2 files changed, 22 insertions, 35 deletions

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 8df95849721d..74c607b37e87 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -29,7 +29,6 @@ extern unsigned int sig_xstate_size;
 extern void fpu_init(void);
 extern void mxcsr_feature_mask_init(void);
 extern int init_fpu(struct task_struct *child);
-extern void __math_state_restore(struct task_struct *);
 extern void math_state_restore(void);
 extern int dump_fpu(struct pt_regs *, struct user_i387_struct *);
 
@@ -269,6 +268,16 @@ static inline int fpu_restore_checking(struct fpu *fpu)
 
 static inline int restore_fpu_checking(struct task_struct *tsk)
 {
+        /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
+           is pending.  Clear the x87 state here by setting it to fixed
+           values. "m" is a random variable that should be in L1 */
+        alternative_input(
+                ASM_NOP8 ASM_NOP2,
+                "emms\n\t"              /* clear stack tags */
+                "fildl %P[addr]",       /* set F?P to defined value */
+                X86_FEATURE_FXSAVE_LEAK,
+                [addr] "m" (tsk->thread.has_fpu));
+
         return fpu_restore_checking(&tsk->thread.fpu);
 }
 
@@ -378,8 +387,10 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
  */
 static inline void switch_fpu_finish(struct task_struct *new, fpu_switch_t fpu)
 {
-        if (fpu.preload)
-                __math_state_restore(new);
+        if (fpu.preload) {
+                if (unlikely(restore_fpu_checking(new)))
+                        __thread_fpu_end(new);
+        }
 }
 
 /*
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 77da5b475ad2..4bbe04d96744 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -571,37 +571,6 @@ asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
 }
 
 /*
- * This gets called with the process already owning the
- * FPU state, and with CR0.TS cleared. It just needs to
- * restore the FPU register state.
- */
-void __math_state_restore(struct task_struct *tsk)
-{
-        /* We need a safe address that is cheap to find and that is already
-           in L1. We've just brought in "tsk->thread.has_fpu", so use that */
-#define safe_address (tsk->thread.has_fpu)
-
-        /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
-           is pending.  Clear the x87 state here by setting it to fixed
-           values. safe_address is a random variable that should be in L1 */
-        alternative_input(
-                ASM_NOP8 ASM_NOP2,
-                "emms\n\t"              /* clear stack tags */
-                "fildl %P[addr]",       /* set F?P to defined value */
-                X86_FEATURE_FXSAVE_LEAK,
-                [addr] "m" (safe_address));
-
-        /*
-         * Paranoid restore. send a SIGSEGV if we fail to restore the state.
-         */
-        if (unlikely(restore_fpu_checking(tsk))) {
-                __thread_fpu_end(tsk);
-                force_sig(SIGSEGV, tsk);
-                return;
-        }
-}
-
-/*
  * 'math_state_restore()' saves the current math information in the
  * old math state array, and gets the new ones from the current task
  *
@@ -631,7 +600,14 @@ void math_state_restore(void)
         }
 
         __thread_fpu_begin(tsk);
-        __math_state_restore(tsk);
+        /*
+         * Paranoid restore. send a SIGSEGV if we fail to restore the state.
+         */
+        if (unlikely(restore_fpu_checking(tsk))) {
+                __thread_fpu_end(tsk);
+                force_sig(SIGSEGV, tsk);
+                return;
+        }
 
         tsk->fpu_counter++;
 }