SYSCALLS(2)                Linux Programmer's Manual               SYSCALLS(2)

       none - list of all system calls

       Linux 2.4 system calls.

       The system call is the fundamental interface between an application and
       the Linux kernel. As of Linux  2.4.17,  there  are  1100  system  calls
       listed  in  /usr/src/linux/include/asm-*/unistd.h.  This man page lists
       those that are common to most platforms (providing  hyperlinks  if  you
       read this with a browser).

       _llseek(2),  _newselect(2),  _sysctl(2), accept(2), access(2), acct(2),
       adjtimex(2), afs_syscall, alarm(2), bdflush(2), bind(2), break, brk(2),
       cacheflush(2),  capget(2),  capset(2),  chdir(2),  chmod(2),  chown(2),
       chown32, chroot(2),  clone(2),  close(2),  connect(2),  creat(2),  cre-
       ate_module(2),  delete_module(2),  dup(2), dup2(2), execve(2), exit(2),
       fchdir(2), fchmod(2), fchown(2), fchown32,  fcntl(2),  fcntl64,  fdata-
       sync(2),  flock(2),  fork(2),  fstat(2), fstat64, fstatfs(2), fsync(2),
       ftime, ftruncate(2), ftruncate64, get_kernel_syms(2),  getcwd(2),  get-
       dents(2),  getdents64,  getegid(2),  getegid32,  geteuid(2), geteuid32,
       getgid(2),  getgid32,  getgroups(2),  getgroups32,  getitimer(2),  get-
       pagesize(2),  getpeername(2),  getpmsg,  getpgid(2),  getpgrp(2),  get-
       pid(2), getppid(2),  getpriority(2),  getresgid(2),  getresgid32,  get-
       resuid(2),  getresuid32,  getrlimit(2),  getrusage(2),  getsid(2), get-
       sockname(2), getsockopt(2), gettid,  gettimeofday(2),  getuid(2),  get-
       uid32,   gtty,  idle,  init_module(2),  ioctl(2),  ioperm(2),  iopl(2),
       ipc(2),  kill(2),  lchown(2),  lchown32,  link(2),   listen(2),   lock,
       lseek(2),   lstat(2),   lstat64,   madvise(2),   mincore(2),  mkdir(2),
       mknod(2),  mlock(2),  mlockall(2),  mmap(2),  modify_ldt(2),  mount(2),
       mprotect(2),  mpx, mremap(2), msync(2), munlock(2), munlockall(2), mun-
       map(2),  nanosleep(2),  nfsservctl(2),  nice(2),  oldfstat,   oldlstat,
       oldolduname, oldstat, oldumount, olduname, open(2), pause(2), personal-
       ity(2), phys,  pipe(2),  pivot_root(2),  poll(2),  prctl(2),  pread(2),
       prof,  profil,  ptrace(2),  putpmsg,  pwrite(2),  query_module(2), quo-
       tactl(2),  read(2),  readahead,  readdir(2),   readlink(2),   readv(2),
       reboot(2),   recv(2),  recvfrom(2),  recvmsg(2),  rename(2),  rmdir(2),
       rt_sigaction, rt_sigpending, rt_sigprocmask, rt_sigqueueinfo, rt_sigre-
       turn,    rt_sigsuspend,   rt_sigtimedwait,   sched_get_priority_max(2),
       sched_get_priority_min(2),  sched_getparam(2),   sched_getscheduler(2),
       sched_rr_get_interval(2),   sched_setparam(2),   sched_setscheduler(2),
       sched_yield(2), security, select(2), sendfile(2), send(2),  sendmsg(2),
       sendto(2), setdomainname(2), setfsgid(2), setfsgid32, setfsuid(2), set-
       fsuid32,   setgid(2),   setgid32,   setgroups(2),   setgroups32,   set-
       hostname(2),  setitimer(2),  setpgid(2),  setpriority(2),  setregid(2),
       setregid32, setresgid(2), setresgid32, setresuid(2), setresuid32,  set-
       reuid(2),  setreuid32,  setrlimit(2),  setsid(2),  setsockopt(2),  set-
       timeofday(2), setuid(2), setuid32, setup(2), sgetmask(2),  shutdown(2),
       sigaction(2), sigaltstack(2), signal(2), sigpending(2), sigprocmask(2),
       sigreturn(2), sigsuspend(2), socket(2),  socketcall(2),  socketpair(2),
       ssetmask(2),  stat(2),  stat64,  statfs(2), stime(2), stty, swapoff(2),
       swapon(2),  symlink(2),  sync(2),  sysfs(2),   sysinfo(2),   syslog(2),
       time(2),   times(2),   truncate(2),   truncate64,   ulimit,   umask(2),
       umount(2),  uname(2),   unlink(2),   uselib(2),   ustat(2),   utime(2),
       vfork(2), vhangup(2), vm86(2), vm86old, wait4(2), waitpid(2), write(2),

