2 * Copyright (c) 2006,2017 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Copyright (c) 1982, 1986, 1991, 1993
36 * The Regents of the University of California. All rights reserved.
37 * (c) UNIX System Laboratories, Inc.
38 * All or some portions of this file are derived from material licensed
39 * to the University of California by American Telephone and Telegraph
40 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
41 * the permission of UNIX System Laboratories, Inc.
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. Neither the name of the University nor the names of its contributors
52 * may be used to endorse or promote products derived from this software
53 * without specific prior written permission.
55 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67 * @(#)kern_resource.c 8.5 (Berkeley) 1/21/94
69 #include <sys/resource.h>
70 #include <sys/spinlock.h>
74 #include <sys/lockf.h>
75 #include <sys/kern_syscall.h>
77 #include <vm/vm_param.h>
79 #include <vm/vm_map.h>
81 #include <machine/pmap.h>
83 #include <sys/spinlock2.h>
85 static MALLOC_DEFINE(M_PLIMIT, "plimit", "resource limits");
87 static void plimit_copy(struct plimit *olimit, struct plimit *nlimit);
90 * Initialize proc0's plimit structure. All later plimit structures
91 * are inherited through fork.
94 plimit_init0(struct plimit *limit)
99 for (i = 0; i < RLIM_NLIMITS; ++i) {
100 limit->pl_rlimit[i].rlim_cur = RLIM_INFINITY;
101 limit->pl_rlimit[i].rlim_max = RLIM_INFINITY;
103 limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur = maxfiles;
104 limit->pl_rlimit[RLIMIT_NOFILE].rlim_max = maxfiles;
105 limit->pl_rlimit[RLIMIT_NPROC].rlim_cur = maxproc;
106 limit->pl_rlimit[RLIMIT_NPROC].rlim_max = maxproc;
107 lim = ptoa((rlim_t)vmstats.v_free_count);
108 limit->pl_rlimit[RLIMIT_RSS].rlim_max = lim;
109 limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_max = lim;
110 limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = lim / 3;
111 limit->p_cpulimit = RLIM_INFINITY;
113 spin_init(&limit->p_spin, "plimitinit");
117 * Return a plimit for use by a new forked process given the one
118 * contained in the parent process.
121 plimit_fork(struct proc *p1)
123 struct plimit *olimit = p1->p_limit;
124 struct plimit *nlimit;
128 * Try to share the parent's plimit structure. If we cannot, make
131 * NOTE: (count) value is field prior to increment.
133 count = atomic_fetchadd_int(&olimit->p_refcnt, 1);
135 if (count & PLIMITF_EXCLUSIVE) {
136 if ((count & PLIMITF_MASK) == 1 && p1->p_nthreads == 1) {
137 atomic_clear_int(&olimit->p_refcnt, PLIMITF_EXCLUSIVE);
139 nlimit = kmalloc(sizeof(*nlimit), M_PLIMIT, M_WAITOK);
140 plimit_copy(olimit, nlimit);
148 * This routine is called when a new LWP is created for a process. We
149 * must force exclusivity to ensure that p->p_limit remains stable.
151 * LWPs share the same process structure so this does not bump refcnt.
154 plimit_lwp_fork(struct proc *p)
156 struct plimit *olimit = p->p_limit;
157 struct plimit *nlimit;
160 count = olimit->p_refcnt;
162 if ((count & PLIMITF_EXCLUSIVE) == 0) {
164 nlimit = kmalloc(sizeof(*nlimit), M_PLIMIT, M_WAITOK);
165 plimit_copy(olimit, nlimit);
170 atomic_set_int(&olimit->p_refcnt, PLIMITF_EXCLUSIVE);
175 * This routine is called to fixup a process's p_limit structure prior
176 * to it being modified. If index >= 0 the specified modification is also
179 * This routine must make the limit structure exclusive. If we are threaded,
180 * the structure will already be exclusive. A later fork will convert it
181 * back to copy-on-write if possible.
183 * We can count on p->p_limit being stable since if we had created any
184 * threads it will have already been made exclusive.
187 plimit_modify(struct proc *p, int index, struct rlimit *rlim)
189 struct plimit *olimit;
190 struct plimit *nlimit;
197 count = olimit->p_refcnt;
199 if ((count & PLIMITF_EXCLUSIVE) == 0) {
201 nlimit = kmalloc(sizeof(*nlimit), M_PLIMIT, M_WAITOK);
202 plimit_copy(olimit, nlimit);
207 atomic_set_int(&olimit->p_refcnt, PLIMITF_EXCLUSIVE);
214 if (p->p_nthreads == 1) {
215 p->p_limit->pl_rlimit[index] = *rlim;
217 spin_lock(&olimit->p_spin);
218 p->p_limit->pl_rlimit[index].rlim_cur = rlim->rlim_cur;
219 p->p_limit->pl_rlimit[index].rlim_max = rlim->rlim_max;
220 spin_unlock(&olimit->p_spin);
226 * Destroy a process's plimit structure.
229 plimit_free(struct plimit *limit)
233 count = atomic_fetchadd_int(&limit->p_refcnt, -1);
235 if ((count & ~PLIMITF_EXCLUSIVE) == 1) {
236 limit->p_refcnt = -999;
237 kfree(limit, M_PLIMIT);
242 * Modify a resource limit (from system call)
245 kern_setrlimit(u_int which, struct rlimit *limp)
247 struct proc *p = curproc;
248 struct plimit *limit;
249 struct rlimit *alimp;
252 if (which >= RLIM_NLIMITS)
256 * We will be modifying a resource, make a copy if necessary.
258 plimit_modify(p, -1, NULL);
260 alimp = &limit->pl_rlimit[which];
263 * Preserve historical bugs by treating negative limits as unsigned.
