| /* Run time dynamic linker. |
| Copyright (C) 1995-2018 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 |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include <dlfcn.h> |
| #include <fcntl.h> |
| #include <stdbool.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <sys/mman.h> |
| #include <sys/param.h> |
| #include <sys/stat.h> |
| #include <ldsodefs.h> |
| #include <_itoa.h> |
| #include <entry.h> |
| #include <fpu_control.h> |
| #include <hp-timing.h> |
| #include <libc-lock.h> |
| #include "dynamic-link.h" |
| #include <dl-librecon.h> |
| #include <unsecvars.h> |
| #include <dl-cache.h> |
| #include <dl-osinfo.h> |
| #include <dl-procinfo.h> |
| #include <tls.h> |
| #include <stap-probe.h> |
| #include <stackinfo.h> |
| |
| #include <assert.h> |
| |
| /* Avoid PLT use for our local calls at startup. */ |
| extern __typeof (__mempcpy) __mempcpy attribute_hidden; |
| |
| /* GCC has mental blocks about _exit. */ |
| extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden; |
| #define _exit exit_internal |
| |
| /* Iterate over auxv, find AT_EXECFN if any. */ |
| static char * get_at_execfn(ElfW(auxv_t) *auxv); |
| |
| /* Given file path, return fully resolved directory path. */ |
| static char * get_directory (const char *file_path); |
| |
| /* Helper function to handle errors while resolving symbols. */ |
| static void print_unresolved (int errcode, const char *objname, |
| const char *errsting); |
| |
| /* Helper function to handle errors when a version is missing. */ |
| static void print_missing_version (int errcode, const char *objname, |
| const char *errsting); |
| |
| /* Print the various times we collected. */ |
| static void print_statistics (hp_timing_t *total_timep); |
| |
| /* Add audit objects. */ |
| static void process_dl_audit (char *str); |
| |
| /* This is a list of all the modes the dynamic loader can be in. */ |
| enum mode { normal, list, verify, trace }; |
| |
| /* Process all environments variables the dynamic linker must recognize. |
| Since all of them start with `LD_' we are a bit smarter while finding |
| all the entries. */ |
| static void process_envvars (enum mode *modep); |
| |
| /* Set GLRO(google_exec_origin_dir). */ |
| static void set_exec_origin_dir(const char *exe_path); |
| |
| #ifdef DL_ARGV_NOT_RELRO |
| int _dl_argc attribute_hidden; |
| char **_dl_argv = NULL; |
| /* Nonzero if we were run directly. */ |
| unsigned int _dl_skip_args attribute_hidden; |
| #else |
| int _dl_argc attribute_relro attribute_hidden; |
| char **_dl_argv attribute_relro = NULL; |
| unsigned int _dl_skip_args attribute_relro attribute_hidden; |
| #endif |
| rtld_hidden_data_def (_dl_argv) |
| |
| #ifndef THREAD_SET_STACK_GUARD |
| /* Only exported for architectures that don't store the stack guard canary |
| in thread local area. */ |
| uintptr_t __stack_chk_guard attribute_relro; |
| #endif |
| |
| /* Only exported for architectures that don't store the pointer guard |
| value in thread local area. */ |
| uintptr_t __pointer_chk_guard_local |
| attribute_relro attribute_hidden __attribute__ ((nocommon)); |
| #ifndef THREAD_SET_POINTER_GUARD |
| strong_alias (__pointer_chk_guard_local, __pointer_chk_guard) |
| #endif |
| |
| /* Length limits for names and paths, to protect the dynamic linker, |
| particularly when __libc_enable_secure is active. */ |
| #ifdef NAME_MAX |
| # define SECURE_NAME_LIMIT NAME_MAX |
| #else |
| # define SECURE_NAME_LIMIT 255 |
| #endif |
| #ifdef PATH_MAX |
