LXR linux/arch/x86/um/stub

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#include <as-layout.h>
   3
   4.section .__syscall_stub, "ax"
   5        .globl batch_syscall_stub
   6batch_syscall_stub:
   7        mov     $(STUB_DATA), %rbx
   8        /* load pointer to first operation */
   9        mov     %rbx, %rsp
  10        add     $0x10, %rsp
  11again:
  12        /* load length of additional data */
  13        mov     0x0(%rsp), %rax
  14
  15        /* if(length == 0) : end of list */
  16        /* write possible 0 to header */
  17        mov     %rax, 8(%rbx)
  18        cmp     $0, %rax
  19        jz      done
  20
  21        /* save current pointer */
  22        mov     %rsp, 8(%rbx)
  23
  24        /* skip additional data */
  25        add     %rax, %rsp
  26
  27        /* load syscall-# */
  28        pop     %rax
  29
  30        /* load syscall params */
  31        pop     %rdi
  32        pop     %rsi
  33        pop     %rdx
  34        pop     %r10
  35        pop     %r8
  36        pop     %r9
  37
  38        /* execute syscall */
  39        syscall
  40
  41        /* check return value */
  42        pop     %rcx
  43        cmp     %rcx, %rax
  44        je      again
  45
  46done:
  47        /* save return value */
  48        mov     %rax, (%rbx)
  49
  50        /* stop */
  51        int3
  52