System calls about processes and threads: exit(), execve(), fork(), waitpid(), threads, IDs, process groups and sessions, memory (sbrk(), mmap(), munmap()), and the machine (uname(), reboot(), sethostname()). More...

#include "syscalls.h"

Functions
long	sys_exit (int code)
	Implements _exit(): ends the calling process.
long	sys_execve (const char path, char const argp[], char *const envp[])
	Implements execve(): runs another program in the calling process.
long	sys_fork (void)
	Implements fork(): makes a child process, a copy of the caller.
long	sys_getpid (void)
	Implements getpid().
long	sys_sbrk (ptrdiff_t incr)
	Implements sbrk(): grows or shrinks the heap.
long	sys_times (struct aquila_tms *buf)
	Implements times(): the CPU times of the process and of its children that it waited for, in ticks (AQUILA_CLK_TCK a second).
long	sys_waitpid (int pid, int *stat_loc, int options)
	Implements waitpid(): waits for a child to end (or stop, or continue, if asked), and reaps it if it ended.
long	sys_uname (struct utsname *name)
	Implements uname(): the system's name, release, version and machine, and the host name.
long	sys_thread_create (struct aquila_thread_args *__uthread)
	Makes a new thread in the calling process (for pthread_create()), and makes it ready to run.
long	sys_thread_exit (void *value_ptr)
	Ends the calling thread (for pthread_exit()).
long	sys_thread_join (int tid, void **value_ptr)
	Waits for a thread of the calling process to end, and frees it (for pthread_join()).
long	sys_setpgid (pid_t pid, pid_t pgid)
	Implements setpgid(): moves a process (the caller or one of its children) into a process group of its session.
long	sys_setuid (uid_t uid)
	Implements setuid(): sets the process's user ID.
long	sys_setgid (gid_t gid)
	Implements setgid(): sets the process's group ID.
long	sys_getuid (void)
	Implements getuid().
long	sys_getgid (void)
	Implements getgid().
long	sys_mmap (struct aquila_mmap_args uargs, void *ret)
	Implements mmap(): maps anonymous memory or a file into the calling process.
long	sys_munmap (void *addr, size_t len)
	Implements munmap(): removes a mapping.
long	sys_sysconf (int name)
	Implements sysconf(): not supported; the C library answers it.
long	sys_getppid (void)
	Implements getppid().
long	sys_getpgrp (void)
	Implements getpgrp().
long	sys_getrandom (void *buf, size_t len, unsigned flags)
	Implements getrandom() (and the C library's getentropy()): fills a buffer with random bytes.
long	sys_thread_self (void)
	Returns the calling thread's ID, for pthread_self().
long	sys_reboot (unsigned cmd)
	Implements reboot(): restarts, halts or powers off the machine, or sets what Ctrl+Alt+Del does.
long	sys_setsid (void)
	Implements setsid(): makes the calling process the leader of a new session and process group.
long	sys_sethostname (const char *name, size_t len)
	Implements sethostname().

Variables
static char	nodename [sizeof(((struct utsname *) 0) ->nodename)] = UTSNAME_NODENAME

Detailed Description

System calls about processes and threads: exit(), execve(), fork(), waitpid(), threads, IDs, process groups and sessions, memory (sbrk(), mmap(), munmap()), and the machine (uname(), reboot(), sethostname()).

Definition in file sys_proc.c.

Function Documentation

◆ sys_execve()

long sys_execve	(	const char *	path,
		char *const	argp[],
		char *const	envp[] )

Implements execve(): runs another program in the calling process.

Parameters

path	the program's path
argp	its arguments, a NULL-terminated array
envp	its environment, a NULL-terminated array

Returns: a negative errno on failure (-ENOENT, -EACCES, -ENOEXEC, -E2BIG, -EFAULT, -ENOMEM); on success it doesn't return, the new program starts

Definition at line 42 of file sys_proc.c.

References curthread, kfree(), LOG_DEBUG, proc_execve(), sched_thread_spawn(), sys_execve(), and upath_get().

Referenced by sys_execve().

◆ sys_exit()

long sys_exit ( int code )

Implements _exit(): ends the calling process.

It doesn't return.

Parameters

code	the exit status, which the parent's wait() reports

Returns: nothing: it doesn't return

Definition at line 16 of file sys_proc.c.

References arch_sleep(), curproc, proc::exit, LOG_DEBUG, PROC_EXIT, proc_kill(), and sys_exit().

