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freebsd-nq/sys/kern/kern_resource.c
Alfred Perlstein 2395531439 Introduce a global lock for the vm subsystem (vm_mtx). 
vm_mtx does not recurse and is required for most low level
vm operations.

faults can not be taken without holding Giant.

Memory subsystems can now call the base page allocators safely.

Almost all atomic ops were removed as they are covered under the
vm mutex.

Alpha and ia64 now need to catch up to i386's trap handlers.

FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).

Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +00:00

911 lines
21 KiB
C
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/*-
* Copyright (c) 1982, 1986, 1991, 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.
*
* @(#)kern_resource.c 8.5 (Berkeley) 1/21/94
* $FreeBSD$
*/
#include "opt_compat.h"
#include "opt_rlimit.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sx.h>
#include <sys/time.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
static int donice __P((struct proc *curp, struct proc *chgp, int n));
/* dosetrlimit non-static: Needed by SysVR4 emulator */
int dosetrlimit __P((struct proc *p, u_int which, struct rlimit *limp));
static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
#define UIHASH(uid) (&uihashtbl[(uid) & uihash])
static struct mtx uihashtbl_mtx;
static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
static u_long uihash; /* size of hash table - 1 */
static struct uidinfo *uilookup __P((uid_t uid));
/*
* Resource controls and accounting.
*/
#ifndef _SYS_SYSPROTO_H_
struct getpriority_args {
int which;
int who;
};
#endif
int
getpriority(curp, uap)
struct proc *curp;
register struct getpriority_args *uap;
{
register struct proc *p;
register int low = PRIO_MAX + 1;
switch (uap->which) {
case PRIO_PROCESS:
if (uap->who == 0)
low = curp->p_nice;
else {
p = pfind(uap->who);
if (p == NULL)
break;
if (p_can(curp, p, P_CAN_SEE, NULL) == 0)
low = p->p_nice;
PROC_UNLOCK(p);
}
break;
case PRIO_PGRP: {
register struct pgrp *pg;
if (uap->who == 0)
pg = curp->p_pgrp;
else if ((pg = pgfind(uap->who)) == NULL)
break;
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
if (!p_can(curp, p, P_CAN_SEE, NULL) && p->p_nice < low)
low = p->p_nice;
}
break;
}
case PRIO_USER:
if (uap->who == 0)
uap->who = curp->p_ucred->cr_uid;
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list)
if (!p_can(curp, p, P_CAN_SEE, NULL) &&
p->p_ucred->cr_uid == uap->who &&
p->p_nice < low)
low = p->p_nice;
sx_sunlock(&allproc_lock);
break;
default:
return (EINVAL);
}
if (low == PRIO_MAX + 1)
return (ESRCH);
curp->p_retval[0] = low;
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct setpriority_args {
int which;
int who;
int prio;
};
#endif
/* ARGSUSED */
int
setpriority(curp, uap)
struct proc *curp;
register struct setpriority_args *uap;
{
register struct proc *p;
int found = 0, error = 0;
switch (uap->which) {
case PRIO_PROCESS:
if (uap->who == 0)
error = donice(curp, curp, uap->prio);
else {
p = pfind(uap->who);
if (p == 0)
break;
if (p_can(curp, p, P_CAN_SEE, NULL) == 0)
