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dff8da6b | 1 | /* Copyright (C) 1994-2024 Free Software Foundation, Inc. |
478b92f0 | 2 | This file is part of the GNU C Library. |
28f540f4 | 3 | |
478b92f0 | 4 | The GNU C Library is free software; you can redistribute it and/or |
41bdb6e2 AJ |
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. | |
28f540f4 | 8 | |
478b92f0 UD |
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 | |
41bdb6e2 | 12 | Lesser General Public License for more details. |
28f540f4 | 13 | |
41bdb6e2 | 14 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 15 | License along with the GNU C Library; if not, see |
5a82c748 | 16 | <https://www.gnu.org/licenses/>. */ |
28f540f4 RM |
17 | |
18 | #include <sys/types.h> | |
19 | #include <sys/mman.h> | |
20 | #include <errno.h> | |
c02b2645 | 21 | #include <ldsodefs.h> |
28f540f4 RM |
22 | #include <hurd.h> |
23 | #include <hurd/fd.h> | |
24 | ||
25 | /* Map addresses starting near ADDR and extending for LEN bytes. from | |
26 | OFFSET into the file FD describes according to PROT and FLAGS. If ADDR | |
27 | is nonzero, it is the desired mapping address. If the MAP_FIXED bit is | |
28 | set in FLAGS, the mapping will be at ADDR exactly (which must be | |
29 | page-aligned); otherwise the system chooses a convenient nearby address. | |
f17a4233 | 30 | The return value is the actual mapping address chosen or (void *) -1 |
28f540f4 RM |
31 | for errors (in which case `errno' is set). A successful `mmap' call |
32 | deallocates any previous mapping for the affected region. */ | |
33 | ||
f17a4233 JM |
34 | void * |
35 | __mmap (void *addr, size_t len, int prot, int flags, int fd, off_t offset) | |
28f540f4 RM |
36 | { |
37 | error_t err; | |
5a5358b7 | 38 | vm_prot_t vmprot, max_vmprot; |
28f540f4 | 39 | memory_object_t memobj; |
70b9173c | 40 | vm_address_t mapaddr, mask; |
19c3b318 | 41 | boolean_t copy, anywhere; |
65bf5fa3 | 42 | |
57a491d1 RM |
43 | mapaddr = (vm_address_t) addr; |
44 | ||
fbf86dda | 45 | /* ADDR and OFFSET must be page-aligned. */ |
51a3985d | 46 | if ((mapaddr & (__vm_page_size - 1)) || (offset & (__vm_page_size - 1))) |
f17a4233 | 47 | return (void *) (long int) __hurd_fail (EINVAL); |
fbf86dda | 48 | |
27cb2bb9 SB |
49 | if ((flags & MAP_EXCL) && ! (flags & MAP_FIXED)) |
50 | return (void *) (long int) __hurd_fail (EINVAL); | |
51 | ||
28f540f4 RM |
52 | vmprot = VM_PROT_NONE; |
53 | if (prot & PROT_READ) | |
54 | vmprot |= VM_PROT_READ; | |
55 | if (prot & PROT_WRITE) | |
56 | vmprot |= VM_PROT_WRITE; | |
57 | if (prot & PROT_EXEC) | |
58 | vmprot |= VM_PROT_EXECUTE; | |
59 | ||
08fc6df2 | 60 | copy = ! (flags & MAP_SHARED); |
19c3b318 | 61 | anywhere = ! (flags & MAP_FIXED); |
08fc6df2 | 62 | |
6afeac12 | 63 | #ifdef __x86_64__ |
c02b2645 SB |
64 | if ((addr == NULL) && (prot & PROT_EXEC) |
