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freebsd-skq/sys/kern/kern_resource.c
Konstantin Belousov 0659df6fad vm_map_protect: allow to set prot and max_prot in one go. 
This prevents a situation where other thread modifies map entries
permissions between setting max_prot, then relocking, then setting prot,
confusing the operation outcome.  E.g. you can get an error that is not
possible if operation is performed atomic.

Also enable setting rwx for max_prot even if map does not allow to set
effective rwx protection.

Reviewed by:	brooks, markj (previous version)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D28117
2021-01-13 01:35:22 +02:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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. 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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/priv.h>
#include <sys/proc.h>
#include <sys/refcount.h>
#include <sys/racct.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/sx.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/time.h>
#include <sys/umtx.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
static MALLOC_DEFINE(M_PLIMIT, "plimit", "plimit structures");
static MALLOC_DEFINE(M_UIDINFO, "uidinfo", "uidinfo structures");
#define UIHASH(uid) (&uihashtbl[(uid) & uihash])
static struct rwlock uihashtbl_lock;
static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
static u_long uihash; /* size of hash table - 1 */
static void calcru1(struct proc *p, struct rusage_ext *ruxp,
struct timeval *up, struct timeval *sp);
static int donice(struct thread *td, struct proc *chgp, int n);
static struct uidinfo *uilookup(uid_t uid);
static void ruxagg_ext_locked(struct rusage_ext *rux, struct thread *td);
/*
* Resource controls and accounting.
*/
#ifndef _SYS_SYSPROTO_H_
struct getpriority_args {
int which;
int who;
};
#endif
int
sys_getpriority(struct thread *td, struct getpriority_args *uap)
{
return (kern_getpriority(td, uap->which, uap->who));
}
int
kern_getpriority(struct thread *td, int which, int who)
{
struct proc *p;
struct pgrp *pg;
int error, low;
error = 0;
low = PRIO_MAX + 1;
switch (which) {
case PRIO_PROCESS:
if (who == 0)
low = td->td_proc->p_nice;
else {
p = pfind(who);
if (p == NULL)
break;
if (p_cansee(td, p) == 0)
low = p->p_nice;
PROC_UNLOCK(p);
}
break;
case PRIO_PGRP:
sx_slock(&proctree_lock);
if (who == 0) {
pg = td->td_proc->p_pgrp;
PGRP_LOCK(pg);
} else {
pg = pgfind(who);
if (pg == NULL) {
sx_sunlock(&proctree_lock);
break;
}
}
sx_sunlock(&proctree_lock);
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
if (p->p_state == PRS_NORMAL &&
p_cansee(td, p) == 0) {
if (p->p_nice < low)
low = p->p_nice;
}
PROC_UNLOCK(p);
}
PGRP_UNLOCK(pg);
break;
case PRIO_USER:
if (who == 0)
who = td->td_ucred->cr_uid;
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_state == PRS_NORMAL &&
p_cansee(td, p) == 0 &&
p->p_ucred->cr_uid == who) {
if (p->p_nice < low)
low = p->p_nice;
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
break;
default:
error = EINVAL;
break;
}
if (low == PRIO_MAX + 1 && error == 0)
error = ESRCH;
td->td_retval[0] = low;
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct setpriority_args {
int which;
int who;
int prio;
};
#endif
int
sys_setpriority(struct thread *td, struct setpriority_args *uap)
{
return (kern_setpriority(td, uap->which, uap->who, uap->prio));
}
int
kern_setpriority(struct thread *td, int which, int who, int prio)
{
struct proc *curp, *p;
struct pgrp *pg;
int found = 0, error = 0;
curp = td->td_proc;
switch (which) {
case PRIO_PROCESS:
if (who == 0) {
PROC_LOCK(curp);
error = donice(td, curp, prio);
PROC_UNLOCK(curp);
} else {
p = pfind(who);
if (p == NULL)
break;
error = p_cansee(td, p);
if (error == 0)
error = donice(td, p, prio);
PROC_UNLOCK(p);
}
found++;
break;
case PRIO_PGRP:
sx_slock(&proctree_lock);
if (who == 0) {
pg = curp->p_pgrp;
PGRP_LOCK(pg);
} else {
pg = pgfind(who);
if (pg == NULL) {
sx_sunlock(&proctree_lock);
break;
}
}
sx_sunlock(&proctree_lock);
LIST_FOREACH(p, &pg->pg_members, p_pglist) {
PROC_LOCK(p);
if (p->p_state == PRS_NORMAL &&
p_cansee(td, p) == 0) {
error = donice(td, p, prio);
found++;
}
PROC_UNLOCK(p);
}
PGRP_UNLOCK(pg);
break;
case PRIO_USER:
if (who == 0)
who = td->td_ucred->cr_uid;
sx_slock(&allproc_lock);
FOREACH_PROC_IN_SYSTEM(p) {
PROC_LOCK(p);
if (p->p_state == PRS_NORMAL &&
p->p_ucred->cr_uid == who &&
p_cansee(td, p) == 0) {
error = donice(td, p, prio);
found++;
}
PROC_UNLOCK(p);
}
sx_sunlock(&allproc_lock);
break;
default:
error = EINVAL;
break;
}
if (found == 0 && error == 0)
error = ESRCH;
return (error);
}
/*
* Set "nice" for a (whole) process.
