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authorH.J. Lu <hjl.tools@gmail.com>2021-06-23 14:27:58 -0700
committerH.J. Lu <hjl.tools@gmail.com>2021-06-23 17:35:47 -0700
commitea26ff03227d7cacef5de6036df57734373449b4 (patch)
tree2d0fe48737fe826586c8c2e0fca3fd914e726f3f /sysdeps/x86
parenta775a7a3eb1e85b54af0b4ee5ff4dcf66772a1fb (diff)
downloadglibc-ea26ff03227d7cacef5de6036df57734373449b4.tar.gz
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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.
Diffstat (limited to 'sysdeps/x86')
-rw-r--r--sysdeps/x86/cpu-features.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 81275dbdfa..a1d8d11cc4 100644
--- 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))
     {