diff options
Diffstat (limited to 'elf/dl-sym.c')
| -rw-r--r-- | elf/dl-sym.c | 142 |
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; |