Linux System Call Table

The following table lists the system calls for the Linux 2.2 kernel. It could also be thought of as an API for the interface between user space and kernel space. My motivation for making this table was to make programming in assembly language easier when using only system calls and not the C library (for more information on this topic, go to On the left are the numbers of the system calls. This number will be put in register %eax. On the right of the table are the types of values to be put into the remaining registers before calling the software interrupt 'int 0x80'. After each syscall, an integer is returned in %eax.

For convenience, links go from the "Name" column to the man page for most of the system calls. Links to the kernel source file where each system call is located are linked to in the column labelled "Source". (You can also download a version of this page which has links directly to the source that is installed on your system.) Links to definitions are provided for the parameters that are typedefs or structs.

%eaxNameSource %ebx%ecx%edx%esx%edi
1sys_exitkernel/exit.c int----
2sys_forkarch/i386/kernel/process.c struct pt_regs----
3sys_readfs/read_write.c unsigned intchar *size_t--
4sys_writefs/read_write.c unsigned intconst char *size_t--
5sys_openfs/open.c const char *intint--
6sys_closefs/open.c unsigned int----
7sys_waitpidkernel/exit.c pid_tunsigned int *int--
8sys_creatfs/open.c const char *int---
9sys_linkfs/namei.c const char *const char *---
10sys_unlinkfs/namei.c const char *----
11sys_execvearch/i386/kernel/process.c struct pt_regs----
12sys_chdirfs/open.c const char *----
13sys_timekernel/time.c int *----
14sys_mknodfs/namei.c const char *intdev_t--
15sys_chmodfs/open.c const char *mode_t---
16sys_lchownfs/open.c const char *uid_tgid_t--
18sys_statfs/stat.c char *struct __old_kernel_stat *---
19sys_lseekfs/read_write.c unsigned intoff_tunsigned int--
20sys_getpidkernel/sched.c -----
21sys_mountfs/super.c char *char *char *--
22sys_oldumountfs/super.c char *----
23sys_setuidkernel/sys.c uid_t----
24sys_getuidkernel/sched.c -----
25sys_stimekernel/time.c int *----
26sys_ptracearch/i386/kernel/ptrace.c longlonglonglong-
27sys_alarmkernel/sched.c unsigned int----
28sys_fstatfs/stat.c unsigned intstruct __old_kernel_stat *---
29sys_pausearch/i386/kernel/sys_i386.c -----
30sys_utimefs/open.c char *struct utimbuf *---
33sys_accessfs/open.c const char *int---
34sys_nicekernel/sched.c int----
36sys_syncfs/buffer.c -----
37sys_killkernel/signal.c intint---
38sys_renamefs/namei.c const char *const char *---
39sys_mkdirfs/namei.c const char *int---
40sys_rmdirfs/namei.c const char *----
41sys_dupfs/fcntl.c unsigned int----
42sys_pipearch/i386/kernel/sys_i386.c unsigned long *----
43sys_timeskernel/sys.c struct tms *----
45sys_brkmm/mmap.c unsigned long----
46sys_setgidkernel/sys.c gid_t----
47sys_getgidkernel/sched.c -----
48sys_signalkernel/signal.c int__sighandler_t---
49sys_geteuidkernel/sched.c -----
50sys_getegidkernel/sched.c -----
51sys_acctkernel/acct.c const char *----
52sys_umountfs/super.c char *int---
54sys_ioctlfs/ioctl.c unsigned intunsigned intunsigned long--
55sys_fcntlfs/fcntl.c unsigned intunsigned intunsigned long--
57sys_setpgidkernel/sys.c pid_tpid_t---
59sys_oldunamearch/i386/kernel/sys_i386.c struct oldold_utsname *----
60sys_umaskkernel/sys.c int----
61sys_chrootfs/open.c const char *----
62sys_ustatfs/super.c dev_tstruct ustat *---
