glibc/elf/dl-find_object.h
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

116 lines
4.0 KiB
C

/* Locating objects in the process image. ld.so implementation.
Copyright (C) 2021-2022 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
<https://www.gnu.org/licenses/>. */
#ifndef _DL_FIND_EH_FRAME_H
#define _DL_FIND_EH_FRAME_H
#include <assert.h>
#include <dlfcn.h>
#include <ldsodefs.h>
#include <stdbool.h>
#include <stdint.h>
/* Internal version of struct dl_find_object. Does not include the
(yet unused) flags member. We need to make a copy of data also in
struct link_map to support non-contiguous mappings, and to support
software transactional memory (the link map is not covered by
transactions). */
struct dl_find_object_internal
{
uintptr_t map_start;
uintptr_t map_end; /* Set to map_start by dlclose. */
struct link_map *map; /* Set to NULL by dlclose. */
void *eh_frame;
#if DLFO_STRUCT_HAS_EH_DBASE
void *eh_dbase;
#endif
#if DLFO_STRUCT_HAS_EH_COUNT
int eh_count;
#endif
};
static inline void
_dl_find_object_to_external (struct dl_find_object_internal *internal,
struct dl_find_object *external)
{
external->dlfo_flags = 0;
external->dlfo_map_start = (void *) internal->map_start;
external->dlfo_map_end = (void *) internal->map_end;
external->dlfo_link_map = internal->map;
external->dlfo_eh_frame = internal->eh_frame;
# if DLFO_STRUCT_HAS_EH_DBASE
external->dlfo_eh_dbase = internal->eh_dbase;
# endif
# if DLFO_STRUCT_HAS_EH_COUNT
external->dlfo_eh_count = internal->eh_count;
# endif
}
/* Extract the object location data from a link map and writes it to
*RESULT. */
static void __attribute__ ((unused))
_dl_find_object_from_map (struct link_map *l,
struct dl_find_object_internal *result)
{
result->map_start = (uintptr_t) l->l_map_start;
result->map_end = (uintptr_t) l->l_map_end;
result->map = l;
#if DLFO_STRUCT_HAS_EH_DBASE
result->eh_dbase = (void *) l->l_info[DT_PLTGOT];
#endif
for (const ElfW(Phdr) *ph = l->l_phdr, *ph_end = l->l_phdr + l->l_phnum;
ph < ph_end; ++ph)
if (ph->p_type == DLFO_EH_SEGMENT_TYPE)
{
result->eh_frame = (void *) (ph->p_vaddr + l->l_addr);
#if DLFO_STRUCT_HAS_EH_COUNT
result->eh_count = ph->p_memsz / 8;
#endif
return;
}
/* Object has no exception handling segment. */
result->eh_frame = NULL;
#if DLFO_STRUCT_HAS_EH_COUNT
result->eh_count = 0;
#endif
}
/* Called by the dynamic linker to set up the data structures for the
initially loaded objects. This creates a few persistent
allocations, so it should be called with the minimal malloc. */
void _dl_find_object_init (void) attribute_hidden;
/* Called by dlopen/dlmopen to add new objects to the DWARF EH frame
data structures. NEW_MAP is the dlopen'ed link map. Link maps on
the l_next list are added if l_object_processed is 0. Needs to
be protected by loader write lock. Returns true on success, false
on malloc failure. */
bool _dl_find_object_update (struct link_map *new_map) attribute_hidden;
/* Called by dlclose to remove the link map from the DWARF EH frame
data structures. Needs to be protected by loader write lock. */
void _dl_find_object_dlclose (struct link_map *l) attribute_hidden;
/* Called from __libc_freeres to deallocate malloc'ed memory. */
void _dl_find_object_freeres (void) attribute_hidden;
#endif /* _DL_FIND_OBJECT_H */