1 files changed, 23 insertions, 1 deletions

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 815c5b2b9f57..a73a8d5a5e69 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -31,7 +31,6 @@ extern void mxcsr_feature_mask_init(void);
 extern int init_fpu(struct task_struct *child);
 extern asmlinkage void math_state_restore(void);
 extern void __math_state_restore(void);
-extern void init_thread_xstate(void);
 extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
 
 extern user_regset_active_fn fpregs_active, xfpregs_active;
@@ -58,11 +57,25 @@ extern int restore_i387_xstate_ia32(void __user *buf);
 
 #define X87_FSW_ES (1 << 7)     /* Exception Summary */
 
+static __always_inline __pure bool use_xsaveopt(void)
+{
+        return static_cpu_has(X86_FEATURE_XSAVEOPT);
+}
+
 static __always_inline __pure bool use_xsave(void)
 {
         return static_cpu_has(X86_FEATURE_XSAVE);
 }
 
+extern void __sanitize_i387_state(struct task_struct *);
+
+static inline void sanitize_i387_state(struct task_struct *tsk)
+{
+        if (!use_xsaveopt())
+                return;
+        __sanitize_i387_state(tsk);
+}
+
 #ifdef CONFIG_X86_64
 
 /* Ignore delayed exceptions from user space */
@@ -127,6 +140,15 @@ static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
 {
         int err;
 
+        /*
+         * Clear the bytes not touched by the fxsave and reserved
+         * for the SW usage.
+         */
+        err = __clear_user(&fx->sw_reserved,
+                           sizeof(struct _fpx_sw_bytes));
+        if (unlikely(err))
+                return -EFAULT;
+
         asm volatile("1:  rex64/fxsave (%[fx])\n\t"
                      "2:\n"
                      ".section .fixup,\"ax\"\n"