The Linux Kernel/Syscalls

__NOTOC__ Linux kernel system calls as exported by glibc, all on one sheet System sys/ioctl.h: ioctl sys/random.h: getrandom pci.h: pciconfig_read pciconfig_write linux/sysctl.h: sysctl linux/membarrier.h: membarrier sys/klog.h: syslog linux/bpf.h: bpf grp.h: setgroups sys/utsname.h: uname linux/getcpu.h: getcpu sys/sysinfo.h: sysinfo sys/personality.h: personality sys/ptrace.h: ptrace linux/kexec.h: kexec_file_load kexec_load linux/reboot.h: reboot Unexported: delete_module init_module finit_module perf_event_open rseq Time sys/time.h: futimesat utimes gettimeofday settimeofday getitimer, setitimer time.h: clock_settime clock_gettime clock_getres clock_nanosleep time stime nanosleep posix-timers.c: timer_create timer_gettime timer_getoverrun timer_settime timer_delete sys/timerfd.h: timerfd_create timerfd_settime timerfd_gettime sys/eventfd.h: eventfd2 eventfd utime.h: utime sys/times.h: times bits/time.h: clock_adjtime sys/timex.h: adjtimex Processes unistd.h: fork, vfork brk getpid, getppid, getpgrp uselib execve, execveat nice getgroups getgid, setgid getuid, setuid getresuid, setresuid getresgid, setresgid getsid, setsid setpgid, getpgid getegid, geteuid setreuid, setregid pause alarm acct sys/prctl.h: prctl sched.h: clone sched_setscheduler sched_setparam sched_setattr sched_getscheduler sched_getparam sched_getattr sched_setaffinity sched_getaffinity sched_yield sched_get_priority_max sched_get_priority_min sched_rr_get_interval unshare setns linux/unistd.h: set_tid_address exit_group sys/resource.h: setpriority, getpriority getrlimit setrlimit getrusage gettid linux/kcmp.h: kcmp sys/capability.h: capget, capset stdlib.h: exit Synchronization sys/sem.h: semget semctl semtimedop semop mqueue.h: mq_open mq_unlink mq_timedsend mq_timedreceive mq_notify sys/msg.h: msgget msgctl msgsnd msgrcv sys/wait.h: waitid wait4 waitpid sys/signalfd.h: signalfd4 signalfd signal.h: kill sigtimedwait sigaltstack sigpending sigprocmask sigaction signal sigsuspend Unexported: futex set_robust_list get_robust_list restart_syscall tgkill rt_sigqueueinfo rt_tgsigqueueinfo mq_getsetattr Memory numaif.h: mbind set_mempolicy migrate_pages get_mempolicy numaif.h: move_pages sys/mman.h: msync mincore munmap remap_file_pages mremap mlock, mlock2 munlockmlockall munlockall mprotect pkey_mprotect pkey_alloc pkey_free madvise sys/shm.h: shmget, shmctl shmat, shmdt sys/swap.h: swapoff, swapon sys/memfd.h: memfd_create Security sys/fsuid.h: setfsuid setfsgid keyutils.h: add_key request_key keyctl Unexported: seccomp Metadata sys/stat.h: stat sys/statfs.h: statfs fstatfs sys/inotify.h: inotify_init1 inotify_init inotify_add_watch inotify_rm_watch sys/fanotify.h: fanotify_init fanotify_mark sys/xattr.h: setxattr lsetxattr fsetxattr getxattr lgetxattr fgetxattr listxattr llistxattr flistxattr removexattr lremovexattr fremovexattr sys/quota.h: quotactl stdio.h: renameat rename Unexported: statx io_getevents io_pgetevents fsopen fspick lookup_dcookie renameat2 fsinfo open_tree fsmount move_mount pivot_root getdents vmsplice name_to_handle_at open_by_handle_at pselect6 userfaultfd mmap_pgoff ioprio_set ioprio_get Data fcntl.h: open, openat fcntl sync_file_range fallocate creat splice tee readahead unistd.h: truncate, ftruncate faccessat, access fchdir, chdir chroot fchownat, chown lchown, fchown close vhangup pipe, pipe2 sync, syncfs fsync, fdatasync dup, dup2, dup3 lseek read, write copy_file_range sys/uio.h: readv, writev preadv, pwritev preadv2, pwritev2 process_vm_readv process_vm_writev sys/file.h: flock sys/mount.h: mount, umount Nonblocking IO sys/epoll.h: epoll_create1 epoll_create epoll_ctl epoll_wait epoll_pwait sys/select.h: select poll.h: poll, ppoll linux/aio_abi.h: io_setup io_destroy io_submit io_cancel Network sys/socket.h: socket, socketpair bind listen accept, accept4 connect getsockname getpeername send, recv sendto, recvfrom setsockopt, getsockopt shutdown sendmsg, sendmmsg recvmsg, recvmmsg linux/net.h: socketcall sys/sendfile.h: sendfile unistd.h: sethostname gethostname setdomainname Obsolete: ipc, sgetmask, ssetmask, sysfs Descriptions acceptaccept, accept4accept4 - accept a connection on a socket accessaccess, faccessatfaccessat - check user's permissions for a file acctacct - switch process accounting on or off add_keyadd_key - add a key to