*/
static int
donice(struct thread *td, struct proc *p, int n)
{
int error;
PROC_LOCK_ASSERT(p, MA_OWNED);
if ((error = p_cansched(td, p)))
return (error);
if (n > PRIO_MAX)
n = PRIO_MAX;
if (n < PRIO_MIN)
n = PRIO_MIN;
if (n < p->p_nice && priv_check(td, PRIV_SCHED_SETPRIORITY) != 0)
return (EACCES);
sched_nice(p, n);
return (0);
}
static int unprivileged_idprio;
SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_idprio, CTLFLAG_RW,
&unprivileged_idprio, 0, "Allow non-root users to set an idle priority");
/*
* Set realtime priority for LWP.
*/
#ifndef _SYS_SYSPROTO_H_
struct rtprio_thread_args {
int function;
lwpid_t lwpid;
struct rtprio *rtp;
};
#endif
int
sys_rtprio_thread(struct thread *td, struct rtprio_thread_args *uap)
{
struct proc *p;
struct rtprio rtp;
struct thread *td1;
int cierror, error;
/* Perform copyin before acquiring locks if needed. */
if (uap->function == RTP_SET)
cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
else
cierror = 0;
if (uap->lwpid == 0 || uap->lwpid == td->td_tid) {
p = td->td_proc;
td1 = td;
PROC_LOCK(p);
} else {
td1 = tdfind(uap->lwpid, -1);
if (td1 == NULL)
return (ESRCH);
p = td1->td_proc;
}
switch (uap->function) {
case RTP_LOOKUP:
if ((error = p_cansee(td, p)))
break;
pri_to_rtp(td1, &rtp);
PROC_UNLOCK(p);
return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
case RTP_SET:
if ((error = p_cansched(td, p)) || (error = cierror))
break;
/* Disallow setting rtprio in most cases if not superuser. */
/*
* Realtime priority has to be restricted for reasons which
* should be obvious. However, for idleprio processes, 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
*
* This problem is not only related to idleprio process.
* A user level program can obtain a file lock and hold it
* indefinitely. Additionally, without idleprio processes it is
* still conceivable that a program with low priority will never
* get to run. In short, allowing this feature might make it
* easier to lock a resource indefinitely, but it is not the
* only thing that makes it possible.
*/
if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
(RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
unprivileged_idprio == 0)) {
error = priv_check(td, PRIV_SCHED_RTPRIO);
if (error)
break;
}
error = rtp_to_pri(&rtp, td1);
break;
default:
error = EINVAL;
break;
}
PROC_UNLOCK(p);
return (error);
}
/*
* Set realtime priority.
*/
#ifndef _SYS_SYSPROTO_H_
struct rtprio_args {
int function;
pid_t pid;
struct rtprio *rtp;
};
#endif
int
sys_rtprio(struct thread *td, struct rtprio_args *uap)
{
struct proc *p;
struct thread *tdp;
struct rtprio rtp;
int cierror, error;
/* Perform copyin before acquiring locks if needed. */
if (uap->function == RTP_SET)
cierror = copyin(uap->rtp, &rtp, sizeof(struct rtprio));
else
cierror = 0;
if (uap->pid == 0) {
p = td->td_proc;
PROC_LOCK(p);
} else {
p = pfind(uap->pid);
if (p == NULL)
return (ESRCH);
}
switch (uap->function) {
case RTP_LOOKUP:
if ((error = p_cansee(td, p)))
break;
/*
* Return OUR priority if no pid specified,
* or if one is, report the highest priority
* in the process. There isn't much more you can do as
* there is only room to return a single priority.
* Note: specifying our own pid is not the same
* as leaving it zero.
*/
if (uap->pid == 0) {
pri_to_rtp(td, &rtp);
} else {
struct rtprio rtp2;
rtp.type = RTP_PRIO_IDLE;
rtp.prio = RTP_PRIO_MAX;
FOREACH_THREAD_IN_PROC(p, tdp) {
pri_to_rtp(tdp, &rtp2);
if (rtp2.type < rtp.type ||
(rtp2.type == rtp.type &&
rtp2.prio < rtp.prio)) {
rtp.type = rtp2.type;
rtp.prio = rtp2.prio;
}
}
}
PROC_UNLOCK(p);
return (copyout(&rtp, uap->rtp, sizeof(struct rtprio)));
case RTP_SET:
if ((error = p_cansched(td, p)) || (error = cierror))
break;
/*
* Disallow setting rtprio in most cases if not superuser.
* See the comment in sys_rtprio_thread about idprio
* threads holding a lock.
*/
if (RTP_PRIO_BASE(rtp.type) == RTP_PRIO_REALTIME ||
(RTP_PRIO_BASE(rtp.type) == RTP_PRIO_IDLE &&
!unprivileged_idprio)) {
error = priv_check(td, PRIV_SCHED_RTPRIO);
if (error)
break;
}
/*
* If we are setting our own priority, set just our
* thread but if we are doing another process,
* do all the threads on that process. If we
* specify our own pid we do the latter.
