From 710f7bab59b9bb02f1cd46fa2db14e2b4b0a806a Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Mon, 3 Jun 1996 04:46:40 +0000 Subject: Mon Jun 3 00:30:35 1996 Roland McGrath * elf/dl-lookup.c (_dl_lookup_symbol): Take new arg RELOC_ADDR and don't allow a defn resolving to that address. * elf/link.h: Update prototype and comment. * elf/dl-runtime.c (fixup): Define local `resolve' function and pass it to elf_machine_relplt. * elf/dl-reloc.c (_dl_relocate_object: resolve): Take new arg RELOC_ADDR and pass it through to _dl_lookup_symbol. * elf/do-rel.h (elf_dynamic_do_rel): Pass RESOLVE to elf_machine_rel instead of calling it ourselves and passing its results. (elf_dynamic_do_rel): RESOLVE fn takes new arg RELOC_ADDR. * elf/rtld.c (dl_main): Pass 0 for RELOC_ADDR to _dl_lookup_symbol. * sysdeps/i386/dl-machine.h (elf_machine_rel): Remove SYM_LOADADDR arg. Add RESOLVE function ptr arg. Call *RESOLVE as necessary. * sysdeps/m68k/dl-machine.h (elf_machine_rela): Likewise. * sysdeps/stub/dl-machine.h: Likewise. * csu/initfini.c (_fini): Add extern decl for i_am_not_a_leaf. * elf/dlfcn.h (dl_open_mode): Enumerated type removed. (RTLD_LAZY, RTLD_NOW): Define these as macros instead. (RTLD_GLOBAL): New macro. (dlopen): Take arg of type int instead of dl_open_mode. * elf/dlopen.c: Likewise. * math/math.h (_Mldbl): New macro, either produces L suffix or not. (M_*): Use it for these constants. --- elf/dl-lookup.c | 7 +++++-- elf/dl-reloc.c | 5 +++-- elf/dl-runtime.c | 31 ++++++------------------------- elf/dlfcn.h | 18 ++++++++++-------- elf/dlopen.c | 4 ++-- elf/do-rel.h | 25 ++----------------------- elf/link.h | 7 +++++-- elf/rtld.c | 2 +- 8 files changed, 34 insertions(+), 65 deletions(-) (limited to 'elf') diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index 90c9b6a18d..b72a6a27d5 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -23,13 +23,15 @@ Cambridge, MA 02139, USA. */ #include /* Search loaded objects' symbol tables for a definition of the symbol - UNDEF_NAME. If NOPLT is nonzero, then a PLT entry cannot satisfy the - reference; some different binding must be found. */ + UNDEF_NAME. The chosen value can't be RELOC_ADDR. If NOPLT is nonzero, + then a PLT entry cannot satisfy the reference; some different binding + must be found. */ Elf32_Addr _dl_lookup_symbol (const char *undef_name, const Elf32_Sym **ref, struct link_map *symbol_scope, const char *reference_name, + Elf32_Addr reloc_addr, int noplt) { unsigned long int hash = elf_hash (undef_name); @@ -59,6 +61,7 @@ _dl_lookup_symbol (const char *undef_name, const Elf32_Sym **ref, const Elf32_Sym *sym = &symtab[symidx]; if (sym->st_value == 0 || /* No value. */ + reloc_addr == map->l_addr + sym->st_value || /* Self ref. */ (noplt && sym->st_shndx == SHN_UNDEF)) /* Unwanted PLT entry. */ continue; diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c index 46fc4c4def..424d303800 100644 --- a/elf/dl-reloc.c +++ b/elf/dl-reloc.c @@ -60,10 +60,11 @@ _dl_relocate_object (struct link_map *l, int lazy) = ((void *) l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr); - Elf32_Addr resolve (const Elf32_Sym **ref, int noplt) + Elf32_Addr resolve (const Elf32_Sym **ref, + Elf32_Addr reloc_addr, int noplt) { return _dl_lookup_symbol (strtab + (*ref)->st_name, ref, scope, - l->l_name, noplt); + l->l_name, reloc_addr, noplt); } real_next = l->l_next; diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c index 941a306df9..0beba769fa 100644 --- a/elf/dl-runtime.c +++ b/elf/dl-runtime.c @@ -67,34 +67,15 @@ fixup ( = (const void *) (l->l_addr + l->l_info[DT_JMPREL]->d_un.d_ptr + reloc_offset); - const Elf32_Sym *definer; - Elf32_Addr loadbase; - struct link_map *scope, *real_next; - - /* Look up the symbol's run-time value. */ - - real_next = l->l_next; - if (l->l_info[DT_SYMBOLIC]) + Elf32_Addr resolve (const Elf32_Sym **ref, + Elf32_Addr reloc_addr, int noplt) { - l->l_next = _dl_loaded; - if (l->l_prev) - l->l_prev->l_next = real_next; - scope = l; + return _dl_lookup_symbol (strtab + (*ref)->st_name, ref, _dl_loaded, + l->l_name, reloc_addr, noplt); } - else - scope = _dl_loaded; - - definer = &symtab[ELF32_R_SYM (reloc->r_info)]; - loadbase = _dl_lookup_symbol (strtab + definer->st_name, &definer, - scope, l->l_name, 1); - - /* Restore list frobnication done above for DT_SYMBOLIC. */ - l->l_next = real_next; - if (l->l_prev) - l->l_prev->l_next = l; - /* Apply the relocation with that value. */ - elf_machine_relplt (l, reloc, loadbase, definer); + /* Perform the specified relocation. */ + elf_machine_relplt (l, reloc, &symtab[ELF32_R_SYM (reloc->r_info)], resolve); return *(Elf32_Addr *) (l->l_addr + reloc->r_offset); } diff --git a/elf/dlfcn.h b/elf/dlfcn.h index e5d68f82be..a405baa473 100644 --- a/elf/dlfcn.h +++ b/elf/dlfcn.h @@ -1,5 +1,5 @@ /* dlfcn.h -- User functions for run-time dynamic loading. -Copyright (C) 1995 Free Software Foundation, Inc. +Copyright (C) 1995, 1996 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 @@ -21,16 +21,18 @@ Cambridge, MA 02139, USA. */ #define _DLFCN_H 1 -/* Type of the second argument to `dlopen'. */ -typedef enum - { - RTLD_LAZY = 1, /* Lazy function call binding. */ - RTLD_NOW = 2 /* Immediate function call binding. */ - } dl_open_mode; +/* The MODE argument to `dlopen' contains one of the following: */ +#define RTLD_LAZY 0x001 /* Lazy function call binding. */ +#define RTLD_NOW 0x002 /* Immediate function call binding. */ + +/* If the following bit is set in the MODE argument to `dlopen', + the symbols of the loaded object and its dependencies are made + visible as if the object were linked directly into the program. */ +#define RTLD_GLOBAL 0x100 /* Open the shared object FILE and map it in; return a handle that can be passed to `dlsym' to get symbol values from it. */ -extern void *dlopen (const char *__file, dl_open_mode); +extern void *dlopen (const char *__file, int __mode); /* Unmap and close a shared object opened by `dlopen'. The handle cannot be used again after calling `dlclose'. */ diff --git a/elf/dlopen.c b/elf/dlopen.c index de65a20d97..26ed35ace6 100644 --- a/elf/dlopen.c +++ b/elf/dlopen.c @@ -1,5 +1,5 @@ /* dlopen -- Load a shared object at run time. -Copyright (C) 1995 Free Software Foundation, Inc. +Copyright (C) 1995, 1996 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 @@ -22,7 +22,7 @@ Cambridge, MA 02139, USA. */ #include void * -dlopen (const char *file, dl_open_mode mode) +dlopen (const char *file, int mode) { struct link_map *new, *l; diff --git a/elf/do-rel.h b/elf/do-rel.h index a265550cae..438613a32d 100644 --- a/elf/do-rel.h +++ b/elf/do-rel.h @@ -38,7 +38,7 @@ static inline void elf_dynamic_do_rel (struct link_map *map, int reltag, int sztag, Elf32_Addr (*resolve) (const Elf32_Sym **symbol, - int noplt), + Elf32_Addr reloc_addr, int noplt), int lazy) { const Elf32_Sym *const symtab @@ -53,28 +53,7 @@ elf_dynamic_do_rel (struct link_map *map, elf_machine_lazy_rel (map, r); else for (; r < end; ++r) - { - const Elf32_Sym *definer = &symtab[ELF32_R_SYM (r->r_info)]; - Elf32_Addr loadbase; - - if (ELF32_R_SYM (r->r_info) == STN_UNDEF) - loadbase = 0; /* This value will not be consulted. */ - else if (ELF32_ST_BIND (definer->st_info) == STB_LOCAL) - /* Local symbols always refer to the containing object. */ - loadbase = map->l_addr; - else - { - if (resolve) - loadbase = (*resolve) - (&definer, elf_machine_pltrel_p (ELF32_R_TYPE (r->r_info))); - else - { - assert (definer->st_shndx != SHN_UNDEF); - loadbase = map->l_addr; - } - } - elf_machine_rel (map, r, loadbase, definer); - } + elf_machine_rel (map, r, &symtab[ELF32_R_SYM (r->r_info)], resolve); } #undef elf_dynamic_do_rel diff --git a/elf/link.h b/elf/link.h index cd75263e0a..a19a2ce0b3 100644 --- a/elf/link.h +++ b/elf/link.h @@ -185,12 +185,15 @@ extern void _dl_setup_hash (struct link_map *map); reference; it is replaced with the defining symbol, and the base load address of the defining object is returned. SYMBOL_SCOPE is the head of the chain used for searching. REFERENCE_NAME should name the object - containing the reference; it is used in error messages. If NOPLT is - nonzero, then the reference must not be resolved to a PLT entry. */ + containing the reference; it is used in error messages. RELOC_ADDR is + the address being fixed up and the chosen symbol cannot be one with this + value. If NOPLT is nonzero, then the reference must not be resolved to + a PLT entry. */ extern Elf32_Addr _dl_lookup_symbol (const char *undef, const Elf32_Sym **sym, struct link_map *symbol_scope, const char *reference_name, + Elf32_Addr reloc_addr, int noplt); diff --git a/elf/rtld.c b/elf/rtld.c index 157cde51d9..511d19cb15 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -318,7 +318,7 @@ of this helper program; chances are you did not intend to run this program.\n", const Elf32_Sym *ref = NULL; Elf32_Addr loadbase = _dl_lookup_symbol (_dl_argv[i], &ref, _dl_loaded, "argument", - 0); + 0, 0); char buf[20], *bp; buf[sizeof buf - 1] = '\0'; bp = _itoa (ref->st_value, &buf[sizeof buf - 1], 16, 0); -- cgit v1.2.3