the kernel's key management facility adjtimexadjtimex, ntp_adjtimentp_adjtime - tune kernel clock afs_syscall, break, fattach, fdetach, ftime, getmsg, getpmsg, gtty, isastream, lock, madvise1, mpx, prof, profil, putmsg, putpmsg, security, stty, tuxcall, ulimit, vserver - unimplemented system calls alarmalarm - set an alarm clock for delivery of a signal alloc_hugepagesalloc_hugepages, free_hugepagesfree_hugepages - allocate or free huge pages arch_prctlarch_prctl - set architecture-specific thread state bdflushbdflush - start, flush, or tune buffer-dirty-flush daemon bindbind - bind a name to a socket bpfbpf - perform a command on an extended BPF map or program brkbrk, sbrksbrk - change data segment size cacheflushcacheflush - flush contents of instruction and/or data cache capgetcapget, capsetcapset - set/get capabilities of thread(s) chdirchdir, fchdirfchdir - change working directory chmodchmod, fchmod, fchmodatfchmodat - change permissions of a file chownchown, fchown, lchown, fchownatfchownat - change ownership of a file chrootchroot - change root directory clock_getresclock_getres, clock_gettime, clock_settimeclock_settime - clock and time functions clock_nanosleepclock_nanosleep - high-resolution sleep with specifiable clock cloneclone, __clone2__clone2 - create a child process closeclose - close a file descriptor connectconnect - initiate a connection on a socket copy_file_rangecopy_file_range - Copy a range of data from one file to another create_modulecreate_module - create a loadable module entry delete_moduledelete_module - unload a kernel module dupdup, dup2, dup3dup3 - duplicate a file descriptor epoll_createepoll_create, epoll_create1epoll_create1 - open an epoll file descriptor epoll_ctlepoll_ctl - control interface for an epoll file descriptor epoll_waitepoll_wait, epoll_pwaitepoll_pwait - wait for an I/O event on an epoll file descriptor eventfdeventfd - create a file descriptor for event notification execveatexecveat - execute program relative to a directory file descriptor execveexecve - execute program _exit_exit, _Exit_Exit - terminate the calling process exit_groupexit_group - exit all threads in a process fallocatefallocate - manipulate file space fanotify_initfanotify_init - create and initialize fanotify group fanotify_markfanotify_mark - add, remove, or modify an fanotify mark on a filesystem object fcntlfcntl - manipulate file descriptor flockflock - apply or remove an advisory lock on an open file forkfork - create a child process fsyncfsync, fdatasyncfdatasync - synchronize a file's in-core state with storage device futexfutex - fast user-space locking futimesatfutimesat - change timestamps of a file relative to a directory file descriptor getcontextgetcontext, setcontextsetcontext - get or set the user context getcpugetcpu - determine CPU and NUMA node on which the calling thread is running getcwdgetcwd, getwd, get_current_dir_nameget_current_dir_name - get current working directory getdentsgetdents, getdents64getdents64 - get directory entries getdomainnamegetdomainname, setdomainnamesetdomainname - get/set NIS domain name getdtablesizegetdtablesize - get file descriptor table size getgidgetgid, getegidgetegid - get group identity getgroupsgetgroups, setgroupssetgroups - get/set list of supplementary group IDs gethostidgethostid, sethostidsethostid - get or set the unique identifier of the current host gethostnamegethostname, sethostnamesethostname - get/set hostname getitimergetitimer, setitimersetitimer - get or set value of an interval timer get_kernel_symsget_kernel_syms - retrieve exported kernel and module symbols get_mempolicyget_mempolicy - retrieve NUMA memory policy for a thread getpagesizegetpagesize - get memory page size getpeernamegetpeername - get name of connected peer socket getpidgetpid, getppidgetppid - get process identification getprioritygetpriority, setprioritysetpriority - get/set program scheduling priority getrandomgetrandom - obtain a series of random bytes getresuidgetresuid, getresgidgetresgid - get real, effective and saved user/group IDs getrlimitgetrlimit, setrlimit, prlimitprlimit - get/set resource limits get_robust_listget_robust_list, set_robust_listset_robust_list - get/set list of robust futexes getrusagegetrusage - get resource usage getsidgetsid - get session ID getsocknamegetsockname - get