63sys_dup2fs/fcntl.c unsigned intunsigned int---
64sys_getppidkernel/sched.c -----
65sys_getpgrpkernel/sys.c -----
66sys_setsidkernel/sys.c -----
67sys_sigactionarch/i386/kernel/signal.c intconst struct old_sigaction *struct old_sigaction *--
68sys_sgetmaskkernel/signal.c -----
69sys_ssetmaskkernel/signal.c int----
70sys_setreuidkernel/sys.c uid_tuid_t---
71sys_setregidkernel/sys.c gid_tgid_t---
72sys_sigsuspendarch/i386/kernel/signal.c intintold_sigset_t--
73sys_sigpendingkernel/signal.c old_sigset_t *----
74sys_sethostnamekernel/sys.c char *int---
75sys_setrlimitkernel/sys.c unsigned intstruct rlimit *---
76sys_getrlimitkernel/sys.c unsigned intstruct rlimit *---
77sys_getrusagekernel/sys.c intstruct rusage *---
78sys_gettimeofdaykernel/time.c struct timeval *struct timezone *---
79sys_settimeofdaykernel/time.c struct timeval *struct timezone *---
80sys_getgroupskernel/sys.c intgid_t *---
81sys_setgroupskernel/sys.c intgid_t *---
82old_selectarch/i386/kernel/sys_i386.c struct sel_arg_struct *----
83sys_symlinkfs/namei.c const char *const char *---
84sys_lstatfs/stat.c char *struct __old_kernel_stat *---
85sys_readlinkfs/stat.c const char *char *int--
86sys_uselibfs/exec.c const char *----
87sys_swaponmm/swapfile.c const char *int---
88sys_rebootkernel/sys.c intintintvoid *-
89old_readdirfs/readdir.c unsigned intvoid *unsigned int--
90old_mmaparch/i386/kernel/sys_i386.c struct mmap_arg_struct *----
91sys_munmapmm/mmap.c unsigned longsize_t---
92sys_truncatefs/open.c const char *unsigned long---
93sys_ftruncatefs/open.c unsigned intunsigned long---
94sys_fchmodfs/open.c unsigned intmode_t---
95sys_fchownfs/open.c unsigned intuid_tgid_t--
96sys_getprioritykernel/sys.c intint---
97sys_setprioritykernel/sys.c intintint--
99sys_statfsfs/open.c const char *struct statfs *---
100sys_fstatfsfs/open.c unsigned intstruct statfs *---
101sys_iopermarch/i386/kernel/ioport.c unsigned longunsigned longint--
102sys_socketcallnet/socket.c intunsigned long *---
103sys_syslogkernel/printk.c intchar *int--
104sys_setitimerkernel/itimer.c intstruct itimerval *struct itimerval *--
105sys_getitimerkernel/itimer.c intstruct itimerval *---
106sys_newstatfs/stat.c char *struct stat *---
107sys_newlstatfs/stat.c char *struct stat *---
108sys_newfstatfs/stat.c unsigned intstruct stat *---
109sys_unamearch/i386/kernel/sys_i386.c struct old_utsname *----
110sys_ioplarch/i386/kernel/ioport.c unsigned long----
111sys_vhangupfs/open.c -----
112sys_idlearch/i386/kernel/process.c -----
113sys_vm86oldarch/i386/kernel/vm86.c unsigned longstruct vm86plus_struct *---
114sys_wait4kernel/exit.c pid_tunsigned long *int optionsstruct rusage *-
115sys_swapoffmm/swapfile.c const char *----
116sys_sysinfokernel/info.c struct sysinfo *----
117sys_ipc(*Note)arch/i386/kernel/sys_i386.c uintintintintvoid *
118sys_fsyncfs/buffer.c unsigned int----
119sys_sigreturnarch/i386/kernel/signal.c unsigned long----
120sys_clonearch/i386/kernel/process.c struct pt_regs----
121sys_setdomainnamekernel/sys.c char *int---
122sys_newunamekernel/sys.c struct new_utsname *----
123sys_modify_ldtarch/i386/kernel/ldt.c intvoid *unsigned long--
124sys_adjtimexkernel/time.c struct timex *----
125sys_mprotectmm/mprotect.c unsigned longsize_tunsigned long--
126sys_sigprocmaskkernel/signal.c intold_sigset_t *old_sigset_t *--
127sys_create_modulekernel/module.c const char *size_t---
128sys_init_modulekernel/module.c const char *struct module *---
