kern_uidinfo.c revision 1.4.2.2
1 1.4.2.2 mjf /* $NetBSD: kern_uidinfo.c,v 1.4.2.2 2009/01/17 13:29:19 mjf Exp $ */ 2 1.4.2.2 mjf 3 1.4.2.2 mjf /*- 4 1.4.2.2 mjf * Copyright (c) 1982, 1986, 1991, 1993 5 1.4.2.2 mjf * The Regents of the University of California. All rights reserved. 6 1.4.2.2 mjf * (c) UNIX System Laboratories, Inc. 7 1.4.2.2 mjf * All or some portions of this file are derived from material licensed 8 1.4.2.2 mjf * to the University of California by American Telephone and Telegraph 9 1.4.2.2 mjf * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 1.4.2.2 mjf * the permission of UNIX System Laboratories, Inc. 11 1.4.2.2 mjf * 12 1.4.2.2 mjf * Redistribution and use in source and binary forms, with or without 13 1.4.2.2 mjf * modification, are permitted provided that the following conditions 14 1.4.2.2 mjf * are met: 15 1.4.2.2 mjf * 1. Redistributions of source code must retain the above copyright 16 1.4.2.2 mjf * notice, this list of conditions and the following disclaimer. 17 1.4.2.2 mjf * 2. Redistributions in binary form must reproduce the above copyright 18 1.4.2.2 mjf * notice, this list of conditions and the following disclaimer in the 19 1.4.2.2 mjf * documentation and/or other materials provided with the distribution. 20 1.4.2.2 mjf * 3. Neither the name of the University nor the names of its contributors 21 1.4.2.2 mjf * may be used to endorse or promote products derived from this software 22 1.4.2.2 mjf * without specific prior written permission. 23 1.4.2.2 mjf * 24 1.4.2.2 mjf * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 1.4.2.2 mjf * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 1.4.2.2 mjf * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 1.4.2.2 mjf * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 1.4.2.2 mjf * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 1.4.2.2 mjf * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 1.4.2.2 mjf * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 1.4.2.2 mjf * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 1.4.2.2 mjf * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 1.4.2.2 mjf * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 1.4.2.2 mjf * SUCH DAMAGE. 35 1.4.2.2 mjf */ 36 1.4.2.2 mjf 37 1.4.2.2 mjf #include <sys/cdefs.h> 38 1.4.2.2 mjf __KERNEL_RCSID(0, "$NetBSD: kern_uidinfo.c,v 1.4.2.2 2009/01/17 13:29:19 mjf Exp $"); 39 1.4.2.2 mjf 40 1.4.2.2 mjf #include <sys/param.h> 41 1.4.2.2 mjf #include <sys/systm.h> 42 1.4.2.2 mjf #include <sys/kmem.h> 43 1.4.2.2 mjf #include <sys/proc.h> 44 1.4.2.2 mjf #include <sys/atomic.h> 45 1.4.2.2 mjf #include <sys/uidinfo.h> 46 1.4.2.2 mjf 47 1.4.2.2 mjf static SLIST_HEAD(uihashhead, uidinfo) *uihashtbl; 48 1.4.2.2 mjf static u_long uihash; 49 1.4.2.2 mjf 50 1.4.2.2 mjf #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) 51 1.4.2.2 mjf 52 1.4.2.2 mjf void 53 1.4.2.2 mjf uid_init(void) 54 1.4.2.2 mjf { 55 1.4.2.2 mjf 56 1.4.2.2 mjf /* 57 1.4.2.2 mjf * In case of MP system, SLIST_FOREACH would force a cache line 58 1.4.2.2 mjf * write-back for every modified 'uidinfo', thus we try to keep the 59 1.4.2.2 mjf * lists short. 