| # define SECURE_PATH_LIMIT PATH_MAX |
| #else |
| # define SECURE_PATH_LIMIT 1024 |
| #endif |
| |
| /* Check that AT_SECURE=0, or that the passed name does not contain |
| directories and is not overly long. Reject empty names |
| unconditionally. */ |
| static bool |
| dso_name_valid_for_suid (const char *p) |
| { |
| if (__glibc_unlikely (__libc_enable_secure)) |
| { |
| /* Ignore pathnames with directories for AT_SECURE=1 |
| programs, and also skip overlong names. */ |
| size_t len = strlen (p); |
| if (len >= SECURE_NAME_LIMIT || memchr (p, '/', len) != NULL) |
| return false; |
| } |
| return *p != '\0'; |
| } |
| |
| /* LD_AUDIT variable contents. Must be processed before the |
| audit_list below. */ |
| const char *audit_list_string; |
| |
| /* Cyclic list of auditing DSOs. audit_list->next is the first |
| element. */ |
| static struct audit_list |
| { |
| const char *name; |
| struct audit_list *next; |
| } *audit_list; |
| |
| /* Iterator for audit_list_string followed by audit_list. */ |
| struct audit_list_iter |
| { |
| /* Tail of audit_list_string still needing processing, or NULL. */ |
| const char *audit_list_tail; |
| |
| /* The list element returned in the previous iteration. NULL before |
| the first element. */ |
| struct audit_list *previous; |
| |
| /* Scratch buffer for returning a name which is part of |
| audit_list_string. */ |
| char fname[SECURE_NAME_LIMIT]; |
| }; |
| |
| /* Initialize an audit list iterator. */ |
| static void |
| audit_list_iter_init (struct audit_list_iter *iter) |
| { |
| iter->audit_list_tail = audit_list_string; |
| iter->previous = NULL; |
| } |
| |
| /* Iterate through both audit_list_string and audit_list. */ |
| static const char * |
| audit_list_iter_next (struct audit_list_iter *iter) |
| { |
| if (iter->audit_list_tail != NULL) |
| { |
| /* First iterate over audit_list_string. */ |
| while (*iter->audit_list_tail != '\0') |
| { |
| /* Split audit list at colon. */ |
| size_t len = strcspn (iter->audit_list_tail, ":"); |
| if (len > 0 && len < sizeof (iter->fname)) |
| { |
| memcpy (iter->fname, iter->audit_list_tail, len); |
| iter->fname[len] = '\0'; |
| } |
| else |
| /* Do not return this name to the caller. */ |
| iter->fname[0] = '\0'; |
| |
| /* Skip over the substring and the following delimiter. */ |
| iter->audit_list_tail += len; |
| if (*iter->audit_list_tail == ':') |
| ++iter->audit_list_tail; |
| |
| /* If the name is valid, return it. */ |
| if (dso_name_valid_for_suid (iter->fname)) |
| return iter->fname; |
| /* Otherwise, wrap around and try the next name. */ |
| } |
| /* Fall through to the procesing of audit_list. */ |
| } |
| |
| if (iter->previous == NULL) |
| { |
| if (audit_list == NULL) |
| /* No pre-parsed audit list. */ |
| return NULL; |
| /* Start of audit list. The first list element is at |
| audit_list->next (cyclic list). */ |
| iter->previous = audit_list->next; |
| return iter->previous->name; |
| } |
| if (iter->previous == audit_list) |
| /* Cyclic list wrap-around. */ |
| return NULL; |
| iter->previous = iter->previous->next; |
| return iter->previous->name; |
| } |
| |
| #ifndef HAVE_INLINED_SYSCALLS |
| /* Set nonzero during loading and initialization of executable and |
| libraries, cleared before the executable's entry point runs. This |
| must not be initialized to nonzero, because the unused dynamic |
| linker loaded in for libc.so's "ld.so.1" dep will provide the |
| definition seen by libc.so's initializer; that value must be zero, |
