1 /* OpenBSD host-specific hook definitions.
2 Copyright (C) 2004-2018 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published
8 by the Free Software Foundation; either version 3, or (at your
9 option) any later version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "hosthooks.h"
24 #include "hosthooks-def.h"
25
26
27 #undef HOST_HOOKS_GT_PCH_GET_ADDRESS
28 #define HOST_HOOKS_GT_PCH_GET_ADDRESS openbsd_gt_pch_get_address
29 #undef HOST_HOOKS_GT_PCH_USE_ADDRESS
30 #define HOST_HOOKS_GT_PCH_USE_ADDRESS openbsd_gt_pch_use_address
31
32 /* For various ports, try to guess a fixed spot in the vm space
33 that's probably free. */
34 #if defined(__amd64__)
35 # define TRY_EMPTY_VM_SPACE 0x400000000000
36 #elif defined(__hppa__)
37 # define TRY_EMPTY_VM_SPACE 0xb0000000
38 #elif defined(__i386__)
39 # define TRY_EMPTY_VM_SPACE 0xb0000000
40 #else
41 # define TRY_EMPTY_VM_SPACE 0
42 #endif
43
44 /* Determine a location where we might be able to reliably allocate
45 SIZE bytes. FD is the PCH file, though we should return with the
46 file unmapped. */
47
48 static void *
openbsd_gt_pch_get_address(size_t size,int fd)49 openbsd_gt_pch_get_address (size_t size, int fd)
50 {
51 void *addr;
52
53 addr = mmap ((void *) TRY_EMPTY_VM_SPACE, size, PROT_READ | PROT_WRITE,
54 MAP_PRIVATE, fd, 0);
55
56 /* If we failed the map, that means there's *no* free space. */
57 if (addr == (void *) MAP_FAILED)
58 return NULL;
59 /* Unmap the area before returning. */
60 munmap (addr, size);
61
62 return addr;
63 }
64
65 /* Map SIZE bytes of FD+OFFSET at BASE. Return 1 if we succeeded at
66 mapping the data at BASE, -1 if we couldn't. */
67
68 static int
openbsd_gt_pch_use_address(void * base,size_t size,int fd,size_t offset)69 openbsd_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
70 {
71 void *addr;
72
73 /* We're called with size == 0 if we're not planning to load a PCH
74 file at all. This allows the hook to free any static space that
75 we might have allocated at link time. */
76 if (size == 0)
77 return -1;
78
79 addr = mmap (base, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, offset);
80
81 return addr == base ? 1 : -1;
82 }
83
84
85 const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;
86