65 | && HAS_ARCH_FEATURE (Prefer_MAP_32BIT_EXEC)) | |
66 | flags |= MAP_32BIT; | |
67 | #endif | |
70b9173c SB |
68 | mask = (flags & MAP_32BIT) ? ~(vm_address_t) 0x7FFFFFFF : 0; |
69 | ||
28f540f4 RM |
70 | switch (flags & MAP_TYPE) |
71 | { | |
72 | default: | |
f17a4233 | 73 | return (void *) (long int) __hurd_fail (EINVAL); |
28f540f4 RM |
74 | |
75 | case MAP_ANON: | |
76 | memobj = MACH_PORT_NULL; | |
5a5358b7 | 77 | max_vmprot = VM_PROT_ALL; |
28f540f4 RM |
78 | break; |
79 | ||
80 | case MAP_FILE: | |
7752137a | 81 | case 0: /* Allow, e.g., just MAP_SHARED. */ |
28f540f4 RM |
82 | { |
83 | mach_port_t robj, wobj; | |
84 | if (err = HURD_DPORT_USE (fd, __io_map (port, &robj, &wobj))) | |
edc7ae46 RM |
85 | { |
86 | if (err == MIG_BAD_ID || err == EOPNOTSUPP || err == ENOSYS) | |
87 | err = ENODEV; /* File descriptor doesn't support mmap. */ | |
f17a4233 | 88 | return (void *) (long int) __hurd_dfail (fd, err); |
edc7ae46 | 89 | } |
28f540f4 RM |
90 | switch (prot & (PROT_READ|PROT_WRITE)) |
91 | { | |
e86c5b64 ST |
92 | /* Although it apparently doesn't make sense to map a file with |
93 | protection set to PROT_NONE, it is actually sometimes done. | |
94 | In particular, that's how localedef reserves some space for | |
95 | the locale archive file, the rationale being that some | |
96 | implementations take into account whether the mapping is | |
97 | anonymous or not when selecting addresses. */ | |
98 | case PROT_NONE: | |
28f540f4 | 99 | case PROT_READ: |
5a5358b7 SB |
100 | max_vmprot = VM_PROT_READ|VM_PROT_EXECUTE; |
101 | if (wobj == robj) | |
102 | max_vmprot |= VM_PROT_WRITE; | |
28f540f4 | 103 | memobj = robj; |
35b7bf2f | 104 | if (MACH_PORT_VALID (wobj)) |
1a3a58fd | 105 | __mach_port_deallocate (__mach_task_self (), wobj); |
28f540f4 RM |
106 | break; |
107 | case PROT_WRITE: | |
5a5358b7 SB |
108 | max_vmprot = VM_PROT_WRITE; |
109 | if (robj == wobj) | |
110 | max_vmprot |= VM_PROT_READ|VM_PROT_EXECUTE; | |
28f540f4 | 111 | memobj = wobj; |
35b7bf2f | 112 | if (MACH_PORT_VALID (robj)) |
1a3a58fd | 113 | __mach_port_deallocate (__mach_task_self (), robj); |
28f540f4 RM |
114 | break; |
115 | case PROT_READ|PROT_WRITE: | |
5a5358b7 | 116 | max_vmprot = VM_PROT_ALL; |
28f540f4 | 117 | if (robj == wobj) |
1a3a58fd RM |
118 | { |
119 | memobj = wobj; | |
120 | /* Remove extra reference. */ | |
121 | __mach_port_deallocate (__mach_task_self (), memobj); | |
122 | } | |
a04549c1 | 123 | else if (wobj == MACH_PORT_NULL /* Not writable by mapping. */ |
08fc6df2 | 124 | && copy) |
1a3a58fd RM |
125 | /* The file can only be mapped for reading. Since we are |
126 | making a private mapping, we will never try to write the | |
127 | object anyway, so we don't care. */ | |
128 | memobj = robj; | |
28f540f4 RM |
129 | else |
130 | { | |
131 | __mach_port_deallocate (__mach_task_self (), wobj); | |