| and will be since that dynamic linker's _dl_start and dl_main will |
| never be called. */ |
| int _dl_starting_up = 0; |
| rtld_hidden_def (_dl_starting_up) |
| #endif |
| |
| /* This is the structure which defines all variables global to ld.so |
| (except those which cannot be added for some reason). */ |
| struct rtld_global _rtld_global = |
| { |
| /* Generally the default presumption without further information is an |
| * executable stack but this is not true for all platforms. */ |
| ._dl_stack_flags = DEFAULT_STACK_PERMS, |
| #ifdef _LIBC_REENTRANT |
| ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER, |
| ._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER, |
| #endif |
| ._dl_nns = 1, |
| ._dl_ns = |
| { |
| #ifdef _LIBC_REENTRANT |
| [LM_ID_BASE] = { ._ns_unique_sym_table |
| = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } } |
| #endif |
| } |
| }; |
| /* If we would use strong_alias here the compiler would see a |
| non-hidden definition. This would undo the effect of the previous |
| declaration. So spell out was strong_alias does plus add the |
| visibility attribute. */ |
| extern struct rtld_global _rtld_local |
| __attribute__ ((alias ("_rtld_global"), visibility ("hidden"))); |
| |
| |
| /* This variable is similar to _rtld_local, but all values are |
| read-only after relocation. */ |
| struct rtld_global_ro _rtld_global_ro attribute_relro = |
| { |
| /* Get architecture specific initializer. */ |
| #include <dl-procinfo.c> |
| #ifdef NEED_DL_SYSINFO |
| ._dl_sysinfo = DL_SYSINFO_DEFAULT, |
| #endif |
| ._dl_debug_fd = STDERR_FILENO, |
| ._dl_use_load_bias = -2, |
| ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID, |
| #if !HAVE_TUNABLES |
| ._dl_hwcap_mask = HWCAP_IMPORTANT, |
| #endif |
| ._dl_lazy = 1, |
| ._dl_fpu_control = _FPU_DEFAULT, |
| ._dl_pagesize = EXEC_PAGESIZE, |
| ._dl_inhibit_cache = 0, |
| |
| /* Function pointers. */ |
| ._dl_debug_printf = _dl_debug_printf, |
| ._dl_mcount = _dl_mcount, |
| ._dl_lookup_symbol_x = _dl_lookup_symbol_x, |
| ._dl_check_caller = _dl_check_caller, |
| ._dl_open = _dl_open, |
| ._dl_close = _dl_close, |
| ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft, |
| ._dl_position_hash_cutoff = DL_POSITION_HASH_CUTOFF_DEFAULT, |
| #ifdef HAVE_DL_DISCOVER_OSVERSION |
| ._dl_discover_osversion = _dl_discover_osversion |
| #endif |
| }; |
| /* If we would use strong_alias here the compiler would see a |
| non-hidden definition. This would undo the effect of the previous |
| declaration. So spell out was strong_alias does plus add the |
| visibility attribute. */ |
| extern struct rtld_global_ro _rtld_local_ro |
| __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden"))); |
| |
| |
| static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum, |
| ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv); |
| |
| /* These two variables cannot be moved into .data.rel.ro. */ |
| static struct libname_list _dl_rtld_libname; |
| static struct libname_list _dl_rtld_libname2; |
| |
| /* Variable for statistics. */ |
| #ifndef HP_TIMING_NONAVAIL |
| static hp_timing_t relocate_time; |
| static hp_timing_t load_time attribute_relro; |
| static hp_timing_t start_time attribute_relro; |
| #endif |
| |
| /* Additional definitions needed by TLS initialization. */ |
| #ifdef TLS_INIT_HELPER |
| TLS_INIT_HELPER |
| #endif |
| |
| /* Helper function for syscall implementation. */ |
| #ifdef DL_SYSINFO_IMPLEMENTATION |
| DL_SYSINFO_IMPLEMENTATION |
