List of Linux/i386 system calls

Copyright (C) 1999-2000 by Konstantin Boldyshev

This list is NOT READY and is under heavy construction, a lot of entries are missing, and some may be incorrect. This is more a template than a real document. Meanwhile, I suggest you to examine this list by H-Peter Recktenwald.

Table of Contents (template)

2.1 What is system call?
2.2 View from the Kernel side
2.3 View from the userland
2.4 Using system calls

3.1 Complete list of system calls with description
3.2 List by system call number
3.3 List by system call name
3.4 List by kernel source

1. Introduction

First of all note that these are not libc "system calls", but real system calls provided by Linux Kernel.

List is intended to cover Linux 2.4 / 2.2 / 2.0.

2. System call in depth

.. not ready yet ..

3. Linux/i386 system calls

All system calls introduced/removed in specific Linux version are marked with (VER+/-) label (f.e. 2.2+ means that this call was introduced in Linux 2.2, and is missing in Linux 2.0). Square brackets hold real kernel name of system call from arch/i386/kernel/entry.S (as appeared in Syntax), if it differs from "official" in include/asm-i386/unistd.h.

Complete list of system calls with description

0. sys_setup

Syntax: int sys_setup(void)

Source: fs/filesystems.c

Action: return -ENOSYS on Linux 2.2

Details: old sys_setup call

1. sys_exit

Syntax: int sys_exit(int status)

Source: kernel/exit.c

Action: terminate the current process

Details: status is return code

2. sys_fork

Syntax: int sys_fork()

Source: arch/i386/kernel/process.c

Action: create a child process

Details:

3. sys_read

Syntax: ssize_t sys_read(unsigned int fd, char * buf, size_t count)

Source: fs/read_write.c

Action: read from a file descriptor

Details:

4. sys_write

Syntax: ssize_t sys_write(unsigned int fd, const char * buf, size_t count)

Source: fs/read_write.c

Action: write to a file descriptor

Details:

5. sys_open

Syntax: int sys_open(const char * filename, int flags, int mode)

Source: fs/open.c

Action: open and possibly create a file or device

Details:

6. sys_close

Syntax: sys_close(unsigned int fd)

Source: fs/open.c

Action: close a file descriptor

Details:

7. sys_waitpid

Syntax: int sys_waitpid(pid_t pid,unsigned int * stat_addr, int options)

Source: kernel/exit.c

Action: wait for process termination

Details:

8. sys_creat

Syntax: int sys_creat(const char * pathname, int mode)

Source: fs/open.c

Action: create a file or device

Details:

9. sys_link

Syntax: int sys_link(const char * oldname, const char * newname)

Source: fs/namei.c

Action: make a new name for a file

Details:

10. sys_unlink

Syntax: int sys_unlink(const char * pathname)

Source: fs/namei.c

Action: delete a name and possibly the file it refers to

Details:

11. sys_execve

Syntax: int sys_execve(struct pt_regs regs)

Source: arch/i386/kernel/process.c

Action: execute program

Details:

12. sys_chdir

Syntax: int sys_chdir(const char * filename)

Source: fs/open.c

Action: change working directory

Details:

13. sys_time

Syntax: int sys_time(int * tloc)

Source: kernel/time.c

Action: get time in seconds

Details:

14. sys_mknod

Syntax: int sys_mknod(const char * filename, int mode, dev_t dev)

Source: fs/namei.c

Action: create a directory or special or ordinary file

Details:

15. sys_chmod

Syntax: int sys_chmod(const char * filename, mode_t mode)

Source: fs/open.c

Action: change permissions of a file

Details:

16. sys_lchown

Syntax: int sys_lchown(const char * filename, uid_t user, gid_t group)

Source: fs/open.c

Action: change ownership of a file

Details:

17. sys_break

Syntax: int sys_break()

Source: kernel/sys.c

Action: return -ENOSYS

Details: call exists only for compatibility

18. sys_oldstat

Syntax: int sys_stat(char * filename, struct __old_kernel_stat * statbuf)

