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-rw-r--r--arch/x86/kernel/i387.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 009183276bb7..6185d3141219 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -173,6 +173,21 @@ static void init_thread_xstate(void)
xstate_size = sizeof(struct i387_fxsave_struct);
else
xstate_size = sizeof(struct i387_fsave_struct);
+
+ /*
+ * Quirk: we don't yet handle the XSAVES* instructions
+ * correctly, as we don't correctly convert between
+ * standard and compacted format when interfacing
+ * with user-space - so disable it for now.
+ *
+ * The difference is small: with recent CPUs the
+ * compacted format is only marginally smaller than
+ * the standard FPU state format.
+ *
+ * ( This is easy to backport while we are fixing
+ * XSAVES* support. )
+ */
+ setup_clear_cpu_cap(X86_FEATURE_XSAVES);
}
/*