syscall.S 1.6 KB

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  1. /* Copyright (C) 2001, 2003 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, write to the Free
  13. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  14. 02111-1307 USA. */
  15. /* Please consult the file sysdeps/unix/sysv/linux/x86-64/sysdep.h for
  16. more information about the value -4095 used below. */
  17. /* Usage: long syscall (syscall_number, arg1, arg2, arg3, arg4, arg5, arg6)
  18. We need to do some arg shifting, the syscall_number will be in
  19. rax. */
  20. .text
  21. .globl syscall
  22. .type syscall,%function
  23. .align 16
  24. syscall:
  25. movq %rdi, %rax /* Syscall number -> rax. */
  26. movq %rsi, %rdi /* shift arg1 - arg5. */
  27. movq %rdx, %rsi
  28. movq %rcx, %rdx
  29. movq %r8, %r10
  30. movq %r9, %r8
  31. movq 8(%rsp),%r9 /* arg6 is on the stack. */
  32. syscall /* Do the system call. */
  33. cmpq $-4095, %rax /* Check %rax for error. */
  34. jae __syscall_error /* Branch forward if it failed. */
  35. ret /* Return to caller. */
  36. .size syscall,.-syscall