freebsd-skq/sys/kern/init_main.c
rwatson 647037845a Refresh the credential on the first initproc thread following divorcing
the initproc credential from the proc0 credential.  Otherwise, the
proc0 credential is used instead of initproc's credentil when authorizing
start_init() activities prior to initproc hitting userland for the
first time.  This could result in the incorrect credential being used
to authorize mounting of the root file system, which could in turn cause
problems for NFS when used in combination with uid/gid ipfw rules, or
with MAC.

Discussed with:	julian
2002-08-07 17:53:31 +00:00

696 lines
19 KiB
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
* $FreeBSD$
*/
#include "opt_init_path.h"
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mac.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 <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>
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;
struct thread thread0;
static struct procsig procsig0;
static struct filedesc0 filedesc0;
static struct plimit limit0;
static struct vmspace vmspace0;
struct proc *initproc;
int cmask = CMASK;
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.
*/
SET_DECLARE(sysinit_set, struct sysinit);
struct sysinit **sysinit, **sysinit_end;
struct sysinit **newsysinit, **newsysinit_end;
/*
* 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 **set_end)
{
struct sysinit **newset;
struct sysinit **sipp;
struct sysinit **xipp;
int count;
count = set_end - set;
if (newsysinit)
count += newsysinit_end - newsysinit;
else
count += sysinit_end - sysinit;
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 < newsysinit_end; sipp++)
*xipp++ = *sipp;
else
for (sipp = sysinit; sipp < sysinit_end; sipp++)
*xipp++ = *sipp;
for (sipp = set; sipp < set_end; sipp++)
*xipp++ = *sipp;
if (newsysinit)
free(newsysinit, M_TEMP);
newsysinit = newset;
newsysinit_end = newset + count;
}
/*
* 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*/
if (sysinit == NULL) {
sysinit = SET_BEGIN(sysinit_set);
sysinit_end = SET_LIMIT(sysinit_set);
}
restart:
/*
* Perform a bubble sort of the system initialization objects by
* their subsystem (primary key) and order (secondary key).
*/
for (sipp = sysinit; sipp < sysinit_end; sipp++) {
for (xipp = sipp + 1; xipp < sysinit_end; 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 < sysinit_end; 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 != SET_BEGIN(sysinit_set))
free(sysinit, M_TEMP);
sysinit = newsysinit;
sysinit_end = newsysinit_end;
newsysinit = NULL;
newsysinit_end = 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)
static struct sysentvec null_sysvec;
/*
***************************************************************************
****
**** 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;
struct thread *td;
struct ksegrp *kg;
struct kse *ke;
GIANT_REQUIRED;
p = &proc0;
td = &thread0;
/*
* Initialize magic number.
*/
p->p_magic = P_MAGIC;
/*
* Initialize thread, process and pgrp structures.
*/
procinit();
threadinit();
/*
* 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);
mtx_init(&pgrp0.pg_mtx, "process group", NULL, MTX_DEF | MTX_DUPOK);
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;
mtx_init(&session0.s_mtx, "session", NULL, MTX_DEF);
session0.s_count = 1;
session0.s_leader = p;
p->p_sysent = &null_sysvec;
/*
* proc_linkup was already done in init_i386() or alphainit() etc.
* because the earlier code needed to follow td->td_proc. Otherwise
* I would have done it here.. maybe this means this should be
* done earlier too.
