summaryrefslogtreecommitdiff
path: root/gcc/config/alpha/host-osf.c
blob: 0a554b3ec2c6750e6ffba43a3f4c6eaa685e947b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
/* Tru64 UNIX host-specific hook definitions.
   Copyright (C) 2011 Free Software Foundation, Inc.

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published
   by the Free Software Foundation; either version 3, or (at your
   option) any later version.

   GCC is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License
   along with GCC; see the file COPYING3.  If not see
   <http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include <sys/mman.h>
/* Inhibit inclusion of <sys/mount.h>, unnecessary and errors out due to
   use of poisoned bcmp, bcopy.  */
#define _SYS_MOUNT_H_
#include <sys/procfs.h>
#include "hosthooks.h"
#include "hosthooks-def.h"


#undef HOST_HOOKS_GT_PCH_GET_ADDRESS
#define HOST_HOOKS_GT_PCH_GET_ADDRESS osf_gt_pch_get_address
#undef HOST_HOOKS_GT_PCH_USE_ADDRESS
#define HOST_HOOKS_GT_PCH_USE_ADDRESS osf_gt_pch_use_address

/* The mmap ADDR parameter may be ignored without MAP_FIXED set.  Before we
   give up, check existing mappings with ioctl(PIOCMAP) to see if the space
   is really free.  */

static void *
mmap_fixed (void *addr, size_t len, int prot, int flags, int fd, off_t off)
{
  void *base;

  base = mmap ((caddr_t) addr, len, prot, flags, fd, off);
  
  if (base != addr)
    {
      /* PID_MAX is SHRT_MAX on Tru64 UNIX V4.0, but INT_MAX on V5.1.
	 Allow for both.  "/proc/" + INT_MAX + '\0'.  */
      char pname[6+10+1];
      int procfd, nmap;
      prmap_t *pmap;
      int i, overlap = 0;

      if (base != (void *) MAP_FAILED)
	munmap ((caddr_t) base, len);

      /* Check if there's any mapping overlapping [addr, addr+len).  */

      snprintf (pname, sizeof (pname), "/proc/%d", getpid ());
      procfd = open (pname, O_RDONLY);
      if (procfd == -1)
	return ((void *) MAP_FAILED);
      if (ioctl (procfd, PIOCNMAP, &nmap) == -1)
	return ((void *) MAP_FAILED);
      pmap = (prmap_t *) xmalloc (sizeof (*pmap) * (nmap+1));
      if (ioctl (procfd, PIOCMAP, pmap) == -1)
	return ((void *) MAP_FAILED);

      /* It seems like pmap[] is sorted by address, but can we rely on
	 that?  */
      for (i = 0; i < nmap; i++)
	{
	  uintptr_t map_start = (uintptr_t) pmap[i].pr_vaddr;
	  uintptr_t map_end = map_start + pmap[i].pr_size;

	  if ((uintptr_t) addr < map_end
	      && (uintptr_t) addr+len > map_start)
	    {
	      overlap = 1;
	      break;
	    }
	}
      free (pmap);
      close (procfd);

      if (!overlap)
	base = mmap ((caddr_t) addr, len, prot, flags | MAP_FIXED, fd, off);
      else
	base = mmap ((caddr_t) addr, len, prot, flags, fd, off);
    }

  return base;
}

/* For various ports, try to guess a fixed spot in the vm space that's
   probably free.  Take the middle between start of text segment and
   dynamic loader space.  See <sys/machine/addrconf.h> and Tru64 UNIX
   Assembly Language Programmer's Guide, p.6-18, Figure 6-3: Default Layout
   of Memory (User Program View).  */
#define TRY_EMPTY_VM_SPACE	0x20050000000

/* Determine a location where we might be able to reliably allocate
   SIZE bytes.  FD is the PCH file, though we should return with the
   file unmapped.  */

static void *
osf_gt_pch_get_address (size_t size, int fd)
{
  void *addr;

  addr = mmap_fixed ((caddr_t) TRY_EMPTY_VM_SPACE, size,
		     PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);

  /* If we failed the map, that means there's *no* free space.  */
  if (addr == (void *) MAP_FAILED)
    return NULL;
  /* Unmap the area before returning.  */
  munmap ((caddr_t) addr, size);

  return addr;
}

/* Map SIZE bytes of FD+OFFSET at BASE.  Return 1 if we succeeded at 
   mapping the data at BASE, -1 if we couldn't.  */

static int
osf_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
{
  void *addr;

  /* We're called with size == 0 if we're not planning to load a PCH
     file at all.  This allows the hook to free any static space that
     we might have allocated at link time.  */
  if (size == 0)
    return -1;

  addr = mmap_fixed ((caddr_t) base, size,
		     PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, offset);

  return addr == base ? 1 : -1;
}


const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;