Referenced by sys_exit(), and sys_thread_exit().

◆ sys_fork()

long sys_fork ( void )

Implements fork(): makes a child process, a copy of the caller.

Returns: the child's process ID in the parent (the child gets 0), or a negative errno: -ENOMEM, -EAGAIN

Definition at line 76 of file sys_proc.c.

References curthread, queue::head, LOG_DEBUG, NULL, proc::pid, proc_fork(), sched_thread_ready(), sys_fork(), proc::threads, and qnode::value.

Referenced by sys_fork().

◆ sys_getgid()

long sys_getgid ( void )

Implements getgid().

Returns: the calling process's group ID

Definition at line 498 of file sys_proc.c.

References curproc, LOG_DEBUG, and sys_getgid().

Referenced by sys_getgid().

◆ sys_getpgrp()

long sys_getpgrp ( void )

Implements getpgrp().

Returns: the calling process's process group ID

Definition at line 683 of file sys_proc.c.

References curproc, LOG_DEBUG, and sys_getpgrp().

Referenced by sys_getpgrp().

◆ sys_getpid()

long sys_getpid ( void )

Implements getpid().

Returns: the calling process's ID

Definition at line 100 of file sys_proc.c.

References curproc, LOG_DEBUG, and sys_getpid().

Referenced by sys_getpid().

◆ sys_getppid()

long sys_getppid ( void )

Implements getppid().

Returns: the parent's process ID, or 0 if there is none

Definition at line 670 of file sys_proc.c.

References curproc, LOG_DEBUG, and sys_getppid().

Referenced by sys_getppid().

◆ sys_getrandom()

long sys_getrandom	(	void *	buf,
		size_t	len,
		unsigned	flags )

Implements getrandom() (and the C library's getentropy()): fills a buffer with random bytes.

Parameters

buf	the buffer
len	its size
flags	not used

Returns: how many bytes were written, or -EFAULT

Definition at line 698 of file sys_proc.c.

References memset(), MIN, random_get(), sys_getrandom(), and uaccess_check().

Referenced by sys_getrandom().

◆ sys_getuid()

long sys_getuid ( void )

Implements getuid().

Returns: the calling process's user ID

Definition at line 487 of file sys_proc.c.

References curproc, LOG_DEBUG, and sys_getuid().

Referenced by sys_getuid().

◆ sys_mmap()

long sys_mmap	(	struct aquila_mmap_args *	uargs,
		void **	ret )

Implements mmap(): maps anonymous memory or a file into the calling process.

Pages are brought in by page faults, when first touched.

Parameters

uargs	the arguments, in user memory: the address, length, protection, flags, descriptor and offset
ret	where to put the mapping's address

Returns: 0, or a negative errno: -EBADF, -EINVAL, -ENODEV, -ENOMEM, -EFAULT

Definition at line 514 of file sys_proc.c.

References vm_entry::base, curproc, fd_file(), FILE_SOCKET, file::flags, vm_entry::flags, kfree(), LOG_DEBUG, NULL, vm_entry::off, PAGE_MASK, PAGE_ROUND, vm_entry::qnode, vm_entry::size, sys_mmap(), uaccess_check(), vfs_map(), vm_entry_new(), vm_entry::vm_object, vm_object_decref(), vm_object_incref(), vm_object_vnode(), VM_SHARED, vm_space_insert(), VM_UR, VM_UW, and VM_UX.

Referenced by sys_mmap().

◆ sys_munmap()

long sys_munmap	(	void *	addr,
		size_t	len )

Implements munmap(): removes a mapping.

Only a whole mapping can be removed, not a part of one; the heap and the stack can't be.

Parameters

addr	the mapping's address
len	its length

Returns: 0, or -EINVAL if no mapping has that address and length

Definition at line 622 of file sys_proc.c.

References vm_entry::base, curproc, kfree(), LOG_DEBUG, PAGE_ROUND, vm_entry::qnode, queue_for, vm_entry::size, sys_munmap(), vm_space::vm_entries, vm_entry_destroy(), and vm_unmap_full().

Referenced by sys_munmap().

◆ sys_reboot()

long sys_reboot ( unsigned cmd )

Implements reboot(): restarts, halts or powers off the machine, or sets what Ctrl+Alt+Del does.

Only root may.

Parameters

cmd	the command (RB_*)

Returns: 0 for the Ctrl+Alt+Del commands, -EPERM, or -EINVAL; the others don't return

Definition at line 740 of file sys_proc.c.