socket name getsockoptgetsockopt, setsockoptsetsockopt - get and set options on sockets get_thread_areaget_thread_area, set_thread_areaset_thread_area - set a GDT entry for thread-local storage gettidgettid - get thread identification gettimeofdaygettimeofday, settimeofdaysettimeofday - get / set time getuidgetuid, geteuidgeteuid - get user identity getunwindgetunwind - copy the unwind data to caller's buffer idleidle - make process 0 idle init_moduleinit_module, finit_modulefinit_module - load a kernel module inotify_add_watchinotify_add_watch - add a watch to an initialized inotify instance inotify_initinotify_init, inotify_init1inotify_init1 - initialize an inotify instance inotify_rm_watchinotify_rm_watch - remove an existing watch from an inotify instance introintro - introduction to system calls io_cancelio_cancel - cancel an outstanding asynchronous I/O operation ioctl_consoleioctl_console - ioctls for console terminal and virtual consoles ioctlioctl - control device ioctl_fatioctl_fat - manipulating the FAT filesystem ioctl_ficlonerangeioctl_ficlonerange, ioctl_ficloneioctl_ficlone - share some the data of one file with another file ioctl_fideduperangeioctl_fideduperange - share some the data of one file with another file ioctl_getfsmapioctl_getfsmap - retrieve the physical layout of the filesystem ioctl_iflagsioctl_iflags - ioctl() operations for inode flags ioctl_listioctl_list - list of ioctl calls in Linux/i386 kernel ioctl_nsioctl_ns - ioctl() operations for Linux namespaces ioctl_ttyioctl_tty - ioctls for terminals and serial lines ioctl_userfaultfdioctl_userfaultfd - create a file descriptor for handling page faults in user space io_destroyio_destroy - destroy an asynchronous I/O context io_geteventsio_getevents - read asynchronous I/O events from the completion queue iopermioperm - set port input/output permissions iopliopl - change I/O privilege level ioprio_getioprio_get, ioprio_setioprio_set - get/set I/O scheduling class and priority io_setupio_setup - create an asynchronous I/O context io_submitio_submit - submit asynchronous I/O blocks for processing ipcipc - System V IPC system calls kcmpkcmp - compare two processes to determine if they share a kernel resource kexec_loadkexec_load, kexec_file_loadkexec_file_load - load a new kernel for later execution keyctlkeyctl - manipulate the kernel's key management facility killpgkillpg - send signal to a process group killkill - send signal to a process linklink, linkatlinkat - make a new name for a file listenlisten - listen for connections on a socket _llseek_llseek - reposition read/write file offset lookup_dcookielookup_dcookie - return a directory entry's path lseeklseek - reposition read/write file offset madvisemadvise - give advice about use of memory mbindmbind - set memory policy for a memory range membarriermembarrier - issue memory barriers on a set of threads memfd_creatememfd_create - create an anonymous file migrate_pagesmigrate_pages - move all pages in a process to another set of nodes mincoremincore - determine whether pages are resident in memory mkdirmkdir, mkdiratmkdirat - create a directory mknodmknod, mknodatmknodat - create a special or ordinary file mlockmlock, mlock2, munlock, mlockall, munlockallmunlockall - lock and unlock memory mmap2mmap2 - map files or devices into memory mmapmmap, munmapmunmap - map or unmap files or devices into memory modify_ldtmodify_ldt - get or set a per-process LDT entry mountmount - mount filesystem move_pagesmove_pages - move individual pages of a process to another node mprotectmprotect, pkey_mprotectpkey_mprotect - set protection on a region of memory mq_getsetattrmq_getsetattr - get/set message queue attributes mq_notifymq_notify - register for notification when a message is available mq_openmq_open - open a message queue mq_receivemq_receive, mq_timedreceivemq_timedreceive - receive a message from a message queue mq_sendmq_send, mq_timedsendmq_timedsend - send a message to a message queue mq_unlinkmq_unlink - remove a message queue mremapmremap - remap a virtual memory address msgctlmsgctl - System V message control operations msggetmsgget - get a System V message queue identifier msgrcvmsgrcv, msgsndmsgsnd - System V message queue operations msyncmsync - synchronize a file with a memory map name_to_handle_atname_to_handle_at, open_by_handle_atopen_by_handle_at - obtain handle for a pathname and open file via a handle nanosleepnanosleep - high-resolution sleep nfsservctlnfsservctl - syscall interface to kernel nfs daemon nicenice - change process priority openopen, openat, creatcreat - open and possibly create a file outboutb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_pinl_p - port I/O pausepause - wait for signal pciconfig_readpciconfig_read, pciconfig_write, pciconfig_iobasepciconfig_iobase - pci device information handling perf_event_openperf_event_open - set up performance monitoring perfmonctlperfmonctl - interface to IA-64 performance monitoring unit personalitypersonality - set the process execution domain pipepipe, pipe2pipe2 - create pipe pivot_rootpivot_root - change the root filesystem pkey_allocpkey_alloc, pkey_freepkey_free - allocate or free a protection key pollpoll, ppollppoll - wait for some event on a file descriptor posix_fadviseposix_fadvise - predeclare an access pattern for file data prctlprctl - operations on a process preadpread, pwritepwrite - read from or write to a file descriptor at a given offset process_vm_readvprocess_vm_readv, process_vm_writevprocess_vm_writev - transfer data between process address spaces ptraceptrace - process trace query_modulequery_module - query the kernel for various bits pertaining to modules quotactlquotactl - manipulate disk quotas readaheadreadahead - initiate file readahead into page cache readdirreaddir - read directory entry readlinkreadlink, readlinkatreadlinkat - read value of a symbolic link readread - read from a file descriptor readvreadv, writev, preadv, pwritev, preadv2, pwritev2pwritev2 - read or write data into multiple buffers rebootreboot - reboot or enable/disable Ctrl-Alt-Del recvmmsgrecvmmsg - receive multiple messages on a socket recvrecv, recvfrom, recvmsgrecvmsg - receive a message from a socket remap_file_pagesremap_file_pages - create a nonlinear file mapping renamerename, renameat, renameat2renameat2 - change the name or location of a file request_keyrequest_key - request a key from the kernel's key management facility restart_syscallrestart_syscall - restart a system call after interruption by a stop signal rmdirrmdir - delete a directory rt_sigqueueinfort_sigqueueinfo, rt_tgsigqueueinfort_tgsigqueueinfo - queue a signal and data s390_pci_mmio_writes390_pci_mmio_write, s390_pci_mmio_reads390_pci_mmio_read - transfer data to/from PCI MMIO memory page s390_runtime_instrs390_runtime_instr - enable/disable s390 CPU run-time instrumentation s390_sthyis390_sthyi - emulate STHYI instruction sched_get_priority_maxsched_get_priority_max, sched_get_priority_min - get static priority range sched_rr_get_intervalsched_rr_get_interval - get the SCHED_RR interval for the named process sched_setaffinitysched_setaffinity, sched_getaffinitysched_getaffinity - set and get a thread's CPU affinity mask sched_setattrsched_setattr, sched_getattrsched_getattr - set and get scheduling policy and attributes sched_setparamsched_setparam, sched_getparamsched_getparam - set and get scheduling parameters sched_setschedulersched_setscheduler, sched_getschedulersched_getscheduler - set and get scheduling policy/parameters sched_yieldsched_yield - yield the processor seccompseccomp - operate on Secure Computing state of the process selectselect, pselect, FD_CLR, FD_ISSET, FD_SET, FD_ZEROFD_ZERO - synchronous I/O multiplexing semctlsemctl - System V semaphore control operations semgetsemget - get a System V semaphore set identifier semopsemop, semtimedopsemtimedop - System V semaphore operations sendfilesendfile - transfer data between file descriptors sendmmsgsendmmsg - send multiple messages on a socket sendsend, sendto, sendmsgsendmsg - send a message on a socket seteuidseteuid, setegidsetegid - set effective user or group ID setfsgidsetfsgid - set group identity used for filesystem checks setfsuidsetfsuid - set user identity used for filesystem checks setgidsetgid - set group identity set_mempolicyset_mempolicy - set default NUMA memory policy for a thread and its children setnssetns - reassociate thread with a namespace setpgidsetpgid, getpgid, setpgrp, getpgrpgetpgrp - set/get process group setresuidsetresuid, setresgidsetresgid - set real, effective and saved user or group ID setreuidsetreuid, setregidsetregid - set real and/or