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Diffstat (limited to 'arch/x86/kernel/traps.c')
-rw-r--r--arch/x86/kernel/traps.c43
1 files changed, 14 insertions, 29 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 482ec3af2067..4bbe04d96744 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -571,41 +571,18 @@ asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
}
/*
- * __math_state_restore assumes that cr0.TS is already clear and the
- * fpu state is all ready for use. Used during context switch.
- */
-void __math_state_restore(void)
-{
- struct thread_info *thread = current_thread_info();
- struct task_struct *tsk = thread->task;
-
- /*
- * Paranoid restore. send a SIGSEGV if we fail to restore the state.
- */
- if (unlikely(restore_fpu_checking(tsk))) {
- stts();
- force_sig(SIGSEGV, tsk);
- return;
- }
-
- thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
- tsk->fpu_counter++;
-}
-
-/*
* 'math_state_restore()' saves the current math information in the
* old math state array, and gets the new ones from the current task
*
* Careful.. There are problems with IBM-designed IRQ13 behaviour.
* Don't touch unless you *really* know how it works.
*
- * Must be called with kernel preemption disabled (in this case,
- * local interrupts are disabled at the call-site in entry.S).
+ * Must be called with kernel preemption disabled (eg with local
+ * local interrupts as in the case of do_device_not_available).
*/
-asmlinkage void math_state_restore(void)
+void math_state_restore(void)
{
- struct thread_info *thread = current_thread_info();
- struct task_struct *tsk = thread->task;
+ struct task_struct *tsk = current;
if (!tsk_used_math(tsk)) {
local_irq_enable();
@@ -622,9 +599,17 @@ asmlinkage void math_state_restore(void)
local_irq_disable();
}
- clts(); /* Allow maths ops (or we recurse) */
+ __thread_fpu_begin(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;
+ }
- __math_state_restore();
+ tsk->fpu_counter++;
}
EXPORT_SYMBOL_GPL(math_state_restore);