diff options
| -rw-r--r-- | elf/dl-lookup.c | 380 |
1 files changed, 44 insertions, 336 deletions
diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index 925f01c102..b05404f815 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -68,14 +68,7 @@ struct sym_val #endif - -/* We have two different situations when looking up a simple: with or - without versioning. gcc is not able to optimize a single function - definition serving for both purposes so we define two functions. */ -#define VERSIONED 0 -#include "do-lookup.h" - -#define VERSIONED 1 +/* The actual lookup code. */ #include "do-lookup.h" @@ -208,20 +201,6 @@ add_dependency (struct link_map *undef_map, struct link_map *map) return result; } -static int -internal_function -_dl_do_lookup (const char *undef_name, unsigned long int hash, - const ElfW(Sym) *ref, struct sym_val *result, - struct r_scope_elem *scope, size_t i, int flags, - struct link_map *skip, int type_class); -static int -internal_function -_dl_do_lookup_versioned (const char *undef_name, unsigned long int hash, - const ElfW(Sym) *ref, struct sym_val *result, - struct r_scope_elem *scope, size_t i, - const struct r_found_version *const version, - struct link_map *skip, int type_class); - static void internal_function _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, @@ -230,208 +209,51 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, const struct r_found_version *version, int type_class, int protected); -/* Search loaded objects' symbol tables for a definition of the symbol - UNDEF_NAME. */ - -lookup_t -internal_function -_dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, - const ElfW(Sym) **ref, struct r_scope_elem *symbol_scope[], - int type_class, int flags) -{ - const unsigned long int hash = _dl_elf_hash (undef_name); - struct sym_val current_value = { NULL, NULL }; - struct r_scope_elem **scope; - int protected; - - bump_num_relocations (); - - /* Search the relevant loaded objects for a definition. */ - for (scope = symbol_scope; *scope; ++scope) - if (do_lookup (undef_name, hash, *ref, ¤t_value, *scope, 0, flags, - NULL, type_class)) - break; - - if (__builtin_expect (current_value.s == NULL, 0)) - { - const char *reference_name = undef_map ? undef_map->l_name : NULL; - - if (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK) - /* We could find no value for a strong reference. */ - /* XXX We cannot translate the messages. */ - _dl_signal_cerror (0, (reference_name[0] - ? reference_name - : (rtld_progname ?: "<main program>")), - N_("relocation error"), - make_string (undefined_msg, undef_name)); - *ref = NULL; - return 0; - } - - protected = *ref && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED; - if (__builtin_expect (protected != 0, 0)) - { - /* It is very tricky. We need to figure out what value to - return for the protected symbol. */ - if (type_class == ELF_RTYPE_CLASS_PLT) - { - if (current_value.s != NULL && current_value.m != undef_map) - { - current_value.s = *ref; - current_value.m = undef_map; - } - } - else - { - struct sym_val protected_value = { NULL, NULL }; - - for (scope = symbol_scope; *scope; ++scope) - if (_dl_do_lookup (undef_name, hash, *ref, - &protected_value, *scope, 0, flags, - NULL, ELF_RTYPE_CLASS_PLT)) - break; - - if (protected_value.s != NULL - && protected_value.m != undef_map) - { - current_value.s = *ref; - current_value.m = undef_map; - } - } - } - - /* We have to check whether this would bind UNDEF_MAP to an object - in the global scope which was dynamically loaded. In this case - we have to prevent the latter from being unloaded unless the - UNDEF_MAP object is also unloaded. */ - if (__builtin_expect (current_value.m->l_type == lt_loaded, 0) - /* Don't do this for explicit lookups as opposed to implicit - runtime lookups. */ - && (flags & DL_LOOKUP_ADD_DEPENDENCY) != 0 - /* Add UNDEF_MAP to the dependencies. */ - && add_dependency (undef_map, current_value.m) < 