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authorskrll <skrll@NetBSD.org>2005-10-13 11:14:09 +0000
committerskrll <skrll@NetBSD.org>2005-10-13 11:14:09 +0000
commitbd7cbb198e00248b4dc67fd9fe3c7be6ce83a35d (patch)
tree4b7a2ffec557beba666c5deac11565d972912869 /libexec
parent34cace8bd12553bca9b205787277130747cf004c (diff)
Correct the lookup order of _rtld_symlook_default and make
_rtld_find_symdef use _rtld_symlook_default. This reduces the code size and means that dlsym(RTLD_DEFAULT,...) has the correct lookup order. Reviewed by kleink. Thanks.
Diffstat (limited to 'libexec')
-rw-r--r--libexec/ld.elf_so/symbol.c122
1 files changed, 40 insertions, 82 deletions
diff --git a/libexec/ld.elf_so/symbol.c b/libexec/ld.elf_so/symbol.c
index 537c026bfe1..91e27010c39 100644
--- a/libexec/ld.elf_so/symbol.c
+++ b/libexec/ld.elf_so/symbol.c
@@ -1,4 +1,4 @@
-/* $NetBSD: symbol.c,v 1.39 2005/05/10 13:15:56 chs Exp $ */
+/* $NetBSD: symbol.c,v 1.40 2005/10/13 11:14:09 skrll Exp $ */
/*
* Copyright 1996 John D. Polstra.
@@ -40,7 +40,7 @@
#include <sys/cdefs.h>
#ifndef lint
-__RCSID("$NetBSD: symbol.c,v 1.39 2005/05/10 13:15:56 chs Exp $");
+__RCSID("$NetBSD: symbol.c,v 1.40 2005/10/13 11:14:09 skrll Exp $");
#endif /* not lint */
#include <err.h>
@@ -196,79 +196,33 @@ _rtld_find_symdef(unsigned long symnum, const Obj_Entry *refobj,
{
const Elf_Sym *ref;
const Elf_Sym *def;
- const Elf_Sym *symp;
- const Obj_Entry *obj;
const Obj_Entry *defobj;
- const Objlist_Entry *elm;
const char *name;
unsigned long hash;
ref = refobj->symtab + symnum;
name = refobj->strtab + ref->st_name;
- hash = _rtld_elf_hash(name);
- def = NULL;
- defobj = NULL;
-
- /* Look first in the referencing object if linked symbolically */
- if (refobj->symbolic) {
- symp = _rtld_symlook_obj(name, hash, refobj, in_plt);
- if (symp != NULL) {
- def = symp;
- defobj = refobj;
- }
- }
-
- /* Search all objects loaded at program start up. */
- if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
- rdbg(("search _rtld_list_main"));
- symp = _rtld_symlook_list(name, hash, &_rtld_list_main, &obj, in_plt);
- if (symp != NULL &&
- (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
- def = symp;
- defobj = obj;
- }
- }
-
- /* Search all RTLD_GLOBAL objects. */
- if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
- rdbg(("search _rtld_list_global"));
- symp = _rtld_symlook_list(name, hash, &_rtld_list_global, &obj, in_plt);
- if (symp != NULL &&
- (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
- def = symp;
- defobj = obj;
- }
- }
-
- /* Search all dlopened DAGs containing the referencing object. */
- SIMPLEQ_FOREACH(elm, &refobj->dldags, link) {
- if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
- break;
- rdbg(("search DAG with root %p (%s)", elm->obj, elm->obj->path));
- symp = _rtld_symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt);
- if (symp != NULL &&
- (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
- def = symp;
- defobj = obj;
- }
- }
-
/*
- * Search the dynamic linker itself, and possibly resolve the
- * symbol from there. This is how the application links to
- * dynamic linker services such as dlopen. Only the values listed
- * in the "_rtld_exports" array can be resolved from the dynamic linker.
+ * We don't have to do a full scale lookup if the symbol is local.