*/
if (uap->pid == 0) {
error = rtp_to_pri(&rtp, td);
} else {
FOREACH_THREAD_IN_PROC(p, td) {
if ((error = rtp_to_pri(&rtp, td)) != 0)
break;
}
}
break;
default:
error = EINVAL;
break;
}
PROC_UNLOCK(p);
return (error);
}
int
rtp_to_pri(struct rtprio *rtp, struct thread *td)
{
u_char newpri, oldclass, oldpri;
switch (RTP_PRIO_BASE(rtp->type)) {
case RTP_PRIO_REALTIME:
if (rtp->prio > RTP_PRIO_MAX)
return (EINVAL);
newpri = PRI_MIN_REALTIME + rtp->prio;
break;
case RTP_PRIO_NORMAL:
if (rtp->prio > (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE))
return (EINVAL);
newpri = PRI_MIN_TIMESHARE + rtp->prio;
break;
case RTP_PRIO_IDLE:
if (rtp->prio > RTP_PRIO_MAX)
return (EINVAL);
newpri = PRI_MIN_IDLE + rtp->prio;
break;
default:
return (EINVAL);
}
thread_lock(td);
oldclass = td->td_pri_class;
sched_class(td, rtp->type); /* XXX fix */
oldpri = td->td_user_pri;
sched_user_prio(td, newpri);
if (td->td_user_pri != oldpri && (oldclass != RTP_PRIO_NORMAL ||
td->td_pri_class != RTP_PRIO_NORMAL))
sched_prio(td, td->td_user_pri);
if (TD_ON_UPILOCK(td) && oldpri != newpri) {
critical_enter();
thread_unlock(td);
umtx_pi_adjust(td, oldpri);
critical_exit();
} else
thread_unlock(td);
return (0);
}
void
pri_to_rtp(struct thread *td, struct rtprio *rtp)
{
thread_lock(td);
switch (PRI_BASE(td->td_pri_class)) {
case PRI_REALTIME:
rtp->prio = td->td_base_user_pri - PRI_MIN_REALTIME;
break;
case PRI_TIMESHARE:
rtp->prio = td->td_base_user_pri - PRI_MIN_TIMESHARE;
break;
case PRI_IDLE:
rtp->prio = td->td_base_user_pri - PRI_MIN_IDLE;
break;
default:
break;
}
rtp->type = td->td_pri_class;
thread_unlock(td);
}
#if defined(COMPAT_43)
#ifndef _SYS_SYSPROTO_H_
struct osetrlimit_args {
u_int which;
struct orlimit *rlp;
};
#endif
int
osetrlimit(struct thread *td, struct osetrlimit_args *uap)
{
struct orlimit olim;
struct rlimit lim;
int error;
if ((error = copyin(uap->rlp, &olim, sizeof(struct orlimit))))
return (error);
lim.rlim_cur = olim.rlim_cur;
lim.rlim_max = olim.rlim_max;
error = kern_setrlimit(td, uap->which, &lim);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct ogetrlimit_args {
u_int which;
struct orlimit *rlp;
};
#endif
int
ogetrlimit(struct thread *td, struct ogetrlimit_args *uap)
{
struct orlimit olim;
struct rlimit rl;
int error;
if (uap->which >= RLIM_NLIMITS)
return (EINVAL);
lim_rlimit(td, uap->which, &rl);
/*
* XXX would be more correct to convert only RLIM_INFINITY to the
* old RLIM_INFINITY and fail with EOVERFLOW for other larger
* values. Most 64->32 and 32->16 conversions, including not
* unimportant ones of uids are even more broken than what we
* do here (they blindly truncate). We don't do this correctly
* here since we have little experience with EOVERFLOW yet.
* Elsewhere, getuid() can't fail...
*/
olim.rlim_cur = rl.rlim_cur > 0x7fffffff ? 0x7fffffff : rl.rlim_cur;
olim.rlim_max = rl.rlim_max > 0x7fffffff ? 0x7fffffff : rl.rlim_max;
error = copyout(&olim, uap->rlp, sizeof(olim));
return (error);
}
#endif /* COMPAT_43 */
#ifndef _SYS_SYSPROTO_H_
struct __setrlimit_args {
u_int which;
struct rlimit *rlp;
};
#endif
int
sys_setrlimit(struct thread *td, struct __setrlimit_args *uap)
{
struct rlimit alim;
int error;
if ((error = copyin(uap->rlp, &alim, sizeof(struct rlimit))))
return (error);
error = kern_setrlimit(td, uap->which, &alim);
return (error);
}
static void
lim_cb(void *arg)
{
struct rlimit rlim;
struct thread *td;
struct proc *p;
p = arg;
PROC_LOCK_ASSERT(p, MA_OWNED);
/*
* Check if the process exceeds its cpu resource allocation. If
* it reaches the max, arrange to kill the process in ast().
