kernel/syscall/sigaltstack.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include <sys/param.h>
  33 #include <sys/types.h>
  34 #include <sys/sysmacros.h>
  35 #include <sys/systm.h>
  36 #include <sys/errno.h>
  37 #include <sys/proc.h>
  38 #include <sys/fault.h>
  39 #include <sys/signal.h>
  40 #include <sys/siginfo.h>
  41 #include <sys/debug.h>
  42
  43 int
  44 sigaltstack(struct sigaltstack *ssp, struct sigaltstack *oss)
  45 {
  46         klwp_t *lwp = ttolwp(curthread);
  47         struct sigaltstack ss;
  48
  49         /*
  50          * User's oss and ss might be the same address, so copyin first and
  51          * save before copying out.
  52          */
  53         if (ssp) {
  54                 if (lwp->lwp_sigaltstack.ss_flags & SS_ONSTACK)
  55                         return (set_errno(EPERM));
  56                 if (copyin(ssp, &ss, sizeof (ss)))
  57                         return (set_errno(EFAULT));
  58                 if (ss.ss_flags & ~SS_DISABLE)
  59                         return (set_errno(EINVAL));
  60                 if (!(ss.ss_flags & SS_DISABLE) && ss.ss_size < MINSIGSTKSZ)
  61                         return (set_errno(ENOMEM));
  62         }
  63
  64         if (oss) {
  65                 if (copyout(&lwp->lwp_sigaltstack,
  66                     oss, sizeof (struct sigaltstack)))
  67                         return (set_errno(EFAULT));
  68         }
  69
  70         if (ssp)
  71                 lwp->lwp_sigaltstack = ss;
  72
  73         return (0);
  74 }
  75
  76 #ifdef _LP64
  77 int
  78 sigaltstack32(struct sigaltstack32 *ssp, struct sigaltstack32 *oss)
  79 {
  80         klwp_t *lwp = ttolwp(curthread);
  81         struct sigaltstack   *ss;
  82         struct sigaltstack32 ss32, oss32;
  83
  84         /*
  85          * User's oss and ss might be the same address, so copyin first and
  86          * save before copying out.
  87          */
  88         if (ssp) {
  89                 if (lwp->lwp_sigaltstack.ss_flags & SS_ONSTACK)
  90                         return (set_errno(EPERM));
  91                 if (copyin(ssp, &ss32, sizeof (ss32)))
  92                         return (set_errno(EFAULT));
  93                 if (ss32.ss_flags & ~SS_DISABLE)
  94                         return (set_errno(EINVAL));
  95                 if (!(ss32.ss_flags & SS_DISABLE) && ss32.ss_size < MINSIGSTKSZ)
  96                         return (set_errno(ENOMEM));
  97         }
  98
  99         if (oss) {
 100                 /*
 101                  * copy to ILP32 struct before copyout.
 102                  */
 103                 ss = &lwp->lwp_sigaltstack;
 104                 oss32.ss_sp    = (caddr32_t)(uintptr_t)ss->ss_sp;
 105                 oss32.ss_size  = (size32_t)ss->ss_size;
 106                 oss32.ss_flags = ss->ss_flags;
 107
 108                 if (copyout(&oss32, oss, sizeof (oss32)))
 109                         return (set_errno(EFAULT));
 110         }
 111
 112         if (ssp) {
 113                 ss = &lwp->lwp_sigaltstack;
 114                 ss->ss_sp = (void *)(uintptr_t)ss32.ss_sp;
 115                 ss->ss_size = (size_t)ss32.ss_size;
 116                 ss->ss_flags = ss32.ss_flags;
 117         }
 118
 119         return (0);
 120 }
 121 #endif /* _LP64 */