kern_uidinfo.c revision 1.5.2.2
1 1.5.2.2 yamt /* $NetBSD: kern_uidinfo.c,v 1.5.2.2 2009/05/04 08:13:47 yamt Exp $ */ 2 1.5.2.2 yamt 3 1.5.2.2 yamt /*- 4 1.5.2.2 yamt * Copyright (c) 1982, 1986, 1991, 1993 5 1.5.2.2 yamt * The Regents of the University of California. All rights reserved. 6 1.5.2.2 yamt * (c) UNIX System Laboratories, Inc. 7 1.5.2.2 yamt * All or some portions of this file are derived from material licensed 8 1.5.2.2 yamt * to the University of California by American Telephone and Telegraph 9 1.5.2.2 yamt * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 1.5.2.2 yamt * the permission of UNIX System Laboratories, Inc. 11 1.5.2.2 yamt * 12 1.5.2.2 yamt * Redistribution and use in source and binary forms, with or without 13 1.5.2.2 yamt * modification, are permitted provided that the following conditions 14 1.5.2.2 yamt * are met: 15 1.5.2.2 yamt * 1. Redistributions of source code must retain the above copyright 16 1.5.2.2 yamt * notice, this list of conditions and the following disclaimer. 17 1.5.2.2 yamt * 2. Redistributions in binary form must reproduce the above copyright 18 1.5.2.2 yamt * notice, this list of conditions and the following disclaimer in the 19 1.5.2.2 yamt * documentation and/or other materials provided with the distribution. 20 1.5.2.2 yamt * 3. Neither the name of the University nor the names of its contributors 21 1.5.2.2 yamt * may be used to endorse or promote products derived from this software 22 1.5.2.2 yamt * without specific prior written permission. 23 1.5.2.2 yamt * 24 1.5.2.2 yamt * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 1.5.2.2 yamt * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 1.5.2.2 yamt * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 1.5.2.2 yamt * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 1.5.2.2 yamt * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 1.5.2.2 yamt * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 1.5.2.2 yamt * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 1.5.2.2 yamt * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 1.5.2.2 yamt * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 1.5.2.2 yamt * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 1.5.2.2 yamt * SUCH DAMAGE. 35 1.5.2.2 yamt */ 36 1.5.2.2 yamt 37 1.5.2.2 yamt #include <sys/cdefs.h> 38 1.5.2.2 yamt __KERNEL_RCSID(0, "$NetBSD: kern_uidinfo.c,v 1.5.2.2 2009/05/04 08:13:47 yamt Exp $"); 39 1.5.2.2 yamt 40 1.5.2.2 yamt #include <sys/param.h> 41 1.5.2.2 yamt #include <sys/systm.h> 42 1.5.2.2 yamt #include <sys/kmem.h> 43 1.5.2.2 yamt #include <sys/proc.h> 44 1.5.2.2 yamt #include <sys/atomic.h> 45 1.5.2.2 yamt #include <sys/uidinfo.h> 46 1.5.2.2 yamt #include <sys/cpu.h> 47 1.5.2.2 yamt 48 1.5.2.2 yamt static SLIST_HEAD(uihashhead, uidinfo) *uihashtbl; 49 1.5.2.2 yamt static u_long uihash; 50 1.5.2.2 yamt 51 1.5.2.2 yamt #define UIHASH(uid) (&uihashtbl[(uid) & uihash]) 52 1.5.2.2 yamt 53 1.5.2.2 yamt void 54 1.5.2.2 yamt uid_init(void) 55 1.5.2.2 yamt { 56 1.5.2.2 yamt 57 1.5.2.2 yamt /* 58 1.5.2.2 yamt * In case of MP system, SLIST_FOREACH would force a cache line 59 1.5.2.2 yamt * write-back for every modified 'uidinfo', thus we try to keep the 60 1.5.2.2 yamt * lists short. 