References curproc, kernel_reboot(), LOG_DEBUG, and sys_reboot().

Referenced by sys_reboot().

◆ sys_sbrk()

long sys_sbrk ( ptrdiff_t incr )

Implements sbrk(): grows or shrinks the heap.

The heap may grow up to the next mapping (or the stack).

Parameters

incr	how many bytes to add (or take off, if negative)

Returns: the old end of the heap, or (uintptr_t) -1 if the heap can't change that much

Definition at line 114 of file sys_proc.c.

References vm_entry::base, curproc, LOG_DEBUG, qnode::next, PAGE_ROUND, sys_sbrk(), USER_STACK_BASE, and qnode::value.

Referenced by sys_sbrk().

◆ sys_setgid()

long sys_setgid ( gid_t gid )

Implements setgid(): sets the process's group ID.

Root may set any ID, other users only their own.

Parameters

gid	the group ID

Returns: 0, or -EPERM

Definition at line 470 of file sys_proc.c.

References curproc, LOG_DEBUG, and sys_setgid().

Referenced by sys_setgid().

◆ sys_sethostname()

long sys_sethostname	(	const char *	name,
		size_t	len )

Implements sethostname().

Only root may.

Parameters

name	the host name (not NUL-terminated)
len	its length

Returns: 0, or a negative errno: -EPERM, -EINVAL if it's too long, -EFAULT

Definition at line 793 of file sys_proc.c.

References curproc, LOG_DEBUG, memcpy(), nodename, and sys_sethostname().

Referenced by sys_sethostname().

◆ sys_setpgid()

long sys_setpgid	(	pid_t	pid,
		pid_t	pgid )

Implements setpgid(): moves a process (the caller or one of its children) into a process group of its session.

Parameters

pid	the process, or 0 for the caller
pgid	the group's ID, or 0 for the process's own ID (a new group)

Returns: 0, or a negative errno: -EINVAL, -ESRCH, -EPERM, -ENOMEM

Definition at line 418 of file sys_proc.c.

References curproc, session::leader, LOG_DEBUG, proc::parent, proc::pgrp, proc::pid, proc_pid_find(), proc_setpgid(), pgroup::session, and sys_setpgid().

Referenced by sys_setpgid().

◆ sys_setsid()

long sys_setsid ( void )

Implements setsid(): makes the calling process the leader of a new session and process group.

Returns: the new session's ID (the caller's process ID), or a negative errno: -EPERM for a process group leader, -ENOMEM

Definition at line 758 of file sys_proc.c.

References curproc, LOG_DEBUG, pgroup::pgid, proc::pgrp, proc::pgrp_node, pgrp_release(), proc::pid, pgroup::procs, session_new(), and sys_setsid().

Referenced by sys_setsid().

◆ sys_setuid()

long sys_setuid ( uid_t uid )

Implements setuid(): sets the process's user ID.

There are no separate effective or saved IDs: root may set any ID, other users only their own.

Parameters

uid	the user ID

Returns: 0, or -EPERM

Definition at line 451 of file sys_proc.c.

References curproc, LOG_DEBUG, and sys_setuid().

Referenced by sys_setuid().

◆ sys_sysconf()

long sys_sysconf ( int name )

Implements sysconf(): not supported; the C library answers it.

Parameters

name	the variable

Returns: -ENOSYS

Definition at line 659 of file sys_proc.c.

References LOG_DEBUG, and sys_sysconf().

Referenced by sys_sysconf().

◆ sys_thread_create()

long sys_thread_create ( struct aquila_thread_args * __uthread )

Makes a new thread in the calling process (for pthread_create()), and makes it ready to run.

Parameters

__uthread the arguments, in user memory: the thread's stack, the C library's start, the thread's function and its argument

Returns: the new thread's ID, or a negative errno: -EFAULT, -ENOMEM

Definition at line 286 of file sys_proc.c.

References curthread, LOG_DEBUG, NULL, sched_thread_ready(), thread::stack, sys_thread_create(), thread_create(), thread::tid, and uaccess_check().

Referenced by sys_thread_create().

◆ sys_thread_exit()

long sys_thread_exit ( void * value_ptr )

Ends the calling thread (for pthread_exit()).

It stays as a zombie until another thread joins it. The last live thread ending ends the process. It doesn't return.

Parameters

value_ptr the value that thread_join() returns

Returns: nothing: it doesn't return

Definition at line 325 of file sys_proc.c.