error = donice(curp, p, uap->prio);
PROC_UNLOCK(p);
}
found++;
break;
case PRIO_PGRP: {
register struct pgrp *pg;
if (uap->who == 0)
pg = curp->p_pgrp;
else if ((pg = pgfind(uap->who)) == NULL)
break;
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
if (!p_can(curp, p, P_CAN_SEE, NULL)) {
error = donice(curp, p, uap->prio);
found++;
}
}
break;
}
case PRIO_USER:
if (uap->who == 0)
uap->who = curp->p_ucred->cr_uid;
sx_slock(&allproc_lock);
LIST_FOREACH(p, &allproc, p_list)
if (p->p_ucred->cr_uid == uap->who &&
!p_can(curp, p, P_CAN_SEE, NULL)) {
error = donice(curp, p, uap->prio);
found++;
}
sx_sunlock(&allproc_lock);
break;
default:
return (EINVAL);
}
if (found == 0)
return (ESRCH);
return (error);
}
static int
donice(curp, chgp, n)
register struct proc *curp, *chgp;
register int n;
{
int error;
if ((error = p_can(curp, chgp, P_CAN_SCHED, NULL)))
return (error);
if (n > PRIO_MAX)
n = PRIO_MAX;
if (n < PRIO_MIN)
n = PRIO_MIN;
if (n < chgp->p_nice && suser(curp))
return (EACCES);
chgp->p_nice = n;
(void)resetpriority(chgp);
return (0);
}
/* rtprio system call */
#ifndef _SYS_SYSPROTO_H_
struct rtprio_args {
int function;
pid_t pid;
struct rtprio *rtp;
};
#endif
/*
* Set realtime priority
*/
/* ARGSUSED */
int
rtprio(curp, uap)
struct proc *curp;
register struct rtprio_args *uap;
{
register struct proc *p;
struct rtprio rtp;
int error;
if (uap->pid == 0) {
p = curp;
PROC_LOCK(p);
} else
p = pfind(uap->pid);
if (p == NULL)
return (ESRCH);
switch (uap->function) {
case RTP_LOOKUP:
if ((error = p_can(curp, p, P_CAN_SEE, NULL)))
break;
pri_to_rtp(&p->p_pri, &rtp);
error = copyout(&rtp, uap->rtp, sizeof(struct rtprio));
break;
case RTP_SET:
if ((error = p_can(curp, p, P_CAN_SCHED, NULL)) ||
(error = copyin(uap->rtp, &rtp, sizeof(struct rtprio))))
break;
/* disallow setting rtprio in most cases if not superuser */
if (suser(curp) != 0) {
/* can't set someone else's */
if (uap->pid) {
error = EPERM;
break;
}
/* can't set realtime priority */
/*
* Realtime priority has to be restricted for reasons which should be
* obvious. However, for idle priority, there is a potential for
* system deadlock if an idleprio process gains a lock on a resource
* that other processes need (and the idleprio process can't run
* due to a CPU-bound normal process). Fix me! XXX
*/
#if 0
if (RTP_PRIO_IS_REALTIME(rtp.type))
#endif
if (rtp.type != RTP_PRIO_NORMAL) {
error = EPERM;
break;
}
}
error = rtp_to_pri(&rtp, &p->p_pri);
break;
default:
error = EINVAL;
break;
}
PROC_UNLOCK(p);
return (error);
}
int
rtp_to_pri(struct rtprio *rtp, struct priority *pri)
{
if (rtp->prio > RTP_PRIO_MAX)
return (EINVAL);
switch (RTP_PRIO_BASE(rtp->type)) {
case RTP_PRIO_REALTIME:
pri->pri_level = PRI_MIN_REALTIME + rtp->prio;
break;
case RTP_PRIO_NORMAL:
pri->pri_level = PRI_MIN_TIMESHARE + rtp->prio;
break;
case RTP_PRIO_IDLE:
pri->pri_level = PRI_MIN_IDLE + rtp->prio;
break;
default:
return (EINVAL);
}
pri->pri_class = rtp->type;
pri->pri_native = pri->pri_level;
pri->pri_user = pri->pri_level;
return (0);
}
void
pri_to_rtp(struct priority *pri, struct rtprio *rtp)
{
switch (PRI_BASE(pri->pri_class)) {