129sys_delete_modulekernel/module.c const char *----
130sys_get_kernel_symskernel/module.c struct kernel_sym *----
131sys_quotactlfs/dquot.c intconst char *intcaddr_t-
132sys_getpgidkernel/sys.c pid_t----
133sys_fchdirfs/open.c unsigned int----
134sys_bdflushfs/buffer.c intlong---
135sys_sysfsfs/super.c intunsigned longunsigned long--
136sys_personalitykernel/exec_domain.c unsigned long----
138sys_setfsuidkernel/sys.c uid_t----
139sys_setfsgidkernel/sys.c gid_t----
140sys_llseekfs/read_write.c unsigned intunsigned longunsigned longloff_t *unsigned int
141sys_getdentsfs/readdir.c unsigned intvoid *unsigned int--
142sys_selectfs/select.c intfd_set *fd_set *fd_set *struct timeval *
143sys_flockfs/locks.c unsigned intunsigned int---
144sys_msyncmm/filemap.c unsigned longsize_tint--
145sys_readvfs/read_write.c unsigned longconst struct iovec *unsigned long--
146sys_writevfs/read_write.c unsigned longconst struct iovec *unsigned long--
147sys_getsidkernel/sys.c pid_t----
148sys_fdatasyncfs/buffer.c unsigned int----
149sys_sysctlkernel/sysctl.c struct __sysctl_args *----
150sys_mlockmm/mlock.c unsigned longsize_t---
151sys_munlockmm/mlock.c unsigned longsize_t---
152sys_mlockallmm/mlock.c int----
153sys_munlockallmm/mlock.c -----
154sys_sched_setparamkernel/sched.c pid_tstruct sched_param *---
155sys_sched_getparamkernel/sched.c pid_tstruct sched_param *---
156sys_sched_setschedulerkernel/sched.c pid_tintstruct sched_param *--
157sys_sched_getschedulerkernel/sched.c pid_t----
158sys_sched_yieldkernel/sched.c -----
159sys_sched_get_priority_maxkernel/sched.c int----
160sys_sched_get_priority_minkernel/sched.c int----
161sys_sched_rr_get_intervalkernel/sched.c pid_tstruct timespec *---
162sys_nanosleepkernel/sched.c struct timespec *struct timespec *---
163sys_mremapmm/mremap.c unsigned longunsigned longunsigned longunsigned long-
164sys_setresuidkernel/sys.c uid_tuid_tuid_t--
165sys_getresuidkernel/sys.c uid_t *uid_t *uid_t *--
166sys_vm86arch/i386/kernel/vm86.c struct vm86_struct *----
167sys_query_modulekernel/module.c const char *intchar *size_tsize_t *
168sys_pollfs/select.c struct pollfd *unsigned intlong--
169sys_nfsservctlfs/filesystems.c intvoid *void *--
170sys_setresgidkernel/sys.c gid_tgid_tgid_t--
171sys_getresgidkernel/sys.c gid_t *gid_t *gid_t *--
172sys_prctlkernel/sys.c intunsigned longunsigned longunsigned longunsigned long
173sys_rt_sigreturnarch/i386/kernel/signal.c unsigned long----
174sys_rt_sigactionkernel/signal.c intconst struct sigaction *struct sigaction *size_t-
175sys_rt_sigprocmaskkernel/signal.c intsigset_t *sigset_t *size_t-
176sys_rt_sigpendingkernel/signal.c sigset_t *size_t---
177sys_rt_sigtimedwaitkernel/signal.c const sigset_t *siginfo_t *const struct timespec *size_t-
178sys_rt_sigqueueinfokernel/signal.c intintsiginfo_t *--
179sys_rt_sigsuspendarch/i386/kernel/signal.c sigset_t *size_t---
180sys_preadfs/read_write.c unsigned intchar *size_tloff_t-
181sys_pwritefs/read_write.c unsigned intconst char *size_tloff_t-
182sys_chownfs/open.c const char *uid_tgid_t--
183sys_getcwdfs/dcache.c char *unsigned long---
184sys_capgetkernel/capability.c cap_user_header_tcap_user_data_t---
185sys_capsetkernel/capability.c cap_user_header_tconst cap_user_data_t---
186sys_sigaltstackarch/i386/kernel/signal.c const stack_t *stack_t *---
187sys_sendfilemm/filemap.c intintoff_t *size_t-
190sys_vforkarch/i386/kernel/process.c struct pt_regs----