       Of the above, 9 are obsolete,  namely  getrlimit,  oldfstat,  oldlstat,
       oldolduname,  oldstat,  olduname, readdir, select and vm86old (see also
       obsolete(2)), and 15 are unimplemented in the standard  kernel,  namely
       afs_syscall,  break, ftime, getpmsg, gtty, idle, lock, mpx, phys, prof,
       profil, putpmsg, security, stty and ulimit (see also unimplemented(2)).
       However,  ftime(3),  profil(3) and ulimit(3) exist as library routines.
       The slot for phys is in use since 2.1.116 for umount; phys  will  never
       be  implemented.  The getpmsg and putpmsg calls are for kernels patched
       to support streams, and may never be in the standard kernel. The  secu-
       rity call is for future use.

       Roughly  speaking,  the  code  belonging to the system call with number
       __NR_xxx defined in /usr/include/asm/unistd.h can be found in the  ker-
       nel  source in the routine sys_xxx().  (The dispatch table for i386 can
       be found in /usr/src/linux/arch/i386/kernel/entry.S.)  There  are  many
       exceptions,  however, mostly because older system calls were superseded
       by newer ones, and this has been treated somewhat unsystematically.  On
       platforms with proprietary OS emulation, such as parisc, sparc, sparc64
       and alpha, there are many additional system calls; mips64 also contains
       a full set of 32-bit system calls.  Below the details for Linux 2.4.17.

       The defines __NR_oldstat and __NR_stat refer to the routines sys_stat()
       and  sys_newstat(),  and similarly for fstat and lstat.  Similarly, the
       defines __NR_oldolduname, __NR_olduname and  __NR_uname  refer  to  the
       routines   sys_olduname(),   sys_uname()   and  sys_newuname().   Thus,
       __NR_stat and __NR_uname have always referred to the latest version  of
       the system call, and the older ones are for backward compatibility.

       It  is  different with select and mmap.  These use five or more parame-
       ters, and caused problems the way parameter passing on the i386 used to
       be  set  up.  Thus,  while  other  architectures  have sys_select() and
       sys_mmap() corresponding to __NR_select  and  __NR_mmap,  on  i386  one
       finds  old_select()  and  old_mmap()  (routines that use a pointer to a
       parameter block) instead. These days passing five parameters is  not  a
       problem  any more, and there is a __NR__newselect (used by libc 6) that
       corresponds directly to sys_select() and similarly __NR_mmap2.

       Two other system call numbers, __NR__llseek and  __NR__sysctl  have  an
       additional underscore absent in sys_llseek() and sys_sysctl().

       Then  there  is __NR_readdir corresponding to old_readdir(), which will
       read at most one directory entry  at  a  time,  and  is  superseded  by

       On  many  platforms,  including  i386, socket calls are all multiplexed
       through socketcall() and System V IPC calls through ipc().

       On newer platforms that only have 64-bit file access  and  32-bit  uids
       (e.g.  alpha, ia64, s390x) there are no *64 or *32 calls. Where the *64
       and *32 calls exist, the other versions are obsolete.

       The chown and lchown system calls were swapped in 2.1.81. The  *64  and
       *32  calls were added for kernel 2.4, as were the new versions of getr-
       limit and mmap, and the new calls pivot_root, mincore,  madvise,  secu-
       rity, gettid and readahead.

Linux 2.4                         2002-01-07                       SYSCALLS(2)