case PRI_REALTIME:
rtp->prio = pri->pri_level - PRI_MIN_REALTIME;
break;
case PRI_TIMESHARE:
rtp->prio = pri->pri_level - PRI_MIN_TIMESHARE;
break;
case PRI_IDLE:
rtp->prio = pri->pri_level - PRI_MIN_IDLE;
break;
default:
break;
}
rtp->type = pri->pri_class;
}
#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
#ifndef _SYS_SYSPROTO_H_
struct osetrlimit_args {
u_int which;
struct orlimit *rlp;
};
#endif
/* ARGSUSED */
int
osetrlimit(p, uap)
struct proc *p;
register struct osetrlimit_args *uap;
{
struct orlimit olim;
struct rlimit lim;
int error;
if ((error =
copyin((caddr_t)uap->rlp, (caddr_t)&olim, sizeof(struct orlimit))))
return (error);
lim.rlim_cur = olim.rlim_cur;
lim.rlim_max = olim.rlim_max;
return (dosetrlimit(p, uap->which, &lim));
}
#ifndef _SYS_SYSPROTO_H_
struct ogetrlimit_args {
u_int which;
struct orlimit *rlp;
};
#endif
/* ARGSUSED */
int
ogetrlimit(p, uap)
struct proc *p;
register struct ogetrlimit_args *uap;
{
struct orlimit olim;
if (uap->which >= RLIM_NLIMITS)
return (EINVAL);
olim.rlim_cur = p->p_rlimit[uap->which].rlim_cur;
if (olim.rlim_cur == -1)
olim.rlim_cur = 0x7fffffff;
olim.rlim_max = p->p_rlimit[uap->which].rlim_max;
if (olim.rlim_max == -1)
olim.rlim_max = 0x7fffffff;
return (copyout((caddr_t)&olim, (caddr_t)uap->rlp, sizeof(olim)));
}
#endif /* COMPAT_43 || COMPAT_SUNOS */
#ifndef _SYS_SYSPROTO_H_
struct __setrlimit_args {
u_int which;
struct rlimit *rlp;
};
#endif
/* ARGSUSED */
int
setrlimit(p, uap)
struct proc *p;
register struct __setrlimit_args *uap;
{
struct rlimit alim;
int error;
if ((error =
copyin((caddr_t)uap->rlp, (caddr_t)&alim, sizeof (struct rlimit))))
return (error);
return (dosetrlimit(p, uap->which, &alim));
}
int
dosetrlimit(p, which, limp)
struct proc *p;
u_int which;
struct rlimit *limp;
{
register struct rlimit *alimp;
int error;
if (which >= RLIM_NLIMITS)
return (EINVAL);
alimp = &p->p_rlimit[which];
/*
* Preserve historical bugs by treating negative limits as unsigned.
*/
if (limp->rlim_cur < 0)
limp->rlim_cur = RLIM_INFINITY;
if (limp->rlim_max < 0)
limp->rlim_max = RLIM_INFINITY;
if (limp->rlim_cur > alimp->rlim_max ||
limp->rlim_max > alimp->rlim_max)
if ((error = suser_xxx(0, p, PRISON_ROOT)))
return (error);
if (limp->rlim_cur > limp->rlim_max)
limp->rlim_cur = limp->rlim_max;
if (p->p_limit->p_refcnt > 1 &&
(p->p_limit->p_lflags & PL_SHAREMOD) == 0) {
p->p_limit->p_refcnt--;
p->p_limit = limcopy(p->p_limit);
alimp = &p->p_rlimit[which];
}
switch (which) {
case RLIMIT_CPU:
if (limp->rlim_cur > RLIM_INFINITY / (rlim_t)1000000)
p->p_limit->p_cpulimit = RLIM_INFINITY;
else
p->p_limit->p_cpulimit =
(rlim_t)1000000 * limp->rlim_cur;
break;
case RLIMIT_DATA:
if (limp->rlim_cur > MAXDSIZ)
limp->rlim_cur = MAXDSIZ;
if (limp->rlim_max > MAXDSIZ)
limp->rlim_max = MAXDSIZ;
break;
case RLIMIT_STACK:
if (limp->rlim_cur > MAXSSIZ)
limp->rlim_cur = MAXSSIZ;
if (limp->rlim_max > MAXSSIZ)
limp->rlim_max = MAXSSIZ;
/*
* Stack is allocated to the max at exec time with only
* "rlim_cur" bytes accessible. If stack limit is going
* up make more accessible, if going down make inaccessible.