Note for sys_ipc (117): this syscall takes six arguments, so it can't fit into the five registers %ebx - %edi; the last parameter (not shown) is of type 'long'. This syscall requires a special call method where a pointer is put in %ebx which points to an array containing the six arguments.

System Call Numbers

For the numbers of the syscalls, look in arch/i386/kernel/entry.S for sys_call_table. The syscall numbers are offsets into that table. Several spots in the table are occupied by the syscall sys_ni_syscall. This is a placeholder that either replaces an obsolete syscall or reserves a spot for future syscalls.

Incidentally, the system calls are called from the function system_call in the same file; in particular, they are called with the assembly instruction 'call *SYMBOL_NAME(sys_call_table)(,%eax,4)'. The part '*SYMBOL_NAME(sys_call_table)' just gets replaced by a symbol name in sys_call_table. SYMBOL_NAME is a macro defined in include/linux/linkage.h, and it just replaces itself with its argument.


Here are the typedef declarations in the prototypes above:

atomic_t include/asm/atomic.h:
#ifdef __SMP__
typedef struct { volatile int counter; } atomic_t;
typedef struct { int counter; } atomic_t;
caddr_t include/asm/posix_types.h:typedef char * __kernel_caddr_t;
include/linux/types.h:typedef __kernel_caddr_t caddr_t;
cap_user_header_t include/linux/capability.h:
typedef struct __user_cap_header_struct {
     __u32 version;
     int pid;
} *cap_user_header_t;
cap_user_data_t include/linux/capability.h:
typedef struct __user_cap_data_struct {
     __u32 effective;
     __u32 permitted;
     __u32 inheritable;
} *cap_user_data_t;
clock_t include/asm/posix_types.h:typedef long __kernel_clock_t;
include/linux/types.h:typedef __kernel_clock_t clock_t;
dev_t include/asm/posix_types.h:typedef unsigned short __kernel_dev_t;
include/linux/types.h:typedef __kernel_dev_t dev_t;
fd_set include/linux/posix_types.h
#define __FD_SETSIZE 1024
#define __NFDBITS (8 * sizeof(unsigned long))
(==> __FDSET_LONGS == 32)

typedef struct {
     unsigned long fds_bits [__FDSET_LONGS];
} __kernel_fd_set;
include/linux/types.h:typedef __kernel_fd_set fd_set;
gid_t include/asm/posix_types.h:typedef unsigned short __kernel_gid_t;
include/linux/types.h:typedef __kernel_gid_t gid_t;
__kernel_daddr_t include/asm/posix_types.h:typedef int __kernel_daddr_t;
__kernel_fsid_t include/asm/posix_types.h:
typedef struct {
     int __val[2];
} __kernel_fsid_t;

__kernel_ino_t include/asm/posix_types.h:typedef unsigned long __kernel_ino_t;
__kernel_size_t include/asm/posix_types.h:typedef unsigned int __kernel_size_t;
loff_t include/asm/posix_types.h:typedef long long __kernel_loff_t;
include/linux/types.h:typedef __kernel_loff_t loff_t;
mode_t include/asm/posix_types.h:typedef unsigned short __kernel_mode_t;
include/linux/types.h:typedef __kernel_mode_t mode_t;
off_t include/asm/posix_types.h:typedef long __kernel_off_t; include/linux/types.h:typedef __kernel_off_t off_t;
old_sigset_t include/asm/signal.h:typedef unsigned long old_sigset_t;
pid_t include/asm/posix_types.h:typedef int __kernel_pid_t;
include/linux/types.h:typedef __kernel_pid_t pid_t;
__sighandler_t include/asm/signal.h:typedef void (*__sighandler_t)(int);
siginfo_t include/asm/siginfo.h:
#define SI_MAX_SIZE 128
#define SI_PAD_SIZE ((SI_MAX_SIZE/sizeof(int)) - 3)
(==> SI_PAD_SIZE == 29)

typedef struct siginfo {
     int si_signo;
     int si_errno;
     int si_code;

     union {
          int _pad[SI_PAD_SIZE];

