sys_openat 440 include/linux/syscalls.h asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, sys_openat 184 include/uapi/asm-generic/unistd.h __SYSCALL(__NR_openat, sys_openat) sys_openat 184 tools/include/uapi/asm-generic/unistd.h __SYSCALL(__NR_openat, sys_openat)