2 * Copyright (c) 2006 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>
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52 * may be used to endorse or promote products derived from this software
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67 * @(#)kern_resource.c 8.5 (Berkeley) 1/21/94
68 * $FreeBSD: src/sys/kern/kern_resource.c,v 1.55.2.5 2001/11/03 01:41:08 ps Exp $
69 * $DragonFly: src/sys/kern/kern_plimit.c,v 1.3 2008/05/08 01:26:00 dillon Exp $
72 #include <sys/resource.h>
73 #include <sys/spinlock.h>
77 #include <sys/lockf.h>
78 #include <sys/kern_syscall.h>
80 #include <vm/vm_param.h>
82 #include <vm/vm_map.h>
84 #include <machine/pmap.h>
86 #include <sys/spinlock2.h>
88 static void plimit_copy(struct plimit
*olimit
, struct plimit
*nlimit
);
91 * Initialize proc0's plimit structure. All later plimit structures
92 * are inherited through fork.
95 plimit_init0(struct plimit
*limit
)
100 for (i
= 0; i
< RLIM_NLIMITS
; ++i
) {
101 limit
->pl_rlimit
[i
].rlim_cur
= RLIM_INFINITY
;
102 limit
->pl_rlimit
[i
].rlim_max
= RLIM_INFINITY
;
104 limit
->pl_rlimit
[RLIMIT_NOFILE
].rlim_cur
= maxfiles
;
105 limit
->pl_rlimit
[RLIMIT_NOFILE
].rlim_max
= maxfiles
;
106 limit
->pl_rlimit
[RLIMIT_NPROC
].rlim_cur
= maxproc
;
107 limit
->pl_rlimit
[RLIMIT_NPROC
].rlim_max
= maxproc
;
108 lim
= ptoa((rlim_t
)vmstats
.v_free_count
);
109 limit
->pl_rlimit
[RLIMIT_RSS
].rlim_max
= lim
;
110 limit
->pl_rlimit
[RLIMIT_MEMLOCK
].rlim_max
= lim
;
111 limit
->pl_rlimit
[RLIMIT_MEMLOCK
].rlim_cur
= lim
/ 3;
112 limit
->p_cpulimit
= RLIM_INFINITY
;
114 spin_init(&limit
->p_spin
);
118 * Return a plimit for use by a new forked process given the one
119 * contained in the parent process.
124 plimit_fork(struct proc
*p1
)
126 struct plimit
*olimit
= p1
->p_limit
;
127 struct plimit
*nlimit
= NULL
;
128 struct plimit
*rlimit
;
131 * If we are exclusive (but not threaded-exclusive), but have only
132 * one reference, we can convert the structure to copy-on-write
135 * If we were threaded but are no longer threaded we can do the same
138 if (olimit
->p_exclusive
== 1) {
139 KKASSERT(olimit
->p_refcnt
== 1);
140 olimit
->p_exclusive
= 0;
141 } else if (olimit
->p_exclusive
== 2 && p1
->p_nthreads
== 1) {
142 KKASSERT(olimit
->p_refcnt
== 1);
143 olimit
->p_exclusive
= 0;
147 * Take a short-cut that requires limited spin locks. If we aren't
148 * exclusive we will not be threaded and we can just bump the ref
149 * count. If that is true and we also have only one ref then there
150 * can be no other accessors.
152 if (olimit
->p_exclusive
== 0) {
153 if (olimit
->p_refcnt
== 1) {
156 spin_lock_wr(&olimit
->p_spin
);
158 spin_unlock_wr(&olimit
->p_spin
);
164 * Full-blown code-up.
167 spin_lock_wr(&olimit
->p_spin
);
170 if (olimit
->p_exclusive
== 0) {
176 plimit_copy(olimit
, nlimit
);
181 spin_unlock_wr(&olimit
->p_spin
);
182 nlimit
= kmalloc(sizeof(*nlimit
), M_SUBPROC
, M_WAITOK
);
183 spin_lock_wr(&olimit
->p_spin
);
185 spin_unlock_wr(&olimit
->p_spin
);
187 kfree(nlimit
, M_SUBPROC
);
192 * This routine is called when a new LWP is created for a process. We
193 * must force exclusivity (=2) so p->p_limit remains stable.
195 * LWPs share the same process structure so this does not bump refcnt.