          /* kill() */
          struct {
               pid_t _pid; /* sender's pid */
               uid_t _uid; /* sender's uid */
          } _kill;

          /* POSIX.1b timers */
          struct {
               unsigned int _timer1;
               unsigned int _timer2;
          } _timer;

          /* POSIX.1b signals */
          struct {
               pid_t _pid; /* sender's pid */
               uid_t _uid; /* sender's uid */
               sigval_t _sigval;
          } _rt;

          /* SIGCHLD */
          struct {
               pid_t _pid; /* which child */
               uid_t _uid; /* sender's uid */
               int _status; /* exit code */
               clock_t _utime;
               clock_t _stime;
          } _sigchld;

          struct {
               void *_addr; /* faulting insn/memory ref. */
          } _sigfault;

          /* SIGPOLL */
          struct {
               int _band; /* POLL_IN, POLL_OUT, POLL_MSG */
               int _fd;
          } _sigpoll;
     } _sifields;
} siginfo_t;
sigset_t include/asm/signal.h:typedef unsigned long sigset_t;
size_t include/asm/posix_types.h:typedef unsigned int __kernel_size_t;
include/linux/types.h:typedef __kernel_size_t size_t;
ssize_t include/asm/posix_types.h:typedef int __kernel_ssize_t;
include/linux/types.h:typedef __kernel_ssize_t ssize_t;
stack_t include/asm/signal.h:
typedef struct sigaltstack {
     void *ss_sp;
     int ss_flags;
     size_t ss_size;
} stack_t;
suseconds_t include/asm/posix_types.h:typedef long __kernel_suseconds_t;
include/linux/types.h:typedef __kernel_suseconds_t suseconds_t;
time_t include/asm/posix_types.h:typedef long __kernel_time_t;
include/linux/types.h:typedef __kernel_time_t time_t;
uid_t include/asm/posix_types.h:typedef unsigned short __kernel_uid_t;
include/linux/types.h:typedef __kernel_uid_t uid_t;
uint include/linux/types.h:typedef unsigned int uint;
__u32 include/asm/types.h:typedef unsigned int __u32;



Here are the struct declarations for the table at the top:

exception_table_entry include/linux/module.h:
struct exception_table_entry {
     unsigned long insn, fixup;
iovec include/linux/uio.h:
struct iovec {
     void *iov_base;
     __kernel_size_t iov_len; };
itimerval include/linux/time.h:
struct itimerval {
     struct timeval it_interval; /* timer interval */
     struct timeval it_value; /* current value */
kernel_sym include/linux/module.h:
struct kernel_sym {
     unsigned long value;
     char name[60];
mmap_arg_struct arch/i386/kernel/sys_i386.c:
struct mmap_arg_struct {
     unsigned long addr;
     unsigned long len;
     unsigned long prot;
     unsigned long flags;
     unsigned long fd;
     unsigned long offset;
module include/linux/module.h:
struct module {
     unsigned long size_of_struct; /* sizeof(module) */
     struct module *next;
     const char *name;
     unsigned long size;
     union {
          atomic_t usecount;
          long pad;
     } uc;
     unsigned long flags; /* AUTOCLEAN et al */
     unsigned nsyms;
     unsigned ndeps;