Source: fs/stat.c

Action:

Details: obsolote

19. sys_lseek

Syntax: off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin)

Source: fs/read_write.c

Action: reposition read/write file offset

Details:

20. sys_getpid

Syntax: int sys_getpid(void)

Source: kernel/sched.c

Action: get process identification

Details:

21. sys_mount

Syntax: int sys_mount(char * dev_name, char * dir_name, char * type, unsigned long new_flags, void * data)

Source: fs/super.c

Action: mount filesystems

Details:

22. sys_umount

Syntax: int sys_oldumount(char * name)

Source: fs/super.c

Action: unmount filesystem

Details:

23. sys_setuid

Syntax: int sys_setuid(uid_t uid)

Source: kernel/sys.c

Action: set user identity

Details:

24. sys_getuid

Syntax: int sys_getuid(void)

Source: kernel/sys.c

Action: get user identity

Details:

25. sys_stime

Syntax: int sys_stime(int * tptr)

Source: kernel/time.c

Action: set time

Details:

26. sys_ptrace

Syntax: int sys_ptrace(long request, long pid, long addr, long data)

Source: arch/i386/kernel/ptrace.c

Action: process trace

Details:

27. sys_alarm

Syntax: unsigned int sys_alarm(unsigned int seconds)

Source: kernel/sched.c

Action: set an alarm clock for delivery of a signal

Details:

28. sys_oldfstat

Syntax: int sys_fstat(unsigned int fd, struct __old_kernel_stat * statbuf)

Source: fs/stat.c

Action:

Details: obsolete

29. sys_pause

Syntax: int sys_pause(void)

Source: arch/i386/kernel/sys_i386.c

Action: wait for signal

Details:

30. sys_utime

Syntax: int sys_utime(char * filename, struct utimbuf * times)

Source: fs/open.c

Action: change access and/or modification times of an inode

Details:

...

List by system call number

List by system call name

.. not ready yet ..

List by kernel source

arch/i386/ (23) fs/ (62) ipc/ (11) kernel/ (81) mm/ (12) net/ (1)

arch/i386/

arch/i386/kernel/sys_i386.c

int sys_pipe(unsigned long * fildes)
int sys_ipc (uint call, int first, int second, int third, void *ptr, long fifth)
int sys_uname(struct old_utsname * name)
int sys_olduname(struct oldold_utsname * name)
int sys_pause(void)
int old_mmap(struct mmap_arg_struct *arg)

arch/i386/kernel/ioport.c

int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
int sys_iopl(unsigned long unused)

arch/i386/kernel/process.c

int sys_idle(void)
int sys_fork(struct pt_regs regs)
int sys_clone(struct pt_regs regs)
int sys_vfork(struct pt_regs regs)
int sys_execve(struct pt_regs regs)

arch/i386/kernel/vm86.c

int sys_vm86old(struct vm86_struct * v86)
int sys_vm86(unsigned long subfunction, struct vm86plus_struct * v86)

arch/i386/kernel/ptrace.c

int sys_ptrace(long request, long pid, long addr, long data)

arch/i386/kernel/signal.c

int sys_sigsuspend(int history0, int history1, old_sigset_t mask)
int sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize)
int sys_sigaction(int sig, const struct old_sigaction *act, struct old_sigaction *oact)
int sys_sigaltstack(const stack_t *uss, stack_t *uoss)
int sys_sigreturn(unsigned long __unused)
int sys_rt_sigreturn(unsigned long __unused)

arch/i386/kernel/ldt.c

int sys_modify_ldt(int func, void *ptr, unsigned long bytecount)

fs/

fs/stat.c

int sys_stat(char * filename, struct __old_kernel_stat * statbuf)
int sys_newstat(char * filename, struct stat * statbuf)
int sys_lstat(char * filename, struct __old_kernel_stat * statbuf)
int sys_newlstat(char * filename, struct stat * statbuf)
int sys_fstat(unsigned int fd, struct __old_kernel_stat * statbuf)
int sys_newfstat(unsigned int fd, struct stat * statbuf)
int sys_readlink(const char * path, char * buf, int bufsiz)