+ * We know it will bind to the instance in this load module; to
+ * which we already have a pointer (ie ref).
*/
- if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
- rdbg(("search rtld itself"));
- symp = _rtld_symlook_obj(name, hash, &_rtld_objself, in_plt);
- if (symp != NULL && _rtld_is_exported(symp)) {
- def = symp;
- defobj = &_rtld_objself;
- }
+ if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
+ if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
+ _rtld_error("%s: Bogus symbol table entry %lu",
+ refobj->path, symnum);
+ }
+
+ hash = _rtld_elf_hash(name);
+ defobj = NULL;
+ def = _rtld_symlook_default(name, hash, refobj, &defobj, in_plt);
+ } else {
+ rdbg(("STB_LOCAL symbol %s in %s", name, refobj->path));
+ def = ref;
+ defobj = refobj;
}
-
+
/*
* If we found no definition and the reference is weak, treat the
* symbol as having the value zero.
@@ -309,6 +263,7 @@ _rtld_symlook_default(const char *name, unsigned long hash,
/* Look first in the referencing object if linked symbolically. */
if (refobj->symbolic) {
+ rdbg(("search referencing object"));
symp = _rtld_symlook_obj(name, hash, refobj, in_plt);
if (symp != NULL) {
def = symp;
@@ -318,33 +273,36 @@ _rtld_symlook_default(const char *name, unsigned long hash,
/* Search all objects loaded at program start up. */
if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
- symp = _rtld_symlook_list(name, hash, &_rtld_list_main, &obj, in_plt);
+ rdbg(("search _rtld_list_main"));
+ symp = _rtld_symlook_list(name, hash, &_rtld_list_main, &obj,
+ in_plt);
if (symp != NULL &&
- (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
+ (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
def = symp;
defobj = obj;
}
}
- /* Search all dlopened DAGs containing the referencing object. */
- SIMPLEQ_FOREACH(elm, &refobj->dldags, link) {
- if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
- break;
- symp = _rtld_symlook_list(name, hash, &elm->obj->dagmembers, &obj,
- in_plt);
+ /* Search all RTLD_GLOBAL objects. */
+ if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
+ rdbg(("search _rtld_list_global"));
+ symp = _rtld_symlook_list(name, hash, &_rtld_list_global,
+ &obj, in_plt);
if (symp != NULL &&
(def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
def = symp;
defobj = obj;
}
}
-
- /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
- SIMPLEQ_FOREACH(elm, &_rtld_list_global, link) {
+
+ /* Search all dlopened DAGs containing the referencing object. */
+ SIMPLEQ_FOREACH(elm, &refobj->dldags, link) {
if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
break;
- symp = _rtld_symlook_list(name, hash, &elm->obj->dagmembers, &obj,
- in_plt);
+ rdbg(("search DAG with root %p (%s)", elm->obj,
+ elm->obj->path));
+ symp = _rtld_symlook_list(name, hash, &elm->obj->dagmembers,
+ &obj, in_plt);
if (symp != NULL &&
(def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
def = symp;
@@ -352,21 +310,21 @@ _rtld_symlook_default(const char *name, unsigned long hash,
}
}
-#ifdef notyet
/*
* Search the dynamic linker itself, and possibly resolve the
* symbol from there. This is how the application links to
* dynamic linker services such as dlopen. Only the values listed
- * in the "exports" array can be resolved from the dynamic linker.
+ * in the "_rtld_exports" array can be resolved from the dynamic
+ * linker.
*/
if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
+ rdbg(("Search the dynamic linker itself."));
symp = _rtld_symlook_obj(name, hash, &_rtld_objself, in_plt);
- if (symp != NULL && is_exported(symp)) {
+ if (symp != NULL && _rtld_is_exported(symp)) {
def = symp;
defobj = &_rtld_objself;
}
}
-#endif
if (def != NULL)
*defobj_out = defobj;