60 1.4.2.2 mjf */ 61 1.4.2.2 mjf const u_int uihash_sz = (maxproc > 1 ? 1024 : 64); 62 1.4.2.2 mjf 63 1.4.2.2 mjf uihashtbl = hashinit(uihash_sz, HASH_SLIST, true, &uihash); 64 1.4.2.2 mjf 65 1.4.2.2 mjf /* 66 1.4.2.2 mjf * Ensure that uid 0 is always in the user hash table, as 67 1.4.2.2 mjf * sbreserve() expects it available from interrupt context. 68 1.4.2.2 mjf */ 69 1.4.2.2 mjf (void)uid_find(0); 70 1.4.2.2 mjf } 71 1.4.2.2 mjf 72 1.4.2.2 mjf struct uidinfo * 73 1.4.2.2 mjf uid_find(uid_t uid) 74 1.4.2.2 mjf { 75 1.4.2.2 mjf struct uidinfo *uip, *uip_first, *newuip; 76 1.4.2.2 mjf struct uihashhead *uipp; 77 1.4.2.2 mjf 78 1.4.2.2 mjf uipp = UIHASH(uid); 79 1.4.2.2 mjf newuip = NULL; 80 1.4.2.2 mjf 81 1.4.2.2 mjf /* 82 1.4.2.2 mjf * To make insertion atomic, abstraction of SLIST will be violated. 83 1.4.2.2 mjf */ 84 1.4.2.2 mjf uip_first = uipp->slh_first; 85 1.4.2.2 mjf again: 86 1.4.2.2 mjf SLIST_FOREACH(uip, uipp, ui_hash) { 87 1.4.2.2 mjf if (uip->ui_uid != uid) 88 1.4.2.2 mjf continue; 89 1.4.2.2 mjf if (newuip != NULL) 90 1.4.2.2 mjf kmem_free(newuip, sizeof(*newuip)); 91 1.4.2.2 mjf return uip; 92 1.4.2.2 mjf } 93 1.4.2.2 mjf if (newuip == NULL) 94 1.4.2.2 mjf newuip = kmem_zalloc(sizeof(*newuip), KM_SLEEP); 95 1.4.2.2 mjf newuip->ui_uid = uid; 96 1.4.2.2 mjf 97 1.4.2.2 mjf /* 98 1.4.2.2 mjf * If atomic insert is unsuccessful, another thread might be 99 1.4.2.2 mjf * allocated this 'uid', thus full re-check is needed. 100 1.4.2.2 mjf */ 101 1.4.2.2 mjf newuip->ui_hash.sle_next = uip_first; 102 1.4.2.2 mjf membar_producer(); 103 1.4.2.2 mjf uip = atomic_cas_ptr(&uipp->slh_first, uip_first, newuip); 104 1.4.2.2 mjf if (uip != uip_first) { 105 1.4.2.2 mjf uip_first = uip; 106 1.4.2.2 mjf goto again; 107 1.4.2.2 mjf } 108 1.4.2.2 mjf 109 1.4.2.2 mjf return newuip; 110 1.4.2.2 mjf } 111 1.4.2.2 mjf 112 1.4.2.2 mjf /* 113 1.4.2.2 mjf * Change the count associated with number of processes 114 1.4.2.2 mjf * a given user is using. 115 1.4.2.2 mjf */ 116 1.4.2.2 mjf int 117 1.4.2.2 mjf chgproccnt(uid_t uid, int diff) 118 1.4.2.2 mjf { 119 1.4.2.2 mjf struct uidinfo *uip; 120 1.4.2.2 mjf long proccnt; 121 1.4.2.2 mjf 122 1.4.2.2 mjf uip = uid_find(uid); 123 1.4.2.2 mjf proccnt = atomic_add_long_nv(&uip->ui_proccnt, diff); 124 1.4.2.2 mjf KASSERT(proccnt >= 0); 125 1.4.2.2 mjf return proccnt; 126 1.4.2.2 mjf } 127 1.4.2.2 mjf 128 1.4.2.2 mjf int 129 1.4.2.2 mjf chgsbsize(struct uidinfo *uip, u_long *hiwat, u_long to, rlim_t xmax) 130 1.4.2.2 mjf { 131 1.4.2.2 mjf rlim_t nsb; 132 1.4.2.2 mjf const long diff = to - *hiwat; 133 1.4.2.2 mjf 134 1.4.2.2 mjf nsb = (rlim_t)atomic_add_long_nv((long *)&uip->ui_sbsize, diff); 135 1.4.2.2 mjf if (diff > 0 && nsb > xmax) { 136 1.4.2.2 mjf atomic_add_long((long *)&uip->ui_sbsize, -diff); 137 1.4.2.2 mjf return 0; 138 1.4.2.2 mjf } 139 1.4.2.2 mjf *hiwat = to; 140 1.4.2.2 mjf return 1; 141 1.4.2.2 mjf } 142
Indexes created Tue Sep 30 20:09:53 GMT 2025