FreeBSD/Linux Kernel Cross Reference
sys/kern/init_main.c

     /*
      * Copyright (c) 1995 Terrence R. Lambert
      * All rights reserved.
      *
      * Copyright (c) 1982, 1986, 1989, 1991, 1992, 1993
      *      The Regents of the University of California.  All rights reserved.
      * (c) UNIX System Laboratories, Inc.
      * All or some portions of this file are derived from material licensed
      * to the University of California by American Telephone and Telegraph
     * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     * the permission of UNIX System Laboratories, Inc.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Berkeley and its contributors.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      @(#)init_main.c 8.9 (Berkeley) 1/21/94
     * $FreeBSD: src/sys/kern/init_main.c,v 1.51.2.8 1999/09/05 08:14:48 peter Exp $
     */
    
    #include "opt_rlimit.h"
    #include "opt_devfs.h"
    
    #include <sys/param.h>
    #include <sys/filedesc.h>
    #include <sys/kernel.h>
    #include <sys/sysctl.h>
    #include <sys/proc.h>
    #include <sys/resourcevar.h>
    #include <sys/signalvar.h>
    #include <sys/systm.h>
    #include <sys/vnode.h>
    #include <sys/sysent.h>
    #include <sys/reboot.h>
    #include <sys/sysproto.h>
    #include <sys/vmmeter.h>
    
    #include <machine/cpu.h>
    
    #include <vm/vm.h>
    #include <vm/vm_param.h>
    #include <vm/vm_prot.h>
    #include <vm/lock.h>
    #include <vm/pmap.h>
    #include <vm/vm_map.h>
    #include <sys/user.h>
    
    extern struct linker_set        sysinit_set;    /* XXX */
    
    extern void __main __P((void));
    extern void main __P((void *framep));
    
    /* Components of the first process -- never freed. */
    static struct session session0;
    static struct pgrp pgrp0;
    struct  proc proc0;
    static struct pcred cred0;
    static struct filedesc0 filedesc0;
    static struct plimit limit0;
    static struct vmspace vmspace0;
    struct  proc *curproc = &proc0;
    struct  proc *initproc;
    
    int cmask = CMASK;
    extern  struct user *proc0paddr;
    
    struct  vnode *rootvp;
    int     boothowto;
    
    struct  timeval boottime;
    SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime,
            CTLFLAG_RW, &boottime, timeval, "");
    
    static int shutdowntimeout = 120;
    SYSCTL_INT(_kern, OID_AUTO, shutdown_timeout,
           CTLFLAG_RW, &shutdowntimeout, 0, "");
   
   struct  timeval runtime;
   
   /*
    * Promiscuous argument pass for start_init()
    *
    * This is a kludge because we use a return from main() rather than a call
    * to a new routine in locore.s to kick the kernel alive from locore.s.
    */
   static void     *init_framep;
   
   
   #if __GNUC__ >= 2
   void __main() {}
   #endif
   
   
   /*
    * This ensures that there is at least one entry so that the sysinit_set
    * symbol is not undefined.  A sybsystem ID of SI_SUB_DUMMY is never
    * executed.
    */
   SYSINIT(placeholder, SI_SUB_DUMMY,SI_ORDER_ANY, NULL, NULL)
   
   
   /*
    * System startup; initialize the world, create process 0, mount root
    * filesystem, and fork to create init and pagedaemon.  Most of the
    * hard work is done in the lower-level initialization routines including
    * startup(), which does memory initialization and autoconfiguration.
    *
    * This allows simple addition of new kernel subsystems that require
    * boot time initialization.  It also allows substitution of subsystem
    * (for instance, a scheduler, kernel profiler, or VM system) by object
    * module.  Finally, it allows for optional "kernel threads", like an LFS
    * cleaner.
    */
   void
   main(framep)
           void *framep;
   {
   
           register struct sysinit **sipp;         /* system initialization*/
           register struct sysinit **xipp;         /* interior loop of sort*/
           register struct sysinit *save;          /* bubble*/
           int                     rval[2];        /* SI_TYPE_KTHREAD support*/
   
           /*
            * Save the locore.s frame pointer for start_init().
            */
           init_framep = framep;
   