198 plimit_lwp_fork(struct proc
*p
)
200 struct plimit
*olimit
;
204 if (olimit
->p_exclusive
== 2) {
205 KKASSERT(olimit
->p_refcnt
== 1);
208 if (olimit
->p_refcnt
== 1) {
209 olimit
->p_exclusive
= 2;
212 plimit_modify(p
, -1, NULL
);
217 * This routine is called to fixup a proces's p_limit structure prior
218 * to it being modified. If index >= 0 the specified modification is also
221 * This routine must make the limit structure exclusive. A later fork
222 * will convert it back to copy-on-write if possible.
224 * We can count on p->p_limit being stable since if we had created any
225 * threads it will have already been made exclusive (=2).
230 plimit_modify(struct proc
*p
, int index
, struct rlimit
*rlim
)
232 struct plimit
*olimit
;
233 struct plimit
*nlimit
;
234 struct plimit
*rlimit
;
237 * Shortcut. If we are not threaded we may be able to trivially
238 * set the structure to exclusive access without needing to acquire
239 * any spinlocks. The p_limit structure will be stable.
242 if (p
->p_nthreads
== 1) {
243 if (olimit
->p_exclusive
== 0 && olimit
->p_refcnt
== 1)
244 olimit
->p_exclusive
= 1;
245 if (olimit
->p_exclusive
) {
247 p
->p_limit
->pl_rlimit
[index
] = *rlim
;
253 * Full-blown code-up. Make a copy if we aren't exclusive. If
254 * we have only one ref we can safely convert the structure to
255 * exclusive without copying.
258 spin_lock_wr(&olimit
->p_spin
);
261 if (olimit
->p_refcnt
== 1) {
262 if (olimit
->p_exclusive
== 0)
263 olimit
->p_exclusive
= 1;
267 KKASSERT(olimit
->p_exclusive
== 0);
269 plimit_copy(olimit
, nlimit
);
270 nlimit
->p_exclusive
= 1;
276 spin_unlock_wr(&olimit
->p_spin
);
277 nlimit
= kmalloc(sizeof(*nlimit
), M_SUBPROC
, M_WAITOK
);
278 spin_lock_wr(&olimit
->p_spin
);
281 rlimit
->pl_rlimit
[index
] = *rlim
;
282 spin_unlock_wr(&olimit
->p_spin
);
284 kfree(nlimit
, M_SUBPROC
);
288 * Destroy a process's plimit structure.
293 plimit_free(struct proc
*p
)
295 struct plimit
*limit
;
297 if ((limit
= p
->p_limit
) != NULL
) {
300 if (limit
->p_refcnt
== 1) {
301 limit
->p_refcnt
= -999;
302 kfree(limit
, M_SUBPROC
);
304 spin_lock_wr(&limit
->p_spin
);
305 if (--limit
->p_refcnt
== 0) {
306 spin_unlock_wr(&limit
->p_spin
);
307 kfree(limit
, M_SUBPROC
);
309 spin_unlock_wr(&limit
->p_spin
);
316 * Modify a resource limit (from system call)
321 kern_setrlimit(u_int which
, struct rlimit
*limp
)
323 struct proc
*p
= curproc
;
324 struct plimit
*limit
;
325 struct rlimit
*alimp
;
328 if (which
>= RLIM_NLIMITS
)
332 * We will be modifying a resource, make a copy if necessary.
334 plimit_modify(p
, -1, NULL
);
336 alimp
= &limit
->pl_rlimit
[which
];
339 * Preserve historical bugs by treating negative limits as unsigned.
341 if (limp
->rlim_cur
< 0)
342 limp
->rlim_cur
= RLIM_INFINITY
;
343 if (limp
->rlim_max
< 0)
344 limp
->rlim_max
= RLIM_INFINITY
;
346 spin_lock_rd(&limit
->p_spin
);
347 if (limp
->rlim_cur
> alimp
->rlim_max
||
348 limp
->rlim_max
> alimp
->rlim_max
) {
349 spin_unlock_rd(&limit
->p_spin
);
350 if ((error
= priv_check_cred(p
->p_ucred
, PRIV_ROOT
, PRISON_ROOT
)))
353 spin_unlock_rd(&limit
->p_spin
);
355 if (limp
->rlim_cur
> limp
->rlim_max
)
356 limp
->rlim_cur
= limp
->rlim_max
;
360 spin_lock_wr(&limit
->p_spin
);
361 if (limp
->rlim_cur
> RLIM_INFINITY
/ (rlim_t
)1000000)
362 limit
->p_cpulimit
= RLIM_INFINITY
;
364 limit
->p_cpulimit
= (rlim_t
)1000000 * limp
->rlim_cur
;
365 spin_unlock_wr(&limit
->p_spin
);
368 if (limp
->rlim_cur
> maxdsiz
)
369 limp
->rlim_cur
= maxdsiz
;
370 if (limp
->rlim_max
> maxdsiz
)
371 limp
->rlim_max
= maxdsiz
;
375 if (limp
->rlim_cur
> maxssiz
)
376 limp
->rlim_cur
= maxssiz
;
377 if (limp
->rlim_max
> maxssiz
)
378 limp
->rlim_max
= maxssiz
;
380 * Stack is allocated to the max at exec time with only
381 * "rlim_cur" bytes accessible. If stack limit is going
382 * up make more accessible, if going down make inaccessible.
