diff options
| -rw-r--r-- | ChangeLog | 15 | ||||
| -rw-r--r-- | elf/dl-lookup.c | 82 | ||||
| -rw-r--r-- | elf/dl-reloc.c | 55 | ||||
| -rw-r--r-- | include/link.h | 16 | ||||
| -rw-r--r-- | sysdeps/generic/ldsodefs.h | 15 | ||||
| -rw-r--r-- | sysdeps/i386/dl-machine.h | 7 |
6 files changed, 83 insertions, 107 deletions
@@ -1,11 +1,24 @@ 2001-08-26 Ulrich Drepper <drepper@redhat.com> + * include/link.h (struct link_map): Add l_lookup_cache element. + * elf/dl-reloc.c (RESOLVE): Add symbol caching here. + (RESOLVE_MAP): Likewise. + (_dl_relocate_object): Remove cache initialization. + * elf/dl-lookup.c: Rip out cache handling code. + * sysdeps/generic/ldsodefs.h: Remove lookup_cache struct and variable + declarations. + + * elf/dl-lookup.c (_dl_lookup_symbol): Reorder some conditions and + remove some __builtin_expect. + (_dl_lookup_versioned_symbol): Likewise. + * config.h.in: Add HAVE_Z_COMBRELOC. * configure.in: Add test for -z combreloc. * sysdeps/i386/dl-machine.h (elf_machine_rel): Minor cleanups and optimizations. Use HAVE_Z_COMBRELOC to avoid generaton of - R_386_RELATIVE handling for ld.so startup. + R_386_RELATIVE handling for ld.so startup. Reduce RTLD_BOOTSTRAP + case to almost no code. 2001-08-25 Ulrich Drepper <drepper@redhat.com> diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index 047ce4b..71dda25 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -60,7 +60,6 @@ struct sym_val /* Statistics function. */ unsigned long int _dl_num_relocations; -unsigned long int _dl_num_cache_relocations; /* We have two different situations when looking up a simple: with or @@ -185,8 +184,6 @@ _dl_do_lookup_versioned (const char *undef_name, unsigned long int hash, const struct r_found_version *const version, struct link_map *skip, int noexec, int noplt); -struct lookup_cache _dl_lookup_cache; -struct lookup_cache _dl_lookup_cache_versioned; /* Search loaded objects' symbol tables for a definition of the symbol UNDEF_NAME. */ @@ -197,29 +194,15 @@ _dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, const ElfW(Sym) **ref, struct r_scope_elem *symbol_scope[], int reloc_type, int explicit) { - unsigned long int hash; - struct sym_val current_value; + unsigned long int hash = _dl_elf_hash (undef_name); + struct sym_val current_value = { NULL, NULL }; struct r_scope_elem **scope; int protected; int noexec = elf_machine_lookup_noexec_p (reloc_type); int noplt = elf_machine_lookup_noplt_p (reloc_type); - /* First check if we can find it in the cache. */ - if (__builtin_expect (*ref == _dl_lookup_cache.sym, 0) - && _dl_lookup_cache.map == undef_map - && _dl_lookup_cache.noexec == noexec - && _dl_lookup_cache.noplt == noplt) - { - ++_dl_num_cache_relocations; - *ref = _dl_lookup_cache.ret; - return _dl_lookup_cache.value; - } - ++_dl_num_relocations; - hash = _dl_elf_hash (undef_name); - current_value = ((struct sym_val) { NULL, NULL }); - /* 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, NULL, @@ -229,13 +212,12 @@ _dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, 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_global, 0) - && (__builtin_expect (current_value.m->l_type, lt_library) - == lt_loaded) + if (__builtin_expect (current_value.m->l_type == lt_loaded, 0) + && current_value.m->l_global && undef_map != current_value.m /* Don't do this for explicit lookups as opposed to implicit runtime lookups. */ - && __builtin_expect (! explicit, 1) + && ! explicit /* Add UNDEF_MAP to the dependencies. */ && add_dependency (undef_map, current_value.m) < 0) /* Something went wrong. Perhaps the object we tried to reference @@ -246,11 +228,6 @@ _dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, break; } - /* Update common information in the cache. */ - _dl_lookup_cache.sym = *ref; - _dl_lookup_cache.noexec = noexec; - _dl_lookup_cache.noplt = noplt; - if (__builtin_expect (current_value.s == NULL, 0)) { const char *reference_name = undef_map ? undef_map->l_name : NULL; @@ -262,8 +239,6 @@ _dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, ? reference_name : (_dl_argv[0] ?: "<main program>")), make_string (undefined_msg, undef_name)); - _dl_lookup_cache.ret = NULL; - _dl_lookup_cache.value = 0; *ref = NULL; return 0; } @@ -284,8 +259,6 @@ _dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, if (__builtin_expect (protected == 0, 1)) { - _dl_lookup_cache.ret = current_value.s; - _dl_lookup_cache.value = LOOKUP_VALUE (current_value.m); *ref = current_value.s; return LOOKUP_VALUE (current_value.m); } @@ -302,13 +275,9 @@ _dl_lookup_symbol (const char *undef_name, struct link_map *undef_map, if (protected_value.s == NULL || protected_value.m == undef_map) { - _dl_lookup_cache.ret = current_value.s; - _dl_lookup_cache.value = LOOKUP_VALUE (current_value.m); *ref = current_value.s; return LOOKUP_VALUE (current_value.m); } - _dl_lookup_cache.ret = *ref; - _dl_lookup_cache.value = LOOKUP_VALUE (undef_map); return LOOKUP_VALUE (undef_map); } @@ -407,30 +376,15 @@ _dl_lookup_versioned_symbol (const char *undef_name, const struct r_found_version *version, int reloc_type, int explicit) { - unsigned long int hash; - struct sym_val current_value; + unsigned long int hash = _dl_elf_hash (undef_name); + struct sym_val current_value = { NULL, NULL }; struct r_scope_elem **scope; int protected; int noexec = elf_machine_lookup_noexec_p (reloc_type); int noplt = elf_machine_lookup_noplt_p (reloc_type); - /* First check if we can find it in the cache. */ - if (__builtin_expect (*ref == _dl_lookup_cache_versioned.sym, 0) - && _dl_lookup_cache_versioned.map == undef_map - && _dl_lookup_cache_versioned.noexec == noexec - && _dl_lookup_cache_versioned.noplt == noplt - && _dl_lookup_cache_versioned.version == version) - { - ++_dl_num_cache_relocations; - *ref = _dl_lookup_cache_versioned.ret; - return _dl_lookup_cache_versioned.value; - } - ++_dl_num_relocations; - hash = _dl_elf_hash (undef_name); - current_value = ((struct sym_val) { NULL, NULL }); - /* Search the relevant loaded objects for a definition. */ for (scope = symbol_scope; *scope; ++scope) { @@ -442,13 +396,12 @@ _dl_lookup_versioned_symbol (const char *undef_name, 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_global, 0) - && (__builtin_expect (current_value.m->l_type, lt_library) - == lt_loaded) + if (__builtin_expect (current_value.m->l_type == lt_loaded, 0) + && current_value.m->l_global && undef_map != current_value.m /* Don't do this for explicit lookups as opposed to implicit runtime lookups. */ - && __builtin_expect (! explicit, 1) + && ! explicit /* Add UNDEF_MAP to the dependencies. */ && add_dependency (undef_map, current_value.m) < 0) /* Something went wrong. Perhaps the object we tried to reference @@ -482,12 +435,6 @@ _dl_lookup_versioned_symbol (const char *undef_name, } } - /* Update common information in the cache. */ - _dl_lookup_cache_versioned.sym = *ref; - _dl_lookup_cache_versioned.noexec = noexec; - _dl_lookup_cache_versioned.noplt = noplt; - _dl_lookup_cache_versioned.version = version; - if (__builtin_expect (current_value.s == NULL, 0)) { if (*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK) @@ -503,9 +450,6 @@ _dl_lookup_versioned_symbol (const char *undef_name, ", version ", version->name ?: NULL)); } - - _dl_lookup_cache_versioned.ret = NULL; - _dl_lookup_cache_versioned.value = 0; *ref = NULL; return 0; } @@ -527,8 +471,6 @@ _dl_lookup_versioned_symbol (const char *undef_name, if (__builtin_expect (protected == 0, 1)) { - _dl_lookup_cache_versioned.ret = current_value.s; - _dl_lookup_cache_versioned.value = LOOKUP_VALUE (current_value.m); *ref = current_value.s; return LOOKUP_VALUE (current_value.m); } @@ -545,14 +487,10 @@ _dl_lookup_versioned_symbol (const char *undef_name, if (protected_value.s == NULL || protected_value.m == undef_map) { - _dl_lookup_cache_versioned.ret = current_value.s; - _dl_lookup_cache_versioned.value = LOOKUP_VALUE (current_value.m); *ref = current_value.s; return LOOKUP_VALUE (current_value.m); } - _dl_lookup_cache_versioned.ret = *ref; - _dl_lookup_cache_versioned.value = LOOKUP_VALUE (undef_map); return LOOKUP_VALUE (undef_map); } } diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c index 99cb189..276aea0 100644 --- a/elf/dl-reloc.c +++ b/elf/dl-reloc.c @@ -27,6 +27,9 @@ #include <sys/types.h> #include "dynamic-link.h" +/* Statistics function. */ +unsigned long int _dl_num_cache_relocations; + void _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[], @@ -74,31 +77,51 @@ cannot make segment writable for relocation")); /* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */ #define RESOLVE_MAP(ref, version, flags) \ (ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \ - ? ((version) != NULL && (version)->hash != 0 \ - ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, l, (ref), \ - scope, (version), (flags), 0) \ - : _dl_lookup_symbol (strtab + (*ref)->st_name, l, (ref), scope, \ - (flags), 0)) \ + ? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \ + && elf_machine_lookup_noexec_p (flags) == l->l_lookup_cache.noexec \ + && elf_machine_lookup_noplt_p (flags) == l->l_lookup_cache.noplt) \ + ? (++_dl_num_cache_relocations, \ + (*ref) = l->l_lookup_cache.ret, \ + l->l_lookup_cache.value) \ + : ({ lookup_t _lr; \ + l->l_lookup_cache.sym = (*ref); \ + l->l_lookup_cache.noexec = elf_machine_lookup_noexec_p (flags); \ + l->l_lookup_cache.noplt = elf_machine_lookup_noplt_p (flags); \ + _lr = ((version) != NULL && (version)->hash != 0 \ + ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, \ + l, (ref), scope, \ + (version), (flags), 0) \ + : _dl_lookup_symbol (strtab + (*ref)->st_name, l, (ref), \ + scope, (flags), 0)); \ + l->l_lookup_cache.ret = (*ref); \ + l->l_lookup_cache.value = _lr; })) \ : l) #define RESOLVE(ref, version, flags) \ (ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \ - ? ((version) != NULL && (version)->hash != 0 \ - ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, l, (ref), \ - scope, (version), (flags), 0) \ - : _dl_lookup_symbol (strtab + (*ref)->st_name, l, (ref), scope, \ - (flags), 0)) \ + ? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \ + && elf_machine_lookup_noexec_p (flags) == l->l_lookup_cache.noexec \ + && elf_machine_lookup_noplt_p (flags) == l->l_lookup_cache.noplt) \ + ? (++_dl_num_cache_relocations, \ + (*ref) = l->l_lookup_cache.ret, \ + l->l_lookup_cache.value) \ + : ({ lookup_t _lr; \ + l->l_lookup_cache.sym = (*ref); \ + l->l_lookup_cache.noexec = elf_machine_lookup_noexec_p (flags); \ + l->l_lookup_cache.noplt = elf_machine_lookup_noplt_p (flags); \ + _lr = ((version) != NULL && (version)->hash != 0 \ + ? _dl_lookup_versioned_symbol (strtab + (*ref)->st_name, \ + l, (ref), scope, \ + (version), (flags), 0) \ + : _dl_lookup_symbol (strtab + (*ref)->st_name, l, (ref), \ + scope, (flags), 0)); \ + l->l_lookup_cache.ret = (*ref); \ + l->l_lookup_cache.value = _lr; })) \ : l->l_addr) #include "dynamic-link.h" - /* Start symbol lookup caching for this object. */ - _dl_lookup_cache.map = l; - _dl_lookup_cache_versioned.map = l; ELF_DYNAMIC_RELOCATE (l, lazy, consider_profiling); - _dl_lookup_cache.map = NULL; - _dl_lookup_cache_versioned.map = NULL; - if (__builtin_expect (consider_profiling, 0)) { /* Allocate the array which will contain the already found diff --git a/include/link.h b/include/link.h index 9345c92..5aba874 100644 --- a/include/link.h +++ b/include/link.h @@ -1,6 +1,6 @@ /* Data structure for communication from the run-time dynamic linker for loaded ELF shared objects. - Copyright (C) 1995-1999, 2000 Free Software Foundation, Inc. + Copyright (C) 1995-1999, 2000, 2001 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 @@ -34,6 +34,7 @@ #include <bits/elfclass.h> /* Defines __ELF_NATIVE_CLASS. */ #include <bits/link.h> +#include <dl-lookupcfg.h> /* Rendezvous structure used by the run-time dynamic linker to communicate details of shared object loading to the debugger. If the executable's @@ -231,6 +232,19 @@ struct link_map unsigned int l_idx; struct link_map_machine l_mach; + + struct + { + const ElfW(Sym) *sym; + int noexec; + int noplt; +#ifdef DL_LOOKUP_RETURNS_MAP + struct link_map *value; +#else + ElfW(Addr) value; +#endif + const ElfW(Sym) *ret; + } l_lookup_cache; }; struct dl_phdr_info diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index 5e093fc..6d196c7 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -327,21 +327,6 @@ extern void _dl_map_object_deps (struct link_map *map, /* Cache the locations of MAP's hash table. */ extern void _dl_setup_hash (struct link_map *map) internal_function; -/* This holds symbol lookup cache. */ -struct lookup_cache - { - const ElfW(Sym) *sym; - struct link_map *map; - const struct r_found_version *version; - int noexec; - int noplt; - lookup_t value; - const ElfW(Sym) *ret; - }; - -extern struct lookup_cache _dl_lookup_cache; -extern struct lookup_cache _dl_lookup_cache_versioned; - /* Search loaded objects' symbol tables for a definition of the symbol referred to by UNDEF. *SYM is the symbol table entry containing the diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h index 53d8022..e7a1b10 100644 --- a/sysdeps/i386/dl-machine.h +++ b/sysdeps/i386/dl-machine.h @@ -334,13 +334,16 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc, if (sym) value += sym->st_value; +#ifdef RTLD_BOOTSTRAP + assert (r_type == R_386_GLOB_DAT || r_type == R_386_JMP_SLOT); + *reloc_addr = value; +#else switch (r_type) { case R_386_GLOB_DAT: case R_386_JMP_SLOT: *reloc_addr = value; break; -#ifndef RTLD_BOOTSTRAP case R_386_32: *reloc_addr += value; break; @@ -372,8 +375,8 @@ elf_machine_rel (struct link_map *map, const Elf32_Rel *reloc, if we are still debugging. */ _dl_reloc_bad_type (map, r_type, 0); break; -#endif } +#endif } } |