freebsd-skq/sys/vm/vm_unix.c
David Malone a77c9610f2 If a process is over its resource limit for datasize, still allow
it to lower its memory usage. This was mentioned on the mailing
lists ages ago, and I've lost the name of the person who brought
it up.

Reviewed by:	alc
2000-10-06 13:03:50 +00:00

131 lines
3.8 KiB
C

/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
*
* from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
*
* @(#)vm_unix.c 8.1 (Berkeley) 6/11/93
* $FreeBSD$
*/
/*
* Traditional sbrk/grow interface to VM
*/
#include <sys/param.h>
#include <sys/sysproto.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <sys/lock.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#ifndef _SYS_SYSPROTO_H_
struct obreak_args {
char *nsize;
};
#endif
/* ARGSUSED */
int
obreak(p, uap)
struct proc *p;
struct obreak_args *uap;
{
register struct vmspace *vm = p->p_vmspace;
vm_offset_t new, old, base;
int rv;
base = round_page((vm_offset_t) vm->vm_daddr);
new = round_page((vm_offset_t)uap->nsize);
old = base + ctob(vm->vm_dsize);
if (new > base) {
/*
* We check resource limits here, but alow processes to
* reduce their usage, even if they remain over the limit.
*/
if (new > old &&
(new - base) > (unsigned) p->p_rlimit[RLIMIT_DATA].rlim_cur)
return ENOMEM;
if (new >= VM_MAXUSER_ADDRESS)
return (ENOMEM);
} else if (new < base) {
/*
* This is simply an invalid value. If someone wants to
* do fancy address space manipulations, mmap and munmap
* can do most of what the user would want.
*/
return EINVAL;
}
if (new > old) {
vm_size_t diff;
diff = new - old;
rv = vm_map_find(&vm->vm_map, NULL, 0, &old, diff, FALSE,
VM_PROT_ALL, VM_PROT_ALL, 0);
if (rv != KERN_SUCCESS) {
return (ENOMEM);
}
vm->vm_dsize += btoc(diff);
} else if (new < old) {
rv = vm_map_remove(&vm->vm_map, new, old);
if (rv != KERN_SUCCESS) {
return (ENOMEM);
}
vm->vm_dsize -= btoc(old - new);
}
return (0);
}
#ifndef _SYS_SYSPROTO_H_
struct ovadvise_args {
int anom;
};
#endif
/* ARGSUSED */
int
ovadvise(p, uap)
struct proc *p;
struct ovadvise_args *uap;
{
return (EINVAL);
}