*/
if (p->p_cpulimit == RLIM_INFINITY)
return;
PROC_STATLOCK(p);
FOREACH_THREAD_IN_PROC(p, td) {
ruxagg(p, td);
}
PROC_STATUNLOCK(p);
if (p->p_rux.rux_runtime > p->p_cpulimit * cpu_tickrate()) {
lim_rlimit_proc(p, RLIMIT_CPU, &rlim);
if (p->p_rux.rux_runtime >= rlim.rlim_max * cpu_tickrate()) {
killproc(p, "exceeded maximum CPU limit");
} else {
if (p->p_cpulimit < rlim.rlim_max)
p->p_cpulimit += 5;
kern_psignal(p, SIGXCPU);
}
}
if ((p->p_flag & P_WEXIT) == 0)
callout_reset_sbt(&p->p_limco, SBT_1S, 0,
lim_cb, p, C_PREL(1));
}
int
kern_setrlimit(struct thread *td, u_int which, struct rlimit *limp)
{
return (kern_proc_setrlimit(td, td->td_proc, which, limp));
}
int
kern_proc_setrlimit(struct thread *td, struct proc *p, u_int which,
struct rlimit *limp)
{
struct plimit *newlim, *oldlim;
struct rlimit *alimp;
struct rlimit oldssiz;
int error;
if (which >= RLIM_NLIMITS)
return (EINVAL);
/*
* 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;
oldssiz.rlim_cur = 0;
newlim = lim_alloc();
PROC_LOCK(p);
oldlim = p->p_limit;
alimp = &oldlim->pl_rlimit[which];
if (limp->rlim_cur > alimp->rlim_max ||
limp->rlim_max > alimp->rlim_max)
if ((error = priv_check(td, PRIV_PROC_SETRLIMIT))) {
PROC_UNLOCK(p);
lim_free(newlim);
return (error);
}
if (limp->rlim_cur > limp->rlim_max)
limp->rlim_cur = limp->rlim_max;
lim_copy(newlim, oldlim);
alimp = &newlim->pl_rlimit[which];
switch (which) {
case RLIMIT_CPU:
if (limp->rlim_cur != RLIM_INFINITY &&
p->p_cpulimit == RLIM_INFINITY)
callout_reset_sbt(&p->p_limco, SBT_1S, 0,
lim_cb, p, C_PREL(1));
p->p_cpulimit = 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;
oldssiz = *alimp;
if (p->p_sysent->sv_fixlimit != NULL)
p->p_sysent->sv_fixlimit(&oldssiz,
RLIMIT_STACK);
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;
}
if (p->p_sysent->sv_fixlimit != NULL)
p->p_sysent->sv_fixlimit(limp, which);
*alimp = *limp;
p->p_limit = newlim;
PROC_UPDATE_COW(p);
PROC_UNLOCK(p);
lim_free(oldlim);
if (which == RLIMIT_STACK &&
/*
* Skip calls from exec_new_vmspace(), done when stack is
* not mapped yet.
*/
(td != curthread || (p->p_flag & P_INEXEC) == 0)) {
/*
* 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 != oldssiz.rlim_cur) {
vm_offset_t addr;
vm_size_t size;
vm_prot_t prot;
if (limp->rlim_cur > oldssiz.rlim_cur) {
prot = p->p_sysent->sv_stackprot;
size = limp->rlim_cur - oldssiz.rlim_cur;
addr = p->p_sysent->sv_usrstack -
limp->rlim_cur;
} else {
prot = VM_PROT_NONE;
size = oldssiz.rlim_cur - limp->rlim_cur;
addr = p->p_sysent->sv_usrstack -
oldssiz.rlim_cur;
}
addr = trunc_page(addr);
size = round_page(size);
(void)vm_map_protect(&p->p_vmspace->vm_map,
addr, addr + size, prot, 0,
VM_MAP_PROTECT_SET_PROT);
}
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct __getrlimit_args {
u_int which;
struct rlimit *rlp;
};
#endif
/* ARGSUSED */
int
sys_getrlimit(struct thread *td, struct __getrlimit_args *uap)
{
struct rlimit rlim;
int error;
if (uap->which >= RLIM_NLIMITS)
return (EINVAL);
lim_rlimit(td, uap->which, &rlim);
error = copyout(&rlim, uap->rlp, sizeof(struct rlimit));
return (error);
}
/*
* Transform the running time and tick information for children of proc p
* into user and system time usage.
*/
void
calccru(struct proc *p, struct timeval *up, struct timeval *sp)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
calcru1(p, &p->p_crux, up, sp);
}
/*
* Transform the running time and tick information in proc p into user
* and system time usage. If appropriate, include the current time slice
* on this CPU.
*/
void
calcru(struct proc *p, struct timeval *up, struct timeval *sp)
{
struct thread *td;
uint64_t runtime, u;
PROC_LOCK_ASSERT(p, MA_OWNED);
PROC_STATLOCK_ASSERT(p, MA_OWNED);
/*
* If we are getting stats for the current process, then add in the
* stats that this thread has accumulated in its current time slice.
* We reset the thread and CPU state as if we had performed a context
* switch right here.