           /*
            * Perform a bubble sort of the system initialization objects by
            * their subsystem (primary key) and order (secondary key).
            *
            * Since some things care about execution order, this is the
            * operation which ensures continued function.
            */
           for( sipp = (struct sysinit **)sysinit_set.ls_items; *sipp; sipp++) {
                   for( xipp = sipp + 1; *xipp; xipp++) {
                           if( (*sipp)->subsystem < (*xipp)->subsystem ||
                               ( (*sipp)->subsystem == (*xipp)->subsystem &&
                                 (*sipp)->order < (*xipp)->order))
                                   continue;       /* skip*/
                           save = *sipp;
                           *sipp = *xipp;
                           *xipp = save;
                   }
           }
   
           /*
            * Traverse the (now) ordered list of system initialization tasks.
            * Perform each task, and continue on to the next task.
            *
            * The last item on the list is expected to be the scheduler,
            * which will not return.
            */
           for( sipp = (struct sysinit **)sysinit_set.ls_items; *sipp; sipp++) {
                   if( (*sipp)->subsystem == SI_SUB_DUMMY)
                           continue;       /* skip dummy task(s)*/
   
                   switch( (*sipp)->type) {
                   case SI_TYPE_DEFAULT:
                           /* no special processing*/
                           (*((*sipp)->func))( (*sipp)->udata);
                           break;
   
                   case SI_TYPE_KTHREAD:
                           /* kernel thread*/
                           if (fork(&proc0, NULL, rval))
                                   panic("fork kernel process");
                           if (rval[1]) {
                                   (*((*sipp)->func))( (*sipp)->udata);
                                   /*
                                    * The call to start "init" returns
                                    * here after the scheduler has been
                                    * started, and returns to the caller
                                    * in i386/i386/locore.s.  This is a
                                    * necessary part of initialization
                                    * and is rather non-obvious.
                                    *
                                    * No other "kernel threads" should
                                    * return here.  Call panic() instead.
                                    */
                                   return;
                           }
                           break;
   
                   default:
                           panic( "init_main: unrecognized init type");
                   }
           }
   
           /* NOTREACHED*/
   }
   
   
   /*
    * Start a kernel process.  This is called after a fork() call in
    * main() in the file kern/init_main.c.
    *
    * This function is used to start "internal" daemons.
    */
   /* ARGSUSED*/
   void
   kproc_start(udata)
           void *udata;
   {
           struct kproc_desc       *kp = udata;
           struct proc             *p = curproc;
   
           /* save a global descriptor, if desired*/
           if( kp->global_procpp != NULL)
                   *kp->global_procpp      = p;
   
           /* this is a non-swapped system process*/
           p->p_flag |= P_INMEM | P_SYSTEM;
   
           /* set up arg0 for 'ps', et al*/
           strcpy( p->p_comm, kp->arg0);
   
           /* call the processes' main()...*/
           (*kp->func)();
   
           /* NOTREACHED */
           panic("kproc_start: %s", kp->arg0);
   }
   
   
   /*
    ***************************************************************************
    ****
    **** The following SYSINIT's belong elsewhere, but have not yet
    **** been moved.
    ****
    ***************************************************************************
    */
   #ifdef OMIT
   /*
    * Handled by vfs_mountroot (bad idea) at this time... should be
    * done the same as 4.4Lite2.
    */
   SYSINIT(swapinit, SI_SUB_SWAP, SI_ORDER_FIRST, swapinit, NULL)
   #endif  /* OMIT*/
   
   /*
    * Should get its own file...
    */
   #ifdef HPFPLIB
   char    copyright[] =
   "Copyright (c) 1982, 1986, 1989, 1991, 1993\n\tThe Regents of the University of California.\nCopyright (c) 1992 Hewlett-Packard Company\nCopyright (c) 1992 Motorola Inc.\nAll rights reserved.\n\n";
   #else
   char    copyright[] =
   "Copyright (c) 1992-1998 FreeBSD Inc.\n"
   #ifdef PC98
   "Copyright (c) 1994-1998  FreeBSD(98) porting team.\n"
   "Copyright (c) 1982, 1986, 1989, 1991, 1993\n\tThe Regents of the University of California.\n"
   "Copyright (c) 1992  A.Kojima F.Ukai M.Ishii (KMC).\n"
   "\tAll rights reserved.\n\n";
   #else
   "Copyright (c) 1982, 1986, 1989, 1991, 1993\n\tThe Regents of the University of California.  All rights reserved.\n\n";
   #endif
   #endif
   static void print_caddr_t __P((void *data));
   static void
   print_caddr_t(data)
           void *data;
   {
           printf("%s", (char *)data);
   }
   SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t, copyright)
   