     struct module_symbol *syms;
     struct module_ref *deps;
     struct module_ref *refs;
     int (*init)(void);
     void (*cleanup)(void);
     const struct exception_table_entry *ex_table_start;
     const struct exception_table_entry *ex_table_end;
/* Members past this point are extensions to the basic
module support and are optional. Use mod_opt_member()
to examine them. */
     const struct module_persist *persist_start;
     const struct module_persist *persist_end;
     int (*can_unload)(void);
module_persist include/linux/module.h:
struct module_persist; /* yes, it's empty */
module_ref include/linux/module.h:
struct module_ref {
     struct module *dep; /* "parent" pointer */
     struct module *ref; /* "child" pointer */
     struct module_ref *next_ref;
module_symbol include/linux/module.h:
struct module_symbol {
     unsigned long value;
     const char *name;
new_utsname include/linux/utsname.h:
struct new_utsname {
     char sysname[65];
     char nodename[65];
     char release[65];
     char version[65];
     char machine[65];
     char domainname[65];
__old_kernel_stat include/asm/stat.h:
struct __old_kernel_stat {
     unsigned short st_dev;
     unsigned short st_ino;
     unsigned short st_mode;
     unsigned short st_nlink;
     unsigned short st_uid;
     unsigned short st_gid;
     unsigned short st_rdev;
     unsigned long st_size;
     unsigned long st_atime;
     unsigned long st_mtime;
     unsigned long st_ctime;
oldold_utsname include/linux/utsname.h:
struct oldold_utsname {
     char sysname[9];
     char nodename[9];
     char release[9];
     char version[9];
     char machine[9];
old_sigaction include/asm/signal.h:
struct old_sigaction {
     __sighandler_t sa_handler;
     old_sigset_t sa_mask;
     unsigned long sa_flags;
     void (*sa_restorer)(void);
old_utsname include/linux/utsname.h:
struct old_utsname {
     char sysname[65];
     char nodename[65];
     char release[65];
     char version[65];
     char machine[65];
pollfd include/asm/poll.h:
struct pollfd {
     int fd;
     short events;
     short revents;
pt_regs include/asm/ptrace.h:
struct pt_regs {
     long ebx;
     long ecx;
     long edx;
     long esi;
     long edi;
     long ebp;
     long eax;
     int xds;
     int xes;
     long orig_eax;
     long eip;
     int xcs;
     long eflags;
     long esp;
     int xss;
revectored_struct include/asm/vm86.h:
struct revectored_struct {
     unsigned long __map[8];
rlimit include/linux/resource.h:
struct rlimit {
     long rlim_cur;
     long rlim_max;
rusage include/linux/resource.h:
struct rusage {
     struct timeval ru_utime; /* user time used */
     struct timeval ru_stime; /* system time used */
     long ru_maxrss; /* maximum resident set size */
     long ru_ixrss; /* integral shared memory size */
     long ru_idrss; /* integral unshared data size */
     long ru_isrss; /* integral unshared stack size */
     long ru_minflt; /* page reclaims */
     long ru_majflt; /* page faults */
     long ru_nswap; /* swaps */
     long ru_inblock; /* block input operations */
     long ru_oublock; /* block output operations */
     long ru_msgsnd; /* messages sent */
     long ru_msgrcv; /* messages received */
     long ru_nsignals; /* signals received */
     long ru_nvcsw; /* voluntary context switches */
     long ru_nivcsw; /* involuntary '' */
sched_param include/linux/sched.h:
struct sched_param {
     int sched_priority;
sel_arg_struct arch/i386/kernel/sys_i386.c:
struct sel_arg_struct {
     unsigned long n;
     fd_set *inp, *outp, *exp;
     struct timeval *tvp;
sigaction include/asm/signal.h:
struct sigaction {
     __sighandler_t sa_handler;
     unsigned long sa_flags;
     void (*sa_restorer)(void);
     sigset_t sa_mask; /* mask last for extensibility */
stat include/asm/stat.h:
struct stat {
     unsigned short st_dev;
     unsigned short __pad1;
     unsigned long st_ino;
     unsigned short st_mode;
     unsigned short st_nlink;
     unsigned short st_uid;
     unsigned short st_gid;
     unsigned short st_rdev;
     unsigned short __pad2;
     unsigned long st_size;
     unsigned long st_blksize;
     unsigned long st_blocks;
     unsigned long st_atime;
     unsigned long __unused1;
     unsigned long st_mtime;
     unsigned long __unused2;
     unsigned long st_ctime;
     unsigned long __unused3;
     unsigned long __unused4;
     unsigned long __unused5;
statfs include/asm/statfs.h:
struct statfs {
     long f_type;
     long f_bsize;
     long f_blocks;
     long f_bfree;
     long f_bavail;
     long f_files;
     long f_ffree;
     __kernel_fsid_t f_fsid;
     long f_namelen;
     long f_spare[6];
__sysctl_args include/linux/sysctl.h
struct __sysctl_args {
     int *name;
     int nlen;
     void *oldval;
     size_t *oldlenp;
     void *newval;
     size_t newlen;
     unsigned long __unused[4];
sysinfo include/linux/kernel.h:
struct sysinfo {
     long uptime; /* Seconds since boot */
     unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
     unsigned long totalram; /* Total usable main memory size */
     unsigned long freeram; /* Available memory size */
     unsigned long sharedram; /* Amount of shared memory */
     unsigned long bufferram; /* Memory used by buffers */
     unsigned long totalswap; /* Total swap space size */
     unsigned long freeswap; /* swap space still available */
     unsigned short procs; /* Number of current processes */
     char _f[22]; /* Pads structure to 64 bytes */
timex include/linux/timex.h:
struct timex {
     unsigned int modes; /* mode selector */
     long offset; /* time offset (usec) */
     long freq; /* frequency offset (scaled ppm) */
     long maxerror; /* maximum error (usec) */
     long esterror; /* estimated error (usec) */
     int status; /* clock command/status */
     long constant; /* pll time constant */
     long precision; /* clock precision (usec) (read only) */
     long tolerance; /* clock frequency tolerance (ppm)
      * (read only)
     struct timeval time; /* (read only) */
     long tick; /* (modified) usecs between clock ticks */
     long ppsfreq; /* pps frequency (scaled ppm) (ro) */
     long jitter; /* pps jitter (us) (ro) */
     int shift; /* interval duration (s) (shift) (ro) */
     long stabil; /* pps stability (scaled ppm) (ro) */
     long jitcnt; /* jitter limit exceeded (ro) */
     long calcnt; /* calibration intervals (ro) */
     long errcnt; /* calibration errors (ro) */
     long stbcnt; /* stability limit exceeded (ro) */

