interrupt service routine crashes on iret

I am working on an interrupt service routine for a 32 bit protected mode kernel I was writing (with the help from GPL codes from the net; from GazOS). I am working on the IDT and enabling of irq 1 to test out the keyboard handler. The ISR looks like this :=

.globl keyb_ISR

keyb_ISR:

  pusha 
  pushw %ds 
  pushw %es 
  pushw %ss 
  pushw %ss
  popw %ds 
  popw %es 

  call keyboard_handler

  popw %es
  popw %ds
  popa 
  iret

However, when I reach iret, the processor crashes/hangs. My IDT is setup this way :=

desc_table(IDT, 256)
{
};

struct
{
  unsigned short limit __attribute__ ((packed));

  union DT_entry *idt  __attribute__ ((packed));
} __IDT__ = { (256 * sizeof(union DT_entry) - 1), IDT };

void set_vector(void *handler, unsigned char interrupt, 
unsigned short     control_major,unsigned int selector)
{

   IDT[interrupt].gate.offset_low    = (unsigned short) (((unsigned long)handler)&0xffff);
  IDT[interrupt].gate.selector      = selector;
  IDT[interrupt].gate.access        = control_major;
  IDT[interrupt].gate.offset_high   = (unsigned short) (((unsigned long)handler) >> 16);
}

Where the vector is set this way :=
set_vector(keyb_ISR, M_VEC+1, D_PRESENT + D_INT + D_DPL3, KERNEL_CS);

The problem is it either hangs when I reach the iret instruction (if I keep the printk routine inside the keyboard_handler) or it crashes the CPU emulator (I am running on Virtual Box) if there is no printk statement inside the handler. I know we are not supposed to have printk inside a handler, so something is wrong. Thanks

I was able to see this error message in Bochs :=

00076701521p[CPU0 ] >>PANIC<< prefetch: getHostMemAddr vetoed direct read, pAddr=0x00000000000a0000

00076701521i[CPU0 ] CPU is in protected mode (active)

00076701521i[CPU0 ] CS.d_b = 32 bit

00076701521i[CPU0 ] SS.d_b = 32 bit

00076701521i[CPU0 ] | EAX=ffff111b EBX=46ed0000 ECX=de000000 EDX=ff2f0011

00076701521i[CPU0 ] | ESP=0000ff35 EBP=00460000 ESI=00104790 EDI=6b00ffff

00076701521i[CPU0 ] | IOPL=0 id vip vif ac vm rf nt of df if tf SF zf AF PF cf

00076701521i[CPU0 ] | SEG selector base limit GD

00076701521i[CPU0 ] | SEG sltr(index|ti|rpl) base limit GD

00076701521i[CPU0 ] | CS:0010( 0002| 0| 0) 00000000 ffffffff 1 1

00076701521i[CPU0 ] | DS:0018( 0003| 0| 0) 00000000 ffffffff 1 1

00076701521i[CPU0 ] | SS:0018( 0003| 0| 0) 00000000 ffffffff 1 1

00076701521i[CPU0 ] | ES:0018( 0003| 0| 0) 00000000 ffffffff 1 1

00076701521i[CPU0 ] | FS:002b( 0005| 0| 3) 00000000 ffffffff 1 1

00076701521i[CPU0 ] | GS:0018( 0003| 0| 0) 00000000 ffffffff 1 1

00076701521i[CPU0 ] | EIP=000a0000 (0009ffff)

00076701521i[CPU0 ] | CR0=0x60000011 CR2=0x00000000

00076701521i[CPU0 ] | CR3=0x00000000 CR4=0x00000000

00076701521i[CPU0 ] 0x0009ffff: (instruction unavailable) page split instruction

00076701521i[CMOS ] Last time is 1367097632 (Sat Apr 27 17:20:32 2013)

00076701521i[XGUI ] Exit

00076701521i[ ] restoring default signal behavior

========================================================================

Bochs is exiting with the following message:

[CPU0 ] prefetch: getHostMemAddr vetoed direct read, pAddr=0x00000000000a0000

========================================================================

链接地址: http://www.djcxy.com/p/85908.html

上一篇: itoa实施崩溃？

下一篇: 中断服务程序在iret上崩溃