256 lines
6.4 KiB
C
256 lines
6.4 KiB
C
/* Support for memory-mapped windows into a BFD.
|
|
Copyright 1995, 1996, 2001, 2002, 2003, 2005, 2007, 2008
|
|
Free Software Foundation, Inc.
|
|
Written by Cygnus Support.
|
|
|
|
This file is part of BFD, the Binary File Descriptor library.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
|
|
MA 02110-1301, USA. */
|
|
|
|
#include "sysdep.h"
|
|
|
|
#include "bfd.h"
|
|
#include "libbfd.h"
|
|
|
|
/* Currently, if USE_MMAP is undefined, none of the window stuff is
|
|
used. Enabled by --with-mmap. */
|
|
|
|
#ifdef USE_MMAP
|
|
|
|
#undef HAVE_MPROTECT /* code's not tested yet */
|
|
|
|
#if HAVE_MMAP || HAVE_MPROTECT || HAVE_MADVISE
|
|
#include <sys/mman.h>
|
|
#endif
|
|
|
|
#ifndef MAP_FILE
|
|
#define MAP_FILE 0
|
|
#endif
|
|
|
|
static int debug_windows;
|
|
|
|
/* The idea behind the next and refcount fields is that one mapped
|
|
region can suffice for multiple read-only windows or multiple
|
|
non-overlapping read-write windows. It's not implemented yet
|
|
though. */
|
|
|
|
/*
|
|
INTERNAL_DEFINITION
|
|
|
|
.struct _bfd_window_internal {
|
|
. struct _bfd_window_internal *next;
|
|
. void *data;
|
|
. bfd_size_type size;
|
|
. int refcount : 31; {* should be enough... *}
|
|
. unsigned mapped : 1; {* 1 = mmap, 0 = malloc *}
|
|
.};
|
|
*/
|
|
|
|
void
|
|
bfd_init_window (bfd_window *windowp)
|
|
{
|
|
windowp->data = 0;
|
|
windowp->i = 0;
|
|
windowp->size = 0;
|
|
}
|
|
|
|
void
|
|
bfd_free_window (bfd_window *windowp)
|
|
{
|
|
bfd_window_internal *i = windowp->i;
|
|
windowp->i = 0;
|
|
windowp->data = 0;
|
|
if (i == 0)
|
|
return;
|
|
i->refcount--;
|
|
if (debug_windows)
|
|
fprintf (stderr, "freeing window @%p<%p,%lx,%p>\n",
|
|
windowp, windowp->data, windowp->size, windowp->i);
|
|
if (i->refcount != 0)
|
|
return;
|
|
|
|
if (i->mapped)
|
|
{
|
|
#ifdef HAVE_MMAP
|
|
munmap (i->data, i->size);
|
|
goto no_free;
|
|
#else
|
|
abort ();
|
|
#endif
|
|
}
|
|
#ifdef HAVE_MPROTECT
|
|
mprotect (i->data, i->size, PROT_READ | PROT_WRITE);
|
|
#endif
|
|
free (i->data);
|
|
#ifdef HAVE_MMAP
|
|
no_free:
|
|
#endif
|
|
i->data = 0;
|
|
/* There should be no more references to i at this point. */
|
|
free (i);
|
|
}
|
|
|
|
static int ok_to_map = 1;
|
|
|
|
bfd_boolean
|
|
bfd_get_file_window (bfd *abfd,
|
|
file_ptr offset,
|
|
bfd_size_type size,
|
|
bfd_window *windowp,
|
|
bfd_boolean writable)
|
|
{
|
|
static size_t pagesize;
|
|
bfd_window_internal *i = windowp->i;
|
|
bfd_size_type size_to_alloc = size;
|
|
|
|
if (debug_windows)
|
|
fprintf (stderr, "bfd_get_file_window (%p, %6ld, %6ld, %p<%p,%lx,%p>, %d)",
|
|
abfd, (long) offset, (long) size,
|
|
windowp, windowp->data, (unsigned long) windowp->size,
|
|
windowp->i, writable);
|
|
|
|
/* Make sure we know the page size, so we can be friendly to mmap. */
|
|
if (pagesize == 0)
|
|
pagesize = getpagesize ();
|
|
if (pagesize == 0)
|
|
abort ();
|
|
|
|
if (i == 0)
|
|
{
|
|
i = bfd_zmalloc (sizeof (bfd_window_internal));
|
|
windowp->i = i;
|
|
if (i == 0)
|
|
return FALSE;
|
|
i->data = 0;
|
|
}
|
|
#ifdef HAVE_MMAP
|
|
if (ok_to_map