   
   /*
    ***************************************************************************
    ****
    **** The two following SYSINT's are proc0 specific glue code.  I am not
    **** convinced that they can not be safely combined, but their order of
    **** operation has been maintained as the same as the original init_main.c
    **** for right now.
    ****
    **** These probably belong in init_proc.c or kern_proc.c, since they
    **** deal with proc0 (the fork template process).
    ****
    ***************************************************************************
    */
   /* ARGSUSED*/
   static void proc0_init __P((void *dummy));
   static void
   proc0_init(dummy)
           void *dummy;
   {
           register struct proc            *p;
           register struct filedesc0       *fdp;
           register unsigned i;
   
           /*
            * Initialize the current process pointer (curproc) before
            * any possible traps/probes to simplify trap processing.
            */
           p = &proc0;
           curproc = p;                    /* XXX redundant*/
   
           /*
            * Initialize process and pgrp structures.
            */
           procinit();
   
           /*
            * Initialize sleep queue hash table
            */
           sleepinit();
   
           /*
            * Create process 0 (the swapper).
            */
           LIST_INSERT_HEAD(&allproc, p, p_list);
           p->p_pgrp = &pgrp0;
           LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
           LIST_INIT(&pgrp0.pg_members);
           LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);
   
           pgrp0.pg_session = &session0;
           session0.s_count = 1;
           session0.s_leader = p;
   
           p->p_sysent = &aout_sysvec;
   
           p->p_flag = P_INMEM | P_SYSTEM;
           p->p_stat = SRUN;
           p->p_nice = NZERO;
           p->p_rtprio.type = RTP_PRIO_NORMAL;
           p->p_rtprio.prio = 0;
   
           bcopy("swapper", p->p_comm, sizeof ("swapper"));
   
           /* Create credentials. */
           cred0.p_refcnt = 1;
           p->p_cred = &cred0;
           p->p_ucred = crget();
           p->p_ucred->cr_ngroups = 1;     /* group 0 */
   
           /* Create the file descriptor table. */
           fdp = &filedesc0;
           p->p_fd = &fdp->fd_fd;
           fdp->fd_fd.fd_refcnt = 1;
           fdp->fd_fd.fd_cmask = cmask;
           fdp->fd_fd.fd_ofiles = fdp->fd_dfiles;
           fdp->fd_fd.fd_ofileflags = fdp->fd_dfileflags;
           fdp->fd_fd.fd_nfiles = NDFILE;
   
           /* Create the limits structures. */
           p->p_limit = &limit0;
           for (i = 0; i < sizeof(p->p_rlimit)/sizeof(p->p_rlimit[0]); i++)
                   limit0.pl_rlimit[i].rlim_cur =
                       limit0.pl_rlimit[i].rlim_max = RLIM_INFINITY;
           limit0.pl_rlimit[RLIMIT_NOFILE].rlim_cur = NOFILE;
           limit0.pl_rlimit[RLIMIT_NPROC].rlim_cur = MAXUPRC;
           i = ptoa(cnt.v_free_count);
           limit0.pl_rlimit[RLIMIT_RSS].rlim_max = i;
           limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_max = i;
           limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = i / 3;
           limit0.p_refcnt = 1;
   
           /* Allocate a prototype map so we have something to fork. */
           p->p_vmspace = &vmspace0;
           vmspace0.vm_refcnt = 1;
           pmap_pinit(&vmspace0.vm_pmap);
           vm_map_init(&vmspace0.vm_map, round_page(VM_MIN_ADDRESS),
               trunc_page(VM_MAXUSER_ADDRESS), TRUE);
           vmspace0.vm_map.pmap = &vmspace0.vm_pmap;
           p->p_addr = proc0paddr;                         /* XXX */
   
