fusl/arch/x86_64/syscall_arch.h

#define __SYSCALL_LL_E(x) (x)
#define __SYSCALL_LL_O(x) (x)

static __inline long __syscall0(long n) {
  unsigned long ret;
  __asm__ __volatile__("syscall" : "=a"(ret) : "a"(n) : "rcx", "r11", "memory");
  return ret;
}

static __inline long __syscall1(long n, long a1) {
  unsigned long ret;
  __asm__ __volatile__("syscall"
                       : "=a"(ret)
                       : "a"(n), "D"(a1)
                       : "rcx", "r11", "memory");
  return ret;
}

static __inline long __syscall2(long n, long a1, long a2) {
  unsigned long ret;
  __asm__ __volatile__("syscall"
                       : "=a"(ret)
                       : "a"(n), "D"(a1), "S"(a2)
                       : "rcx", "r11", "memory");
  return ret;
}

static __inline long __syscall3(long n, long a1, long a2, long a3) {
  unsigned long ret;
  __asm__ __volatile__("syscall"
                       : "=a"(ret)
                       : "a"(n), "D"(a1), "S"(a2), "d"(a3)
                       : "rcx", "r11", "memory");
  return ret;
}

static __inline long __syscall4(long n, long a1, long a2, long a3, long a4) {
  unsigned long ret;
  register long r10 __asm__("r10") = a4;
  __asm__ __volatile__("syscall"
                       : "=a"(ret)
                       : "a"(n), "D"(a1), "S"(a2), "d"(a3), "r"(r10)
                       : "rcx", "r11", "memory");
  return ret;
}

static __inline long __syscall5(long n,
                                long a1,
                                long a2,
                                long a3,
                                long a4,
                                long a5) {
  unsigned long ret;
  register long r10 __asm__("r10") = a4;
  register long r8 __asm__("r8") = a5;
  __asm__ __volatile__("syscall"
                       : "=a"(ret)
                       : "a"(n), "D"(a1), "S"(a2), "d"(a3), "r"(r10), "r"(r8)
                       : "rcx", "r11", "memory");
  return ret;
}

static __inline long
__syscall6(long n, long a1, long a2, long a3, long a4, long a5, long a6) {
  unsigned long ret;
  register long r10 __asm__("r10") = a4;
  register long r8 __asm__("r8") = a5;
  register long r9 __asm__("r9") = a6;
  __asm__ __volatile__("syscall"
                       : "=a"(ret)
                       : "a"(n), "D"(a1), "S"(a2), "d"(a3), "r"(r10), "r"(r8),
                         "r"(r9)
                       : "rcx", "r11", "memory");
  return ret;
}

#define VDSO_USEFUL
#define VDSO_CGT_SYM "__vdso_clock_gettime"
#define VDSO_CGT_VER "LINUX_2.6"