== NOTIFY_STOP)
return;
+ /*
+ * Let others (NMI) know that the debug stack is in use
+ * as we may switch to the interrupt stack.
+ */
+ debug_stack_usage_inc();
preempt_conditional_sti(regs);
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
preempt_conditional_cli(regs);
+ debug_stack_usage_dec();
}
#ifdef CONFIG_X86_64
SIGTRAP) == NOTIFY_STOP)
return;
+ /*
+ * Let others (NMI) know that the debug stack is in use
+ * as we may switch to the interrupt stack.
+ */
+ debug_stack_usage_inc();
+
/* It's safe to allow irq's after DR6 has been saved */
preempt_conditional_sti(regs);
handle_vm86_trap((struct kernel_vm86_regs *) regs,
error_code, 1);
preempt_conditional_cli(regs);
+ debug_stack_usage_dec();
return;
}
if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
send_sigtrap(tsk, regs, error_code, si_code);
preempt_conditional_cli(regs);
+ debug_stack_usage_dec();
return;
}
}
/*
- * __math_state_restore assumes that cr0.TS is already clear and the
- * fpu state is all ready for use. Used during context switch.
+ * 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(void)
+void __math_state_restore(struct task_struct *tsk)
{
- struct thread_info *thread = current_thread_info();
- struct task_struct *tsk = thread->task;
+ /* 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))) {
- stts();
+ __thread_fpu_end(tsk);
force_sig(SIGSEGV, tsk);
return;
}
-
- thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
- tsk->fpu_counter++;
}
/*
* 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();
local_irq_disable();
}
- clts(); /* Allow maths ops (or we recurse) */
+ __thread_fpu_begin(tsk);
+ __math_state_restore(tsk);
- __math_state_restore();
+ tsk->fpu_counter++;
}
EXPORT_SYMBOL_GPL(math_state_restore);
cpu_init();
x86_init.irqs.trap_init();
+
+#ifdef CONFIG_X86_64
+ memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16);
+ set_nmi_gate(1, &debug);
+ set_nmi_gate(3, &int3);
+#endif
}