| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Unmap a shared object's segments. NaCl version. |
| 2 | Copyright (C) 2015-2016 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 | <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 */ |