*/
td = curthread;
if (td->td_proc == p) {
u = cpu_ticks();
runtime = u - PCPU_GET(switchtime);
td->td_runtime += runtime;
td->td_incruntime += runtime;
PCPU_SET(switchtime, u);
}
/* Make sure the per-thread stats are current. */
FOREACH_THREAD_IN_PROC(p, td) {
if (td->td_incruntime == 0)
continue;
ruxagg(p, td);
}
calcru1(p, &p->p_rux, up, sp);
}
/* Collect resource usage for a single thread. */
void
rufetchtd(struct thread *td, struct rusage *ru)
{
struct proc *p;
uint64_t runtime, u;
p = td->td_proc;
PROC_STATLOCK_ASSERT(p, MA_OWNED);
THREAD_LOCK_ASSERT(td, MA_OWNED);
/*
* If we are getting stats for the current thread, then add in the
* stats that this thread has accumulated in its current time slice.
* We reset the thread and CPU state as if we had performed a context
* switch right here.
*/
if (td == curthread) {
u = cpu_ticks();
runtime = u - PCPU_GET(switchtime);
td->td_runtime += runtime;
td->td_incruntime += runtime;
PCPU_SET(switchtime, u);
}
ruxagg_locked(p, td);
*ru = td->td_ru;
calcru1(p, &td->td_rux, &ru->ru_utime, &ru->ru_stime);
}
/* XXX: the MI version is too slow to use: */
#ifndef __HAVE_INLINE_FLSLL
#define flsll(x) (fls((x) >> 32) != 0 ? fls((x) >> 32) + 32 : fls(x))
#endif
static uint64_t
mul64_by_fraction(uint64_t a, uint64_t b, uint64_t c)
{
uint64_t acc, bh, bl;
int i, s, sa, sb;
/*
* Calculate (a * b) / c accurately enough without overflowing. c
* must be nonzero, and its top bit must be 0. a or b must be
* <= c, and the implementation is tuned for b <= c.
*
* The comments about times are for use in calcru1() with units of
* microseconds for 'a' and stathz ticks at 128 Hz for b and c.
*
* Let n be the number of top zero bits in c. Each iteration
* either returns, or reduces b by right shifting it by at least n.
* The number of iterations is at most 1 + 64 / n, and the error is
* at most the number of iterations.
*
* It is very unusual to need even 2 iterations. Previous
* implementations overflowed essentially by returning early in the
* first iteration, with n = 38 giving overflow at 105+ hours and
* n = 32 giving overlow at at 388+ days despite a more careful
* calculation. 388 days is a reasonable uptime, and the calculation
* needs to work for the uptime times the number of CPUs since 'a'
* is per-process.
*/
if (a >= (uint64_t)1 << 63)
return (0); /* Unsupported arg -- can't happen. */
acc = 0;
for (i = 0; i < 128; i++) {
sa = flsll(a);
sb = flsll(b);
if (sa + sb <= 64)
/* Up to 105 hours on first iteration. */
return (acc + (a * b) / c);
if (a >= c) {
/*
* This reduction is based on a = q * c + r, with the
* remainder r < c. 'a' may be large to start, and
* moving bits from b into 'a' at the end of the loop
* sets the top bit of 'a', so the reduction makes
* significant progress.
*/
acc += (a / c) * b;
a %= c;
sa = flsll(a);
if (sa + sb <= 64)
/* Up to 388 days on first iteration. */
return (acc + (a * b) / c);
}
/*
* This step writes a * b as a * ((bh << s) + bl) =
* a * (bh << s) + a * bl = (a << s) * bh + a * bl. The 2
* additive terms are handled separately. Splitting in
* this way is linear except for rounding errors.
*
* s = 64 - sa is the maximum such that a << s fits in 64
* bits. Since a < c and c has at least 1 zero top bit,
* sa < 64 and s > 0. Thus this step makes progress by
* reducing b (it increases 'a', but taking remainders on
* the next iteration completes the reduction).
*
* Finally, the choice for s is just what is needed to keep
* a * bl from overflowing, so we don't need complications
* like a recursive call mul64_by_fraction(a, bl, c) to
* handle the second additive term.
*/
s = 64 - sa;
bh = b >> s;
bl = b - (bh << s);
acc += (a * bl) / c;
a <<= s;
b = bh;
}
return (0); /* Algorithm failure -- can't happen. */
}
static void
calcru1(struct proc *p, struct rusage_ext *ruxp, struct timeval *up,
struct timeval *sp)
{
/* {user, system, interrupt, total} {ticks, usec}: */
uint64_t ut, uu, st, su, it, tt, tu;
ut = ruxp->rux_uticks;
st = ruxp->rux_sticks;
it = ruxp->rux_iticks;
tt = ut + st + it;
if (tt == 0) {
/* Avoid divide by zero */
st = 1;
tt = 1;
}
tu = cputick2usec(ruxp->rux_runtime);
if ((int64_t)tu < 0) {
/* XXX: this should be an assert /phk */
printf("calcru: negative runtime of %jd usec for pid %d (%s)\n",
(intmax_t)tu, p->p_pid, p->p_comm);
tu = ruxp->rux_tu;
}
/* Subdivide tu. Avoid overflow in the multiplications. */
if (__predict_true(tu <= ((uint64_t)1 << 38) && tt <= (1 << 26))) {
/* Up to 76 hours when stathz is 128. */
uu = (tu * ut) / tt;
su = (tu * st) / tt;
} else {
uu = mul64_by_fraction(tu, ut, tt);
su = mul64_by_fraction(tu, st, tt);
}
if (tu >= ruxp->rux_tu) {
/*
* The normal case, time increased.