|
|
&& (i->data == 0 || i->mapped == 1)
|
|
&& (abfd->flags & BFD_IN_MEMORY) == 0)
|
|
{
|
|
file_ptr file_offset, offset2;
|
|
size_t real_size;
|
|
int fd;
|
|
|
|
/* Find the real file and the real offset into it. */
|
|
while (abfd->my_archive != NULL)
|
|
{
|
|
offset += abfd->origin;
|
|
abfd = abfd->my_archive;
|
|
}
|
|
|
|
/* Seek into the file, to ensure it is open if cacheable. */
|
|
if (abfd->iostream == NULL
|
|
&& (abfd->iovec == NULL
|
|
|| abfd->iovec->bseek (abfd, offset, SEEK_SET) != 0))
|
|
return FALSE;
|
|
fd = fileno ((FILE *) abfd->iostream);
|
|
|
|
/* Compute offsets and size for mmap and for the user's data. */
|
|
offset2 = offset % pagesize;
|
|
if (offset2 < 0)
|
|
abort ();
|
|
file_offset = offset - offset2;
|
|
real_size = offset + size - file_offset;
|
|
real_size = real_size + pagesize - 1;
|
|
real_size -= real_size % pagesize;
|
|
|
|
/* If we're re-using a memory region, make sure it's big enough. */
|
|
if (i->data && i->size < size)
|
|
{
|
|
munmap (i->data, i->size);
|
|
i->data = 0;
|
|
}
|
|
i->data = mmap (i->data, real_size,
|
|
writable ? PROT_WRITE | PROT_READ : PROT_READ,
|
|
(writable
|
|
? MAP_FILE | MAP_PRIVATE
|
|
: MAP_FILE | MAP_SHARED),
|
|
fd, file_offset);
|
|
if (i->data == (void *) -1)
|
|
{
|
|
/* An error happened. Report it, or try using malloc, or
|
|
something. */
|
|
bfd_set_error (bfd_error_system_call);
|
|
i->data = 0;
|
|
windowp->data = 0;
|
|
if (debug_windows)
|
|
fprintf (stderr, "\t\tmmap failed!\n");
|
|
return FALSE;
|
|
}
|
|
if (debug_windows)
|
|
fprintf (stderr, "\n\tmapped %ld at %p, offset is %ld\n",
|
|
(long) real_size, i->data, (long) offset2);
|
|
i->size = real_size;
|
|
windowp->data = (bfd_byte *) i->data + offset2;
|
|
windowp->size = size;
|
|
i->mapped = 1;
|
|
return TRUE;
|
|
}
|
|
else if (debug_windows)
|
|
{
|
|
if (ok_to_map)
|
|
fprintf (stderr, _("not mapping: data=%lx mapped=%d\n"),
|
|
(unsigned long) i->data, (int) i->mapped);
|
|
else
|
|
fprintf (stderr, _("not mapping: env var not set\n"));
|
|
}
|
|
#else
|
|
ok_to_map = 0;
|
|
#endif
|
|
|
|
#ifdef HAVE_MPROTECT
|
|
if (!writable)
|
|
{
|
|
size_to_alloc += pagesize - 1;
|
|
size_to_alloc -= size_to_alloc % pagesize;
|
|
}
|
|
#endif
|
|
if (debug_windows)
|
|
fprintf (stderr, "\n\t%s(%6ld)",
|
|
i->data ? "realloc" : " malloc", (long) size_to_alloc);
|
|
i->data = bfd_realloc_or_free (i->data, size_to_alloc);
|
|
if (debug_windows)
|
|
fprintf (stderr, "\t-> %p\n", i->data);
|
|
if (i->data == NULL)
|
|
{
|
|
if (size_to_alloc == 0)
|
|
return TRUE;
|
|
return FALSE;
|
|
}
|
|
i->refcount = 1;
|
|
if (bfd_seek (abfd, offset, SEEK_SET) != 0)
|
|
return FALSE;
|
|
i->size = bfd_bread (i->data, size, abfd);
|
|
if (i->size != size)
|
|
return FALSE;
|
|
i->mapped = 0;
|
|
#ifdef HAVE_MPROTECT
|
|
if (!writable)
|
|
{
|
|
if (debug_windows)
|
|
fprintf (stderr, "\tmprotect (%p, %ld, PROT_READ)\n", i->data,
|
|
(long) i->size);
|
|
mprotect (i->data, i->size, PROT_READ);
|
|
}
|
|
#endif
|
|
windowp->data = i->data;
|
|
windowp->size = i->size;
|
|
return TRUE;
|
|
}
|
|
|
|
#endif /* USE_MMAP */
|