diff --git a/sysdeps/x86/isa-level.h b/sysdeps/x86/isa-level.h
index 11fe1ca90c5bfedfa80c95e797003a4abc0ea9f6..2c7f74212b9a27e540c3becdaba3d8153ae6e5d3 100644 (file)
--- a/sysdeps/x86/isa-level.h
+++ b/sysdeps/x86/isa-level.h
@@ -61,8 +61,10 @@
 # define __X86_ISA_V4 0
 #endif
 
-#define MINIMUM_X86_ISA_LEVEL                                                 \
+#ifndef MINIMUM_X86_ISA_LEVEL
+# define MINIMUM_X86_ISA_LEVEL                                                 \
   (__X86_ISA_V1 + __X86_ISA_V2 + __X86_ISA_V3 + __X86_ISA_V4)
+#endif
 
 /* Depending on the minimum ISA level, a feature check result can be a
    compile-time constant.. */