kernel/syscall/sigaction.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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2010 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 /*        All Rights Reserved   */
  29
  30 #include <sys/param.h>
  31 #include <sys/types.h>
  32 #include <sys/sysmacros.h>
  33 #include <sys/systm.h>
  34 #include <sys/user.h>
  35 #include <sys/errno.h>
  36 #include <sys/proc.h>
  37 #include <sys/fault.h>
  38 #include <sys/signal.h>
  39 #include <sys/siginfo.h>
  40 #include <sys/debug.h>
  41
  42 int
  43 sigaction(int sig, struct sigaction *actp, struct sigaction *oactp)
  44 {
  45         struct sigaction act;
  46         struct sigaction oact;
  47         k_sigset_t set;
  48         proc_t *p;
  49         user_t *ua;
  50         int sigcld_look = 0;
  51
  52         if (sig <= 0 || sig >= NSIG ||
  53             (actp != NULL && sigismember(&cantmask, sig)))
  54                 return (set_errno(EINVAL));
  55
  56         /*
  57          * act and oact might be the same address, so copyin act first.
  58          */
  59         if (actp) {
  60                 if (copyin(actp, &act, sizeof (act)))
  61                         return (set_errno(EFAULT));
  62         }
  63
  64         p = curproc;
  65         ua = PTOU(p);
  66         mutex_enter(&p->p_lock);
  67
  68         if (oactp) {
  69                 int flags;
  70                 void (*disp)();
  71
  72                 disp = ua->u_signal[sig - 1];
  73
  74                 flags = 0;
  75                 if (disp != SIG_DFL && disp != SIG_IGN) {
  76                         set = ua->u_sigmask[sig-1];
  77                         if (sigismember(&p->p_siginfo, sig))
  78                                 flags |= SA_SIGINFO;
  79                         if (sigismember(&ua->u_sigrestart, sig))
  80                                 flags |= SA_RESTART;
  81                         if (sigismember(&ua->u_sigonstack, sig))
  82                                 flags |= SA_ONSTACK;
  83                         if (sigismember(&ua->u_sigresethand, sig))
  84                                 flags |= SA_RESETHAND;
  85                         if (sigismember(&ua->u_signodefer, sig))
  86                                 flags |= SA_NODEFER;
  87                 } else
  88                         sigemptyset(&set);
  89
  90                 if (sig == SIGCLD) {
  91                         if (p->p_flag & SNOWAIT)
  92                                 flags |= SA_NOCLDWAIT;
  93                         if (!(p->p_flag & SJCTL))
  94                                 flags |= SA_NOCLDSTOP;
  95                 }
  96
  97                 oact.sa_handler = disp;
  98                 oact.sa_flags = flags;
  99                 sigktou(&set, &oact.sa_mask);
 100         }
 101
 102         if (actp) {
 103                 if (sig == SIGCLD)
 104                         sigcld_look = 1;
 105                 sigutok(&act.sa_mask, &set);
 106                 setsigact(sig, act.sa_handler, &set, act.sa_flags);
 107         }
 108
 109         mutex_exit(&p->p_lock);
 110
 111         if (sigcld_look)
 112                 sigcld_repost();
 113
 114         if (oactp &&
 115             copyout(&oact, oactp, sizeof (oact)))
 116                 return (set_errno(EFAULT));
 117
 118         return (0);
 119 }
 120
 121 #ifdef _SYSCALL32_IMPL
 122
 123 int
 124 sigaction32(int sig, struct sigaction32 *actp, struct sigaction32 *oactp)
 125 {
 126         struct sigaction32 act32;
 127         struct sigaction32 oact32;
 128         k_sigset_t set;
 129         proc_t *p;
 130         user_t *ua;
 131         int sigcld_look = 0;
 132
 133         if (sig <= 0 || sig >= NSIG ||
 134             (actp != NULL && sigismember(&cantmask, sig)))
 135                 return (set_errno(EINVAL));
 136
 137         /*
 138          * act and oact might be the same address, so copyin act first.
 139          */
 140         if (actp) {
 141 #if defined(__sparc)
 142                 void (*handler)();
 143 #endif
 144                 if (copyin(actp, &act32, sizeof (act32)))
 145                         return (set_errno(EFAULT));
 146 #if defined(__sparc)
 147                 /*
 148                  * Check alignment of handler
 149                  */
 150                 handler = (void (*)())(uintptr_t)act32.sa_handler;
 151                 if (handler != SIG_IGN && handler != SIG_DFL &&
 152                     ((uintptr_t)handler & 0x3) != 0)
 153                         return (set_errno(EINVAL));
 154 #endif
 155         }
 156
 157         p = curproc;
 158         ua = PTOU(p);
 159         mutex_enter(&p->p_lock);
 160
 161         if (oactp) {
 162                 int flags;
 163                 void (*disp)();
 164
 165                 disp = ua->u_signal[sig - 1];
 166
 167                 flags = 0;
 168                 if (disp != SIG_DFL && disp != SIG_IGN) {
 169                         set = ua->u_sigmask[sig-1];
 170                         if (sigismember(&p->p_siginfo, sig))
 171                                 flags |= SA_SIGINFO;
 172                         if (sigismember(&ua->u_sigrestart, sig))
 173                                 flags |= SA_RESTART;
 174                         if (sigismember(&ua->u_sigonstack, sig))
 175                                 flags |= SA_ONSTACK;
 176                         if (sigismember(&ua->u_sigresethand, sig))
 177                                 flags |= SA_RESETHAND;
 178                         if (sigismember(&ua->u_signodefer, sig))
 179                                 flags |= SA_NODEFER;
 180                 } else
 181                         sigemptyset(&set);
 182
 183                 if (sig == SIGCLD) {
 184                         if (p->p_flag & SNOWAIT)
 185                                 flags |= SA_NOCLDWAIT;
 186                         if (!(p->p_flag & SJCTL))
 187                                 flags |= SA_NOCLDSTOP;
 188                 }
 189
 190                 oact32.sa_handler = (caddr32_t)(uintptr_t)disp;
 191                 oact32.sa_flags = flags;
 192                 sigktou(&set, &oact32.sa_mask);
 193         }
 194
 195         if (actp) {
 196                 if (sig == SIGCLD)
 197                         sigcld_look = 1;
 198                 sigutok(&act32.sa_mask, &set);
 199                 setsigact(sig, (void (*)())(uintptr_t)act32.sa_handler, &set,
 200                     act32.sa_flags);
 201         }
 202
 203         mutex_exit(&p->p_lock);
 204
 205         if (sigcld_look)
 206                 sigcld_repost();
 207
 208         if (oactp &&
 209             copyout(&oact32, oactp, sizeof (oact32)))
 210                 return (set_errno(EFAULT));
 211
 212         return (0);
 213 }
 214 #endif /* _SYSCALL32_IMPL */