| #endif |
| |
| /* Before ld.so is relocated we must not access variables which need |
| relocations. This means variables which are exported. Variables |
| declared as static are fine. If we can mark a variable hidden this |
| is fine, too. The latter is important here. We can avoid setting |
| up a temporary link map for ld.so if we can mark _rtld_global as |
| hidden. */ |
| #ifdef PI_STATIC_AND_HIDDEN |
| # define DONT_USE_BOOTSTRAP_MAP 1 |
| #endif |
| |
| #ifdef DONT_USE_BOOTSTRAP_MAP |
| static ElfW(Addr) _dl_start_final (void *arg); |
| #else |
| struct dl_start_final_info |
| { |
| struct link_map l; |
| #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE |
| hp_timing_t start_time; |
| #endif |
| }; |
| static ElfW(Addr) _dl_start_final (void *arg, |
| struct dl_start_final_info *info); |
| #endif |
| |
| /* These defined magically in the linker script. */ |
| extern char _begin[] attribute_hidden; |
| extern char _etext[] attribute_hidden; |
| extern char _end[] attribute_hidden; |
| |
| |
| #ifdef RTLD_START |
| RTLD_START |
| #else |
| # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START" |
| #endif |
| |
| /* This is the second half of _dl_start (below). It can be inlined safely |
| under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT |
| references. When the tools don't permit us to avoid using a GOT entry |
| for _dl_rtld_global (no attribute_hidden support), we must make sure |
| this function is not inlined (see below). */ |
| |
| #ifdef DONT_USE_BOOTSTRAP_MAP |
| static inline ElfW(Addr) __attribute__ ((always_inline)) |
| _dl_start_final (void *arg) |
| #else |
| static ElfW(Addr) __attribute__ ((noinline)) |
| _dl_start_final (void *arg, struct dl_start_final_info *info) |
| #endif |
| { |
| ElfW(Addr) start_addr; |
| |
| if (HP_SMALL_TIMING_AVAIL) |
| { |
| /* If it hasn't happen yet record the startup time. */ |
| if (! HP_TIMING_INLINE) |
| HP_TIMING_NOW (start_time); |
| #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL |
| else |
| start_time = info->start_time; |
| #endif |
| } |
| |
| /* Transfer data about ourselves to the permanent link_map structure. */ |
| #ifndef DONT_USE_BOOTSTRAP_MAP |
| GL(dl_rtld_map).l_addr = info->l.l_addr; |
| GL(dl_rtld_map).l_ld = info->l.l_ld; |
| memcpy (GL(dl_rtld_map).l_info, info->l.l_info, |
| sizeof GL(dl_rtld_map).l_info); |
| GL(dl_rtld_map).l_mach = info->l.l_mach; |
| GL(dl_rtld_map).l_relocated = 1; |
| #endif |
| _dl_setup_hash (&GL(dl_rtld_map)); |
| GL(dl_rtld_map).l_real = &GL(dl_rtld_map); |
| GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin; |
| GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end; |
| GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext; |
| /* Copy the TLS related data if necessary. */ |
| #ifndef DONT_USE_BOOTSTRAP_MAP |
| # if NO_TLS_OFFSET != 0 |
| GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET; |
| # endif |
| #endif |
| |
| HP_TIMING_NOW (GL(dl_cpuclock_offset)); |
| |
| /* Initialize the stack end variable. */ |
| __libc_stack_end = __builtin_frame_address (0); |
| |
| /* Call the OS-dependent function to set up life so we can do things like |
| file access. It will call `dl_main' (below) to do all the real work |
| of the dynamic linker, and then unwind our frame and run the user |
| entry point on the same stack we entered on. */ |
| start_addr = _dl_sysdep_start (arg, &dl_main); |
| |
| #ifndef HP_TIMING_NONAVAIL |
| hp_timing_t rtld_total_time; |
