List of Linux system calls

List of system calls of the Linux kernel:

Name x86_64	function	Number in x86 64 (% RAX )	Number in i386	Different name in i386
read	Reads file from file descriptor fd	0	3
write	Writes file to file descriptor fd	1	4th
open	Opens file or device	2	5
close	Closes the file or device	3	6th
stat	Status of a file	4th	18th	oldstat
fstat	Status of a file	5	28	oldfstat
lstat	Status of a file	6th	84	oldlstat
poll	Waiting for event	7th	168
lseek	Repositions the offset of a read / write pointer to files	8th	19th
mmap	Maps file into memory	9	90
mprotect	Protects memory area	10	125
munmap	Removes the mapped file from the memory	11	91
brk	Changes the size of a data segment	12	45
rt_sigaction	Changes the function of a signal (except SIGKILL and SIGSTOP )	13	67	sigaction
rt_sigprocmask	Blocks signals	14th	126	sigprocmask
rt_sigreturn	Resets all signals	15th	119	sigreturn
ioctl	input / output control (communication with devices)	16	54
pread64	Reads file at a specific point	17th	180
pwrite64	Writes file in a specific place	18th	181
readv	Writes file to multiple buffers	19th	145
writev	Reads file into multiple buffers	20th	146
access	Checks a user's authorization for a file	21st	33
pipe	Creates a pipe	22nd	42
select	synchronous I / O multiplexing (monitor several files until they become writable, for example)	23	82
sched_yield	Instructs the process scheduler to move on to the next process	24	158
mremap	Moves a virtual memory address	25th	163
msync	Synchronizes a file with its memory-mapped copy in memory	26th	144
mincore	Determines whether a memory page is not paged out	27	218
madvise	Gives the kernel an indication of whether a memory area will be accessed soon and whether it will be accessed more randomly or sequentially	28	219
shmget	Sets the common memory ( shared memory ) to	29	/
shmat	Binds XSI shared memory a	30th	/
shmctl	Manages properties of shared storage	31	/
dup	Generates a second filehandle for the same file	32	41
dup2	Generates a second filehandle for the same file with a specific number	33	63
Break	Blocks process and waits for any signal	34	29
nanosleep	Blocks process and waits for any high resolution signal	35	162
getitimer	Asks the interval timer from	36
alarm	Sends SIGALARMafter a period has elapsed	37
setitimer	Sets the interval timer	38
getpid	Returns the process identifier (PID)	39
sendfile	Copies data between two file descriptors	40
socket	Opens a socket	41
connect	Establishes a connection with a server (process)	42
accept	Waiting for requests from clients	43
sendto	Sends a message to a socket	44
recvfrom	Receives a message from a socket	45
sendmsg	Sends a message to a socket, possibly with control information	46
recvmsg	Receives a message from a socket, possibly with control information	47
shut down	Closes a socket connection on one or both sides	48
bind	Binds an already open socket to an address	49
list	Marks a socket as passive listening	50
getsockname	Returns the address of a bound socket	51
getpeername	Returns the address of a connected on a socket peers back	52
socketpair	Creates a pair of connected sockets of the desired protocol and type	53
setsockopt	Sets or changes the settings of a socket	54
getsockopt	Returns the settings of a socket	55
clone	Creates a child process with the ability to share resources from the parent process	56
fork	Creates a child process ( fork )	57
vfork	Creates a child process and blocks the parent process	58
execve	Loads the contents of an executable file and starts it	59
exit	Terminates ongoing process	60
wait4	Waits until a child process terminates and returns information on its resource consumption	61
kill	Sends a signal to a process	62
uname	Returns information about the running kernel	63
semget	Generates a pair of semaphores	64
semop	Ensures that the semaphore operations are only carried out if all operations succeed	65
semctl	Controls semaphores	66
shmdt	Releases memory from shared memory	67
msgget	Receives a message queue identifier	68
msgsnd	Sends a message via a message queue	69
msgrcv	Receives a message via a message queue	70
msgctl	Changes or deletes a message queue	71
fcntl	Manipulates a file descriptor	72
flock	Sets or removes an advisory lock on or from an open file	73
fsync	Synchronizes a referenced file with its representation in mass storage	74
fdatasync	As best fsync omitting. non-mandatory metadata	75
truncate	Shortens a file to the required length or extends it with zero bytes	76
ftruncate	How to truncate over referencing with a descriptor	77
getdents	Returns dirent structures of a directory into a buffer	78
getcwd	Returns the current working directory ( Current Working Directory ) back	79
chdir	Sets or changes the current working directory as a path	80
fchdir	Like chdir , but target directory via descriptor	81
rename	Renames a file and moves it if necessary	82
