kern_uidinfo.c revision 1.3.2.2
1 1.3.2.2 haad /* $NetBSD: kern_uidinfo.c,v 1.3.2.2 2008/10/19 22:17:28 haad Exp $ */ 2 1.3.2.2 haad 3 1.3.2.2 haad /*- 4 1.3.2.2 haad * Copyright (c) 1982, 1986, 1991, 1993 5 1.3.2.2 haad * The Regents of the University of California. All rights reserved. 6 1.3.2.2 haad * (c) UNIX System Laboratories, Inc. 7 1.3.2.2 haad * All or some portions of this file are derived from material licensed 8 1.3.2.2 haad * to the University of California by American Telephone and Telegraph 9 1.3.2.2 haad * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 1.3.2.2 haad * the permission of UNIX System Laboratories, Inc. 11 1.3.2.2 haad * 12 1.3.2.2 haad * Redistribution and use in source and binary forms, with or without 13 1.3.2.2 haad * modification, are permitted provided that the following conditions 14 1.3.2.2 haad * are met: 15 1.3.2.2 haad * 1. Redistributions of source code must retain the above copyright 16 1.3.2.2 haad * notice, this list of conditions and the following disclaimer. 17 1.3.2.2 haad * 2. Redistributions in binary form must reproduce the above copyright 18 1.3.2.2 haad * notice, this list of conditions and the following disclaimer in the 19 1.3.2.2 haad * documentation and/or other materials provided with the distribution. 20 1.3.2.2 haad * 3. Neither the name of the University nor the names of its contributors 21 1.3.2.2 haad * may be used to endorse or promote products derived from this software 22 1.3.2.2 haad * without specific prior written permission. 23 1.3.2.2 haad * 24 1.3.2.2 haad * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 1.3.2.2 haad * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 1.3.2.2 haad * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 1.3.2.2 haad * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 1.3.2.2 haad * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 1.3.2.2 haad * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 1.3.2.2 haad * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 1.3.2.2 haad * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 1.3.2.2 haad * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 1.3.2.2 haad * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 1.3.2.2 haad * SUCH DAMAGE. 35 1.3.2.2 haad */ 36 1.3.2.2 haad 37 1.3.2.2 haad #include <sys/cdefs.h> 38 1.3.2.2 haad __KERNEL_RCSID(0, "$NetBSD: kern_uidinfo.c,v 1.3.2.2 2008/10/19 22:17:28 haad Exp $"); 39 1.3.2.2 haad 40 1.3.2.2 haad #include <sys/param.h> 41 1.3.2.2 haad #include <sys/systm.h> 42 1.3.2.2 haad #include <sys/kmem.h> 43 1.3.2.2 haad #include <sys/proc.h> 44 1.3.2.2 haad #include <sys/atomic.h> 45 1.3.2.2 haad #include <sys/uidinfo.h> 46 1.3.2.2 haad 47 1.3.2.2 haad static SLIST_HEAD(uihashhead, uidinfo) *uihashtbl; 48 1.3.2.2 haad static u_long uihash; 49 1.3.2.2 haad 50 1.3.2.2 haad #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) 51 1.3.2.2 haad 52 1.3.2.2 haad void 53 1.3.2.2 haad uid_init(void) 54 1.3.2.2 haad { 55 1.3.2.2 haad 56 1.3.2.2 haad /* 57 1.3.2.2 haad * In case of MP system, SLIST_FOREACH would force a cache line 58 1.3.2.2 haad * write-back for every modified 'uidinfo', thus we try to keep the 59 1.3.2.2 haad * lists short. 