fs/read_write.c

off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin)
int sys_llseek(unsigned int fd, unsigned long offset_high, unsigned long offset_low, loff_t * result, unsigned int origin)
ssize_t sys_read(unsigned int fd, char * buf, size_t count)
ssize_t sys_write(unsigned int fd, const char * buf, size_t count)
ssize_t sys_readv(unsigned long fd, const struct iovec * vector, unsigned long count)
ssize_t sys_writev(unsigned long fd, const struct iovec * vector, unsigned long count)
ssize_t sys_pread(unsigned int fd, char * buf, size_t count, loff_t pos)
ssize_t sys_pwrite(unsigned int fd, const char * buf, size_t count, loff_t pos)

fs/buffer.c

int sys_sync(void)
int sys_fsync(unsigned int fd)
int sys_fdatasync(unsigned int fd)
int sys_bdflush(int func, long data)

fs/open.c

int sys_statfs(const char * path, struct statfs * buf)
int sys_fstatfs(unsigned int fd, struct statfs * buf)
int sys_truncate(const char * path, unsigned long length)
int sys_ftruncate(unsigned int fd, unsigned long length)
int sys_utime(char * filename, struct utimbuf * times)
int sys_utimes(char * filename, struct timeval * utimes)
int sys_access(const char * filename, int mode)
int sys_chdir(const char * filename)
int sys_fchdir(unsigned int fd)
int sys_chroot(const char * filename)
int sys_fchmod(unsigned int fd, mode_t mode)
int sys_chmod(const char * filename, mode_t mode)
int sys_chown(const char * filename, uid_t user, gid_t group)
int sys_lchown(const char * filename, uid_t user, gid_t group)
int sys_fchown(unsigned int fd, uid_t user, gid_t group)
int sys_open(const char * filename, int flags, int mode)
int sys_creat(const char * pathname, int mode)
int sys_close(unsigned int fd)
int sys_vhangup(void)

fs/exec.c

int sys_uselib(const char * library)

fs/super.c

int sys_sysfs(int option, unsigned long arg1, unsigned long arg2)
int sys_ustat(dev_t dev, struct ustat * ubuf)
int sys_umount(char * name, int flags)
int sys_oldumount(char * name)
int sys_mount(char * dev_name, char * dir_name, char * type, unsigned long new_flags, void * data)

fs/fcntl.c

int sys_dup2(unsigned int oldfd, unsigned int newfd)
int sys_dup(unsigned int fildes)
long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)

fs/namei.c

int sys_mknod(const char * filename, int mode, dev_t dev)
int sys_mkdir(const char * pathname, int mode)
int sys_rmdir(const char * pathname)
int sys_unlink(const char * pathname)
int sys_symlink(const char * oldname, const char * newname)
int sys_link(const char * oldname, const char * newname)
int sys_rename(const char * oldname, const char * newname)

fs/ioctl.c

int sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)

fs/select.c

int sys_select(int n, fd_set *inp, fd_set *outp, fd_set *exp, struct timeval *tvp)
int sys_poll(struct pollfd * ufds, unsigned int nfds, long timeout)

fs/locks.c

int sys_flock(unsigned int fd, unsigned int cmd)

fs/filesystems.c

int sys_nfsservctl(int cmd, void *argp, void *resp) [fs/nfsd/nfsctl.c]

fs/dquot.c

int sys_quotactl(int cmd, const char *special, int id, caddr_t addr)

fs/dcache.c

int sys_getcwd(char *buf, unsigned long size)

fs/readdir.c

int sys_getdents(unsigned int fd, void * dirent, unsigned int count)