effective user or group ID setsidsetsid - creates a session and sets the process group ID set_tid_addressset_tid_address - set pointer to thread ID setuidsetuid - set user identity setupsetup - setup devices and filesystems, mount root filesystem sgetmasksgetmask, ssetmaskssetmask - manipulation of signal mask (obsolete) shmatshmat, shmdtshmdt - System V shared memory operations shmctlshmctl - System V shared memory control shmgetshmget - allocates a System V shared memory segment shutdownshutdown - shut down part of a full-duplex connection sigactionsigaction, rt_sigactionrt_sigaction - examine and change a signal action sigaltstacksigaltstack - set and/or get signal stack context signalsignal - ANSI C signal handling signalfdsignalfd - create a file descriptor for accepting signals sigpendingsigpending, rt_sigpendingrt_sigpending - examine pending signals sigprocmasksigprocmask, rt_sigprocmaskrt_sigprocmask - examine and change blocked signals sigqueuesigqueue - queue a signal and data to a process sigreturnsigreturn, rt_sigreturnrt_sigreturn - return from signal handler and cleanup stack frame sigsuspendsigsuspend, rt_sigsuspendrt_sigsuspend - wait for a signal sigwaitinfosigwaitinfo, sigtimedwait, rt_sigtimedwaitrt_sigtimedwait - synchronously wait for queued signals socketcallsocketcall - socket system calls socketsocket - create an endpoint for communication socketpairsocketpair - create a pair of connected sockets splicesplice - splice data to/from a pipe spu_createspu_create - create a new spu context spu_runspu_run - execute an SPU context statfsstatfs, fstatfsfstatfs - get filesystem statistics statstat, fstat, lstat, fstatatfstatat - get file status statvfsstatvfs, fstatvfsfstatvfs - get filesystem statistics statxstatx - get file status (extended) stimestime - set time subpage_protsubpage_prot - define a subpage protection for an address range swaponswapon, swapoffswapoff - start/stop swapping to file/device symlinksymlink, symlinkatsymlinkat - make a new name for a file sync_file_rangesync_file_range - sync a file segment with disk syncsync, syncfssyncfs - commit filesystem caches to disk syscallsyscall - indirect system call _syscall_syscall - invoking a system call without library support (OBSOLETE) syscallssyscalls - Linux system calls sysctlsysctl - read/write system parameters sysfssysfs - get filesystem type information sysinfosysinfo - return system information syslogsyslog, klogctlklogctl - read and/or clear kernel message ring buffer; set console_loglevel teetee - duplicating pipe content timetime - get time in seconds timer_createtimer_create - create a POSIX per-process timer timer_deletetimer_delete - delete a POSIX per-process timer timerfd_createtimerfd_create, timerfd_settime, timerfd_gettimetimerfd_gettime - timers that notify via file descriptors timer_getoverruntimer_getoverrun - get overrun count for a POSIX per-process timer timer_settimetimer_settime, timer_gettimetimer_gettime - arm/disarm and fetch state of POSIX per-process timer timestimes - get process times tkilltkill, tgkilltgkill - send a signal to a thread truncatetruncate, ftruncateftruncate - truncate a file to a specified length umaskumask - set file mode creation mask umountumount, umount2umount2 - unmount filesystem unameuname - get name and information about current kernel unlinkunlink, unlinkatunlinkat - delete a name and possibly the file it refers to unshareunshare - disassociate parts of the process execution context uselibuselib - load shared library userfaultfduserfaultfd - create a file descriptor for handling page faults in user space ustatustat - get filesystem statistics utimensatutimensat, futimensfutimens - change file timestamps with nanosecond precision utimeutime, utimesutimes - change file last access and modification times vforkvfork - create a child process and block parent vhangupvhangup - virtually hangup the current terminal vm86oldvm86old, vm86vm86 - enter virtual 8086 mode vmsplicevmsplice - splice user pages into a pipe wait3wait3, wait4wait4 - wait for process to change state, BSD style waitwait, waitpid, waitidwaitid - wait for process to change state writewrite - write to a file descriptor Links: linux/syscalls.h 2 syscalls Directory of POSIX headers, man section 0 Directory of system calls, man section 2 kernel syscalls System calls