0) - /* Something went wrong. Perhaps the object we tried to reference - was just removed. Try finding another definition. */ - return _dl_lookup_symbol (undef_name, undef_map, ref, symbol_scope, - type_class, flags); - - if (__builtin_expect (GLRO(dl_debug_mask) - & (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK), 0)) - _dl_debug_bindings (undef_name, undef_map, ref, symbol_scope, - ¤t_value, NULL, type_class, protected); - - *ref = current_value.s; - return LOOKUP_VALUE (current_value.m); -} - -/* This function is nearly the same as `_dl_lookup_symbol' but it - skips in the first list all objects until SKIP_MAP is found. I.e., - it only considers objects which were loaded after the described - object. If there are more search lists the object described by - SKIP_MAP is only skipped. */ +/* Search loaded objects' symbol tables for a definition of the symbol + UNDEF_NAME, perhaps with a requested version for the symbol. */ lookup_t internal_function -_dl_lookup_symbol_skip (const char *undef_name, - struct link_map *undef_map, const ElfW(Sym) **ref, - struct r_scope_elem *symbol_scope[], - struct link_map *skip_map) +_dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, + const ElfW(Sym) **ref, + struct r_scope_elem *symbol_scope[], + const struct r_found_version *version, + int type_class, int flags, struct link_map *skip_map) { const unsigned long int hash = _dl_elf_hash (undef_name); struct sym_val current_value = { NULL, NULL }; - struct r_scope_elem **scope; - size_t i; - int protected; + struct r_scope_elem **scope = symbol_scope; bump_num_relocations (); - /* Search the relevant loaded objects for a definition. */ - scope = symbol_scope; - for (i = 0; (*scope)->r_list[i] != skip_map; ++i) - assert (i < (*scope)->r_nlist); - - if (! _dl_do_lookup (undef_name, hash, *ref, ¤t_value, *scope, i, - DL_LOOKUP_RETURN_NEWEST, skip_map, 0)) - while (*++scope) - if (_dl_do_lookup (undef_name, hash, *ref, ¤t_value, *scope, 0, - DL_LOOKUP_RETURN_NEWEST, skip_map, 0)) - break; + /* No other flag than DL_LOOKUP_ADD_DEPENDENCY is allowed if we look + up a versioned symbol. */ + assert (version == NULL || flags == 0 || flags == DL_LOOKUP_ADD_DEPENDENCY); - if (__builtin_expect (current_value.s == NULL, 0)) + size_t i = 0; + if (__builtin_expect (skip_map != NULL, 0)) { - *ref = NULL; - return 0; - } - - protected = *ref && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED; + /* Search the relevant loaded objects for a definition. */ + while ((*scope)->r_list[i] != skip_map) + ++i; - if (__builtin_expect (protected != 0, 0)) - { - /* It is very tricky. We need to figure out what value to - return for the protected symbol. */ - struct sym_val protected_value = { NULL, NULL }; - - if (i >= (*scope)->r_nlist - || !_dl_do_lookup (undef_name, hash, *ref, &protected_value, *scope, - i, DL_LOOKUP_RETURN_NEWEST, skip_map, - ELF_RTYPE_CLASS_PLT)) - while (*++scope) - if (_dl_do_lookup (undef_name, hash, *ref, &protected_value, *scope, - 0, DL_LOOKUP_RETURN_NEWEST, skip_map, - ELF_RTYPE_CLASS_PLT)) - break; - - if (protected_value.s != NULL && protected_value.m != undef_map) - { - current_value.s = *ref; - current_value.m = undef_map; - } + assert (i < (*scope)->r_nlist); } - if (__builtin_expect (GLRO(dl_debug_mask) - & (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK), 0)) - _dl_debug_bindings (undef_name, undef_map, ref, symbol_scope, - ¤t_value, NULL, 0, protected); - - *ref = current_value.s; - return LOOKUP_VALUE (current_value.m); -} - - -/* This function works like _dl_lookup_symbol but it takes an - additional argument with the version number of the requested symbol. - - XXX We'll see whether we need this separate function. */ -lookup_t -internal_function -_dl_lookup_versioned_symbol (const char *undef_name, - struct link_map *undef_map, const ElfW(Sym) **ref, - struct r_scope_elem *symbol_scope[], - const struct r_found_version *version, - int type_class, int flags) -{ - const unsigned long int hash = _dl_elf_hash (undef_name); - struct sym_val current_value = { NULL, NULL }; - struct r_scope_elem **scope; - int protected; - - bump_num_relocations (); - - /* No other flag than DL_LOOKUP_ADD_DEPENDENCY is allowed. */ - assert (flags == 0 || flags == DL_LOOKUP_ADD_DEPENDENCY); - /* Search the relevant loaded objects for a definition. */ - for (scope = symbol_scope; *scope; ++scope) + for (size_t start = i; *scope != NULL; start = 0, ++scope) { - int res = do_lookup_versioned (undef_name, hash, *ref, ¤t_value, - *scope, 0, version, NULL, type_class); + int res = do_lookup_x (undef_name, hash, *ref, ¤t_value, *scope, + start, version, flags, skip_map, type_class); if (res > 0) break; - if (__builtin_expect (res, 0) < 0) + if (__builtin_expect (res, 0) < 0 && skip_map == NULL) { /* Oh, oh. The file named in the relocation entry does not - contain the needed symbol. */ + contain the needed symbol. This code is never reached + for unversioned lookups. */ + assert (version != NULL); const char *reference_name = undef_map ? undef_map->l_name : NULL; /* XXX We cannot translate the message. */ @@ -453,25 +275,28 @@ _dl_lookup_versioned_symbol (const char *undef_name, if (__builtin_expect (current_value.s == NULL, 0)) { - if (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK) + if ((*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK) + && skip_map == NULL) { /* We could find no value for a strong reference. */ const char *reference_name = undef_map ? undef_map->l_name : NULL; + const char *versionstr = version ? ", version " : ""; + const char *versionname = (version && version->name + ? version->name : ""); /* XXX We cannot translate the message. */ _dl_signal_cerror (0, (reference_name[0] ? reference_name : (rtld_progname ?: "<main program>")), NULL, make_string (undefined_msg, undef_name, - ", version ", - version->name ?: NULL)); + versionstr, versionname)); } *ref = NULL; return 0; } - protected = *ref && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED; - + int protected = (*ref + && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED); if (__builtin_expect (protected != 0, 0)) { /* It is very tricky. We need to figure out what value to @@ -488,11 +313,10 @@ _dl_lookup_versioned_symbol (const char *undef_name, { struct sym_val protected_value = { NULL, NULL }; - for (scope = symbol_scope; *scope; ++scope) - if (_dl_do_lookup_versioned (undef_name, hash, *ref, - &protected_value, - *scope, 0, version, NULL, - ELF_RTYPE_CLASS_PLT)) + for (scope = symbol_scope; *scope; i = 0, ++scope) + if (do_lookup_x (undef_name, hash, *ref, &protected_value, + *scope, i, version, flags, skip_map, + ELF_RTYPE_CLASS_PLT) != 0) break; if (protected_value.s != NULL @@ -511,14 +335,14 @@ _dl_lookup_versioned_symbol (const char *undef_name, if (__builtin_expect (current_value.m->l_type == lt_loaded, 0) /* Don't do this for explicit lookups as opposed to implicit runtime lookups. */ - && flags != 0 + && (flags & DL_LOOKUP_ADD_DEPENDENCY) != 0 /* Add UNDEF_MAP to the dependencies. */ && add_dependency (undef_map, current_value.m) < 0) /* Something went wrong. Perhaps the object we tried to reference was just removed. Try finding another definition. */ - return _dl_lookup_versioned_symbol (undef_name, undef_map, ref, - symbol_scope, version, type_class, - flags); + return _dl_lookup_symbol_x (undef_name, undef_map, ref, + symbol_scope, version, type_class, + flags, skip_map); if (__builtin_expect (GLRO(dl_debug_mask) & (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK), 0)) @@ -530,92 +354,6 @@ _dl_lookup_versioned_symbol (const char *undef_name, } -/* Similar to _dl_lookup_symbol_skip but takes an additional argument - with the version we are looking for. */ -lookup_t -internal_function -_dl_lookup_versioned_symbol_skip (const char *undef_name, - struct link_map *undef_map, - const