ipc/

ipc/msg.c

int sys_msgsnd (int msqid, struct msgbuf *msgp, size_t msgsz, int msgflg)
int sys_msgrcv (int msqid, struct msgbuf *msgp, size_t msgsz, long msgtyp, int msgflg)
int sys_msgget (key_t key, int msgflg)
int sys_msgctl (int msqid, int cmd, struct msqid_ds *buf)

ipc/sem.c

int sys_semget (key_t key, int nsems, int semflg)
int sys_semctl (int semid, int semnum, int cmd, union semun arg)
int sys_semop (int semid, struct sembuf *tsops, unsigned nsops)

ipc/shm.c

int sys_shmget (key_t key, int size, int shmflg)
int sys_shmctl (int shmid, int cmd, struct shmid_ds *buf)
int sys_shmat (int shmid, char *shmaddr, int shmflg, ulong *raddr)
int sys_shmdt (char *shmaddr)

kernel/

kernel/sched.c

unsigned int sys_alarm(unsigned int seconds)
int sys_getpid(void)
int sys_getppid(void)
int sys_getuid(void)
int sys_geteuid(void)
int sys_getgid(void)
int sys_getegid(void)
int sys_nice(int increment)
int sys_sched_setscheduler(pid_t pid, int policy, struct sched_param *param)
int sys_sched_setparam(pid_t pid, struct sched_param *param)
int sys_sched_getscheduler(pid_t pid)
int sys_sched_getparam(pid_t pid, struct sched_param *param)
int sys_sched_yield(void)
int sys_sched_get_priority_max(int policy)
int sys_sched_get_priority_min(int policy)
int sys_sched_rr_get_interval(pid_t pid, struct timespec *interval)
int sys_nanosleep(struct timespec *rqtp, struct timespec *rmtp)

kernel/exit.c

int sys_exit(int error_code)
int sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
int sys_waitpid(pid_t pid,unsigned int * stat_addr, int options)

kernel/signal.c

int sys_rt_sigprocmask(int how, sigset_t *set, sigset_t *oset, size_t sigsetsize)
int sys_rt_sigpending(sigset_t *set, size_t sigsetsize)
int sys_rt_sigtimedwait(const sigset_t *uthese, siginfo_t *uinfo, const struct timespec *uts, size_t sigsetsize)
int sys_kill(int pid, int sig)
int sys_rt_sigqueueinfo(int pid, int sig, siginfo_t *uinfo)
int sys_sigprocmask(int how, old_sigset_t *set, old_sigset_t *oset)
int sys_sigpending(old_sigset_t *set)
int sys_rt_sigaction(int sig, const struct sigaction *act, struct sigaction *oact, size_t sigsetsize)
int sys_sgetmask(void)
int sys_ssetmask(int newmask)
unsigned long sys_signal(int sig, __sighandler_t handler)

kernel/printk.c

int sys_syslog(int type, char * buf, int len)

kernel/sys.c

int sys_ni_syscall(void)
int sys_setpriority(int which, int who, int niceval)
int sys_getpriority(int which, int who)
int sys_reboot(int magic1, int magic2, int cmd, void * arg)
int sys_setregid(gid_t rgid, gid_t egid)
int sys_setgid(gid_t gid)
int sys_setreuid(uid_t ruid, uid_t euid)
int sys_setuid(uid_t uid)
int sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
int sys_getresuid(uid_t *ruid, uid_t *euid, uid_t *suid)
int sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
int sys_getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid)
int sys_setfsuid(uid_t uid)
long sys_times(struct tms * tbuf)
int sys_setpgid(pid_t pid, pid_t pgid)
int sys_getpgid(pid_t pid)
int sys_getpgrp(void)
int sys_getsid(pid_t pid)
int sys_setsid(void)
int sys_getgroups(int gidsetsize, gid_t *grouplist)
int sys_setgroups(int gidsetsize, gid_t *grouplist)
int sys_newuname(struct new_utsname * name)
int sys_sethostname(char *name, int len)
int sys_gethostname(char *name, int len)
int sys_setdomainname(char *name, int len)
int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
int sys_setrlimit(unsigned int resource, struct rlimit *rlim)
int sys_getrusage(int who, struct rusage *ru)
int sys_umask(int mask)
int sys_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5)