*/
if (limp->rlim_cur != alimp->rlim_cur) {
vm_offset_t addr;
vm_size_t size;
vm_prot_t prot;
if (limp->rlim_cur > alimp->rlim_cur) {
prot = VM_PROT_ALL;
size = limp->rlim_cur - alimp->rlim_cur;
addr = USRSTACK - limp->rlim_cur;
} else {
prot = VM_PROT_NONE;
size = alimp->rlim_cur - limp->rlim_cur;
addr = USRSTACK - alimp->rlim_cur;
}
addr = trunc_page(addr);
size = round_page(size);
mtx_lock(&vm_mtx);
(void) vm_map_protect(&p->p_vmspace->vm_map,
addr, addr+size, prot, FALSE);
mtx_unlock(&vm_mtx);
}
break;
case RLIMIT_NOFILE:
if (limp->rlim_cur > maxfilesperproc)
limp->rlim_cur = maxfilesperproc;
if (limp->rlim_max > maxfilesperproc)
limp->rlim_max = maxfilesperproc;
break;
case RLIMIT_NPROC:
if (limp->rlim_cur > maxprocperuid)
limp->rlim_cur = maxprocperuid;
if (limp->rlim_max > maxprocperuid)
limp->rlim_max = maxprocperuid;
if (limp->rlim_cur < 1)
limp->rlim_cur = 1;
if (limp->rlim_max < 1)
limp->rlim_max = 1;
break;
}
*alimp = *limp;
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct __getrlimit_args {
u_int which;
struct rlimit *rlp;
};
#endif
/* ARGSUSED */
int
getrlimit(p, uap)
struct proc *p;
register struct __getrlimit_args *uap;
{
if (uap->which >= RLIM_NLIMITS)
return (EINVAL);
return (copyout((caddr_t)&p->p_rlimit[uap->which], (caddr_t)uap->rlp,
sizeof (struct rlimit)));
}
/*
* Transform the running time and tick information in proc p into user,
* system, and interrupt time usage.
*/
void
calcru(p, up, sp, ip)
struct proc *p;
struct timeval *up;
struct timeval *sp;
struct timeval *ip;
{
/* {user, system, interrupt, total} {ticks, usec}; previous tu: */
u_int64_t ut, uu, st, su, it, iu, tt, tu, ptu;
int s;
struct timeval tv;
mtx_assert(&sched_lock, MA_OWNED);
/* XXX: why spl-protect ? worst case is an off-by-one report */
s = splstatclock();
ut = p->p_uticks;
st = p->p_sticks;
it = p->p_iticks;
splx(s);
tt = ut + st + it;
if (tt == 0) {
st = 1;
tt = 1;
}
tu = p->p_runtime;
if (p == curproc) {
/*
* Adjust for the current time slice. This is actually fairly
* important since the error here is on the order of a time
* quantum, which is much greater than the sampling error.
*/
microuptime(&tv);
if (timevalcmp(&tv, PCPU_PTR(switchtime), <))
printf("microuptime() went backwards (%ld.%06ld -> %ld.%06ld)\n",
PCPU_GET(switchtime.tv_sec), PCPU_GET(switchtime.tv_usec),
tv.tv_sec, tv.tv_usec);
else
tu += (tv.tv_usec - PCPU_GET(switchtime.tv_usec)) +
(tv.tv_sec - PCPU_GET(switchtime.tv_sec)) *
(int64_t)1000000;
}
ptu = p->p_uu + p->p_su + p->p_iu;
if (tu < ptu || (int64_t)tu < 0) {
/* XXX no %qd in kernel. Truncate. */
printf("calcru: negative time of %ld usec for pid %d (%s)\n",
(long)tu, p->p_pid, p->p_comm);
tu = ptu;
}
/* Subdivide tu. */
uu = (tu * ut) / tt;
su = (tu * st) / tt;
iu = tu - uu - su;
/* Enforce monotonicity. */
if (uu < p->p_uu || su < p->p_su || iu < p->p_iu) {