mkdir	Creates a directory	83
rmdir	Removes a directory	84
creat	Opens and, if necessary, creates or overwrites a file for writing	85
link	Creates a hard link to a file	86
unlink	Deletes a hard link and, if necessary, a file	87
symlink	Creates a soft link to a file	88
readlink	Returns the content of a soft link	89
chmod	Changes file attributes	90
fchmod	Changes file attributes as a descriptor	91
chown	Changes the owner of a file	92
fchown	Changes the owner of a file as a descriptor	93
lchown	How chown but does not dereference any soft links	94
umask	Sets the rights mask ( umask ) of the calling process	95
gettimeofday	Returns the time or time zone	96
trlimit	Returns information about existing resource limits	97
Getrusage	Returns information about the resource consumption of the calling process, thread or its children	98
sysinfo	Retrieves system statistics	99
times	Returns information about the runtime of the calling process	100
ptrace	Following ( trace ) another process	101
getuid	Returns the actual user ID	102
syslog	Checks the kernel message ring buffer and sets the console_loglevel	103
getgid	Returns the actual group identifier	104
setuid	Sets the effective user ID	105
setgid	Sets the effective group ID	106
good	Returns the effective user ID	107
getegid	Returns the effective group ID	108
setpgid	Sets the process group identifier (PGID)	109
getppid	Returns the process ID of the parent process (PPID)	110
getpgrp	Returns the process group identifier (PGID)	111
setsid	Creates a new session with the calling process as leader and returns the session ID (SID)	112
setreuid	Sets the effective and actual user ID	113
setregid	Sets the effective and actual group ID	114
getgroups	Returns a list of additional group IDs ( supplementary group IDs ) back	115
setgroups	Expect a list of additional group IDs	116
setresuid	Sets actual, effective and set user ID	117
Getresuid	Is the actual, effective and Set User ID back	118
setresgid	Sets actual, effective and group setuid	119
Getresgid	Returns the actual, effective, and group setuid	120
getpgid	Returns the process group ID of a process	121
setfsuid	Changes the user ID for access to the file system	122
setfsgid	Changes the group ID for access to the file system	123
getsid	Returns the session ID	124
capget	Returns the capabilities of a thread	125
capset	Determines the capabilities of a thread	126
rt_sigpending	Returns a mask of outstanding signals	127
rt_sigtimedwait	Interrupts the execution of a thread until certain signals arrive, with a time limit	128
rt_sigqueueinfo	Sends signal and optionally data to a thread group; implements sigqueue and pthread_sigqueue	129
rt_sigsuspend	Replaces the signal mask of the calling process and interrupts it	130
sigaltstack	Returns a signal stack or creates a new one	131
utime	Changes the timestamp of a file	132
mknod	Creates a new entry in the file system	133
uselib	Loads a dynamic library	134
personality	Changes the execution domain	135
ustat	Returns information about a mounted file system in a ustat structure	136
statfs	Returns statistics on a file system referenced by a path	137
fstatfs	Like statfs , but referencing via descriptor	138
sysfs	Returns information about the file systems known to the kernel	139
getpriority	Specifies the process priority back	140
setpriority	Changes the process priority	141
sched_setparam	Changes the scheduling parameters of a process	142
sched_getparam	Returns the scheduling parameters of a process	143
sched_setscheduler	Changes the scheduling parameters and policy of a thread	144
sched_getscheduler	Returns the scheduling policy of a thread	145
sched_get_priority_max	Specifies the max. possible priority	146
sched_get_priority_min	Returns the min. possible priority	147
sched_rr_get_interval	Returns the current SCHED_RR interval of a process	148
mlock	Locks part of the virtual address space of the calling process to prevent it from being swapped out	149
munlock	Unlocks pages protected with mlock	150
mlockall	Like mlock , but protects the entire virtual address space of the process	151
munlockall	Unlocks all pages protected with mlock	152
vhangup	Simulates a hangup of the current terminal	153
modify_ldt	Reads from or writes to the Local descriptor table (LDT)	154
pivot_root	Moves the file system root of the current process	155
_sysctl	Reads or sets kernel parameters	156
prctl	Offers different process control functions	157
arch_prctl	Changes architecture-specific process parameters	158
adjtimex	Reads and sets kernel clock settings	159
setrlimit	Sets resource limits	160
chroot	Changes the root directory of the calling process according to the transferred path	161
sync	Causes all buffered changes to metadata and files to be written to the intended storage media ( flushing )	162
acct	Activates or deactivates process accounting	163
settimeofday	Changes the time or time zone	164
