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Fix handling of STB_GNU_UNIQUE in LD_TRACE_PRELINKING

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This commit is contained in:
Ulrich Drepper 2010-03-24 10:14:22 -07:00
parent 9ac9129d49
commit 4ad43b62d6
4 changed files with 79 additions and 5 deletions
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15
ChangeLog
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@ -1,3 +1,18 @@
2010-03-23 Jakub Jelinek <jakub@redhat.com>
* elf/dl-lookup.c (do_lookup_x): If tab->entries is NULL,
but tab->size != 0, just unlock and goto success, without
allocating anything or entering anything into the hash table.
(_dl_debug_bindings): Temporarily set tab->entries to NULL
around do_lookup_x in undef_map->l_local_scope[0]. If
undef_map->l_symbolic_in_local_scope, lookup also in
symbolic_searchlist of following libraries in l_local_scope
that have DT_SYMBOLIC set.
* elf/dl-deps.c (_dl_map_object_deps): Compute
l_symbolic_in_local_scope.
* include/link.h (struct link_map): Add l_symbolic_in_local_scope
bitfield.
2010-03-24 Ulrich Drepper <drepper@redhat.com>
[BZ #11410]

9
elf/dl-deps.c
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@ -1,5 +1,5 @@
/* Load the dependencies of a mapped object.
Copyright (C) 1996-2003, 2004, 2005, 2006, 2007
Copyright (C) 1996-2003, 2004, 2005, 2006, 2007, 2010
Free Software Foundation, Inc.
This file is part of the GNU C Library.
@ -554,7 +554,12 @@ Filters not supported with LD_TRACE_PRELINKING"));
cnt = _dl_build_local_scope (l_initfini, l);
assert (cnt <= nlist);
for (j = 0; j < cnt; j++)
l_initfini[j]->l_reserved = 0;
{
l_initfini[j]->l_reserved = 0;
if (j && __builtin_expect (l_initfini[j]->l_info[DT_SYMBOLIC]
!= NULL, 0))
l->l_symbolic_in_local_scope = true;
}
l->l_local_scope[0] =
(struct r_scope_elem *) malloc (sizeof (struct r_scope_elem)

54
elf/dl-lookup.c
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@ -1,5 +1,6 @@
/* Look up a symbol in the loaded objects.
Copyright (C) 1995-2005, 2006, 2007, 2009 Free Software Foundation, Inc.
Copyright (C) 1995-2005, 2006, 2007, 2009, 2010
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
@ -414,6 +415,20 @@ do_lookup_x (const char *undef_name, uint_fast32_t new_hash,
assert (!RTLD_CHECK_FOREIGN_CALL);
#endif
#ifdef SHARED
/* If tab->entries is NULL, but tab->size is not, it means
this is the second, conflict finding, lookup for
LD_TRACE_PRELINKING in _dl_debug_bindings. Don't
allocate anything and don't enter anything into the
hash table. */
if (__builtin_expect (tab->size, 0))
{
assert (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK);
__rtld_lock_unlock_recursive (tab->lock);
goto success;
}
#endif
#define INITIAL_NUNIQUE_SYM_TABLE 31
size = INITIAL_NUNIQUE_SYM_TABLE;
entries = calloc (sizeof (struct unique_sym), size);
@ -917,13 +932,48 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map,
{
const uint_fast32_t new_hash = dl_new_hash (undef_name);
unsigned long int old_hash = 0xffffffff;
struct unique_sym *saved_entries
= GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries;
GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries = NULL;
do_lookup_x (undef_name, new_hash, &old_hash, *ref, &val,
undef_map->l_local_scope[0], 0, version, 0, NULL,
type_class, undef_map);
if (val.s != value->s || val.m != value->m)
conflict = 1;
else if (__builtin_expect (undef_map->l_symbolic_in_local_scope, 0)
&& val.s
&& __builtin_expect (ELFW(ST_BIND) (val.s->st_info),
STB_GLOBAL) == STB_GNU_UNIQUE)
{
/* If it is STB_GNU_UNIQUE and undef_map's l_local_scope
contains any DT_SYMBOLIC libraries, unfortunately there
can be conflicts even if the above is equal. As symbol
resolution goes from the last library to the first and
if a STB_GNU_UNIQUE symbol is found in some late DT_SYMBOLIC
library, it would be the one that is looked up. */
struct sym_val val2 = { NULL, NULL };
size_t n;
struct r_scope_elem *scope = undef_map->l_local_scope[0];
for (n = 0; n < scope->r_nlist; n++)
if (scope->r_list[n] == val.m)
break;
for (n++; n < scope->r_nlist; n++)
if (scope->r_list[n]->l_info[DT_SYMBOLIC] != NULL
&& do_lookup_x (undef_name, new_hash, &old_hash, *ref,
&val2,
&scope->r_list[n]->l_symbolic_searchlist,
0, version, 0, NULL, type_class,
undef_map) > 0)
{
conflict = 1;
val = val2;
break;
}
}
GL(dl_ns)[LM_ID_BASE]._ns_unique_sym_table.entries = saved_entries;
}
if (value->s)

6
include/link.h
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@ -1,6 +1,6 @@
/* Data structure for communication from the run-time dynamic linker for
loaded ELF shared objects.
Copyright (C) 1995-2006, 2007, 2009 Free Software Foundation, Inc.
Copyright (C) 1995-2006, 2007, 2009, 2010 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
@ -188,6 +188,10 @@ struct link_map
unsigned int l_contiguous:1; /* Nonzero if inter-segment holes are
mprotected or if no holes are present at
all. */
unsigned int l_symbolic_in_local_scope:1; /* Nonzero if l_local_scope
during LD_TRACE_PRELINKING=1
contains any DT_SYMBOLIC
libraries. */
/* Collected information about own RPATH directories. */
struct r_search_path_struct l_rpath_dirs;