elf/dl-conflict.c

   1 /* Resolve conflicts against already prelinked libraries.
   2    Copyright (C) 2001-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <errno.h>
  21 #include <libintl.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <ldsodefs.h>
  25 #include <sys/mman.h>
  26 #include <sys/param.h>
  27 #include <sys/types.h>
  28 #include "dynamic-link.h"
  29
  30 /* Used at loading time solely for prelink executable.  It is not called
  31    concurrently so it is be safe to defined as static.  */
  32 static struct link_map *resolve_conflict_map __attribute__ ((__unused__));
  33
  34     /* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code.  */
  35 #define RESOLVE_MAP(map, scope, ref, version, flags) (*ref = NULL, NULL)
  36 #define RESOLVE(ref, version, flags) (*ref = NULL, 0)
  37 #define RESOLVE_CONFLICT_FIND_MAP(map, r_offset) \
  38   do {                                                                        \
  39     while ((resolve_conflict_map->l_map_end < (ElfW(Addr)) (r_offset))        \
  40            || (resolve_conflict_map->l_map_start > (ElfW(Addr)) (r_offset)))  \
  41       resolve_conflict_map = resolve_conflict_map->l_next;                    \
  42                                                                               \
  43     (map) = resolve_conflict_map;                                             \
  44   } while (0)
  45
  46 #include "dynamic-link.h"
  47
  48 void
  49 _dl_resolve_conflicts (struct link_map *l, ElfW(Rela) *conflict,
  50                        ElfW(Rela) *conflictend)
  51 {
  52 #if ! ELF_MACHINE_NO_RELA
  53   if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_RELOC))
  54     _dl_debug_printf ("\nconflict processing: %s\n", DSO_FILENAME (l->l_name));
  55
  56   {
  57     /* Do the conflict relocation of the object and library GOT and other
  58        data.  */
  59
  60     /* Prelinking makes no sense for anything but the main namespace.  */
  61     assert (l->l_ns == LM_ID_BASE);
  62     resolve_conflict_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
  63
  64     /* Override these, defined in dynamic-link.h.  */
  65 #undef CHECK_STATIC_TLS
  66 #define CHECK_STATIC_TLS(ref_map, sym_map) ((void) 0)
  67 #undef TRY_STATIC_TLS
  68 #define TRY_STATIC_TLS(ref_map, sym_map) (0)
  69
  70     GL(dl_num_cache_relocations) += conflictend - conflict;
  71
  72     for (; conflict < conflictend; ++conflict)
  73       elf_machine_rela (l, NULL, conflict, NULL, NULL,
  74                         (void *) conflict->r_offset, 0);
  75   }
  76 #endif
  77 }