if (uu < p->p_uu)
uu = p->p_uu;
else if (uu + p->p_su + p->p_iu > tu)
uu = tu - p->p_su - p->p_iu;
if (st == 0)
su = p->p_su;
else {
su = ((tu - uu) * st) / (st + it);
if (su < p->p_su)
su = p->p_su;
else if (uu + su + p->p_iu > tu)
su = tu - uu - p->p_iu;
}
KASSERT(uu + su + p->p_iu <= tu,
("calcru: monotonisation botch 1"));
iu = tu - uu - su;
KASSERT(iu >= p->p_iu,
("calcru: monotonisation botch 2"));
}
p->p_uu = uu;
p->p_su = su;
p->p_iu = iu;
up->tv_sec = uu / 1000000;
up->tv_usec = uu % 1000000;
sp->tv_sec = su / 1000000;
sp->tv_usec = su % 1000000;
if (ip != NULL) {
ip->tv_sec = iu / 1000000;
ip->tv_usec = iu % 1000000;
}
}
#ifndef _SYS_SYSPROTO_H_
struct getrusage_args {
int who;
struct rusage *rusage;
};
#endif
/* ARGSUSED */
int
getrusage(p, uap)
register struct proc *p;
register struct getrusage_args *uap;
{
register struct rusage *rup;
switch (uap->who) {
case RUSAGE_SELF:
rup = &p->p_stats->p_ru;
mtx_lock_spin(&sched_lock);
calcru(p, &rup->ru_utime, &rup->ru_stime, NULL);
mtx_unlock_spin(&sched_lock);
break;
case RUSAGE_CHILDREN:
rup = &p->p_stats->p_cru;
break;
default:
return (EINVAL);
}
return (copyout((caddr_t)rup, (caddr_t)uap->rusage,
sizeof (struct rusage)));
}
void
ruadd(ru, ru2)
register struct rusage *ru, *ru2;
{
register long *ip, *ip2;
register int i;
timevaladd(&ru->ru_utime, &ru2->ru_utime);
timevaladd(&ru->ru_stime, &ru2->ru_stime);
if (ru->ru_maxrss < ru2->ru_maxrss)
ru->ru_maxrss = ru2->ru_maxrss;
ip = &ru->ru_first; ip2 = &ru2->ru_first;
for (i = &ru->ru_last - &ru->ru_first; i >= 0; i--)
*ip++ += *ip2++;
}
/*
* Make a copy of the plimit structure.
* We share these structures copy-on-write after fork,
* and copy when a limit is changed.
*/
struct plimit *
limcopy(lim)
struct plimit *lim;
{
register struct plimit *copy;
MALLOC(copy, struct plimit *, sizeof(struct plimit),
M_SUBPROC, M_WAITOK);
bcopy(lim->pl_rlimit, copy->pl_rlimit, sizeof(struct plimit));
copy->p_lflags = 0;
copy->p_refcnt = 1;
return (copy);
}
/*
* Find the uidinfo structure for a uid. This structure is used to
* track the total resource consumption (process count, socket buffer
* size, etc.) for the uid and impose limits.
*/
void
uihashinit()
{
uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
mtx_init(&uihashtbl_mtx, "uidinfo hash", MTX_DEF);
}
/*
* lookup a uidinfo struct for the parameter uid.
* uihashtbl_mtx must be locked.
*/
static struct uidinfo *
uilookup(uid)
uid_t uid;
{
struct uihashhead *uipp;
struct uidinfo *uip;
mtx_assert(&uihashtbl_mtx, MA_OWNED);
uipp = UIHASH(uid);
LIST_FOREACH(uip, uipp, ui_hash)
if (uip->ui_uid == uid)
break;
return (uip);
}
/*
* Find or allocate a struct uidinfo for a particular uid.
* Increase refcount on uidinfo struct returned.
* uifree() should be called on a struct uidinfo when released.
