freebsd-dev/sys/kern/subr_param.c
Andre Oppermann 0060bab556 Prevent long type overflow of realmem calculation on ILP32 by forcing
calculation to be in quad_t space.  Fix style issue with second parameter
to qmin().

Reported by:	alc
Reviewed by:	bde, alc
2012-12-10 12:19:03 +00:00

364 lines
11 KiB
C

/*-
* Copyright (c) 1980, 1986, 1989, 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.
* 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.
*
* @(#)param.c 8.3 (Berkeley) 8/20/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_param.h"
#include "opt_msgbuf.h"
#include "opt_maxusers.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/msgbuf.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
/*
* System parameter formulae.
*/
#ifndef HZ
# if defined(__mips__) || defined(__arm__)
# define HZ 100
# else
# define HZ 1000
# endif
# ifndef HZ_VM
# define HZ_VM 100
# endif
#else
# ifndef HZ_VM
# define HZ_VM HZ
# endif
#endif
#define NPROC (20 + 16 * maxusers)
#ifndef NBUF
#define NBUF 0
#endif
#ifndef MAXFILES
#define MAXFILES (maxproc * 2)
#endif
static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS);
int hz;
int tick;
int maxusers; /* base tunable */
int maxproc; /* maximum # of processes */
int maxprocperuid; /* max # of procs per user */
int maxfiles; /* sys. wide open files limit */
int maxfilesperproc; /* per-proc open files limit */
int msgbufsize; /* size of kernel message buffer */
int ncallout; /* maximum # of timer events */
int nbuf;
int ngroups_max; /* max # groups per process */
int nswbuf;
quad_t maxmbufmem; /* max mbuf memory */
pid_t pid_max = PID_MAX;
long maxswzone; /* max swmeta KVA storage */
long maxbcache; /* max buffer cache KVA storage */
long maxpipekva; /* Limit on pipe KVA */
int vm_guest; /* Running as virtual machine guest? */
u_long maxtsiz; /* max text size */
u_long dfldsiz; /* initial data size limit */
u_long maxdsiz; /* max data size */
u_long dflssiz; /* initial stack size limit */
u_long maxssiz; /* max stack size */
u_long sgrowsiz; /* amount to grow stack */
SYSCTL_INT(_kern, OID_AUTO, hz, CTLFLAG_RDTUN, &hz, 0,
"Number of clock ticks per second");
SYSCTL_INT(_kern, OID_AUTO, ncallout, CTLFLAG_RDTUN, &ncallout, 0,
"Number of pre-allocated timer events");
SYSCTL_INT(_kern, OID_AUTO, nbuf, CTLFLAG_RDTUN, &nbuf, 0,
"Number of buffers in the buffer cache");
SYSCTL_INT(_kern, OID_AUTO, nswbuf, CTLFLAG_RDTUN, &nswbuf, 0,
"Number of swap buffers");
SYSCTL_INT(_kern, OID_AUTO, msgbufsize, CTLFLAG_RDTUN, &msgbufsize, 0,
"Size of the kernel message buffer");
SYSCTL_LONG(_kern, OID_AUTO, maxswzone, CTLFLAG_RDTUN, &maxswzone, 0,
"Maximum memory for swap metadata");
SYSCTL_LONG(_kern, OID_AUTO, maxbcache, CTLFLAG_RDTUN, &maxbcache, 0,
"Maximum value of vfs.maxbufspace");
SYSCTL_ULONG(_kern, OID_AUTO, maxtsiz, CTLFLAG_RW | CTLFLAG_TUN, &maxtsiz, 0,
"Maximum text size");
SYSCTL_ULONG(_kern, OID_AUTO, dfldsiz, CTLFLAG_RW | CTLFLAG_TUN, &dfldsiz, 0,
"Initial data size limit");
SYSCTL_ULONG(_kern, OID_AUTO, maxdsiz, CTLFLAG_RW | CTLFLAG_TUN, &maxdsiz, 0,
"Maximum data size");
SYSCTL_ULONG(_kern, OID_AUTO, dflssiz, CTLFLAG_RW | CTLFLAG_TUN, &dflssiz, 0,
"Initial stack size limit");
SYSCTL_ULONG(_kern, OID_AUTO, maxssiz, CTLFLAG_RW | CTLFLAG_TUN, &maxssiz, 0,
"Maximum stack size");
SYSCTL_ULONG(_kern, OID_AUTO, sgrowsiz, CTLFLAG_RW | CTLFLAG_TUN, &sgrowsiz, 0,
"Amount to grow stack on a stack fault");
SYSCTL_PROC(_kern, OID_AUTO, vm_guest, CTLFLAG_RD | CTLTYPE_STRING,
NULL, 0, sysctl_kern_vm_guest, "A",
"Virtual machine guest detected? (none|generic|xen)");
/*
* These have to be allocated somewhere; allocating
* them here forces loader errors if this file is omitted
* (if they've been externed everywhere else; hah!).