   #define INCOMPAT_LITES2
   #ifdef INCOMPAT_LITES2
           /*
            * proc0 needs to have a coherent frame base, too.
            * This probably makes the identical call for the init proc
            * that happens later unnecessary since it should inherit
            * it during the fork.
            */
           cpu_set_init_frame(p, init_framep);                     /* XXX! */
   #endif  /* INCOMPAT_LITES2*/
   
           /*
            * We continue to place resource usage info and signal
            * actions in the user struct so they're pageable.
            */
           p->p_stats = &p->p_addr->u_stats;
           p->p_sigacts = &p->p_addr->u_sigacts;
   
           /*
            * Charge root for one process.
            */
           (void)chgproccnt(0, 1);
   }
   SYSINIT(p0init, SI_SUB_INTRINSIC, SI_ORDER_FIRST, proc0_init, NULL)
   
   /* ARGSUSED*/
   static void proc0_post __P((void *dummy));
   static void
   proc0_post(dummy)
           void *dummy;
   {
           struct timeval tv;
   
           /*
            * Now can look at time, having had a chance to verify the time
            * from the file system.  Reset p->p_rtime as it may have been
            * munched in mi_switch() after the time got set.
            */
           proc0.p_stats->p_start = runtime = mono_time = boottime = time;
           proc0.p_rtime.tv_sec = proc0.p_rtime.tv_usec = 0;
   
           /*
            * Give the ``random'' number generator a thump.
            */
           microtime(&tv);
           srandom(tv.tv_sec ^ tv.tv_usec);
   
           /* Initialize signal state for process 0. */
           siginit(&proc0);
   }
   SYSINIT(p0post, SI_SUB_INTRINSIC_POST, SI_ORDER_FIRST, proc0_post, NULL)
   
   
   
   
   /*
    ***************************************************************************
    ****
    **** The following SYSINIT's and glue code should be moved to the
    **** respective files on a per subsystem basis.
    ****
    ***************************************************************************
    */
   /* ARGSUSED*/
   static void sched_setup __P((void *dummy));
   static void
   sched_setup(dummy)
           void *dummy;
   {
           /* Kick off timeout driven events by calling first time. */
           roundrobin(NULL);
           schedcpu(NULL);
   }
   SYSINIT(sched_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, sched_setup, NULL)
   
   /* ARGSUSED */
   static void root_conf __P((void *dummy));
   static void
   root_conf(dummy)
           void *dummy;
   {
           cpu_rootconf();
   }
   SYSINIT(root_conf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, root_conf, NULL)
   
   /* ARGSUSED*/
   static void xxx_vfs_mountroot __P((void *dummy));
   #ifdef BOOTP
   extern void bootpc_init __P((void));
   #endif
   static void
   xxx_vfs_mountroot(dummy)
           void *dummy;
   {
           /* XXX Add a separate SYSINIT entry */
   #ifdef BOOTP
           bootpc_init();
   #endif
           /* Mount the root file system. */
           if ((*mountroot)(mountrootvfsops))
                   panic("cannot mount root");
   }
   SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, xxx_vfs_mountroot, NULL)
   
   /* ARGSUSED*/
   static void xxx_vfs_root_fdtab __P((void *dummy));
   static void
   xxx_vfs_root_fdtab(dummy)
           void *dummy;
   {
           register struct filedesc0       *fdp = &filedesc0;
   
           /* Get the vnode for '/'.  Set fdp->fd_fd.fd_cdir to reference it. */
           if (VFS_ROOT(mountlist.cqh_first, &rootvnode))
                   panic("cannot find root vnode");
           fdp->fd_fd.fd_cdir = rootvnode;
           VREF(fdp->fd_fd.fd_cdir);
           VOP_UNLOCK(rootvnode);
           fdp->fd_fd.fd_rdir = NULL;
   }
   SYSINIT(retrofit, SI_SUB_ROOT_FDTAB, SI_ORDER_FIRST, xxx_vfs_root_fdtab, NULL)
   
