hurd/hurdprio.c

   1 /* Support code for dealing with priorities in the Hurd.
   2    Copyright (C) 1994-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <hurd.h>
  20 #include <hurd/resource.h>
  21 #include <sys/mman.h>
  22 #include <unistd.h>
  23
  24 error_t
  25 _hurd_priority_which_map (enum __priority_which which, int who,
  26                           error_t (*function) (pid_t, struct procinfo *),
  27                           int pi_flags)
  28 {
  29   mach_msg_type_number_t npids = 64, i;
  30   pid_t pidbuf[npids], *pids = pidbuf;
  31   error_t err;
  32   struct procinfo *pip;
  33   int pibuf[sizeof *pip + 5 * sizeof (pip->threadinfos[0])], *pi = pibuf;
  34   mach_msg_type_number_t pisize = sizeof (pibuf) / sizeof (int);
  35
  36   switch (which)
  37     {
  38     default:
  39       return EINVAL;
  40
  41     case PRIO_PROCESS:
  42       err = (*function) (who ?: getpid (), 0); /* XXX special-case self? */
  43       break;
  44
  45     case PRIO_PGRP:
  46       err = __USEPORT (PROC, __proc_getpgrppids (port, who, &pids, &npids));
  47       for (i = 0; !err && i < npids; ++i)
  48         err = (*function) (pids[i], 0);
  49       break;
  50
  51     case PRIO_USER:
  52       if (who == 0)
  53         who = __geteuid ();
  54       err = __USEPORT (PROC, __proc_getallpids (port, &pids, &npids));
  55       for (i = 0; !err && i < npids; ++i)
  56         {
  57           /* Get procinfo to check the owner.  */
  58           int *oldpi = pi;
  59           mach_msg_type_number_t oldpisize = pisize;
  60           char *tw = 0;
  61           size_t twsz = 0;
  62           err = __USEPORT (PROC, __proc_getprocinfo (port, pids[i],
  63                                                      &pi_flags,
  64                                                      &pi, &pisize,
  65                                                      &tw, &twsz));
  66           if (!err)
  67             {
  68               if (twsz)         /* Gratuitous.  */
  69                 __munmap (tw, twsz);
  70               if (pi != oldpi && oldpi != pibuf)
  71                 /* Old buffer from last call was not reused; free it.  */
  72                 __munmap (oldpi, oldpisize * sizeof pi[0]);
  73
  74               pip = (struct procinfo *) pi;
  75               if (pip->owner == (uid_t) who)
  76                 err = (*function) (pids[i], pip);
  77             }
  78         }
  79       break;
  80     }
  81
  82   if (pids != pidbuf)
  83     __munmap (pids, npids * sizeof pids[0]);
  84   if (pi != pibuf)
  85     __munmap (pi, pisize * sizeof pi[0]);
  86
  87   return err;
  88 }