* Enforce monotonicity of bucketed numbers.
*/
if (uu < ruxp->rux_uu)
uu = ruxp->rux_uu;
if (su < ruxp->rux_su)
su = ruxp->rux_su;
} else if (tu + 3 > ruxp->rux_tu || 101 * tu > 100 * ruxp->rux_tu) {
/*
* When we calibrate the cputicker, it is not uncommon to
* see the presumably fixed frequency increase slightly over
* time as a result of thermal stabilization and NTP
* discipline (of the reference clock). We therefore ignore
* a bit of backwards slop because we expect to catch up
* shortly. We use a 3 microsecond limit to catch low
* counts and a 1% limit for high counts.
*/
uu = ruxp->rux_uu;
su = ruxp->rux_su;
tu = ruxp->rux_tu;
} else { /* tu < ruxp->rux_tu */
/*
* What happened here was likely that a laptop, which ran at
* a reduced clock frequency at boot, kicked into high gear.
* The wisdom of spamming this message in that case is
* dubious, but it might also be indicative of something
* serious, so lets keep it and hope laptops can be made
* more truthful about their CPU speed via ACPI.
*/
printf("calcru: runtime went backwards from %ju usec "
"to %ju usec for pid %d (%s)\n",
(uintmax_t)ruxp->rux_tu, (uintmax_t)tu,
p->p_pid, p->p_comm);
}
ruxp->rux_uu = uu;
ruxp->rux_su = su;
ruxp->rux_tu = tu;
up->tv_sec = uu / 1000000;
up->tv_usec = uu % 1000000;
sp->tv_sec = su / 1000000;
sp->tv_usec = su % 1000000;
}
#ifndef _SYS_SYSPROTO_H_
struct getrusage_args {
int who;
struct rusage *rusage;
};
#endif
int
sys_getrusage(struct thread *td, struct getrusage_args *uap)
{
struct rusage ru;
int error;
error = kern_getrusage(td, uap->who, &ru);
if (error == 0)
error = copyout(&ru, uap->rusage, sizeof(struct rusage));
return (error);
}
int
kern_getrusage(struct thread *td, int who, struct rusage *rup)
{
struct proc *p;
int error;
error = 0;
p = td->td_proc;
PROC_LOCK(p);
switch (who) {
case RUSAGE_SELF:
rufetchcalc(p, rup, &rup->ru_utime,
&rup->ru_stime);
break;
case RUSAGE_CHILDREN:
*rup = p->p_stats->p_cru;
calccru(p, &rup->ru_utime, &rup->ru_stime);
break;
case RUSAGE_THREAD:
PROC_STATLOCK(p);
thread_lock(td);
rufetchtd(td, rup);
thread_unlock(td);
PROC_STATUNLOCK(p);
break;
default:
error = EINVAL;
}
PROC_UNLOCK(p);
return (error);
}
void
rucollect(struct rusage *ru, struct rusage *ru2)
{
long *ip, *ip2;
int i;
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++;
}
void
ruadd(struct rusage *ru, struct rusage_ext *rux, struct rusage *ru2,
struct rusage_ext *rux2)
{
rux->rux_runtime += rux2->rux_runtime;
rux->rux_uticks += rux2->rux_uticks;
rux->rux_sticks += rux2->rux_sticks;
rux->rux_iticks += rux2->rux_iticks;
rux->rux_uu += rux2->rux_uu;
rux->rux_su += rux2->rux_su;
rux->rux_tu += rux2->rux_tu;
rucollect(ru, ru2);
}
/*
* Aggregate tick counts into the proc's rusage_ext.
*/
static void
ruxagg_ext_locked(struct rusage_ext *rux, struct thread *td)
{
rux->rux_runtime += td->td_incruntime;
rux->rux_uticks += td->td_uticks;
rux->rux_sticks += td->td_sticks;
rux->rux_iticks += td->td_iticks;
}
void
ruxagg_locked(struct proc *p, struct thread *td)
{
THREAD_LOCK_ASSERT(td, MA_OWNED);
PROC_STATLOCK_ASSERT(td->td_proc, MA_OWNED);
ruxagg_ext_locked(&p->p_rux, td);
ruxagg_ext_locked(&td->td_rux, td);
td->td_incruntime = 0;
td->td_uticks = 0;
td->td_iticks = 0;
td->td_sticks = 0;
}
void
ruxagg(struct proc *p, struct thread *td)
{
thread_lock(td);
ruxagg_locked(p, td);
thread_unlock(td);
}
/*
* Update the rusage_ext structure and fetch a valid aggregate rusage
* for proc p if storage for one is supplied.
