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freebsd-dev/sys/kern/init_main.c
Robert Watson b1fc0ec1a7 o Merge contents of struct pcred into struct ucred. Specifically, add the 
real uid, saved uid, real gid, and saved gid to ucred, as well as the
  pcred->pc_uidinfo, which was associated with the real uid, only rename
  it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
  corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
  original macro that pointed.
  p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
  p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
  cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
  cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
  we figure out locking and optimizations; generally speaking, this
  means moving to a structure like this:
        newcred = crdup(oldcred);
        ...
        p->p_ucred = newcred;
        crfree(oldcred);
  It's not race-free, but better than nothing.  There are also races
  in sys_process.c, all inter-process authorization, fork, exec, and
  exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
  remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
  use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
  pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
  allocation.
o Clean up ktrcanset() to take into account changes, and move to using
  suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
  calls to better document current behavior.  In a couple of places,
  current behavior is a little questionable and we need to check
  POSIX.1 to make sure it's "right".  More commenting work still
  remains to be done.
o Update credential management calls, such as crfree(), to take into
  account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
      change_euid()
      change_egid()
      change_ruid()
      change_rgid()
      change_svuid()
      change_svgid()
  In each case, the call now acts on a credential not a process, and as
  such no longer requires more complicated process locking/etc.  They
  now assume the caller will do any necessary allocation of an
  exclusive credential reference.  Each is commented to document its
  reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
  and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
  questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
  processes and pcreds.  Note that this authorization, as well as
  CANSIGIO(), needs to be updated to use the p_cansignal() and
  p_cansched() centralized authorization routines, as they currently
  do not take into account some desirable restrictions that are handled
  by the centralized routines, as well as being inconsistent with other
  similar authorization instances.
o Update libkvm to take these changes into account.

Obtained from:	TrustedBSD Project
Reviewed by:	green, bde, jhb, freebsd-arch, freebsd-audit
2001-05-25 16:59:11 +00:00

624 lines
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/*
* 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
* $FreeBSD$
*/
#include "opt_init_path.h"
#include <sys/param.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/vnode.h>
#include <sys/sysent.h>
#include <sys/reboot.h>
#include <sys/sx.h>
#include <sys/sysproto.h>
#include <sys/vmmeter.h>
#include <sys/unistd.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <machine/cpu.h>
#include <machine/globals.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <sys/user.h>
#include <sys/copyright.h>
extern struct linker_set sysinit_set; /* XXX */
void mi_startup(void); /* Should be elsewhere */
/* Components of the first process -- never freed. */
static struct session session0;
static struct pgrp pgrp0;
struct proc proc0;
static struct procsig procsig0;
static struct filedesc0 filedesc0;
static struct plimit limit0;
static struct vmspace vmspace0;
struct proc *initproc;
int cmask = CMASK;
extern struct user *proc0paddr;
extern int fallback_elf_brand;
struct vnode *rootvp;
int boothowto = 0; /* initialized so that it can be patched */
SYSCTL_INT(_debug, OID_AUTO, boothowto, CTLFLAG_RD, &boothowto, 0, "");
int bootverbose;
SYSCTL_INT(_debug, OID_AUTO, bootverbose, CTLFLAG_RW, &bootverbose, 0, "");
/*
* 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)
/*
* The sysinit table itself. Items are checked off as the are run.
* If we want to register new sysinit types, add them to newsysinit.
*/
struct sysinit **sysinit = (struct sysinit **)sysinit_set.ls_items;
struct sysinit **newsysinit;
/*
* Merge a new sysinit set into the current set, reallocating it if
* necessary. This can only be called after malloc is running.
*/
void
sysinit_add(struct sysinit **set)
{
struct sysinit **newset;
struct sysinit **sipp;
struct sysinit **xipp;
int count = 0;
if (newsysinit)
for (sipp = newsysinit; *sipp; sipp++)
count++;
else
for (sipp = sysinit; *sipp; sipp++)
count++;
for (sipp = set; *sipp; sipp++)
count++;
count++; /* Trailing NULL */
newset = malloc(count * sizeof(*sipp), M_TEMP, M_NOWAIT);
if (newset == NULL)
panic("cannot malloc for sysinit");
xipp = newset;
if (newsysinit)
for (sipp = newsysinit; *sipp; sipp++)
*xipp++ = *sipp;
else
for (sipp = sysinit; *sipp; sipp++)
*xipp++ = *sipp;
for (sipp = set; *sipp; sipp++)
*xipp++ = *sipp;
*xipp = NULL;
if (newsysinit)
free(newsysinit, M_TEMP);
newsysinit = newset;
}
/*
* 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".
*/
void
mi_startup(void)
{
register struct sysinit **sipp; /* system initialization*/
register struct sysinit **xipp; /* interior loop of sort*/
register struct sysinit *save; /* bubble*/
restart:
/*
* Perform a bubble sort of the system initialization objects by
* their subsystem (primary key) and order (secondary key).