*/
struct buf *swbuf;
/*
* The elements of this array are ordered based upon the values of the
* corresponding enum VM_GUEST members.
*/
static const char *const vm_guest_sysctl_names[] = {
"none",
"generic",
"xen",
NULL
};
#ifndef XEN
static const char *const vm_bnames[] = {
"QEMU", /* QEMU */
"Plex86", /* Plex86 */
"Bochs", /* Bochs */
"Xen", /* Xen */
NULL
};
static const char *const vm_pnames[] = {
"VMware Virtual Platform", /* VMWare VM */
"Virtual Machine", /* Microsoft VirtualPC */
"VirtualBox", /* Sun xVM VirtualBox */
"Parallels Virtual Platform", /* Parallels VM */
NULL
};
/*
* Detect known Virtual Machine hosts by inspecting the emulated BIOS.
*/
static enum VM_GUEST
detect_virtual(void)
{
char *sysenv;
int i;
sysenv = getenv("smbios.bios.vendor");
if (sysenv != NULL) {
for (i = 0; vm_bnames[i] != NULL; i++)
if (strcmp(sysenv, vm_bnames[i]) == 0) {
freeenv(sysenv);
return (VM_GUEST_VM);
}
freeenv(sysenv);
}
sysenv = getenv("smbios.system.product");
if (sysenv != NULL) {
for (i = 0; vm_pnames[i] != NULL; i++)
if (strcmp(sysenv, vm_pnames[i]) == 0) {
freeenv(sysenv);
return (VM_GUEST_VM);
}
freeenv(sysenv);
}
return (VM_GUEST_NO);
}
#endif
/*
* Boot time overrides that are not scaled against main memory
*/
void
init_param1(void)
{
#ifndef XEN
vm_guest = detect_virtual();
#else
vm_guest = VM_GUEST_XEN;
#endif
hz = -1;
TUNABLE_INT_FETCH("kern.hz", &hz);
if (hz == -1)
hz = vm_guest > VM_GUEST_NO ? HZ_VM : HZ;
tick = 1000000 / hz;
#ifdef VM_SWZONE_SIZE_MAX
maxswzone = VM_SWZONE_SIZE_MAX;
#endif
TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
#ifdef VM_BCACHE_SIZE_MAX
maxbcache = VM_BCACHE_SIZE_MAX;
#endif
TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
msgbufsize = MSGBUF_SIZE;
TUNABLE_INT_FETCH("kern.msgbufsize", &msgbufsize);
maxtsiz = MAXTSIZ;
TUNABLE_ULONG_FETCH("kern.maxtsiz", &maxtsiz);
dfldsiz = DFLDSIZ;
TUNABLE_ULONG_FETCH("kern.dfldsiz", &dfldsiz);
maxdsiz = MAXDSIZ;
TUNABLE_ULONG_FETCH("kern.maxdsiz", &maxdsiz);
dflssiz = DFLSSIZ;
TUNABLE_ULONG_FETCH("kern.dflssiz", &dflssiz);
maxssiz = MAXSSIZ;
TUNABLE_ULONG_FETCH("kern.maxssiz", &maxssiz);
sgrowsiz = SGROWSIZ;
TUNABLE_ULONG_FETCH("kern.sgrowsiz", &sgrowsiz);
/*
* Let the administrator set {NGROUPS_MAX}, but disallow values
* less than NGROUPS_MAX which would violate POSIX.1-2008 or
* greater than INT_MAX-1 which would result in overflow.
