i387: math_state_restore() isn't called from asm

[deliverable/linux.git] / arch / x86 / kernel / traps.c

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index fa1191fb679d5bcf3dbc44a259aee1fd143a4db5..982433b5da30ec19aadd33978793ddcf2aac3e65 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -311,9 +311,15 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
                        == 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
@@ -406,6 +412,12 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
                                                        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);
 
@@ -413,6 +425,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
                handle_vm86_trap((struct kernel_vm86_regs *) regs,
                                error_code, 1);
                preempt_conditional_cli(regs);
+               debug_stack_usage_dec();
                return;
        }
 
@@ -432,6 +445,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
        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;
 }
@@ -585,10 +599,10 @@ void __math_state_restore(void)
  * 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;
@@ -718,4 +732,10 @@ void __init trap_init(void)
        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
 }