f17a4233 | 132 | return (void *) (long int) __hurd_fail (EACCES); |
28f540f4 RM |
133 | } |
134 | break; | |
e86c5b64 ST |
135 | default: |
136 | __builtin_unreachable (); | |
28f540f4 RM |
137 | } |
138 | break; | |
139 | /* XXX handle MAP_NOEXTEND */ | |
140 | } | |
141 | } | |
142 | ||
65bf5fa3 RM |
143 | /* XXX handle MAP_INHERIT */ |
144 | ||
5a5358b7 SB |
145 | if (copy) |
146 | max_vmprot = VM_PROT_ALL; | |
147 | ||
19c3b318 SB |
148 | /* When ANYWHERE is true but the caller has provided a preferred address, |
149 | try mapping at that address with anywhere = 0 first. If this fails, | |
150 | we'll retry with anywhere = 1 below. */ | |
28f540f4 | 151 | err = __vm_map (__mach_task_self (), |
70b9173c | 152 | &mapaddr, (vm_size_t) len, mask, |
19c3b318 | 153 | anywhere && (mapaddr == 0), |
28f540f4 | 154 | memobj, (vm_offset_t) offset, |
5a5358b7 | 155 | copy, vmprot, max_vmprot, |
08fc6df2 | 156 | copy ? VM_INHERIT_COPY : VM_INHERIT_SHARE); |
65bf5fa3 | 157 | |
b47b07c9 | 158 | if (flags & MAP_FIXED) |
787e4db9 | 159 | { |
b47b07c9 | 160 | if (err == KERN_NO_SPACE) |
0ea698ae | 161 | { |
27cb2bb9 SB |
162 | if (flags & MAP_EXCL) |
163 | err = EEXIST; | |
164 | else | |
165 | { | |
166 | /* The region is already allocated; deallocate it first. */ | |
167 | /* XXX this is not atomic as it is in unix! */ | |
168 | err = __vm_deallocate (__mach_task_self (), mapaddr, len); | |
169 | if (! err) | |
170 | err = __vm_map (__mach_task_self (), | |
171 | &mapaddr, (vm_size_t) len, mask, | |
172 | 0, memobj, (vm_offset_t) offset, | |
173 | copy, vmprot, max_vmprot, | |
174 | copy ? VM_INHERIT_COPY : VM_INHERIT_SHARE); | |
175 | } | |
0ea698ae | 176 | } |
b47b07c9 ST |
177 | } |
178 | else | |
179 | { | |
19c3b318 | 180 | /* This mmap call is allowed to allocate anywhere, */ |
b47b07c9 | 181 | if (mapaddr != 0 && (err == KERN_NO_SPACE || err == KERN_INVALID_ADDRESS)) |
19c3b318 SB |
182 | /* ...but above, we tried allocating at the specific address, |
183 | and failed to. Now try again, with anywhere = 1 this time. */ | |
787e4db9 | 184 | err = __vm_map (__mach_task_self (), |
70b9173c | 185 | &mapaddr, (vm_size_t) len, mask, |
0ea698ae | 186 | 1, memobj, (vm_offset_t) offset, |
5a5358b7 | 187 | copy, vmprot, max_vmprot, |
08fc6df2 | 188 | copy ? VM_INHERIT_COPY : VM_INHERIT_SHARE); |
787e4db9 | 189 | } |
28f540f4 | 190 | |
35b7bf2f | 191 | if (MACH_PORT_VALID (memobj)) |
28f540f4 RM |
192 | __mach_port_deallocate (__mach_task_self (), memobj); |
193 | ||
5a5358b7 SB |
194 | if (err == KERN_PROTECTION_FAILURE) |
195 | err = EACCES; | |
196 | ||
65bf5fa3 | 197 | if (err) |
f17a4233 | 198 | return (void *) (long int) __hurd_fail (err); |
65bf5fa3 | 199 | |
f17a4233 | 200 | return (void *) mapaddr; |
28f540f4 | 201 | } |
6408bdde | 202 | |
a166531f | 203 | libc_hidden_def (__mmap) |
6408bdde | 204 | weak_alias (__mmap, mmap) |