*/
ngroups_max = NGROUPS_MAX;
TUNABLE_INT_FETCH("kern.ngroups", &ngroups_max);
if (ngroups_max < NGROUPS_MAX)
ngroups_max = NGROUPS_MAX;
/*
* Only allow to lower the maximal pid.
* Prevent setting up a non-bootable system if pid_max is too low.
*/
TUNABLE_INT_FETCH("kern.pid_max", &pid_max);
if (pid_max > PID_MAX)
pid_max = PID_MAX;
else if (pid_max < 300)
pid_max = 300;
}
/*
* Boot time overrides that are scaled against main memory
*/
void
init_param2(long physpages)
{
quad_t realmem;
/* Base parameters */
maxusers = MAXUSERS;
TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
if (maxusers == 0) {
maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE);
if (maxusers < 32)
maxusers = 32;
#ifdef VM_MAX_AUTOTUNE_MAXUSERS
if (maxusers > VM_MAX_AUTOTUNE_MAXUSERS)
maxusers = VM_MAX_AUTOTUNE_MAXUSERS;
#endif
/*
* Scales down the function in which maxusers grows once
* we hit 384.
*/
if (maxusers > 384)
maxusers = 384 + ((maxusers - 384) / 8);
}
/*
* The following can be overridden after boot via sysctl. Note:
* unless overriden, these macros are ultimately based on maxusers.
* Limit maxproc so that kmap entries cannot be exhausted by
* processes.
*/
maxproc = NPROC;
TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
if (maxproc > (physpages / 12))
maxproc = physpages / 12;
maxprocperuid = (maxproc * 9) / 10;
/*
* The default limit for maxfiles is 1/12 of the number of
* physical page but not less than 16 times maxusers.
* At most it can be 1/6 the number of physical pages.
*/
maxfiles = imax(MAXFILES, physpages / 8);
TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
if (maxfiles > (physpages / 4))
maxfiles = physpages / 4;
maxfilesperproc = (maxfiles / 10) * 9;
/*
* Cannot be changed after boot.
*/
nbuf = NBUF;
TUNABLE_INT_FETCH("kern.nbuf", &nbuf);
/*
* XXX: Does the callout wheel have to be so big?
*/
ncallout = 16 + maxproc + maxfiles;
TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
/*
* The default limit for all mbuf related memory is 1/2 of all
* available kernel memory (physical or kmem).
* At most it can be 3/4 of available kernel memory.
*/
realmem = qmin((quad_t)physpages * PAGE_SIZE,
VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS);
maxmbufmem = realmem / 2;
TUNABLE_QUAD_FETCH("kern.maxmbufmem", &maxmbufmem);
if (maxmbufmem > (realmem / 4) * 3)
maxmbufmem = (realmem / 4) * 3;
/*
* The default for maxpipekva is min(1/64 of the kernel address space,
* max(1/64 of main memory, 512KB)). See sys_pipe.c for more details.
*/
maxpipekva = (physpages / 64) * PAGE_SIZE;
TUNABLE_LONG_FETCH("kern.ipc.maxpipekva", &maxpipekva);
if (maxpipekva < 512 * 1024)
maxpipekva = 512 * 1024;
if (maxpipekva > (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / 64)
maxpipekva = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
64;
}
/*
* Sysctl stringiying handler for kern.vm_guest.
*/
static int
sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS)
{
return (SYSCTL_OUT(req, vm_guest_sysctl_names[vm_guest],
strlen(vm_guest_sysctl_names[vm_guest])));
}