arch/x86/um/stub_64.S

   1 #include <as-layout.h>
   2
   3 .section .__syscall_stub, "ax"
   4         .globl batch_syscall_stub
   5 batch_syscall_stub:
   6         mov     $(STUB_DATA), %rbx
   7         /* load pointer to first operation */
   8         mov     %rbx, %rsp
   9         add     $0x10, %rsp
  10 again:
  11         /* load length of additional data */
  12         mov     0x0(%rsp), %rax
  13
  14         /* if(length == 0) : end of list */
  15         /* write possible 0 to header */
  16         mov     %rax, 8(%rbx)
  17         cmp     $0, %rax
  18         jz      done
  19
  20         /* save current pointer */
  21         mov     %rsp, 8(%rbx)
  22
  23         /* skip additional data */
  24         add     %rax, %rsp
  25
  26         /* load syscall-# */
  27         pop     %rax
  28
  29         /* load syscall params */
  30         pop     %rdi
  31         pop     %rsi
  32         pop     %rdx
  33         pop     %r10
  34         pop     %r8
  35         pop     %r9
  36
  37         /* execute syscall */
  38         syscall
  39
  40         /* check return value */
  41         pop     %rcx
  42         cmp     %rcx, %rax
  43         je      again
  44
  45 done:
  46         /* save return value */
  47         mov     %rax, (%rbx)
  48
  49         /* stop */
  50         int3