kernel/module.c

unsigned long sys_create_module(const char *name_user, size_t size)
int sys_init_module(const char *name_user, struct module *mod_user)
int sys_delete_module(const char *name_user)
int sys_query_module(const char *name_user, int which, char *buf, size_t bufsize, size_t *ret)
int sys_get_kernel_syms(struct kernel_sym *table)
unsigned long sys_create_module(const char *name_user, size_t size)

kernel/itimer.c

int sys_getitimer(int which, struct itimerval *value)
int sys_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)

kernel/info.c

int sys_sysinfo(struct sysinfo *info)

kernel/time.c

int sys_time(int * tloc)
int sys_stime(int * tptr)
int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
int sys_settimeofday(struct timeval *tv, struct timezone *tz)
int sys_adjtimex(struct timex *txc_p)

kernel/exec_domain.c

int sys_adjtimex(struct timex *txc_p)

kernel/sysctl.c

int sys_sysctl(struct __sysctl_args *args)

kernel/acct.c

int sys_acct(const char *name)

kernel/capability.c

int sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
int sys_capset(cap_user_header_t header, const cap_user_data_t data)

mm/

mm/mmap.c

unsigned long sys_brk(unsigned long brk)
int sys_munmap(unsigned long addr, size_t len)

mm/mprotect.c

int sys_mprotect(unsigned long start, size_t len, unsigned long prot)

mm/filemap.c

ssize_t sys_sendfile(int out_fd, int in_fd, off_t *offset, size_t count)
int sys_msync(unsigned long start, size_t len, int flags)

mm/mlock.c

int sys_mlock(unsigned long start, size_t len)
int sys_munlock(unsigned long start, size_t len)
int sys_mlockall(int flags)
int sys_munlockall(void)

mm/swapfile.c

int sys_swapoff(const char * specialfile)
int sys_swapon(const char * specialfile, int swap_flags)

mm/mremap.c

unsigned long sys_mremap(unsigned long addr, unsigned long old_len, unsigned long new_len, unsigned long flags)

net/

net/socket.c

int sys_socketcall(int call, unsigned long *args)

 int sys_socket(int family, int type, int protocol)
 int sys_socketpair(int family, int type, int protocol, int usockvec[2])
 int sys_bind(int fd, struct sockaddr *umyaddr, int addrlen)
 int sys_listen(int fd, int backlog)
 int sys_accept(int fd, struct sockaddr *upeer_sockaddr, int *upeer_addrlen)
 int sys_connect(int fd, struct sockaddr *uservaddr, int addrlen)
 int sys_getsockname(int fd, struct sockaddr *usockaddr, int *usockaddr_len)
 int sys_getpeername(int fd, struct sockaddr *usockaddr, int *usockaddr_len)
 int sys_sendto(int fd, void * buff, size_t len, unsigned flags, struct sockaddr *addr, int addr_len)
 int sys_send(int fd, void * buff, size_t len, unsigned flags)
 int sys_recvfrom(int fd, void * ubuf, size_t size, unsigned flags, struct sockaddr *addr, int *addr_len)
 int sys_recv(int fd, void * ubuf, size_t size, unsigned flags)
 int sys_setsockopt(int fd, int level, int optname, char *optval, int optlen)
 int sys_getsockopt(int fd, int level, int optname, char *optval, int *optlen)
 int sys_shutdown(int fd, int how)
 int sys_sendmsg(int fd, struct msghdr *msg, unsigned flags)
 int sys_recvmsg(int fd, struct msghdr *msg, unsigned int flags)

References

Sources of information (except other directly pointed):

include/asm-i386/unistd.h
arch/i386/kernel/entry.S
include/linux/sys.h