mount	Mounts a specified file system in a target directory	165
umount2	Unmounts a mounted file system, allows options to be specified	166
swapon	Designates a specified file or a block-oriented device as a swap area for the main memory	167
swapoff	Ends the swapping of main memory areas into a specified file or a block-oriented device	168
reboot	Restarts the system or activates / deactivates the keystroke for the restart (e.g. Ctrl-Alt-Del)	169
sethostname	Changes the host name	170
setdomainname	Changes the NIS domain	171
iopl	Sets the I / O rights of a process	172
ioperm	sets the access rights for ports	173
create_module	Creates a kernel module entry and reserves memory required for a module	174
init_module	Loads a kernel module	175
delete_module	Removes a kernel module entry that is no longer required	176
get_kernel_syms	Returns a table of exported kernel symbols	177
query_module	Allows kernel queries via modules	178
quotactl	Manages disk quota	179
nfsservctl	Control of the NFS demon	180
getpmsg	Unimplemented system call	181
putpmsg	Unimplemented system call	182
afs_syscall	Unimplemented system call	183
tuxcall	Unimplemented system call, always returns −1	184
security	Unimplemented system call, always returns −1	185
gettid	Returns the ID of a thread . If a process has only one thread, the process identifier (PID) is returned.	186
readahead	Reads file in advance into the page cache	187
setxattr	Sets extended file attributes , file is identified by path	188
lsetxattr	Sets extended file attributes of a symbolic link	189
fsetxattr	Sets extended file attributes, file is identified by file descriptor	190
getxattr	Reads extended file attributes	191
lgetxattr		192
fgetxattr		193
listxattr	Lists extended file attributes	194
llistxattr		195
flistxattr		196
removexattr	Removes an extended file attribute	197
lremovexattr		198
Fremdovexattr		199
tkill	Sends a signal to a thread	200
time	Time	201
futex	Futex , a locking mechanism	202
sched_setaffinity	Determines whether and / or which CPU cores are preferred by a thread ( affinity mask )	203
sched_getaffinity	Queries affinity mask	204
set_thread_area	Creates a thread local storage (TLS) area	205
io_setup	Creates a context for asynchronous communication ( asynchronous I / O )	206
io_destroy	Destroys a context for asynchronous communication	207
io_getevents	Reads asynchronous I / O events from the completion queue	208
io_submit	Submits an asynchronous I / O block for processing	209
io_cancel	Cancels a pending asynchronous I / O operation	210
get_thread_area	Outputs the entry point of a TLS area	211
lookup_dcookie		212
epoll_create	Creates an epoll file descriptor	213
epoll_ctl_old		214
epoll_wait_old		215
remap_file_pages		216
getdents64		217
set_tid_address		218
restart_syscall		219
semtimedop		220
fadvise64		221
timer_create		222
timer_settime		223
timer_gettime		224
timer_getoverrun		225
timer_delete		226
clock_settime		227
clock_gettime		228
clock_getres		229
clock_nanosleep		230
exit_group		231
epoll_wait		232
epoll_ctl		233
tgkill	Sends a signal to a thread	234
utimes	Changes file access and modification stamps	235
vserver	Unimplemented system call	236
mbind	Set NUMA policy for a memory area	237
set_mempolicy	Sets the NUMA default for a thread and its children	238
get_mempolicy	Returns the NUMA policy of a thread	239
mq_open	Opens a message queue	240
mq_unlink	Discards a message queue	241
mq_timedsend	Sends a message to a message queue	242
mq_timedreceive	Retrieves a message from a message queue	243
mq_notify	Activates notification when there is a message in a message queue	244
mq_getsetattr	Returns or changes the attributes of a message queue	245
kexec_load	Loads a new kernel for later execution	246
waitid	Wait until a child process terminates	247
add_key	Adds a key to the key management of the kernel	248
request_key	Retrieves a key from the kernel's key management system	249
keyctl	Control functions for the kernel key management	250
ioprio_set	Gets or changes the I / O scheduling class and priority	251
ioprio_get		252
inotify_init	Initializes an Inotifyinstance	253
inotify_add_watch	Adds a Inotifywatch to an instance or discards one	254
inotify_rm_watch		255
migrate_pages	Moves memory pages e.g. B. to another process	256
openat	Opens file relative to a directory descriptor	257
mkdirat	Creates directory relative to a directory descriptor	258
mknodat	Like mknod, but interprets path information differently	259
fchownat	Like chown, but interprets paths differently	260
futimesat	Changes timestamps of files relative to directory descriptors (obsolete, utimesat bev.)	261
newfstatat		262
unlinked	Like unlink or rmdir, but interprets path information differently	263
renameat	Like rename, but interprets path information differently	264
linkat	Like link, but interprets path information differently	265
