+++ /dev/null
-/* Support for memory-mapped windows into a BFD.
- Copyright (C) 1995-2024 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 */
-
-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
-.typedef 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 *}
-.}
-.bfd_window_internal;
-.
-
-EXTERNAL
-.struct _bfd_window_internal;
-.
-.typedef struct _bfd_window
-.{
-. {* What the user asked for. *}
-. void *data;
-. bfd_size_type size;
-. {* The actual window used by BFD. Small user-requested read-only
-. regions sharing a page may share a single window into the object
-. file. Read-write versions shouldn't until I've fixed things to
-. keep track of which portions have been claimed by the
-. application; don't want to give the same region back when the
-. application wants two writable copies! *}
-. struct _bfd_window_internal *i;
-.}
-.bfd_window;
-.
-*/
-
-/*
-FUNCTION
- bfd_init_window
-
-SYNOPSIS
- void bfd_init_window (bfd_window *);
-
-DESCRIPTION
- Initialise mmap window.
-*/
-
-void
-bfd_init_window (bfd_window *windowp)
-{
- windowp->data = 0;
- windowp->i = 0;
- windowp->size = 0;
-}
-
-/*
-FUNCTION
- bfd_free_window
-
-SYNOPSIS
- void bfd_free_window (bfd_window *);
-
-DESCRIPTION
- Finalise mmap window struct.
-*/
-
-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, (unsigned long) windowp->size, windowp->i);
- if (i->refcount != 0)
- return;
-
- if (i->mapped)
- {
- munmap (i->data, i->size);
- goto no_free;
- }
-#ifdef HAVE_MPROTECT
- mprotect (i->data, i->size, PROT_READ | PROT_WRITE);
-#endif
- free (i->data);
- no_free:
- i->data = 0;
- /* There should be no more references to i at this point. */
- free (i);
-}
-
-/*
-FUNCTION
- bfd_get_file_window
-
-SYNOPSIS
- bool bfd_get_file_window
- (bfd *, file_ptr, bfd_size_type, bfd_window *, bool {*writable*});
-
-DESCRIPTION
- mmap from a bfd's iostream.
-*/
-
-bool
-bfd_get_file_window (bfd *abfd,
- file_ptr offset,
- bfd_size_type size,
- bfd_window *windowp,
- bool writable)
-{
- static int ok_to_map = 1;
- size_t pagesize = _bfd_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);
-
- if (i == NULL)
- {
- i = bfd_zmalloc (sizeof (bfd_window_internal));
- if (i == NULL)
- return false;
- i->data = NULL;
- }
- if (ok_to_map
- && (i->data == NULL || 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
- && !bfd_is_thin_archive (abfd->my_archive))
- {
- offset += abfd->origin;
- abfd = abfd->my_archive;
- }
- offset += abfd->origin;
-
- /* 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))
- goto free_and_fail;
-
- 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 != NULL && i->size < size)
- {
- munmap (i->data, i->size);
- i->data = NULL;
- }
- 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 == MAP_FAILED)
- {
- /* An error happened. Report it, or try using malloc, or
- something. */
- bfd_set_error (bfd_error_system_call);
- windowp->data = 0;
- if (debug_windows)
- fprintf (stderr, "\t\tmmap failed!\n");
- goto free_and_fail;
- }
- 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;
- i->refcount = 1;
- windowp->i = i;
- 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"));
- }
-
-#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)
- {
- windowp->i = i;
- return true;
- }
- goto free_and_fail;
- }
- i->refcount = 1;
- if (bfd_seek (abfd, offset, SEEK_SET) != 0)
- goto free_and_fail;
- i->size = bfd_read (i->data, size, abfd);
- if (i->size != size)
- goto free_and_fail;
- 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;
- windowp->i = i;
- return true;
-
- free_and_fail:
- /* We have a bfd_window_internal, but an error occurred. Free it. */
- free (i);
- return false;
-}
-
-#endif /* USE_MMAP */
projects / thirdparty / binutils-gdb.git / blobdiff