x86_32: introduce restore_fpu_checking()

Impact: cleanup, prepare FPU code unificaton

Like on x86_64, return an error from restore_fpu and kill the task
if it fails.

Also rename restore_fpu to restore_fpu_checking which allows ifdefs
to be removed in math_state_restore().

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
LKML-Reference: <1239190320-23952-1-git-send-email-jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 5 insertions, 9 deletions

diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 71c9e5183982..09a2d6dfd85b 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -185,12 +185,10 @@ static inline void tolerant_fwait(void)
         asm volatile("fnclex ; fwait");
 }
 
-static inline void restore_fpu(struct task_struct *tsk)
+static inline int restore_fpu_checking(struct task_struct *tsk)
 {
-        if (task_thread_info(tsk)->status & TS_XSAVE) {
-                xrstor_checking(&tsk->thread.xstate->xsave);
-                return;
-        }
+        if (task_thread_info(tsk)->status & TS_XSAVE)
+                return xrstor_checking(&tsk->thread.xstate->xsave);
         /*
          * The "nop" is needed to make the instructions the same
          * length.
@@ -200,6 +198,7 @@ static inline void restore_fpu(struct task_struct *tsk)
                 "fxrstor %1",
                 X86_FEATURE_FXSR,
                 "m" (tsk->thread.xstate->fxsave));
+        return 0;
 }
 
 /* We need a safe address that is cheap to find and that is already
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index a1d288327ff0..d696145855b5 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -839,9 +839,6 @@ asmlinkage void math_state_restore(void)
         }
 
         clts();                         /* Allow maths ops (or we recurse) */
-#ifdef CONFIG_X86_32
-        restore_fpu(tsk);
-#else
         /*
          * Paranoid restore. send a SIGSEGV if we fail to restore the state.
          */
@@ -850,7 +847,7 @@ asmlinkage void math_state_restore(void)
                 force_sig(SIGSEGV, tsk);
                 return;
         }
-#endif
+
         thread->status |= TS_USEDFPU;   /* So we fnsave on switch_to() */
         tsk->fpu_counter++;
 }