x86/head: Pass a real pt_regs and trapnr to early_fixup_exception()

[cascardo/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 54cdbd2..0904536 100644 (file)
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -568,29 +568,64 @@ early_idt_handler_common:
        je hlt_loop
        incl %ss:early_recursion_flag
 
-       push %eax               # 16(%esp)
-       push %ecx               # 12(%esp)
-       push %edx               #  8(%esp)
-       push %ds                #  4(%esp)
-       push %es                #  0(%esp)
-       movl $(__KERNEL_DS),%eax
-       movl %eax,%ds
-       movl %eax,%es
+       /* The vector number is in pt_regs->gs */
 
-       cmpl $(__KERNEL_CS),32(%esp)
+       cld
+       pushl   %fs             /* pt_regs->fs */
+       movw    $0, 2(%esp)     /* clear high bits (some CPUs leave garbage) */
+       pushl   %es             /* pt_regs->es */
+       movw    $0, 2(%esp)     /* clear high bits (some CPUs leave garbage) */
+       pushl   %ds             /* pt_regs->ds */
+       movw    $0, 2(%esp)     /* clear high bits (some CPUs leave garbage) */
+       pushl   %eax            /* pt_regs->ax */
+       pushl   %ebp            /* pt_regs->bp */
+       pushl   %edi            /* pt_regs->di */
+       pushl   %esi            /* pt_regs->si */
+       pushl   %edx            /* pt_regs->dx */
+       pushl   %ecx            /* pt_regs->cx */
+       pushl   %ebx            /* pt_regs->bx */
+
+       /* Fix up DS and ES */
+       movl    $(__KERNEL_DS), %ecx
+       movl    %ecx, %ds
+       movl    %ecx, %es
+
+       /* Load the vector number into EDX */
+       movl    PT_GS(%esp), %edx
+
+       /* Load GS into pt_regs->gs and clear high bits */
+       movw    %gs, PT_GS(%esp)
+       movw    $0, PT_GS+2(%esp)
+
+       cmpl $(__KERNEL_CS),PT_CS(%esp)
        jne 10f
 
-       leal 28(%esp),%eax      # Pointer to %eip
-       call early_fixup_exception
-       andl %eax,%eax
-       jnz ex_entry            /* found an exception entry */
+       movl    %esp, %eax      /* args are pt_regs (EAX), trapnr (EDX) */
+       call    early_fixup_exception
+       andl    %eax,%eax
+       jz      10f             /* Exception wasn't fixed up */
+
+       popl    %ebx            /* pt_regs->bx */
+       popl    %ecx            /* pt_regs->cx */
+       popl    %edx            /* pt_regs->dx */
+       popl    %esi            /* pt_regs->si */
+       popl    %edi            /* pt_regs->di */
+       popl    %ebp            /* pt_regs->bp */
+       popl    %eax            /* pt_regs->ax */
+       popl    %ds             /* pt_regs->ds */
+       popl    %es             /* pt_regs->es */
+       popl    %fs             /* pt_regs->fs */
+       popl    %gs             /* pt_regs->gs */
+       decl    %ss:early_recursion_flag
+       addl    $4, %esp        /* pop pt_regs->orig_ax */
+       iret
 
 10:
 #ifdef CONFIG_PRINTK
        xorl %eax,%eax
-       movw %ax,2(%esp)        /* clean up the segment values on some cpus */
-       movw %ax,6(%esp)
-       movw %ax,34(%esp)
+       movw %ax,PT_FS+2(%esp)  /* clean up the segment values on some cpus */
+       movw %ax,PT_DS+2(%esp)
+       movw %ax,PT_ES+2(%esp)
        leal  40(%esp),%eax
        pushl %eax              /* %esp before the exception */
        pushl %ebx
@@ -608,13 +643,6 @@ hlt_loop:
        hlt
        jmp hlt_loop
 
-ex_entry:
-       pop %es
-       pop %ds
-       pop %edx
-       pop %ecx
-       pop %eax
-       decl %ss:early_recursion_flag
 .Lis_nmi:
        addl $8,%esp            /* drop vector number and error code */
        iret