/* $OpenBSD: kern_resource.c,v 1.74 2022/05/28 03:47:43 deraadt Exp $ */ /* $NetBSD: kern_resource.c,v 1.38 1996/10/23 07:19:38 matthias Exp $ */ /*- * 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 #include #include #include #include #include #include #include #include #include #include #include #include /* Resource usage check interval in msec */ #define RUCHECK_INTERVAL 1000 /* SIGXCPU interval in seconds of process runtime */ #define SIGXCPU_INTERVAL 5 struct plimit *lim_copy(struct plimit *); struct plimit *lim_write_begin(void); void lim_write_commit(struct plimit *); void tuagg_sub(struct tusage *, struct proc *); /* * Patchable maximum data and stack limits. */ rlim_t maxdmap = MAXDSIZ; rlim_t maxsmap = MAXSSIZ; /* * Serializes resource limit updates. * This lock has to be held together with ps_mtx when updating * the process' ps_limit. */ struct rwlock rlimit_lock = RWLOCK_INITIALIZER("rlimitlk"); /* * Resource controls and accounting. */ int sys_getpriority(struct proc *curp, void *v, register_t *retval) { struct sys_getpriority_args /* { syscallarg(int) which; syscallarg(id_t) who; } */ *uap = v; struct process *pr; int low = NZERO + PRIO_MAX + 1; switch (SCARG(uap, which)) { case PRIO_PROCESS: if (SCARG(uap, who) == 0) pr = curp->p_p; else pr = prfind(SCARG(uap, who)); if (pr == NULL) break; if (pr->ps_nice < low) low = pr->ps_nice; break; case PRIO_PGRP: { struct pgrp *pg; if (SCARG(uap, who) == 0) pg = curp->p_p->ps_pgrp; else if ((pg = pgfind(SCARG(uap, who))) == NULL) break; LIST_FOREACH(pr, &pg->pg_members, ps_pglist) if (pr->ps_nice < low) low = pr->ps_nice; break; } case PRIO_USER: if (SCARG(uap, who) == 0) SCARG(uap, who) = curp->p_ucred->cr_uid; LIST_FOREACH(pr, &allprocess, ps_list) if (pr->ps_ucred->cr_uid == SCARG(uap, who) && pr->ps_nice < low) low = pr->ps_nice; break; default: return (EINVAL); } if (low == NZERO + PRIO_MAX + 1) return (ESRCH); *retval = low - NZERO; return (0); } int sys_setpriority(struct proc *curp, void *v, register_t *retval) { struct sys_setpriority_args /* { syscallarg(int) which; syscallarg(id_t) who; syscallarg(int) prio; } */ *uap = v; struct process *pr; int found = 0, error = 0; switch (SCARG(uap, which)) { case PRIO_PROCESS: if (SCARG(uap, who) == 0) pr = curp->p_p; else pr = prfind(SCARG(uap, who)); if (pr == NULL) break; error = donice(curp, pr, SCARG(uap, prio)); found = 1; break; case PRIO_PGRP: { struct pgrp *pg; if (SCARG(uap, who) == 0) pg = curp->p_p->ps_pgrp; else if ((pg = pgfind(SCARG(uap, who))) == NULL) break; LIST_FOREACH(pr, &pg->pg_members, ps_pglist) { error = donice(curp, pr, SCARG(uap, prio)); found = 1; } break; } case PRIO_USER: if (SCARG(uap, who) == 0) SCARG(uap, who) = curp->p_ucred->cr_uid; LIST_FOREACH(pr, &allprocess, ps_list) if (pr->ps_ucred->cr_uid == SCARG(uap, who)) { error = donice(curp, pr, SCARG(uap, prio)); found = 1; } break; default: return (EINVAL); } if (!found) return (ESRCH); return (error); } int donice(struct proc *curp, struct process *chgpr, int n) { struct ucred *ucred = curp->p_ucred; struct proc *p; int s; if (ucred->cr_uid != 0 && ucred->cr_ruid != 0 && ucred->cr_uid != chgpr->ps_ucred->cr_uid && ucred->cr_ruid != chgpr->ps_ucred->cr_uid) return (EPERM); if (n > PRIO_MAX) n = PRIO_MAX; if (n < PRIO_MIN) n = PRIO_MIN; n += NZERO; if (n < chgpr->ps_nice && suser(curp)) return (EACCES); chgpr->ps_nice = n; SCHED_LOCK(s); TAILQ_FOREACH(p, &chgpr->ps_threads, p_thr_link) { setpriority(p, p->p_estcpu, n); } SCHED_UNLOCK(s); return (0); } int sys_setrlimit(struct proc *p, void *v, register_t *retval) { struct sys_setrlimit_args /* { syscallarg(int) which; syscallarg(const struct rlimit *) rlp; } */ *uap = v; struct rlimit alim; int error; error = copyin((caddr_t)SCARG(uap, rlp), (caddr_t)&alim, sizeof (struct rlimit)); if (error) return (error); #ifdef KTRACE if (KTRPOINT(p, KTR_STRUCT)) ktrrlimit(p, &alim); #endif return (dosetrlimit(p, SCARG(uap, which), &alim)); } int dosetrlimit(struct proc *p, u_int which, struct rlimit *limp) { struct rlimit *alimp; struct plimit *limit; rlim_t maxlim; int error; if (which >= RLIM_NLIMITS || limp->rlim_cur > limp->rlim_max) return (EINVAL); rw_enter_write(&rlimit_lock); alimp = &p->p_p->ps_limit->pl_rlimit[which]; if (limp->rlim_max > alimp->rlim_max) { if ((error = suser(p)) != 0) { rw_exit_write(&rlimit_lock); return (error); } } /* Get exclusive write access to the limit structure. */ limit = lim_write_begin(); alimp = &limit->pl_rlimit[which]; switch (which) { case RLIMIT_DATA: maxlim = maxdmap; break; case RLIMIT_STACK: maxlim = maxsmap; break; case RLIMIT_NOFILE: maxlim = maxfiles; break; case RLIMIT_NPROC: maxlim = maxprocess; break; default: maxlim = RLIM_INFINITY; break; } if (limp->rlim_max > maxlim) limp->rlim_max = maxlim; if (limp->rlim_cur > limp->rlim_max) limp->rlim_cur = limp->rlim_max; if (which == RLIMIT_CPU && limp->rlim_cur != RLIM_INFINITY && alimp->rlim_cur == RLIM_INFINITY) timeout_add_msec(&p->p_p->ps_rucheck_to, RUCHECK_INTERVAL); if (which == RLIMIT_STACK) { /* * 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) { vaddr_t addr; vsize_t size; vm_prot_t prot; struct vmspace *vm = p->p_vmspace; if (limp->rlim_cur > alimp->rlim_cur) { prot = PROT_READ | PROT_WRITE; size = limp->rlim_cur - alimp->rlim_cur; #ifdef MACHINE_STACK_GROWS_UP addr = (vaddr_t)vm->vm_maxsaddr + alimp->rlim_cur; #else addr = (vaddr_t)vm->vm_minsaddr - limp->rlim_cur; #endif } else { prot = PROT_NONE; size = alimp->rlim_cur - limp->rlim_cur; #ifdef MACHINE_STACK_GROWS_UP addr = (vaddr_t)vm->vm_maxsaddr + limp->rlim_cur; #else addr = (vaddr_t)vm->vm_minsaddr - alimp->rlim_cur; #endif } addr = trunc_page(addr); size = round_page(size); KERNEL_LOCK(); (void) uvm_map_protect(&vm->vm_map, addr, addr+size, prot, FALSE); KERNEL_UNLOCK(); } } *alimp = *limp; lim_write_commit(limit); rw_exit_write(&rlimit_lock); return (0); } int sys_getrlimit(struct proc *p, void *v, register_t *retval) { struct sys_getrlimit_args /* { syscallarg(int) which; syscallarg(struct rlimit *) rlp; } */ *uap = v; struct plimit *limit; struct rlimit alimp; int error; if (SCARG(uap, which) < 0 || SCARG(uap, which) >= RLIM_NLIMITS) return (EINVAL); limit = lim_read_enter(); alimp = limit->pl_rlimit[SCARG(uap, which)]; lim_read_leave(limit); error = copyout(&alimp, SCARG(uap, rlp), sizeof(struct rlimit)); #ifdef KTRACE if (error == 0 && KTRPOINT(p, KTR_STRUCT)) ktrrlimit(p, &alimp); #endif return (error); } void tuagg_sub(struct tusage *tup, struct proc *p) { timespecadd(&tup->tu_runtime, &p->p_rtime, &tup->tu_runtime); tup->tu_uticks += p->p_uticks; tup->tu_sticks += p->p_sticks; tup->tu_iticks += p->p_iticks; } /* * Aggregate a single thread's immediate time counts into the running * totals for the thread and process */ void tuagg_unlocked(struct process *pr, struct proc *p) { tuagg_sub(&pr->ps_tu, p); tuagg_sub(&p->p_tu, p); timespecclear(&p->p_rtime); p->p_uticks = 0; p->p_sticks = 0; p->p_iticks = 0; } void tuagg(struct process *pr, struct proc *p) { int s; SCHED_LOCK(s); tuagg_unlocked(pr, p); SCHED_UNLOCK(s); } /* * Transform the running time and tick information in a struct tusage * into user, system, and interrupt time usage. */ void calctsru(struct tusage *tup, struct timespec *up, struct timespec *sp, struct timespec *ip) { u_quad_t st, ut, it; int freq; st = tup->tu_sticks; ut = tup->tu_uticks; it = tup->tu_iticks; if (st + ut + it == 0) { timespecclear(up); timespecclear(sp); if (ip != NULL) timespecclear(ip); return; } freq = stathz ? stathz : hz; st = st * 1000000000 / freq; sp->tv_sec = st / 1000000000; sp->tv_nsec = st % 1000000000; ut = ut * 1000000000 / freq; up->tv_sec = ut / 1000000000; up->tv_nsec = ut % 1000000000; if (ip != NULL) { it = it * 1000000000 / freq; ip->tv_sec = it / 1000000000; ip->tv_nsec = it % 1000000000; } } void calcru(struct tusage *tup, struct timeval *up, struct timeval *sp, struct timeval *ip) { struct timespec u, s, i; calctsru(tup, &u, &s, ip != NULL ? &i : NULL); TIMESPEC_TO_TIMEVAL(up, &u); TIMESPEC_TO_TIMEVAL(sp, &s); if (ip != NULL) TIMESPEC_TO_TIMEVAL(ip, &i); } int sys_getrusage(struct proc *p, void *v, register_t *retval) { struct sys_getrusage_args /* { syscallarg(int) who; syscallarg(struct rusage *) rusage; } */ *uap = v; struct rusage ru; int error; error = dogetrusage(p, SCARG(uap, who), &ru); if (error == 0) { error = copyout(&ru, SCARG(uap, rusage), sizeof(ru)); #ifdef KTRACE if (error == 0 && KTRPOINT(p, KTR_STRUCT)) ktrrusage(p, &ru); #endif } return (error); } int dogetrusage(struct proc *p, int who, struct rusage *rup) { struct process *pr = p->p_p; struct proc *q; switch (who) { case RUSAGE_SELF: /* start with the sum of dead threads, if any */ if (pr->ps_ru != NULL) *rup = *pr->ps_ru; else memset(rup, 0, sizeof(*rup)); /* add on all living threads */ TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { ruadd(rup, &q->p_ru); tuagg(pr, q); } calcru(&pr->ps_tu, &rup->ru_utime, &rup->ru_stime, NULL); break; case RUSAGE_THREAD: *rup = p->p_ru; calcru(&p->p_tu, &rup->ru_utime, &rup->ru_stime, NULL); break; case RUSAGE_CHILDREN: *rup = pr->ps_cru; break; default: return (EINVAL); } return (0); } void ruadd(struct rusage *ru, struct rusage *ru2) { long *ip, *ip2; int i; timeradd(&ru->ru_utime, &ru2->ru_utime, &ru->ru_utime); timeradd(&ru->ru_stime, &ru2->ru_stime, &ru->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++; } /* * Check if the process exceeds its cpu resource allocation. * If over max, kill it. */ void rucheck(void *arg) { struct rlimit rlim; struct process *pr = arg; time_t runtime; int s; KERNEL_ASSERT_LOCKED(); SCHED_LOCK(s); runtime = pr->ps_tu.tu_runtime.tv_sec; SCHED_UNLOCK(s); mtx_enter(&pr->ps_mtx); rlim = pr->ps_limit->pl_rlimit[RLIMIT_CPU]; mtx_leave(&pr->ps_mtx); if ((rlim_t)runtime >= rlim.rlim_cur) { if ((rlim_t)runtime >= rlim.rlim_max) { prsignal(pr, SIGKILL); } else if (runtime >= pr->ps_nextxcpu) { prsignal(pr, SIGXCPU); pr->ps_nextxcpu = runtime + SIGXCPU_INTERVAL; } } timeout_add_msec(&pr->ps_rucheck_to, RUCHECK_INTERVAL); } struct pool plimit_pool; void lim_startup(struct plimit *limit0) { rlim_t lim; int i; pool_init(&plimit_pool, sizeof(struct plimit), 0, IPL_MPFLOOR, PR_WAITOK, "plimitpl", NULL); for (i = 0; i < nitems(limit0->pl_rlimit); i++) limit0->pl_rlimit[i].rlim_cur = limit0->pl_rlimit[i].rlim_max = RLIM_INFINITY; limit0->pl_rlimit[RLIMIT_NOFILE].rlim_cur = NOFILE; limit0->pl_rlimit[RLIMIT_NOFILE].rlim_max = MIN(NOFILE_MAX, (maxfiles - NOFILE > NOFILE) ? maxfiles - NOFILE : NOFILE); limit0->pl_rlimit[RLIMIT_NPROC].rlim_cur = MAXUPRC; lim = ptoa(uvmexp.free); limit0->pl_rlimit[RLIMIT_RSS].rlim_max = lim; lim = ptoa(64*1024); /* Default to very low */ limit0->pl_rlimit[RLIMIT_MEMLOCK].rlim_max = lim; limit0->pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = lim / 3; refcnt_init(&limit0->pl_refcnt); } /* * 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 * lim_copy(struct plimit *lim) { struct plimit *newlim; newlim = pool_get(&plimit_pool, PR_WAITOK); memcpy(newlim->pl_rlimit, lim->pl_rlimit, sizeof(struct rlimit) * RLIM_NLIMITS); refcnt_init(&newlim->pl_refcnt); return (newlim); } void lim_free(struct plimit *lim) { if (refcnt_rele(&lim->pl_refcnt) == 0) return; pool_put(&plimit_pool, lim); } void lim_fork(struct process *parent, struct process *child) { struct plimit *limit; mtx_enter(&parent->ps_mtx); limit = parent->ps_limit; refcnt_take(&limit->pl_refcnt); mtx_leave(&parent->ps_mtx); child->ps_limit = limit; if (limit->pl_rlimit[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) timeout_add_msec(&child->ps_rucheck_to, RUCHECK_INTERVAL); } /* * Return an exclusive write reference to the process' resource limit structure. * The caller has to release the structure by calling lim_write_commit(). * * This invalidates any plimit read reference held by the calling thread. */ struct plimit * lim_write_begin(void) { struct plimit *limit; struct proc *p = curproc; rw_assert_wrlock(&rlimit_lock); if (p->p_limit != NULL) lim_free(p->p_limit); p->p_limit = NULL; /* * It is safe to access ps_limit here without holding ps_mtx * because rlimit_lock excludes other writers. */ limit = p->p_p->ps_limit; if (P_HASSIBLING(p) || refcnt_shared(&limit->pl_refcnt)) limit = lim_copy(limit); return (limit); } /* * Finish exclusive write access to the plimit structure. * This makes the structure visible to other threads in the process. */ void lim_write_commit(struct plimit *limit) { struct plimit *olimit; struct proc *p = curproc; rw_assert_wrlock(&rlimit_lock); if (limit != p->p_p->ps_limit) { mtx_enter(&p->p_p->ps_mtx); olimit = p->p_p->ps_limit; p->p_p->ps_limit = limit; mtx_leave(&p->p_p->ps_mtx); lim_free(olimit); } } /* * Begin read access to the process' resource limit structure. * The access has to be finished by calling lim_read_leave(). * * Sections denoted by lim_read_enter() and lim_read_leave() cannot nest. */ struct plimit * lim_read_enter(void) { struct plimit *limit; struct proc *p = curproc; struct process *pr = p->p_p; /* * This thread might not observe the latest value of ps_limit * if another thread updated the limits very recently on another CPU. * However, the anomaly should disappear quickly, especially if * there is any synchronization activity between the threads (or * the CPUs). */ limit = p->p_limit; if (limit != pr->ps_limit) { mtx_enter(&pr->ps_mtx); limit = pr->ps_limit; refcnt_take(&limit->pl_refcnt); mtx_leave(&pr->ps_mtx); if (p->p_limit != NULL) lim_free(p->p_limit); p->p_limit = limit; } KASSERT(limit != NULL); return (limit); } /* * Get the value of the resource limit in given process. */ rlim_t lim_cur_proc(struct proc *p, int which) { struct process *pr = p->p_p; rlim_t val; KASSERT(which >= 0 && which < RLIM_NLIMITS); mtx_enter(&pr->ps_mtx); val = pr->ps_limit->pl_rlimit[which].rlim_cur; mtx_leave(&pr->ps_mtx); return (val); }