*/
void
rufetch(struct proc *p, struct rusage *ru)
{
struct thread *td;
PROC_STATLOCK_ASSERT(p, MA_OWNED);
*ru = p->p_ru;
if (p->p_numthreads > 0) {
FOREACH_THREAD_IN_PROC(p, td) {
ruxagg(p, td);
rucollect(ru, &td->td_ru);
}
}
}
/*
* Atomically perform a rufetch and a calcru together.
* Consumers, can safely assume the calcru is executed only once
* rufetch is completed.
*/
void
rufetchcalc(struct proc *p, struct rusage *ru, struct timeval *up,
struct timeval *sp)
{
PROC_STATLOCK(p);
rufetch(p, ru);
calcru(p, up, sp);
PROC_STATUNLOCK(p);
}
/*
* Allocate a new resource limits structure and initialize its
* reference count and mutex pointer.
*/
struct plimit *
lim_alloc()
{
struct plimit *limp;
limp = malloc(sizeof(struct plimit), M_PLIMIT, M_WAITOK);
refcount_init(&limp->pl_refcnt, 1);
return (limp);
}
struct plimit *
lim_hold(struct plimit *limp)
{
refcount_acquire(&limp->pl_refcnt);
return (limp);
}
void
lim_fork(struct proc *p1, struct proc *p2)
{
PROC_LOCK_ASSERT(p1, MA_OWNED);
PROC_LOCK_ASSERT(p2, MA_OWNED);
p2->p_limit = lim_hold(p1->p_limit);
callout_init_mtx(&p2->p_limco, &p2->p_mtx, 0);
if (p1->p_cpulimit != RLIM_INFINITY)
callout_reset_sbt(&p2->p_limco, SBT_1S, 0,
lim_cb, p2, C_PREL(1));
}
void
lim_free(struct plimit *limp)
{
if (refcount_release(&limp->pl_refcnt))
free((void *)limp, M_PLIMIT);
}
void
lim_freen(struct plimit *limp, int n)
{
if (refcount_releasen(&limp->pl_refcnt, n))
free((void *)limp, M_PLIMIT);
}
/*
* Make a copy of the plimit structure.
* We share these structures copy-on-write after fork.
*/
void
lim_copy(struct plimit *dst, struct plimit *src)
{
KASSERT(dst->pl_refcnt <= 1, ("lim_copy to shared limit"));
bcopy(src->pl_rlimit, dst->pl_rlimit, sizeof(src->pl_rlimit));
}
/*
* Return the hard limit for a particular system resource. The
* which parameter specifies the index into the rlimit array.
*/
rlim_t
lim_max(struct thread *td, int which)
{
struct rlimit rl;
lim_rlimit(td, which, &rl);
return (rl.rlim_max);
}
rlim_t
lim_max_proc(struct proc *p, int which)
{
struct rlimit rl;
lim_rlimit_proc(p, which, &rl);
return (rl.rlim_max);
}
/*
* Return the current (soft) limit for a particular system resource.
* The which parameter which specifies the index into the rlimit array
*/
rlim_t
(lim_cur)(struct thread *td, int which)
{
struct rlimit rl;
lim_rlimit(td, which, &rl);
return (rl.rlim_cur);
}
rlim_t
lim_cur_proc(struct proc *p, int which)
{
struct rlimit rl;
lim_rlimit_proc(p, which, &rl);
return (rl.rlim_cur);
}
/*
* Return a copy of the entire rlimit structure for the system limit
* specified by 'which' in the rlimit structure pointed to by 'rlp'.
*/
void
lim_rlimit(struct thread *td, int which, struct rlimit *rlp)
{
struct proc *p = td->td_proc;
MPASS(td == curthread);
KASSERT(which >= 0 && which < RLIM_NLIMITS,
("request for invalid resource limit"));
*rlp = td->td_limit->pl_rlimit[which];
if (p->p_sysent->sv_fixlimit != NULL)
p->p_sysent->sv_fixlimit(rlp, which);
}
void
lim_rlimit_proc(struct proc *p, int which, struct rlimit *rlp)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
KASSERT(which >= 0 && which < RLIM_NLIMITS,
("request for invalid resource limit"));
*rlp = p->p_limit->pl_rlimit[which];
if (p->p_sysent->sv_fixlimit != NULL)
p->p_sysent->sv_fixlimit(rlp, which);
}
void
uihashinit()
{
uihashtbl = hashinit(maxproc / 16, M_UIDINFO, &uihash);
rw_init(&uihashtbl_lock, "uidinfo hash");
}
/*
* Look up a uidinfo struct for the parameter uid.
* uihashtbl_lock must be locked.
* Increase refcount on uidinfo struct returned.
*/
static struct uidinfo *
uilookup(uid_t uid)
{
struct uihashhead *uipp;
struct uidinfo *uip;
rw_assert(&uihashtbl_lock, RA_LOCKED);
uipp = UIHASH(uid);
LIST_FOREACH(uip, uipp, ui_hash)
if (uip->ui_uid == uid) {
uihold(uip);
break;
}
return (uip);
}
/*
* Find or allocate a struct uidinfo for a particular uid.
* Returns with uidinfo struct referenced.
* uifree() should be called on a struct uidinfo when released.