ElfW(Sym) **ref, - struct r_scope_elem *symbol_scope[], - const struct r_found_version *version, - struct link_map *skip_map) -{ - const char *reference_name = undef_map->l_name; - const unsigned long int hash = _dl_elf_hash (undef_name); - struct sym_val current_value = { NULL, NULL }; - struct r_scope_elem **scope; - size_t i; - int protected; - - bump_num_relocations (); - - /* Search the relevant loaded objects for a definition. */ - scope = symbol_scope; - for (i = 0; (*scope)->r_list[i] != skip_map; ++i) - assert (i < (*scope)->r_nlist); - - if (! _dl_do_lookup_versioned (undef_name, hash, *ref, ¤t_value, - *scope, i, version, skip_map, 0)) - while (*++scope) - if (_dl_do_lookup_versioned (undef_name, hash, *ref, ¤t_value, - *scope, 0, version, skip_map, 0)) - break; - - if (__builtin_expect (current_value.s == NULL, 0)) - { - if (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK) - { - /* We could find no value for a strong reference. */ - const size_t len = strlen (undef_name); - char buf[sizeof undefined_msg + len]; - __mempcpy (__mempcpy (buf, undefined_msg, sizeof undefined_msg - 1), - undef_name, len + 1); - /* XXX We cannot translate the messages. */ - _dl_signal_cerror (0, (reference_name[0] - ? reference_name - : (rtld_progname ?: "<main program>")), - NULL, buf); - } - *ref = NULL; - return 0; - } - - protected = *ref && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED; - - if (__builtin_expect (protected != 0, 0)) - { - /* It is very tricky. We need to figure out what value to - return for the protected symbol. */ - struct sym_val protected_value = { NULL, NULL }; - - if (i >= (*scope)->r_nlist - || !_dl_do_lookup_versioned (undef_name, hash, *ref, - &protected_value, *scope, i, version, - skip_map, ELF_RTYPE_CLASS_PLT)) - while (*++scope) - if (_dl_do_lookup_versioned (undef_name, hash, *ref, - &protected_value, *scope, 0, version, - skip_map, ELF_RTYPE_CLASS_PLT)) - break; - - if (protected_value.s != NULL && protected_value.m != undef_map) - { - current_value.s = *ref; - current_value.m = undef_map; - } - } - - if (__builtin_expect (GLRO(dl_debug_mask) - & (DL_DEBUG_BINDINGS|DL_DEBUG_PRELINK), 0)) - _dl_debug_bindings (undef_name, undef_map, ref, symbol_scope, - ¤t_value, version, 0, protected); - - *ref = current_value.s; - return LOOKUP_VALUE (current_value.m); -} - - /* Cache the location of MAP's hash table. */ void @@ -672,14 +410,9 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, { const unsigned long int hash = _dl_elf_hash (undef_name); - if (version == 0) - _dl_do_lookup (undef_name, hash, *ref, &val, - undef_map->l_local_scope[0], 0, 0, NULL, - type_class); - else - _dl_do_lookup_versioned (undef_name, hash, *ref, &val, - undef_map->l_local_scope[0], 0, version, - NULL, type_class); + do_lookup_x (undef_name, hash, *ref, &val, + undef_map->l_local_scope[0], 0, version, 0, NULL, + type_class); if (val.s != value->s || val.m != value->m) conflict = 1; @@ -720,28 +453,3 @@ _dl_debug_bindings (const char *undef_name, struct link_map *undef_map, } #endif } - -/* These are here so that we only inline do_lookup{,_versioned} in the common - case, not everywhere. */ -static int __attribute_noinline__ -internal_function -_dl_do_lookup (const char *undef_name, unsigned long int hash, - const ElfW(Sym) *ref, struct sym_val *result, - struct r_scope_elem *scope, size_t i, int flags, - struct link_map *skip, int type_class) -{ - return do_lookup (undef_name, hash, ref, result, scope, i, flags, skip, - type_class); -} - -static int __attribute_noinline__ -internal_function -_dl_do_lookup_versioned (const char *undef_name, unsigned long int hash, - const ElfW(Sym) *ref, struct sym_val *result, - struct r_scope_elem *scope, size_t i, - const struct r_found_version *const version, - struct link_map *skip, int type_class) -{ - return do_lookup_versioned (undef_name, hash, ref, result, scope, i, - version, skip, type_class); -} |