symlinkat	Like symlink, but interprets path information differently	266
readlinkat	Like readlink, but interprets path information differently	267
fchmodat	Changes file permissions using a file descriptor	268
faccessat	Like access, but interprets path information differently	269
pselect	Assigns a monitoring routine to file descriptors, which informs about I / O events	270
ppoll	Like poll, but waits for availabilities or signals	271
unshare	Separates execution contexts shared with another process after a clone () and creates real copies	272
set_robust_list	Adds a robust Futex added	273
get_robust_list	Queries a list of robust futexes	274
splice	Moves data between a file descriptor and a pipe without going through userspace	275
tea	Doubles a pipe	276
sync_file_range	Synchronizes open file with its physical copy	277
vmsplice	Moves a page of memory to a pipe	278
move_pages	Moves memory pages (NUMA)	279
utimensat	Updates the timestamp of a file with high precision	280
epoll_pwait	Like epoll_wait, but waiting for availabilities or signals	281
signalfd	Creates a file descriptor that receives signals	282
timerfd_create	Creates a file descriptor that references a timer	283
eventfd	Creates a file descriptor that informs about events	284
fallocate	Manipulates memory areas directly using a descriptor	285
timerfd_settime	Controls timers via file descriptor	286
timerfd_gettime	Returns time parameters of a timer via the file descriptor	287
accept4	Like accept, but accepts flags	288
signalfd4		289
eventfd2		290
epoll_create1		291
dup3		292
pipe2		293
inotify_init1		294
preadv	Like readv, but allows an offset to be specified	295
pwritev	Like writev, but allows an offset to be specified	296
rt_tgsigqueueinfo		297
perf_event_open		298
recvmmsg	Like recvmsg, but allows multiple messages to be received with one call	299
fanotify_init	Creates a fanotify notification group	300
fanotify_mark	Adds or removes files and folders from a notification group	301
prlimit64	Sets resource limits for processes	302
name_to_handle_at	Together like openat	303
open_by_handle_at		304
clock_adjtime		305
syncfs	Writes the contents of the file system buffer to the disk	306
sendmmsg	Like sendmsg, but allows multiple messages to be sent per call	307
setns	Reassociates a thread with a namespace	308
getcpu	Returns the processor on which a process (or thread) is currently running	309
process_vm_readv	Moves data between process address spaces	310
process_vm_writev		311
kcmp	Determines whether the resources of two processes are the same	312
finit_module	Loads a kernel module from a file descriptor fd	313
sched_setattr	Defines a scheduling procedure (e.g. round robin )	314
sched_getattr	Determines the scheduling method used	315
renameat2	Atomic renaming of a file	316
seccomp	Sandboxing mechanism ( secure computing mode )	317
trandom	Fills a buffer with high quality entropy	318
memfd_create	Creates a file descriptor for an anonymous memory area (without the need for a tmpfs - Mount Points )	319
kexec_file_load	Loads a signed kernel image	320
bpf	Berkeley Packet Filters	321
execveat	Loads and starts the contents of an executable file relative to a directory descriptor	322
userfaultfd		323
membarrier	Storage barriers	324
mlock2	like mlock , but with flags	325
copy_file_range	Allows quick copying of files	326
preadv2	like preadv , but with flags	327
pwritev2	like pwritev , but with flags	328

literature

• Michael Kerrisk: The Linux Programming Interface. No Starch Press, San Francisco 2010, ISBN 978-1-59327-220-3 .

Individual evidence

1. ↑ Always up-to-date list from Marcin Juszkiewicz
2. ↑ How do I become a UNIX guru? by Arnold Willemer
3. ↑ Memory Mapped Files
4. ↑ ^{a b} http://man7.org/linux/man-pages/man2/init_module.2.html
5. ↑ https://www.kernel.org/doc/Documentation/robust-futexes.txt
6. ^ Preparing for user-space checkpoint / restore , LWN
7. ↑ Loading modules from file descriptors , LWN
8. ↑ ^{a b} http://man7.org/linux/man-pages/man2/sched_setattr.2.html
9. ↑ Exchanging two files , LWN
10. ↑ seccomp: add "seccomp" syscall
11. ↑ [PATCH, RFC] random: introduce Getrandom (2) system call ( memento of the original from September 1, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
12. ↑ David Herrmann: memfd_create (2) , June 10, 2014
13. ↑ Linux 3.17 Lands Memfd, A KDBUS Prerequisite , August 19, 2014
14. ↑ kexec: A new system call to allow in kernel loading (V4) , June 26, 2014
15. ↑ The BPF system call API, version 14 , LWN, September 24, 2014
16. ↑ syscalls, x86, sparc: Add execveat () system call , LWN, November 14, 2014
17. ↑ syscalls, x86: Add execveat () system call (v3) , September 12, 2012
18. ↑ http://man7.org/linux/man-pages/man2/membarrier.2.html
19. ↑ deferred memory locking LWN, July 8, 2015
20. ↑ copy_file_range () , LWN, October 7, 2015
21. ↑ ^{a b} The return of preadv2 () / pwritev2 () , LWN, January 6, 2016