384 spin_lock_rd(&limit
->p_spin
);
385 if (limp
->rlim_cur
!= alimp
->rlim_cur
) {
390 if (limp
->rlim_cur
> alimp
->rlim_cur
) {
392 size
= limp
->rlim_cur
- alimp
->rlim_cur
;
393 addr
= USRSTACK
- limp
->rlim_cur
;
396 size
= alimp
->rlim_cur
- limp
->rlim_cur
;
397 addr
= USRSTACK
- alimp
->rlim_cur
;
399 spin_unlock_rd(&limit
->p_spin
);
400 addr
= trunc_page(addr
);
401 size
= round_page(size
);
402 (void) vm_map_protect(&p
->p_vmspace
->vm_map
,
403 addr
, addr
+size
, prot
, FALSE
);
405 spin_unlock_rd(&limit
->p_spin
);
410 if (limp
->rlim_cur
> maxfilesperproc
)
411 limp
->rlim_cur
= maxfilesperproc
;
412 if (limp
->rlim_max
> maxfilesperproc
)
413 limp
->rlim_max
= maxfilesperproc
;
417 if (limp
->rlim_cur
> maxprocperuid
)
418 limp
->rlim_cur
= maxprocperuid
;
419 if (limp
->rlim_max
> maxprocperuid
)
420 limp
->rlim_max
= maxprocperuid
;
421 if (limp
->rlim_cur
< 1)
423 if (limp
->rlim_max
< 1)
426 case RLIMIT_POSIXLOCKS
:
427 if (limp
->rlim_cur
> maxposixlocksperuid
)
428 limp
->rlim_cur
= maxposixlocksperuid
;
429 if (limp
->rlim_max
> maxposixlocksperuid
)
430 limp
->rlim_max
= maxposixlocksperuid
;
433 spin_lock_wr(&limit
->p_spin
);
435 spin_unlock_wr(&limit
->p_spin
);
440 * The rlimit indexed by which is returned in the second argument.
445 kern_getrlimit(u_int which
, struct rlimit
*limp
)
447 struct proc
*p
= curproc
;
448 struct plimit
*limit
;
450 if (which
>= RLIM_NLIMITS
)
454 spin_lock_rd(&limit
->p_spin
);
455 *limp
= p
->p_rlimit
[which
];
456 spin_unlock_rd(&limit
->p_spin
);
461 * Determine if the cpu limit has been reached and return an operations
462 * code for the caller to perform.
467 plimit_testcpulimit(struct plimit
*limit
, u_int64_t ttime
)
472 mode
= PLIMIT_TESTCPU_OK
;
473 if (limit
->p_cpulimit
!= RLIM_INFINITY
) {
474 spin_lock_rd(&limit
->p_spin
);
475 if (ttime
> limit
->p_cpulimit
) {
476 rlim
= &limit
->pl_rlimit
[RLIMIT_CPU
];
477 if (ttime
/ (rlim_t
)1000000 >= rlim
->rlim_max
+ 5) {
478 mode
= PLIMIT_TESTCPU_KILL
;
480 mode
= PLIMIT_TESTCPU_XCPU
;
483 spin_unlock_rd(&limit
->p_spin
);
489 * Helper routine to copy olimit to nlimit and initialize nlimit for
490 * use. nlimit's reference count will be set to 1 and its exclusive bit
497 plimit_copy(struct plimit
*olimit
, struct plimit
*nlimit
)
501 spin_init(&nlimit
->p_spin
);
502 nlimit
->p_refcnt
= 1;
503 nlimit
->p_exclusive
= 0;