*/
for (sipp = sysinit; *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 = sysinit; *sipp; sipp++) {
if ((*sipp)->subsystem == SI_SUB_DUMMY)
continue; /* skip dummy task(s)*/
if ((*sipp)->subsystem == SI_SUB_DONE)
continue;
/* Call function */
(*((*sipp)->func))((*sipp)->udata);
/* Check off the one we're just done */
(*sipp)->subsystem = SI_SUB_DONE;
/* Check if we've installed more sysinit items via KLD */
if (newsysinit != NULL) {
if (sysinit != (struct sysinit **)sysinit_set.ls_items)
free(sysinit, M_TEMP);
sysinit = newsysinit;
newsysinit = NULL;
goto restart;
}
}
panic("Shouldn't get here!");
/* NOTREACHED*/
}
/*
***************************************************************************
****
**** The following SYSINIT's belong elsewhere, but have not yet
**** been moved.
****
***************************************************************************
*/
static void
print_caddr_t(void *data __unused)
{
printf("%s", (char *)data);
}
SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t, copyright)
SYSINIT(version, SI_SUB_COPYRIGHT, SI_ORDER_SECOND, print_caddr_t, version)
static void
set_boot_verbose(void *data __unused)
{
if (boothowto & RB_VERBOSE)
bootverbose++;
}
SYSINIT(boot_verbose, SI_SUB_TUNABLES, SI_ORDER_ANY, set_boot_verbose, NULL)
/*
***************************************************************************
****
**** 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(void *dummy __unused)
{
register struct proc *p;
register struct filedesc0 *fdp;
register unsigned i;
p = &proc0;
/*
* Initialize magic number.
*/
p->p_magic = P_MAGIC;
/*
* Initialize process and pgrp structures.
*/
procinit();
/*
* Initialize sleep queue hash table
*/
sleepinit();
/*
* additional VM structures
*/
vm_init2();
/*
* Create process 0 (the swapper).
*/
LIST_INSERT_HEAD(&allproc, p, p_list);
LIST_INSERT_HEAD(PIDHASH(0), p, p_hash);
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;
#ifdef __ELF__
p->p_sysent = &elf_freebsd_sysvec;
#else
p->p_sysent = &aout_sysvec;
#endif
p->p_flag = P_SYSTEM;
p->p_sflag = PS_INMEM;
p->p_stat = SRUN;
p->p_nice = NZERO;
p->p_pri.pri_class = PRI_TIMESHARE;
p->p_pri.pri_level = PVM;
p->p_pri.pri_native = PUSER;
p->p_pri.pri_user = PUSER;
p->p_peers = 0;
p->p_leader = p;
bcopy("swapper", p->p_comm, sizeof ("swapper"));
callout_init(&p->p_itcallout, 0);
callout_init(&p->p_slpcallout, 1);
/* Create credentials. */
p->p_ucred = crget();
p->p_ucred->cr_ngroups = 1; /* group 0 */
p->p_ucred->cr_uidinfo = uifind(0);
p->p_ucred->cr_ruidinfo = uifind(0);
p->p_ucred->cr_prison = NULL; /* Don't jail it. */
/* Create procsig. */
p->p_procsig = &procsig0;
p->p_procsig->ps_refcnt = 1;
/* Initialize signal state for process 0. */
siginit(&proc0);
/* 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 =
limit0.pl_rlimit[RLIMIT_NOFILE].rlim_max = maxfiles;
limit0.pl_rlimit[RLIMIT_NPROC].rlim_cur =
limit0.pl_rlimit[RLIMIT_NPROC].rlim_max = maxproc;
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_cpulimit = RLIM_INFINITY;
limit0.p_refcnt = 1;
/* Allocate a prototype map so we have something to fork. */
mtx_lock(&vm_mtx);
pmap_pinit0(vmspace_pmap(&vmspace0));
p->p_vmspace = &vmspace0;
vmspace0.vm_refcnt = 1;
vm_map_init(&vmspace0.vm_map, round_page(VM_MIN_ADDRESS),
trunc_page(VM_MAXUSER_ADDRESS));
vmspace0.vm_map.pmap = vmspace_pmap(&vmspace0);
mtx_unlock(&vm_mtx);
p->p_addr = proc0paddr; /* XXX */
/*
* 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(p->p_ucred->cr_ruidinfo, 1, 0);
}
SYSINIT(p0init, SI_SUB_INTRINSIC, SI_ORDER_FIRST, proc0_init, NULL)
/* ARGSUSED*/
static void
proc0_post(void *dummy __unused)
{
struct timespec ts;
struct proc *p;
/*
* Now we can look at the time, having had a chance to verify the
* time from the file system. Pretend that proc0 started now.
