x86/asm/irq: Stop relying on magic JMP behavior for early_idt_handlers

[karo-tx-linux.git] / arch / x86 / kernel / head_32.S

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index d031bad9e07eadf3a80bc69a449cd13a44ed8080..53eeb226657caa6868c826dd4b1fb83a1bf514a0 100644 (file)
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -478,21 +478,22 @@ is486:
 __INIT
 setup_once:
        /*
-        * Set up a idt with 256 entries pointing to ignore_int,
-        * interrupt gates. It doesn't actually load idt - that needs
-        * to be done on each CPU. Interrupts are enabled elsewhere,
-        * when we can be relatively sure everything is ok.
+        * Set up a idt with 256 interrupt gates that push zero if there
+        * is no error code and then jump to early_idt_handler_common.
+        * It doesn't actually load the idt - that needs to be done on
+        * each CPU. Interrupts are enabled elsewhere, when we can be
+        * relatively sure everything is ok.
         */
 
        movl $idt_table,%edi
-       movl $early_idt_handlers,%eax
+       movl $early_idt_handler_array,%eax
        movl $NUM_EXCEPTION_VECTORS,%ecx
 1:
        movl %eax,(%edi)
        movl %eax,4(%edi)
        /* interrupt gate, dpl=0, present */
        movl $(0x8E000000 + __KERNEL_CS),2(%edi)
-       addl $9,%eax
+       addl $EARLY_IDT_HANDLER_SIZE,%eax
        addl $8,%edi
        loop 1b
 
@@ -524,26 +525,28 @@ setup_once:
        andl $0,setup_once_ref  /* Once is enough, thanks */
        ret
 
-ENTRY(early_idt_handlers)
+ENTRY(early_idt_handler_array)
        # 36(%esp) %eflags
        # 32(%esp) %cs
        # 28(%esp) %eip
        # 24(%rsp) error code
        i = 0
        .rept NUM_EXCEPTION_VECTORS
-       .if (EXCEPTION_ERRCODE_MASK >> i) & 1
-       ASM_NOP2
-       .else
+       .ifeq (EXCEPTION_ERRCODE_MASK >> i) & 1
        pushl $0                # Dummy error code, to make stack frame uniform
        .endif
        pushl $i                # 20(%esp) Vector number
-       jmp early_idt_handler
+       jmp early_idt_handler_common
        i = i + 1
+       .fill early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE - ., 1, 0xcc
        .endr
-ENDPROC(early_idt_handlers)
+ENDPROC(early_idt_handler_array)
        
-       /* This is global to keep gas from relaxing the jumps */
-ENTRY(early_idt_handler)
+early_idt_handler_common:
+       /*
+        * The stack is the hardware frame, an error code or zero, and the
+        * vector number.
+        */
        cld
 
        cmpl $2,(%esp)          # X86_TRAP_NMI
@@ -603,7 +606,7 @@ ex_entry:
 is_nmi:
        addl $8,%esp            /* drop vector number and error code */
        iret
-ENDPROC(early_idt_handler)
+ENDPROC(early_idt_handler_common)
 
 /* This is the default interrupt "handler" :-) */
        ALIGN