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authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /elf/dl-sym.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
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2.5-18.1
Diffstat (limited to 'elf/dl-sym.c')
-rw-r--r--elf/dl-sym.c142
1 files changed, 131 insertions, 11 deletions
diff --git a/elf/dl-sym.c b/elf/dl-sym.c
index ba00ef56f4..fa0e3a67fc 100644
--- a/elf/dl-sym.c
+++ b/elf/dl-sym.c
@@ -1,5 +1,5 @@
/* Look up a symbol in a shared object loaded by `dlopen'.
- Copyright (C) 1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
+ Copyright (C) 1999-2002,2004,2006,2007 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
@@ -17,6 +17,7 @@
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
+#include <assert.h>
#include <stddef.h>
#include <setjmp.h>
#include <libintl.h>
@@ -24,6 +25,7 @@
#include <dlfcn.h>
#include <ldsodefs.h>
#include <dl-hash.h>
+#include <sysdep-cancel.h>
#ifdef USE_TLS
# include <dl-tls.h>
#endif
@@ -58,6 +60,29 @@ _dl_tls_symaddr (struct link_map *map, const ElfW(Sym) *ref)
#endif
+struct call_dl_lookup_args
+{
+ /* Arguments to do_dlsym. */
+ struct link_map *map;
+ const char *name;
+ struct r_found_version *vers;
+ int flags;
+
+ /* Return values of do_dlsym. */
+ lookup_t loadbase;
+ const ElfW(Sym) **refp;
+};
+
+static void
+call_dl_lookup (void *ptr)
+{
+ struct call_dl_lookup_args *args = (struct call_dl_lookup_args *) ptr;
+ args->map = GLRO(dl_lookup_symbol_x) (args->name, args->map, args->refp,
+ args->map->l_scope, args->vers, 0,
+ args->flags, NULL);
+}
+
+
static void *
internal_function
do_sym (void *handle, const char *name, void *who,
@@ -75,19 +100,59 @@ do_sym (void *handle, const char *name, void *who,
for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l != NULL;
l = l->l_next)
- if (caller >= l->l_map_start && caller < l->l_map_end)
+ if (caller >= l->l_map_start && caller < l->l_map_end
+ && (l->l_contiguous || _dl_addr_inside_object (l, caller)))
{
- /* There must be exactly one DSO for the range of the virtual
- memory. Otherwise something is really broken. */
match = l;
break;
}
if (handle == RTLD_DEFAULT)
- /* Search the global scope. */
- result = GLRO(dl_lookup_symbol_x) (name, match, &ref, match->l_scope,
- vers, 0, flags|DL_LOOKUP_ADD_DEPENDENCY,
- NULL);
+ {
+ /* Search the global scope. We have the simple case where
+ we look up in the scope of an object which was part of
+ the initial binary. And then the more complex part
+ where the object is dynamically loaded and the scope
+ array can change. */
+ if (RTLD_SINGLE_THREAD_P)
+ result = GLRO(dl_lookup_symbol_x) (name, match, &ref,
+ match->l_scope, vers, 0,
+ flags | DL_LOOKUP_ADD_DEPENDENCY,
+ NULL);
+ else
+ {
+ struct call_dl_lookup_args args;
+ args.name = name;
+ args.map = match;
+ args.vers = vers;
+ args.flags = flags | DL_LOOKUP_ADD_DEPENDENCY;
+ args.refp = &ref;
+
+ THREAD_GSCOPE_SET_FLAG ();
+
+ const char *objname;
+ const char *errstring = NULL;
+ bool malloced;
+ int err = GLRO(dl_catch_error) (&objname, &errstring, &malloced,
+ call_dl_lookup, &args);
+
+ THREAD_GSCOPE_RESET_FLAG ();
+
+ if (__builtin_expect (errstring != NULL, 0))
+ {
+ /* The lookup was unsuccessful. Rethrow the error. */
+ char *errstring_dup = strdupa (errstring);
+ char *objname_dup = strdupa (objname);
+ if (malloced)
+ free ((char *) errstring);
+
+ GLRO(dl_signal_error) (err, objname_dup, NULL, errstring_dup);
+ /* NOTREACHED */
+ }
+
+ result = args.map;
+ }
+ }
else if (handle == RTLD_NEXT)
{
if (__builtin_expect (match == GL(dl_ns)[LM_ID_BASE]._ns_loaded, 0))
@@ -103,7 +168,7 @@ RTLD_NEXT used in code not dynamically loaded"));
while (l->l_loader != NULL)
l = l->l_loader;
- result = GLRO(dl_lookup_symbol_x) (name, l, &ref, l->l_local_scope,
+ result = GLRO(dl_lookup_symbol_x) (name, match, &ref, l->l_local_scope,
vers, 0, 0, match);
}
else
@@ -116,14 +181,69 @@ RTLD_NEXT used in code not dynamically loaded"));
if (ref != NULL)
{
+ void *value;
+
#if defined USE_TLS && defined SHARED
if (ELFW(ST_TYPE) (ref->st_info) == STT_TLS)
/* The found symbol is a thread-local storage variable.
Return the address for to the current thread. */
- return _dl_tls_symaddr (result, ref);
+ value = _dl_tls_symaddr (result, ref);
+ else
+#endif
+ value = DL_SYMBOL_ADDRESS (result, ref);
+
+#ifdef SHARED
+ /* Auditing checkpoint: we have a new binding. Provide the
+ auditing libraries the possibility to change the value and
+ tell us whether further auditing is wanted. */
+ if (__builtin_expect (GLRO(dl_naudit) > 0, 0))
+ {
+ const char *strtab = (const char *) D_PTR (result,
+ l_info[DT_STRTAB]);
+ /* Compute index of the symbol entry in the symbol table of
+ the DSO with the definition. */
+ unsigned int ndx = (ref - (ElfW(Sym) *) D_PTR (result,
+ l_info[DT_SYMTAB]));
+
+ if ((match->l_audit_any_plt | result->l_audit_any_plt) != 0)
+ {
+ unsigned int altvalue = 0;
+ struct audit_ifaces *afct = GLRO(dl_audit);
+ /* Synthesize a symbol record where the st_value field is
+ the result. */
+ ElfW(Sym) sym = *ref;
+ sym.st_value = (ElfW(Addr)) value;
+
+ for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+ {
+ if (afct->symbind != NULL
+ && ((match->l_audit[cnt].bindflags & LA_FLG_BINDFROM)
+ != 0
+ || ((result->l_audit[cnt].bindflags & LA_FLG_BINDTO)
+ != 0)))
+ {
+ unsigned int flags = altvalue | LA_SYMB_DLSYM;
+ uintptr_t new_value
+ = afct->symbind (&sym, ndx,
+ &match->l_audit[cnt].cookie,
+ &result->l_audit[cnt].cookie,
+ &flags, strtab + ref->st_name);
+ if (new_value != (uintptr_t) sym.st_value)
+ {
+ altvalue = LA_SYMB_ALTVALUE;
+ sym.st_value = new_value;
+ }
+ }
+
+ afct = afct->next;
+ }
+
+ value = (void *) sym.st_value;
+ }
+ }
#endif
- return DL_SYMBOL_ADDRESS (result, ref);
+ return value;
}
return NULL;