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d1e44df1 | 1 | /* Unmap a shared object's segments. NaCl version. |
bfff8b1b | 2 | Copyright (C) 2015-2017 Free Software Foundation, Inc. |
d1e44df1 RM |
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 | <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #ifndef _DL_UNMAP_SEGMENTS_H | |
20 | #define _DL_UNMAP_SEGMENTS_H 1 | |
21 | ||
22 | #include <link.h> | |
23 | #include <sys/mman.h> | |
24 | ||
25 | /* There is always a big gap between the executable segment and the data | |
26 | segments. Other code segments and data pages lie in there. So we must | |
27 | unmap each segment individually (except for a codeless module). */ | |
28 | ||
29 | static void __always_inline | |
30 | _dl_unmap_segments (struct link_map *l) | |
31 | { | |
32 | if (l->l_contiguous) | |
33 | /* Simple case. */ | |
34 | __munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start); | |
35 | else | |
36 | { | |
37 | /* Normally l_phdr points into the RODATA segment, which we will | |
38 | unmap in one iteration of the loop. So we cannot use it directly | |
39 | throughout. */ | |
40 | ||
41 | struct { ElfW(Addr) start, end; } segments[l->l_phnum], *seg = segments; | |
42 | ||
43 | for (const ElfW(Phdr) *ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph) | |
44 | if (ph->p_type == PT_LOAD) | |
45 | { | |
46 | seg->start = (l->l_addr + ph->p_vaddr) & -GLRO(dl_pagesize); | |
47 | seg->end = (l->l_addr + ph->p_vaddr + ph->p_memsz | |
48 | + GLRO(dl_pagesize) - 1) & -GLRO(dl_pagesize); | |
49 | if (seg > segments && seg[-1].end == seg->start) | |
50 | /* Coalesce two adjacent segments into one munmap call. */ | |
51 | seg[-1].end = seg->end; | |
52 | else | |
53 | ++seg; | |
54 | } | |
55 | ||
56 | do | |
57 | { | |
58 | --seg; | |
59 | __munmap ((void *) seg->start, seg->end - seg->start); | |
60 | } | |
61 | while (seg > segments); | |
62 | } | |
63 | } | |
64 | ||
65 | #endif /* dl-unmap-segments.h */ |