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
_hurd_priority_which_map(enum __priority_which which,int who,error_t (* function)(pid_t,struct procinfo *),int pi_flags)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 }
89