x86: Copy IBT and SHSTK usable only if CET is enabled

IBT and SHSTK usable bits are copied from CPUID feature bits and later
cleared if kernel doesn't support CET.  Copy IBT and SHSTK usable only
if CET is enabled so that they aren't set on CET capable processors
with non-CET enabled glibc.

diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 81275dbdfa339e8be380d9e1bdb988a6fa34b6f2..a1d8d11cc4a1fc9f38029fca760979e0ea5917a6 100644 (file)
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -76,7 +76,6 @@ update_usable (struct cpu_features *cpu_features)
   CPU_FEATURE_SET_USABLE (cpu_features, PREFETCHWT1);
   CPU_FEATURE_SET_USABLE (cpu_features, OSPKE);
   CPU_FEATURE_SET_USABLE (cpu_features, WAITPKG);
-  CPU_FEATURE_SET_USABLE (cpu_features, SHSTK);
   CPU_FEATURE_SET_USABLE (cpu_features, GFNI);
   CPU_FEATURE_SET_USABLE (cpu_features, RDPID);
   CPU_FEATURE_SET_USABLE (cpu_features, RDRAND);
@@ -86,7 +85,6 @@ update_usable (struct cpu_features *cpu_features)
   CPU_FEATURE_SET_USABLE (cpu_features, FSRM);
   CPU_FEATURE_SET_USABLE (cpu_features, SERIALIZE);
   CPU_FEATURE_SET_USABLE (cpu_features, TSXLDTRK);
-  CPU_FEATURE_SET_USABLE (cpu_features, IBT);
   CPU_FEATURE_SET_USABLE (cpu_features, LAHF64_SAHF64);
   CPU_FEATURE_SET_USABLE (cpu_features, LZCNT);
   CPU_FEATURE_SET_USABLE (cpu_features, SSE4A);
@@ -99,6 +97,11 @@ update_usable (struct cpu_features *cpu_features)
   CPU_FEATURE_SET_USABLE (cpu_features, FSRCS);
   CPU_FEATURE_SET_USABLE (cpu_features, PTWRITE);
 
+#if CET_ENABLED
+  CPU_FEATURE_SET_USABLE (cpu_features, IBT);
+  CPU_FEATURE_SET_USABLE (cpu_features, SHSTK);
+#endif
+
   /* Can we call xgetbv?  */
   if (CPU_FEATURES_CPU_P (cpu_features, OSXSAVE))
     {