   
   /*
    ***************************************************************************
    ****
    **** The following code probably belongs in another file, like
    **** kern/init_init.c.  It is here for two reasons only:
    ****
    ****   1)      This code returns to startup the system; this is
    ****           abnormal for a kernel thread.
    ****   2)      This code promiscuously uses init_frame
    ****
    ***************************************************************************
    */
   
   static void kthread_init __P((void *dummy));
   SYSINIT_KT(init,SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, kthread_init, NULL)
   
   
   static void start_init __P((struct proc *p, void *framep));
   
   /* ARGSUSED*/
   static void
   kthread_init(dummy)
           void *dummy;
   {
   
           /* Create process 1 (init(8)). */
           start_init(curproc, init_framep);
   
           /*
            * This is the only kernel thread allowed to return yo the
            * caller!!!
            */
           return; 
   }
   
   
   /*
    * List of paths to try when searching for "init".
    */
   static char *initpaths[] = {
           "/sbin/init",
           "/sbin/oinit",
           "/sbin/init.bak",
           "/stand/sysinstall",
           NULL,
   };
   
   /*
    * Start the initial user process; try exec'ing each pathname in "initpaths".
    * The program is invoked with one argument containing the boot flags.
    */
   static void
   start_init(p, framep)
           struct proc *p;
           void *framep;
   {
           vm_offset_t addr;
           struct execve_args args;
           int options, i, retval[2], error;
           char **pathp, *path, *ucp, **uap, *arg0, *arg1;
   
           initproc = p;
   
           /*
            * We need to set the system call frame as if we were entered through
            * a syscall() so that when we call execve() below, it will be able
            * to set the entry point (see setregs) when it tries to exec.  The
            * startup code in "locore.s" has allocated space for the frame and
            * passed a pointer to that space as main's argument.
            */
           cpu_set_init_frame(p, framep);
   
           /*
            * Need just enough stack to hold the faked-up "execve()" arguments.
            */
           addr = trunc_page(VM_MAXUSER_ADDRESS - PAGE_SIZE);
           if (vm_map_find(&p->p_vmspace->vm_map, NULL, 0, &addr, PAGE_SIZE, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0) != 0)
                   panic("init: couldn't allocate argument space");
           p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
           p->p_vmspace->vm_ssize = 1;
   
           for (pathp = &initpaths[0]; (path = *pathp) != NULL; pathp++) {
                   /*
                    * Move out the boot flag argument.
                    */
                   options = 0;
                   ucp = (char *)USRSTACK;
                   (void)subyte(--ucp, 0);         /* trailing zero */
                   if (boothowto & RB_SINGLE) {
                           (void)subyte(--ucp, 's');
                           options = 1;
                   }
   #ifdef notyet
                   if (boothowto & RB_FASTBOOT) {
                           (void)subyte(--ucp, 'f');
                           options = 1;
                   }
   #endif
   
   #ifdef BOOTCDROM
                   (void)subyte(--ucp, 'C');
                   options = 1;
   #endif
   
   #if defined(DEVFS) && defined(DEVFS_ROOT)
                   (void)subyte(--ucp, 'd');
                   options = 1;
   #endif
                   if (options == 0)
                           (void)subyte(--ucp, '-');
                   (void)subyte(--ucp, '-');               /* leading hyphen */
                   arg1 = ucp;
   
                   /*
                    * Move out the file name (also arg 0).
                    */
                   for (i = strlen(path) + 1; i >= 0; i--)
                           (void)subyte(--ucp, path[i]);
                   arg0 = ucp;
   
                   /*
                    * Move out the arg pointers.
                    */
                   uap = (char **)((int)ucp & ~(NBPW-1));
                   (void)suword((caddr_t)--uap, 0);        /* terminator */
                   (void)suword((caddr_t)--uap, (int)arg1);
                   (void)suword((caddr_t)--uap, (int)arg0);
   
                   /*
                    * Point at the arguments.
                    */
                   args.fname = arg0;
                   args.argv = uap;
                   args.envv = NULL;
   
                   /*
                    * Now try to exec the program.  If can't for any reason
                    * other than it doesn't exist, complain.
                    *
                    * Otherwise return to main() which returns to btext
                    * which completes the system startup.
                    */
                   if ((error = execve(p, &args, &retval[0])) == 0)
                           return;
                   if (error != ENOENT)
                           printf("exec %s: error %d\n", path, error);
           }
           printf("init: not found\n");
           panic("no init");
   }

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