sysdeps/posix/sigvec.c

   1 /* Copyright (C) 1991, 92, 94, 95, 96, 97, 98 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <signal.h>
  20 #include <errno.h>
  21 #include <stddef.h>
  22
  23 /* Include macros to convert between `sigset_t' and old-style mask. */
  24 #include "sigset-cvt-mask.h"
  25
  26 /* We use a wrapper handler to support SV_RESETHAND.  */
  27 struct sigvec_wrapper_data
  28 {
  29   __sighandler_t sw_handler;
  30   unsigned int sw_mask;
  31 };
  32
  33 static void sigvec_wrapper_handler __P ((int sig));
  34
  35 static struct sigvec_wrapper_data sigvec_wrapper_data[NSIG];
  36
  37
  38 /* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
  39    of VEC.  The signals in `sv_mask' will be blocked while the handler runs.
  40    If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
  41    reset to SIG_DFL before `sv_handler' is entered.  If OVEC is non-NULL,
  42    it is filled in with the old information for SIG.  */
  43 int
  44 __sigvec (sig, vec, ovec)
  45      int sig;
  46      const struct sigvec *vec;
  47      struct sigvec *ovec;
  48 {
  49   struct sigaction old;
  50
  51   if (vec == NULL || !(vec->sv_flags & SV_RESETHAND))
  52     {
  53       struct sigaction new, *n;
  54
  55       if (vec == NULL)
  56         n = NULL;
  57       else
  58         {
  59           __sighandler_t handler;
  60           unsigned int mask;
  61           unsigned int sv_flags;
  62           unsigned int sa_flags;
  63
  64           handler = vec->sv_handler;
  65           mask = vec->sv_mask;
  66           sv_flags = vec->sv_flags;
  67           sa_flags = 0;
  68           if (sv_flags & SV_ONSTACK)
  69             {
  70 #ifdef SA_ONSTACK
  71               sa_flags |= SA_ONSTACK;
  72 #else
  73               __set_errno (ENOSYS);
  74               return -1;
  75 #endif
  76             }
  77 #ifdef SA_RESTART
  78           if (!(sv_flags & SV_INTERRUPT))
  79             sa_flags |= SA_RESTART;
  80 #endif
  81           n = &new;
  82           new.sa_handler = handler;
  83           sigset_set_old_mask (&new.sa_mask, mask);
  84           new.sa_flags = sa_flags;
  85         }
  86
  87       if (__sigaction (sig, n, &old) < 0)
  88         return -1;
  89     }
  90   else
  91     {
  92       __sighandler_t handler;
  93       unsigned int mask;
  94       struct sigvec_wrapper_data *data;
  95       struct sigaction wrapper;
  96
  97       handler = vec->sv_handler;
  98       mask = (unsigned int)vec->sv_mask;
  99       data = &sigvec_wrapper_data[sig];
 100       wrapper.sa_handler = sigvec_wrapper_handler;
 101       /* FIXME: should we set wrapper.sa_mask, wrapper.sa_flags??  */
 102       data->sw_handler = handler;
 103       data->sw_mask = mask;
 104
 105       if (__sigaction (sig, &wrapper, &old) < 0)
 106         return -1;
 107     }
 108
 109   if (ovec != NULL)
 110     {
 111       __sighandler_t handler;
 112       unsigned int sv_flags;
 113       unsigned int sa_flags;
 114       unsigned int mask;
 115
 116       handler = old.sa_handler;
 117       sv_flags = 0;
 118       sa_flags = old.sa_flags;
 119       if (handler == sigvec_wrapper_handler)
 120         {
 121           handler = sigvec_wrapper_data[sig].sw_handler;
 122           /* should we use data->sw_mask?? */
 123           sv_flags |= SV_RESETHAND;
 124         }
 125       sigset_get_old_mask (&old.sa_mask, mask);
 126 #ifdef SA_ONSTACK
 127      if (sa_flags & SA_ONSTACK)
 128         sv_flags |= SV_ONSTACK;
 129 #endif
 130 #ifdef SA_RESTART
 131      if (!(sa_flags & SA_RESTART))
 132 #endif
 133         sv_flags |= SV_INTERRUPT;
 134       ovec->sv_handler = handler;
 135       ovec->sv_mask = (int)mask;
 136       ovec->sv_flags = (int)sv_flags;
 137     }
 138
 139   return 0;
 140 }
 141
 142 weak_alias (__sigvec, sigvec)
 143
 144
 145 static void
 146 sigvec_wrapper_handler (sig)
 147      int sig;
 148 {
 149   struct sigvec_wrapper_data *data;
 150   unsigned int mask;
 151   struct sigaction act;
 152   int save;
 153   __sighandler_t handler;
 154
 155   data = &sigvec_wrapper_data[sig];
 156   mask = data->sw_mask;
 157   act.sa_handler = SIG_DFL;
 158   sigset_set_old_mask (&act.sa_mask, mask);
 159   act.sa_flags = 0;
 160   save = errno;
 161   handler = data->sw_handler;
 162   (void) __sigaction (sig, &act, (struct sigaction *) NULL);
 163   __set_errno (save);
 164   (*handler) (sig);
 165 }