*/
struct uidinfo *
uifind(uid)
uid_t uid;
{
struct uidinfo *uip;
mtx_lock(&uihashtbl_mtx);
uip = uilookup(uid);
if (uip == NULL) {
struct uidinfo *old_uip;
mtx_unlock(&uihashtbl_mtx);
uip = malloc(sizeof(*uip), M_UIDINFO, M_WAITOK | M_ZERO);
mtx_lock(&uihashtbl_mtx);
/*
* There's a chance someone created our uidinfo while we
* were in malloc and not holding the lock, so we have to
* make sure we don't insert a duplicate uidinfo
*/
if ((old_uip = uilookup(uid)) != NULL) {
/* someone else beat us to it */
free(uip, M_UIDINFO);
uip = old_uip;
} else {
mtx_init(&uip->ui_mtx, "uidinfo struct", MTX_DEF);
uip->ui_uid = uid;
LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
}
}
uihold(uip);
mtx_unlock(&uihashtbl_mtx);
return (uip);
}
/*
* Place another refcount on a uidinfo struct.
*/
void
uihold(uip)
struct uidinfo *uip;
{
mtx_lock(&uip->ui_mtx);
uip->ui_ref++;
mtx_unlock(&uip->ui_mtx);
}
/*-
* Since uidinfo structs have a long lifetime, we use an
* opportunistic refcounting scheme to avoid locking the lookup hash
* for each release.
*
* If the refcount hits 0, we need to free the structure,
* which means we need to lock the hash.
* Optimal case:
* After locking the struct and lowering the refcount, if we find
* that we don't need to free, simply unlock and return.
* Suboptimal case:
* If refcount lowering results in need to free, bump the count
* back up, loose the lock and aquire the locks in the proper
* order to try again.
*/
void
uifree(uip)
struct uidinfo *uip;
{
/* Prepare for optimal case. */
mtx_lock(&uip->ui_mtx);
if (--uip->ui_ref != 0) {
mtx_unlock(&uip->ui_mtx);
return;
}
/* Prepare for suboptimal case. */
uip->ui_ref++;
mtx_unlock(&uip->ui_mtx);
mtx_lock(&uihashtbl_mtx);
mtx_lock(&uip->ui_mtx);
/*
* We must subtract one from the count again because we backed out
* our initial subtraction before dropping the lock.
* Since another thread may have added a reference after we dropped the
* initial lock we have to test for zero again.
*/
if (--uip->ui_ref == 0) {
LIST_REMOVE(uip, ui_hash);
mtx_unlock(&uihashtbl_mtx);
if (uip->ui_sbsize != 0)
/* XXX no %qd in kernel. Truncate. */
printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
uip->ui_uid, (long)uip->ui_sbsize);
if (uip->ui_proccnt != 0)
printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
uip->ui_uid, uip->ui_proccnt);
mtx_destroy(&uip->ui_mtx);
FREE(uip, M_UIDINFO);
return;
}
mtx_unlock(&uihashtbl_mtx);
mtx_unlock(&uip->ui_mtx);
}
/*
* Change the count associated with number of processes
* a given user is using. When 'max' is 0, don't enforce a limit
*/
int
chgproccnt(uip, diff, max)
struct uidinfo *uip;
int diff;
int max;
{
mtx_lock(&uip->ui_mtx);
/* don't allow them to exceed max, but allow subtraction */
if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
mtx_unlock(&uip->ui_mtx);
return (0);
}
uip->ui_proccnt += diff;
if (uip->ui_proccnt < 0)
printf("negative proccnt for uid = %d\n", uip->ui_uid);
mtx_unlock(&uip->ui_mtx);
return (1);
}
/*
* Change the total socket buffer size a user has used.
*/
int
chgsbsize(uip, hiwat, to, max)
struct uidinfo *uip;
u_long *hiwat;
u_long to;
rlim_t max;
{
rlim_t new;
int s;
s = splnet();
mtx_lock(&uip->ui_mtx);
new = uip->ui_sbsize + to - *hiwat;
/* don't allow them to exceed max, but allow subtraction */
if (to > *hiwat && new > max) {
splx(s);
mtx_unlock(&uip->ui_mtx);
return (0);
}
uip->ui_sbsize = new;
*hiwat = to;
if (uip->ui_sbsize < 0)
printf("negative sbsize for uid = %d\n", uip->ui_uid);
splx(s);
mtx_unlock(&uip->ui_mtx);
return (1);
}
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