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4af6982e4c
Before to 490e6c62aa ('elf: Avoid nested functions in the loader
[BZ #27220]'), elf_get_dynamic_info() was defined twice on rtld.c: on
the first dynamic-link.h include and later within _dl_start(). The
former definition did not define DONT_USE_BOOTSTRAP_MAP and it is used
on setup_vdso() (since it is a global definition), while the former does
define DONT_USE_BOOTSTRAP_MAP and it is used on loader self-relocation.
With the commit change, the function is now included and defined once
instead of defined as a nested function. So rtld.c defines without
defining RTLD_BOOTSTRAP and it brokes at least powerpc32.
This patch fixes by moving the get-dynamic-info.h include out of
dynamic-link.h, which then the caller can corirectly set the expected
semantic by defining STATIC_PIE_BOOTSTRAP, RTLD_BOOTSTRAP, and/or
RESOLVE_MAP.
It also required to enable some asserts only for the loader bootstrap
to avoid issues when called from setup_vdso().
As a side note, this is another issues with nested functions: it is
not clear from pre-processed output (-E -dD) how the function will
be build and its semantic (since nested function will be local and
extra C defines may change it).
I checked on x86_64-linux-gnu (w/o --enable-static-pie),
i686-linux-gnu, powerpc64-linux-gnu, powerpc-linux-gnu-power4,
aarch64-linux-gnu, arm-linux-gnu, sparc64-linux-gnu, and
s390x-linux-gnu.
Reviewed-by: Fangrui Song <maskray@google.com>
78 lines
2.8 KiB
C
78 lines
2.8 KiB
C
/* Resolve conflicts against already prelinked libraries.
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Copyright (C) 2001-2021 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, see <https://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <errno.h>
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#include <libintl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <ldsodefs.h>
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#include <sys/mman.h>
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#include <sys/param.h>
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#include <sys/types.h>
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#include "dynamic-link.h"
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/* Used at loading time solely for prelink executable. It is not called
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concurrently so it is be safe to defined as static. */
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static struct link_map *resolve_conflict_map __attribute__ ((__unused__));
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/* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */
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#define RESOLVE_MAP(map, scope, ref, version, flags) (*ref = NULL, NULL)
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#define RESOLVE(ref, version, flags) (*ref = NULL, 0)
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#define RESOLVE_CONFLICT_FIND_MAP(map, r_offset) \
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do { \
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while ((resolve_conflict_map->l_map_end < (ElfW(Addr)) (r_offset)) \
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|| (resolve_conflict_map->l_map_start > (ElfW(Addr)) (r_offset))) \
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resolve_conflict_map = resolve_conflict_map->l_next; \
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\
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(map) = resolve_conflict_map; \
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} while (0)
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#include "dynamic-link.h"
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void
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_dl_resolve_conflicts (struct link_map *l, ElfW(Rela) *conflict,
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ElfW(Rela) *conflictend)
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{
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#if ! ELF_MACHINE_NO_RELA
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if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_RELOC))
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_dl_debug_printf ("\nconflict processing: %s\n", DSO_FILENAME (l->l_name));
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{
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/* Do the conflict relocation of the object and library GOT and other
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data. */
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/* Prelinking makes no sense for anything but the main namespace. */
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assert (l->l_ns == LM_ID_BASE);
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resolve_conflict_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
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/* Override these, defined in dynamic-link.h. */
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#undef CHECK_STATIC_TLS
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#define CHECK_STATIC_TLS(ref_map, sym_map) ((void) 0)
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#undef TRY_STATIC_TLS
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#define TRY_STATIC_TLS(ref_map, sym_map) (0)
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GL(dl_num_cache_relocations) += conflictend - conflict;
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for (; conflict < conflictend; ++conflict)
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elf_machine_rela (l, NULL, conflict, NULL, NULL,
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(void *) conflict->r_offset, 0);
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}
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#endif
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}
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