glibc/sysdeps/nacl/dl-unmap-segments.h

66 lines
2.3 KiB
C

/* Unmap a shared object's segments. NaCl version.
Copyright (C) 2015-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef _DL_UNMAP_SEGMENTS_H
#define _DL_UNMAP_SEGMENTS_H 1
#include <link.h>
#include <sys/mman.h>
/* There is always a big gap between the executable segment and the data
segments. Other code segments and data pages lie in there. So we must
unmap each segment individually (except for a codeless module). */
static void __always_inline
_dl_unmap_segments (struct link_map *l)
{
if (l->l_contiguous)
/* Simple case. */
__munmap ((void *) l->l_map_start, l->l_map_end - l->l_map_start);
else
{
/* Normally l_phdr points into the RODATA segment, which we will
unmap in one iteration of the loop. So we cannot use it directly
throughout. */
struct { ElfW(Addr) start, end; } segments[l->l_phnum], *seg = segments;
for (const ElfW(Phdr) *ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph)
if (ph->p_type == PT_LOAD)
{
seg->start = (l->l_addr + ph->p_vaddr) & -GLRO(dl_pagesize);
seg->end = (l->l_addr + ph->p_vaddr + ph->p_memsz
+ GLRO(dl_pagesize) - 1) & -GLRO(dl_pagesize);
if (seg > segments && seg[-1].end == seg->start)
/* Coalesce two adjacent segments into one munmap call. */
seg[-1].end = seg->end;
else
++seg;
}
do
{
--seg;
__munmap ((void *) seg->start, seg->end - seg->start);
}
while (seg > segments);
}
}
#endif /* dl-unmap-segments.h */