*/
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list) {
microtime(&p->p_stats->p_start);
p->p_runtime = 0;
}
sx_sunlock(&allproc_lock);
microuptime(PCPU_PTR(switchtime));
PCPU_SET(switchticks, ticks);
/*
* Give the ``random'' number generator a thump.
*/
nanotime(&ts);
srandom(ts.tv_sec ^ ts.tv_nsec);
}
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.
****
***************************************************************************
*/
/*
***************************************************************************
****
**** The following code probably belongs in another file, like
**** kern/init_init.c.
****
***************************************************************************
*/
/*
* List of paths to try when searching for "init".
*/
static char init_path[MAXPATHLEN] =
#ifdef INIT_PATH
__XSTRING(INIT_PATH);
#else
"/sbin/init:/sbin/oinit:/sbin/init.bak:/stand/sysinstall";
#endif
SYSCTL_STRING(_kern, OID_AUTO, init_path, CTLFLAG_RD, init_path, 0, "");
/*
* Start the initial user process; try exec'ing each pathname in init_path.
* The program is invoked with one argument containing the boot flags.
*/
static void
start_init(void *dummy)
{
vm_offset_t addr;
struct execve_args args;
int options, error;
char *var, *path, *next, *s;
char *ucp, **uap, *arg0, *arg1;
struct proc *p;
mtx_lock(&Giant);
p = curproc;
/* Get the vnode for '/'. Set p->p_fd->fd_cdir to reference it. */
if (VFS_ROOT(TAILQ_FIRST(&mountlist), &rootvnode))
panic("cannot find root vnode");
p->p_fd->fd_cdir = rootvnode;
VREF(p->p_fd->fd_cdir);
p->p_fd->fd_rdir = rootvnode;
VREF(p->p_fd->fd_rdir);
VOP_UNLOCK(rootvnode, 0, p);
/*
* Need just enough stack to hold the faked-up "execve()" arguments.
*/
addr = trunc_page(USRSTACK - PAGE_SIZE);
mtx_lock(&vm_mtx);
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;
mtx_unlock(&vm_mtx);
if ((var = getenv("init_path")) != NULL) {
strncpy(init_path, var, sizeof init_path);
init_path[sizeof init_path - 1] = 0;
}
if ((var = getenv("kern.fallback_elf_brand")) != NULL)
fallback_elf_brand = strtol(var, NULL, 0);
for (path = init_path; *path != '\0'; path = next) {
while (*path == ':')
path++;
if (*path == '\0')
break;
for (next = path; *next != '\0' && *next != ':'; next++)
/* nothing */ ;
if (bootverbose)
printf("start_init: trying %.*s\n", (int)(next - path),
path);
/*
* 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 (devfs_present) {
(void)subyte(--ucp, 'd');
options = 1;
}
if (options == 0)
(void)subyte(--ucp, '-');
(void)subyte(--ucp, '-'); /* leading hyphen */
arg1 = ucp;
/*
* Move out the file name (also arg 0).
*/
(void)subyte(--ucp, 0);
for (s = next - 1; s >= path; s--)
(void)subyte(--ucp, *s);
arg0 = ucp;
/*
* Move out the arg pointers.
*/
uap = (char **)((intptr_t)ucp & ~(sizeof(intptr_t)-1));
(void)suword((caddr_t)--uap, (long)0); /* terminator */
(void)suword((caddr_t)--uap, (long)(intptr_t)arg1);
(void)suword((caddr_t)--uap, (long)(intptr_t)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 via fork_trampoline() all the way
* to user mode as init!
*/
if ((error = execve(p, &args)) == 0) {
mtx_unlock(&Giant);
return;
}
if (error != ENOENT)
printf("exec %.*s: error %d\n", (int)(next - path),
path, error);
}
printf("init: not found in path %s\n", init_path);
panic("no init");
}
/*
* Like kthread_create(), but runs in it's own address space.
* We do this early to reserve pid 1.
*
* Note special case - do not make it runnable yet. Other work
* in progress will change this more.
*/
static void
create_init(const void *udata __unused)
{
int error;
error = fork1(&proc0, RFFDG | RFPROC | RFSTOPPED, &initproc);
if (error)
panic("cannot fork init: %d\n", error);
PROC_LOCK(initproc);
initproc->p_flag |= P_SYSTEM;
PROC_UNLOCK(initproc);
mtx_lock_spin(&sched_lock);
initproc->p_sflag |= PS_INMEM;
mtx_unlock_spin(&sched_lock);
cpu_set_fork_handler(initproc, start_init, NULL);
}
SYSINIT(init, SI_SUB_CREATE_INIT, SI_ORDER_FIRST, create_init, NULL)
/*
* Make it runnable now.
*/
static void
kick_init(const void *udata __unused)
{
mtx_lock_spin(&sched_lock);
initproc->p_stat = SRUN;
setrunqueue(initproc);
mtx_unlock_spin(&sched_lock);
}
SYSINIT(kickinit, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, kick_init, NULL)
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