60 1.3.2.2 haad */ 61 1.3.2.2 haad const u_int uihash_sz = (maxproc > 1 ? 1024 : 64); 62 1.3.2.2 haad 63 1.3.2.2 haad uihashtbl = hashinit(uihash_sz, HASH_SLIST, true, &uihash); 64 1.3.2.2 haad 65 1.3.2.2 haad /* 66 1.3.2.2 haad * Ensure that uid 0 is always in the user hash table, as 67 1.3.2.2 haad * sbreserve() expects it available from interrupt context. 68 1.3.2.2 haad */ 69 1.3.2.2 haad (void)uid_find(0); 70 1.3.2.2 haad } 71 1.3.2.2 haad 72 1.3.2.2 haad struct uidinfo * 73 1.3.2.2 haad uid_find(uid_t uid) 74 1.3.2.2 haad { 75 1.3.2.2 haad struct uidinfo *uip, *uip_first, *newuip; 76 1.3.2.2 haad struct uihashhead *uipp; 77 1.3.2.2 haad 78 1.3.2.2 haad uipp = UIHASH(uid); 79 1.3.2.2 haad newuip = NULL; 80 1.3.2.2 haad 81 1.3.2.2 haad /* 82 1.3.2.2 haad * To make insertion atomic, abstraction of SLIST will be violated. 83 1.3.2.2 haad */ 84 1.3.2.2 haad uip_first = uipp->slh_first; 85 1.3.2.2 haad again: 86 1.3.2.2 haad SLIST_FOREACH(uip, uipp, ui_hash) { 87 1.3.2.2 haad if (uip->ui_uid != uid) 88 1.3.2.2 haad continue; 89 1.3.2.2 haad if (newuip != NULL) 90 1.3.2.2 haad kmem_free(newuip, sizeof(*newuip)); 91 1.3.2.2 haad return uip; 92 1.3.2.2 haad } 93 1.3.2.2 haad if (newuip == NULL) 94 1.3.2.2 haad newuip = kmem_zalloc(sizeof(*newuip), KM_SLEEP); 95 1.3.2.2 haad newuip->ui_uid = uid; 96 1.3.2.2 haad 97 1.3.2.2 haad /* 98 1.3.2.2 haad * If atomic insert is unsuccessful, another thread might be 99 1.3.2.2 haad * allocated this 'uid', thus full re-check is needed. 100 1.3.2.2 haad */ 101 1.3.2.2 haad newuip->ui_hash.sle_next = uip_first; 102 1.3.2.2 haad membar_producer(); 103 1.3.2.2 haad uip = atomic_cas_ptr(&uipp->slh_first, uip_first, newuip); 104 1.3.2.2 haad if (uip != uip_first) { 105 1.3.2.2 haad uip_first = uip; 106 1.3.2.2 haad goto again; 107 1.3.2.2 haad } 108 1.3.2.2 haad 109 1.3.2.2 haad return newuip; 110 1.3.2.2 haad } 111 1.3.2.2 haad 112 1.3.2.2 haad /* 113 1.3.2.2 haad * Change the count associated with number of processes 114 1.3.2.2 haad * a given user is using. 115 1.3.2.2 haad */ 116 1.3.2.2 haad int 117 1.3.2.2 haad chgproccnt(uid_t uid, int diff) 118 1.3.2.2 haad { 119 1.3.2.2 haad struct uidinfo *uip; 120 1.3.2.2 haad long proccnt; 121 1.3.2.2 haad 122 1.3.2.2 haad uip = uid_find(uid); 123 1.3.2.2 haad proccnt = atomic_add_long_nv(&uip->ui_proccnt, diff); 124 1.3.2.2 haad KASSERT(proccnt >= 0); 125 1.3.2.2 haad return proccnt; 126 1.3.2.2 haad } 127 1.3.2.2 haad 128 1.3.2.2 haad int 129 1.3.2.2 haad chgsbsize(struct uidinfo *uip, u_long *hiwat, u_long to, rlim_t xmax) 130 1.3.2.2 haad { 131 1.3.2.2 haad rlim_t nsb; 132 1.3.2.2 haad const long diff = to - *hiwat; 133 1.3.2.2 haad 134 1.3.2.2 haad nsb = (rlim_t)atomic_add_long_nv((long *)&uip->ui_sbsize, diff); 135 1.3.2.2 haad if (diff > 0 && nsb > xmax) { 136 1.3.2.2 haad atomic_add_long((long *)&uip->ui_sbsize, -diff); 137 1.3.2.2 haad return 0; 138 1.3.2.2 haad } 139 1.3.2.2 haad *hiwat = to; 140 1.3.2.2 haad KASSERT(nsb >= 0); 141 1.3.2.2 haad return 1; 142 1.3.2.2 haad } 143
Indexes created Tue Sep 30 20:09:53 GMT 2025