References arch_cur_thread_kill(), curproc, curthread, LOG_DEBUG, thread::owner, queue_for, thread::state, sys_exit(), sys_thread_exit(), proc::thread_join, proc::threads, waitq_wakeup(), and ZOMBIE.

Referenced by sys_thread_exit().

◆ sys_thread_join()

long sys_thread_join	(	int	tid,
		void **	value_ptr )

Waits for a thread of the calling process to end, and frees it (for pthread_join()).

Parameters

tid	the thread's ID
value_ptr	where to put the value it ended with, or NULL

Returns: the thread's ID, or a negative errno: -ESRCH (no such thread, or joined already), -EDEADLK (the caller itself), -EINTR, -EFAULT

Definition at line 367 of file sys_proc.c.

References curproc, curthread, ERESTARTSYS, thread::exit_value, kfree(), LOG_DEBUG, NULL, thread::owner, queue_for, thread::state, sys_thread_join(), proc::threads, thread::tid, waitq_sleep(), and ZOMBIE.

Referenced by sys_thread_join().

◆ sys_thread_self()

long sys_thread_self ( void )

Returns the calling thread's ID, for pthread_self().

Returns: the thread's ID

Definition at line 727 of file sys_proc.c.

References curthread, and sys_thread_self().

Referenced by sys_thread_self().

◆ sys_times()

long sys_times ( struct aquila_tms * buf )

Implements times(): the CPU times of the process and of its children that it waited for, in ticks (AQUILA_CLK_TCK a second).

Parameters

buf	where to put them

Returns: the real time since boot, in ticks, or -EFAULT

Definition at line 148 of file sys_proc.c.

References arch_rtime_ns(), curproc, LOG_DEBUG, sys_times(), and tick.

Referenced by sys_times().

◆ sys_uname()

long sys_uname ( struct utsname * name )

Implements uname(): the system's name, release, version and machine, and the host name.

Parameters

name	where to put them

Returns: 0, or -EFAULT

Definition at line 259 of file sys_proc.c.

References LOG_DEBUG, memcpy(), memset(), MIN, nodename, sys_uname(), UTSNAME_MACHINE, UTSNAME_RELEASE, UTSNAME_SYSNAME, and UTSNAME_VERSION.

Referenced by sys_uname().

◆ sys_waitpid()

long sys_waitpid	(	int	pid,
		int *	stat_loc,
		int	options )

Implements waitpid(): waits for a child to end (or stop, or continue, if asked), and reaps it if it ended.

Parameters

pid	which child: that one if > 0, any if -1, any in the caller's process group if 0, or any in process group -pid if < -1
stat_loc	where to put its status, or NULL
options	WNOHANG, WUNTRACED, WCONTINUED

Returns: the child's process ID, 0 if WNOHANG and none is ready, or a negative errno: -ECHILD, -EINTR, -EFAULT

Definition at line 181 of file sys_proc.c.

References curproc, ERESTARTSYS, proc::exit, LOG_DEBUG, options(), proc::parent, pgroup::pgid, proc::pgrp, proc::pid, proc_reap(), procs, queue_for, proc::stopped, sys_waitpid(), WAIT_CONTINUED, proc::wait_event, WAIT_STOPPED, waitq_sleep(), and proc::zombie.

Referenced by sys_waitpid().

Variable Documentation

◆ nodename

char nodename[sizeof(((struct utsname *) 0) ->nodename)] = UTSNAME_NODENAME

static

Definition at line 250 of file sys_proc.c.

Referenced by sys_sethostname(), and sys_uname().

Functions

Variables

Detailed Description

Function Documentation

◆ sys_execve()

◆ sys_exit()

◆ sys_fork()

◆ sys_getgid()

◆ sys_getpgrp()

◆ sys_getpid()

◆ sys_getppid()

◆ sys_getrandom()

◆ sys_getuid()

◆ sys_mmap()

◆ sys_munmap()

◆ sys_reboot()

◆ sys_sbrk()

◆ sys_setgid()

◆ sys_sethostname()

◆ sys_setpgid()

◆ sys_setsid()

◆ sys_setuid()

◆ sys_sysconf()

◆ sys_thread_create()

◆ sys_thread_exit()

◆ sys_thread_join()

◆ sys_thread_self()

◆ sys_times()

◆ sys_uname()

◆ sys_waitpid()

Variable Documentation

◆ nodename