     int :32; int :32; int :32; int :32;
     int :32; int :32; int :32; int :32;
     int :32; int :32; int :32; int :32;
timespec include/linux/time.h:
struct timespec {
     time_t tv_sec; /* seconds */
     long tv_nsec; /* nanoseconds */
timeval include/linux/time.h:
struct timeval {
     time_t tv_sec; /* seconds */
     suseconds_t tv_usec; /* microseconds */
timezone include/linux/time.h:
struct timezone {
     int tz_minuteswest; /* minutes west of Greenwich */
     int tz_dsttime; /* type of dst correction */
tms include/linux/times.h
struct tms {
     clock_t tms_utime;
     clock_t tms_stime;
     clock_t tms_cutime;
     clock_t tms_cstime;
ustat include/linux/types.h:
struct ustat {
     __kernel_daddr_t f_tfree;
     __kernel_ino_t f_tinode;
     char f_fname[6];
     char f_fpack[6];
utimbuf include/linux/utime.h:
struct utimbuf {
     time_t actime;
     time_t modtime;
vm86plus_info_struct include/asm/vm86.h:
struct vm86plus_info_struct {
     unsigned long force_return_for_pic:1;
     unsigned long vm86dbg_active:1;
     unsigned long vm86dbg_TFpendig:1;
     unsigned long unused:28;
     unsigned long is_vm86pus:1;
     unsigned char vm86dbg_intxxtab[32];
vm86plus_struct include/asm/vm86.h:
struct vm86plus_struct {
     struct vm86_regs regs;
     unsigned long flags;
     unsigned long screen_bitmap;
     unsigned long cpu_type;
     struct revectored_struct int_revectored;
     struct revectored_struct int21_revectored;
     struct vm86plus_info_struct vm86plus;
vm86_regs include/asm/vm86.h:
struct vm86_regs {
/* normal regs, with special meaning for the segment descriptors.. */
     long ebx;
     long ecx;
     long edx;
     long esi;
     long edi;
     long ebp;
     long eax;
     long __null_ds;
     long __null_es;
     long __null_fs;
     long __null_gs;
     long orig_eax;
     long eip;
     unsigned short cs, __csh;
     long eflags;
     long esp;
     unsigned short ss, __ssh;
/* these are specific to v86 mode: */
     unsigned short es, __esh;
     unsigned short ds, __dsh;
     unsigned short fs, __fsh;
     unsigned short gs, __gsh;
vm86_struct include/asm/vm86.h:
struct vm86_struct {
     struct vm86_regs regs;
     unsigned long flags;
     unsigned long screen_bitmap;
     unsigned long cpu_type;
     struct revectored_struct int_revectored;
     struct revectored_struct int21_revectored;