*/
struct uidinfo *
uifind(uid_t uid)
{
struct uidinfo *new_uip, *uip;
struct ucred *cred;
cred = curthread->td_ucred;
if (cred->cr_uidinfo->ui_uid == uid) {
uip = cred->cr_uidinfo;
uihold(uip);
return (uip);
} else if (cred->cr_ruidinfo->ui_uid == uid) {
uip = cred->cr_ruidinfo;
uihold(uip);
return (uip);
}
rw_rlock(&uihashtbl_lock);
uip = uilookup(uid);
rw_runlock(&uihashtbl_lock);
if (uip != NULL)
return (uip);
new_uip = malloc(sizeof(*new_uip), M_UIDINFO, M_WAITOK | M_ZERO);
racct_create(&new_uip->ui_racct);
refcount_init(&new_uip->ui_ref, 1);
new_uip->ui_uid = uid;
rw_wlock(&uihashtbl_lock);
/*
* 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 ((uip = uilookup(uid)) == NULL) {
LIST_INSERT_HEAD(UIHASH(uid), new_uip, ui_hash);
rw_wunlock(&uihashtbl_lock);
uip = new_uip;
} else {
rw_wunlock(&uihashtbl_lock);
racct_destroy(&new_uip->ui_racct);
free(new_uip, M_UIDINFO);
}
return (uip);
}
/*
* Place another refcount on a uidinfo struct.
*/
void
uihold(struct uidinfo *uip)
{
refcount_acquire(&uip->ui_ref);
}
/*-
* 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, lose the lock and acquire the locks in the proper
* order to try again.
*/
void
uifree(struct uidinfo *uip)
{
if (refcount_release_if_not_last(&uip->ui_ref))
return;
rw_wlock(&uihashtbl_lock);
if (refcount_release(&uip->ui_ref) == 0) {
rw_wunlock(&uihashtbl_lock);
return;
}
racct_destroy(&uip->ui_racct);
LIST_REMOVE(uip, ui_hash);
rw_wunlock(&uihashtbl_lock);
if (uip->ui_sbsize != 0)
printf("freeing uidinfo: uid = %d, sbsize = %ld\n",
uip->ui_uid, uip->ui_sbsize);
if (uip->ui_proccnt != 0)
printf("freeing uidinfo: uid = %d, proccnt = %ld\n",
uip->ui_uid, uip->ui_proccnt);
if (uip->ui_vmsize != 0)
printf("freeing uidinfo: uid = %d, swapuse = %lld\n",
uip->ui_uid, (unsigned long long)uip->ui_vmsize);
free(uip, M_UIDINFO);
}
#ifdef RACCT
void
ui_racct_foreach(void (*callback)(struct racct *racct,
void *arg2, void *arg3), void (*pre)(void), void (*post)(void),
void *arg2, void *arg3)
{
struct uidinfo *uip;
struct uihashhead *uih;
rw_rlock(&uihashtbl_lock);
if (pre != NULL)
(pre)();
for (uih = &uihashtbl[uihash]; uih >= uihashtbl; uih--) {
LIST_FOREACH(uip, uih, ui_hash) {
(callback)(uip->ui_racct, arg2, arg3);
}
}
if (post != NULL)
(post)();
rw_runlock(&uihashtbl_lock);
}
#endif
static inline int
chglimit(struct uidinfo *uip, long *limit, int diff, rlim_t max, const char *name)
{
long new;
/* Don't allow them to exceed max, but allow subtraction. */
new = atomic_fetchadd_long(limit, (long)diff) + diff;
if (diff > 0 && max != 0) {
if (new < 0 || new > max) {
atomic_subtract_long(limit, (long)diff);
return (0);
}
} else if (new < 0)
printf("negative %s for uid = %d\n", name, uip->ui_uid);
return (1);
}
/*
* Change the count associated with number of processes
* a given user is using. When 'max' is 0, don't enforce a limit
*/
int
chgproccnt(struct uidinfo *uip, int diff, rlim_t max)
{
return (chglimit(uip, &uip->ui_proccnt, diff, max, "proccnt"));
}
/*
* Change the total socket buffer size a user has used.
*/
int
chgsbsize(struct uidinfo *uip, u_int *hiwat, u_int to, rlim_t max)
{
int diff, rv;
diff = to - *hiwat;
if (diff > 0 && max == 0) {
rv = 0;
} else {
rv = chglimit(uip, &uip->ui_sbsize, diff, max, "sbsize");
if (rv != 0)
*hiwat = to;
}
return (rv);
}
/*
* Change the count associated with number of pseudo-terminals
* a given user is using. When 'max' is 0, don't enforce a limit
*/
int
chgptscnt(struct uidinfo *uip, int diff, rlim_t max)
{
return (chglimit(uip, &uip->ui_ptscnt, diff, max, "ptscnt"));
}
int
chgkqcnt(struct uidinfo *uip, int diff, rlim_t max)
{
return (chglimit(uip, &uip->ui_kqcnt, diff, max, "kqcnt"));
}
int
chgumtxcnt(struct uidinfo *uip, int diff, rlim_t max)
{
return (chglimit(uip, &uip->ui_umtxcnt, diff, max, "umtxcnt"));
}
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