arch/um/sys-i386/stub.S

   1 #include "uml-config.h"
   2 #include "as-layout.h"
   3
   4         .globl syscall_stub
   5 .section .__syscall_stub, "x"
   6
   7         .globl batch_syscall_stub
   8 batch_syscall_stub:
   9         /* load pointer to first operation */
  10         mov     $(ASM_STUB_DATA+8), %esp
  11
  12 again:
  13         /* load length of additional data */
  14         mov     0x0(%esp), %eax
  15
  16         /* if(length == 0) : end of list */
  17         /* write possible 0 to header */
  18         mov     %eax, ASM_STUB_DATA+4
  19         cmpl    $0, %eax
  20         jz      done
  21
  22         /* save current pointer */
  23         mov     %esp, ASM_STUB_DATA+4
  24
  25         /* skip additional data */
  26         add     %eax, %esp
  27
  28         /* load syscall-# */
  29         pop     %eax
  30
  31         /* load syscall params */
  32         pop     %ebx
  33         pop     %ecx
  34         pop     %edx
  35         pop     %esi
  36         pop     %edi
  37         pop     %ebp
  38
  39         /* execute syscall */
  40         int     $0x80
  41
  42         /* check return value */
  43         pop     %ebx
  44         cmp     %ebx, %eax
  45         je      again
  46
  47 done:
  48         /* save return value */
  49         mov     %eax, ASM_STUB_DATA
  50
  51         /* stop */
  52         int3