265 if (limp->rlim_cur < 0)
266 limp->rlim_cur = RLIM_INFINITY;
267 if (limp->rlim_max < 0)
268 limp->rlim_max = RLIM_INFINITY;
270 spin_lock(&limit->p_spin);
271 if (limp->rlim_cur > alimp->rlim_max ||
272 limp->rlim_max > alimp->rlim_max) {
273 spin_unlock(&limit->p_spin);
274 error = priv_check_cred(p->p_ucred, PRIV_PROC_SETRLIMIT, 0);
278 spin_unlock(&limit->p_spin);
280 if (limp->rlim_cur > limp->rlim_max)
281 limp->rlim_cur = limp->rlim_max;
285 spin_lock(&limit->p_spin);
286 if (limp->rlim_cur > RLIM_INFINITY / (rlim_t)1000000)
287 limit->p_cpulimit = RLIM_INFINITY;
289 limit->p_cpulimit = (rlim_t)1000000 * limp->rlim_cur;
290 spin_unlock(&limit->p_spin);
293 if (limp->rlim_cur > maxdsiz)
294 limp->rlim_cur = maxdsiz;
295 if (limp->rlim_max > maxdsiz)
296 limp->rlim_max = maxdsiz;
300 if (limp->rlim_cur > maxssiz)
301 limp->rlim_cur = maxssiz;
302 if (limp->rlim_max > maxssiz)
303 limp->rlim_max = maxssiz;
305 * Stack is allocated to the max at exec time with only
306 * "rlim_cur" bytes accessible. If stack limit is going
307 * up make more accessible, if going down make inaccessible.
309 spin_lock(&limit->p_spin);
310 if (limp->rlim_cur != alimp->rlim_cur) {
315 if (limp->rlim_cur > alimp->rlim_cur) {
317 size = limp->rlim_cur - alimp->rlim_cur;
318 addr = USRSTACK - limp->rlim_cur;
321 size = alimp->rlim_cur - limp->rlim_cur;
322 addr = USRSTACK - alimp->rlim_cur;
324 spin_unlock(&limit->p_spin);
325 addr = trunc_page(addr);
326 size = round_page(size);
327 vm_map_protect(&p->p_vmspace->vm_map,
328 addr, addr+size, prot, FALSE);
330 spin_unlock(&limit->p_spin);
335 if (limp->rlim_cur > maxfilesperproc)
336 limp->rlim_cur = maxfilesperproc;
337 if (limp->rlim_max > maxfilesperproc)
338 limp->rlim_max = maxfilesperproc;
342 if (limp->rlim_cur > maxprocperuid)
343 limp->rlim_cur = maxprocperuid;
344 if (limp->rlim_max > maxprocperuid)
345 limp->rlim_max = maxprocperuid;
346 if (limp->rlim_cur < 1)
348 if (limp->rlim_max < 1)
351 case RLIMIT_POSIXLOCKS:
352 if (limp->rlim_cur > maxposixlocksperuid)
353 limp->rlim_cur = maxposixlocksperuid;
354 if (limp->rlim_max > maxposixlocksperuid)
355 limp->rlim_max = maxposixlocksperuid;
358 spin_lock(&limit->p_spin);
360 spin_unlock(&limit->p_spin);
365 * The rlimit indexed by which is returned in the second argument.
368 kern_getrlimit(u_int which, struct rlimit *limp)
370 struct proc *p = curproc;
371 struct plimit *limit;
374 * p is NULL when kern_getrlimit is called from a
375 * kernel thread. In this case as the calling proc
376 * isn't available we just skip the limit check.
381 if (which >= RLIM_NLIMITS)
385 *limp = p->p_rlimit[which];
391 * Determine if the cpu limit has been reached and return an operations
392 * code for the caller to perform.
395 plimit_testcpulimit(struct plimit *limit, u_int64_t ttime)
401 * Initial tests without the spinlock. This is the fast path.
402 * Any 32/64 bit glitches will fall through and retest with
405 if (limit->p_cpulimit == RLIM_INFINITY)
406 return(PLIMIT_TESTCPU_OK);
407 if (ttime <= limit->p_cpulimit)
408 return(PLIMIT_TESTCPU_OK);
410 if (ttime > limit->p_cpulimit) {
411 rlim = &limit->pl_rlimit[RLIMIT_CPU];
412 if (ttime / (rlim_t)1000000 >= rlim->rlim_max + 5)
413 mode = PLIMIT_TESTCPU_KILL;
415 mode = PLIMIT_TESTCPU_XCPU;
417 mode = PLIMIT_TESTCPU_OK;
424 * Helper routine to copy olimit to nlimit and initialize nlimit for
425 * use. nlimit's reference count will be set to 1 and its exclusive bit
430 plimit_copy(struct plimit *olimit, struct plimit *nlimit)
434 spin_init(&nlimit->p_spin, "plimitcopy");
435 nlimit->p_refcnt = 1;
439 * This routine returns the value of a resource, downscaled based on
440 * the processes fork depth and chroot depth (up to 50%). This mechanism
441 * is designed to prevent run-aways from blowing up unrelated processes
442 * running under the same UID.
444 * NOTE: Currently only applicable to RLIMIT_NPROC. We could also limit
445 * file descriptors but we shouldn't have to as these are allocated
449 plimit_getadjvalue(int i)
451 struct proc *p = curproc;
452 struct plimit *limit;
457 v = limit->pl_rlimit[i].rlim_cur;
458 if (i == RLIMIT_NPROC) {
460 * 10% per chroot (around 1/3% per fork depth), with a
461 * maximum of 50% downscaling of the resource limit.
466 v -= v * depth / 320;