61 1.5.2.2 yamt */ 62 1.5.2.2 yamt const u_int uihash_sz = (maxcpus > 1 ? 1024 : 64); 63 1.5.2.2 yamt 64 1.5.2.2 yamt uihashtbl = hashinit(uihash_sz, HASH_SLIST, true, &uihash); 65 1.5.2.2 yamt 66 1.5.2.2 yamt /* 67 1.5.2.2 yamt * Ensure that uid 0 is always in the user hash table, as 68 1.5.2.2 yamt * sbreserve() expects it available from interrupt context. 69 1.5.2.2 yamt */ 70 1.5.2.2 yamt (void)uid_find(0); 71 1.5.2.2 yamt } 72 1.5.2.2 yamt 73 1.5.2.2 yamt struct uidinfo * 74 1.5.2.2 yamt uid_find(uid_t uid) 75 1.5.2.2 yamt { 76 1.5.2.2 yamt struct uidinfo *uip, *uip_first, *newuip; 77 1.5.2.2 yamt struct uihashhead *uipp; 78 1.5.2.2 yamt 79 1.5.2.2 yamt uipp = UIHASH(uid); 80 1.5.2.2 yamt newuip = NULL; 81 1.5.2.2 yamt 82 1.5.2.2 yamt /* 83 1.5.2.2 yamt * To make insertion atomic, abstraction of SLIST will be violated. 84 1.5.2.2 yamt */ 85 1.5.2.2 yamt uip_first = uipp->slh_first; 86 1.5.2.2 yamt again: 87 1.5.2.2 yamt SLIST_FOREACH(uip, uipp, ui_hash) { 88 1.5.2.2 yamt if (uip->ui_uid != uid) 89 1.5.2.2 yamt continue; 90 1.5.2.2 yamt if (newuip != NULL) 91 1.5.2.2 yamt kmem_free(newuip, sizeof(*newuip)); 92 1.5.2.2 yamt return uip; 93 1.5.2.2 yamt } 94 1.5.2.2 yamt if (newuip == NULL) 95 1.5.2.2 yamt newuip = kmem_zalloc(sizeof(*newuip), KM_SLEEP); 96 1.5.2.2 yamt newuip->ui_uid = uid; 97 1.5.2.2 yamt 98 1.5.2.2 yamt /* 99 1.5.2.2 yamt * If atomic insert is unsuccessful, another thread might be 100 1.5.2.2 yamt * allocated this 'uid', thus full re-check is needed. 101 1.5.2.2 yamt */ 102 1.5.2.2 yamt newuip->ui_hash.sle_next = uip_first; 103 1.5.2.2 yamt membar_producer(); 104 1.5.2.2 yamt uip = atomic_cas_ptr(&uipp->slh_first, uip_first, newuip); 105 1.5.2.2 yamt if (uip != uip_first) { 106 1.5.2.2 yamt uip_first = uip; 107 1.5.2.2 yamt goto again; 108 1.5.2.2 yamt } 109 1.5.2.2 yamt 110 1.5.2.2 yamt return newuip; 111 1.5.2.2 yamt } 112 1.5.2.2 yamt 113 1.5.2.2 yamt /* 114 1.5.2.2 yamt * Change the count associated with number of processes 115 1.5.2.2 yamt * a given user is using. 116 1.5.2.2 yamt */ 117 1.5.2.2 yamt int 118 1.5.2.2 yamt chgproccnt(uid_t uid, int diff) 119 1.5.2.2 yamt { 120 1.5.2.2 yamt struct uidinfo *uip; 121 1.5.2.2 yamt long proccnt; 122 1.5.2.2 yamt 123 1.5.2.2 yamt uip = uid_find(uid); 124 1.5.2.2 yamt proccnt = atomic_add_long_nv(&uip->ui_proccnt, diff); 125 1.5.2.2 yamt KASSERT(proccnt >= 0); 126 1.5.2.2 yamt return proccnt; 127 1.5.2.2 yamt } 128 1.5.2.2 yamt 129 1.5.2.2 yamt int 130 1.5.2.2 yamt chgsbsize(struct uidinfo *uip, u_long *hiwat, u_long to, rlim_t xmax) 131 1.5.2.2 yamt { 132 1.5.2.2 yamt rlim_t nsb; 133 1.5.2.2 yamt const long diff = to - *hiwat; 134 1.5.2.2 yamt 135 1.5.2.2 yamt nsb = (rlim_t)atomic_add_long_nv((long *)&uip->ui_sbsize, diff); 136 1.5.2.2 yamt if (diff > 0 && nsb > xmax) { 137 1.5.2.2 yamt atomic_add_long((long *)&uip->ui_sbsize, -diff); 138 1.5.2.2 yamt return 0; 139 1.5.2.2 yamt } 140 1.5.2.2 yamt *hiwat = to; 141 1.5.2.2 yamt return 1; 142 1.5.2.2 yamt } 143
Indexes created Tue Sep 30 20:09:53 GMT 2025