*/
ke = &proc0.p_kse; /* XXXKSE */
kg = &proc0.p_ksegrp; /* XXXKSE */
p->p_flag = P_SYSTEM;
p->p_sflag = PS_INMEM;
p->p_state = PRS_NORMAL;
td->td_state = TDS_RUNNING;
kg->kg_nice = NZERO;
kg->kg_pri_class = PRI_TIMESHARE;
kg->kg_user_pri = PUSER;
td->td_priority = PVM;
td->td_base_pri = PUSER;
td->td_kse = ke; /* XXXKSE */
ke->ke_oncpu = 0;
ke->ke_state = KES_THREAD;
ke->ke_thread = td;
/* proc_linkup puts it in the idle queue, that's not what we want. */
TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist);
kg->kg_idle_kses--;
p->p_peers = 0;
p->p_leader = p;
KASSERT((ke->ke_kgrlist.tqe_next != ke), ("linked to self!"));
bcopy("swapper", p->p_comm, sizeof ("swapper"));
callout_init(&p->p_itcallout, 0);
callout_init(&td->td_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. */
#ifdef MAC
mac_create_proc0(p->p_ucred);
#endif
td->td_ucred = crhold(p->p_ucred);
/* 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;
mtx_init(&fdp->fd_fd.fd_mtx, FILEDESC_LOCK_DESC, NULL, MTX_DEF);
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. */
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);
/*
* We continue to place resource usage info and signal
* actions in the user struct so they're pageable.
*/
p->p_stats = &p->p_uarea->u_stats;
p->p_sigacts = &p->p_uarea->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 filesystem. Pretend that proc0 started now.
*/
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list) {
microtime(&p->p_stats->p_start);
p->p_runtime.sec = 0;
p->p_runtime.frac = 0;
}
sx_sunlock(&allproc_lock);
binuptime(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,
"Path used to search the init process");
/*
* 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 thread *td;
struct proc *p;
int init_does_devfs = 0;
mtx_lock(&Giant);
GIANT_REQUIRED;
td = curthread;
p = td->td_proc;
vfs_mountroot();
/* 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");
FILEDESC_LOCK(p->p_fd);
p->p_fd->fd_cdir = rootvnode;
VREF(p->p_fd->fd_cdir);
p->p_fd->fd_rdir = rootvnode;
VREF(p->p_fd->fd_rdir);
FILEDESC_UNLOCK(p->p_fd);
VOP_UNLOCK(rootvnode, 0, td);
#ifdef MAC
mac_create_root_mount(td->td_ucred, TAILQ_FIRST(&mountlist));
#endif
if (devfs_present) {
/*
* For disk based systems, we probably cannot do this yet
* since the fs will be read-only. But a NFS root
* might be ok. It is worth a shot.
*/
error = vn_mkdir("/dev", 0700, UIO_SYSSPACE, td);
if (error == EEXIST)
error = 0;
if (error == 0)
error = kernel_vmount(0, "fstype", "devfs",
"fspath", "/dev", NULL);
if (error != 0)
init_does_devfs = 1;
}
/*
* Need just enough stack to hold the faked-up "execve()" arguments.
*/
addr = trunc_page(USRSTACK - 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;
if ((var = getenv("init_path")) != NULL) {
strncpy(init_path, var, sizeof init_path);
init_path[sizeof init_path - 1] = 0;
freeenv(var);
}
if ((var = getenv("kern.fallback_elf_brand")) != NULL) {
fallback_elf_brand = strtol(var, NULL, 0);
freeenv(var);
}
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 (init_does_devfs) {
(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(td, &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)
{
struct ucred *newcred, *oldcred;
int error;
error = fork1(&thread0, RFFDG | RFPROC | RFSTOPPED, &initproc);
if (error)
panic("cannot fork init: %d\n", error);
/* divorce init's credentials from the kernel's */
newcred = crget();
PROC_LOCK(initproc);
initproc->p_flag |= P_SYSTEM;
oldcred = initproc->p_ucred;
crcopy(newcred, oldcred);
#ifdef MAC
mac_create_proc1(newcred);
#endif
initproc->p_ucred = newcred;
PROC_UNLOCK(initproc);
crfree(oldcred);
cred_update_thread(FIRST_THREAD_IN_PROC(initproc));
mtx_lock_spin(&sched_lock);
initproc->p_sflag |= PS_INMEM;
mtx_unlock_spin(&sched_lock);
cpu_set_fork_handler(FIRST_THREAD_IN_PROC(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)
{
struct thread *td;
td = FIRST_THREAD_IN_PROC(initproc);
mtx_lock_spin(&sched_lock);
setrunqueue(td); /* XXXKSE */
mtx_unlock_spin(&sched_lock);
}
SYSINIT(kickinit, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, kick_init, NULL)