| if (HP_SMALL_TIMING_AVAIL) |
| { |
| hp_timing_t end_time; |
| |
| /* Get the current time. */ |
| HP_TIMING_NOW (end_time); |
| |
| /* Compute the difference. */ |
| HP_TIMING_DIFF (rtld_total_time, start_time, end_time); |
| } |
| #endif |
| |
| if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS)) |
| { |
| #ifndef HP_TIMING_NONAVAIL |
| print_statistics (&rtld_total_time); |
| #else |
| print_statistics (NULL); |
| #endif |
| } |
| |
| return start_addr; |
| } |
| |
| #ifndef NESTING |
| #ifdef DONT_USE_BOOTSTRAP_MAP |
| # define bootstrap_map GL(dl_rtld_map) |
| #else |
| # define bootstrap_map info.l |
| #endif |
| |
| /* This #define produces dynamic linking inline functions for |
| bootstrap relocation instead of general-purpose relocation. |
| Since ld.so must not have any undefined symbols the result |
| is trivial: always the map of ld.so itself. */ |
| #define RTLD_BOOTSTRAP |
| #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map) |
| #include "dynamic-link.h" |
| #endif /* n NESTING */ |
| |
| static ElfW(Addr) __attribute_used__ |
| _dl_start (void *arg) |
| { |
| #ifndef NESTING |
| #ifndef DONT_USE_BOOTSTRAP_MAP |
| struct dl_start_final_info info; |
| #endif /* DUBM */ |
| #else /* NESTING */ |
| #ifdef DONT_USE_BOOTSTRAP_MAP |
| # define bootstrap_map GL(dl_rtld_map) |
| #else |
| struct dl_start_final_info info; |
| # define bootstrap_map info.l |
| #endif |
| |
| /* This #define produces dynamic linking inline functions for |
| bootstrap relocation instead of general-purpose relocation. |
| Since ld.so must not have any undefined symbols the result |
| is trivial: always the map of ld.so itself. */ |
| #define RTLD_BOOTSTRAP |
| #define BOOTSTRAP_MAP (&bootstrap_map) |
| #define RESOLVE_MAP(sym, version, flags) BOOTSTRAP_MAP |
| #include "dynamic-link.h" |
| #endif /* NESTING */ |
| |
| if (HP_TIMING_INLINE && HP_SMALL_TIMING_AVAIL) |
| #ifdef DONT_USE_BOOTSTRAP_MAP |
| HP_TIMING_NOW (start_time); |
| #else |
| HP_TIMING_NOW (info.start_time); |
| #endif |
| |
| /* Partly clean the `bootstrap_map' structure up. Don't use |
| `memset' since it might not be built in or inlined and we cannot |
| make function calls at this point. Use '__builtin_memset' if we |
| know it is available. We do not have to clear the memory if we |
| do not have to use the temporary bootstrap_map. Global variables |
| are initialized to zero by default. */ |
| #ifndef DONT_USE_BOOTSTRAP_MAP |
| # ifdef HAVE_BUILTIN_MEMSET |
| __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info)); |
| # else |
| for (size_t cnt = 0; |
| cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]); |
| ++cnt) |
| bootstrap_map.l_info[cnt] = 0; |
| # endif |
| #endif |
| |
| /* Figure out the run-time load address of the dynamic linker itself. */ |
| bootstrap_map.l_addr = elf_machine_load_address (); |
| |
| /* Read our own dynamic section and fill in the info array. */ |
| bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); |
| elf_get_dynamic_info (&bootstrap_map, NULL); |
| |
| #if NO_TLS_OFFSET != 0 |
| bootstrap_map.l_tls_offset = NO_TLS_OFFSET; |
| #endif |
| |
| #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC |
| ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); |
| #endif |
| |
| if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)]) |
| { |
| /* Relocate ourselves so we can do normal function calls and |
| data access using the global offset table. */ |
| |
| ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0, 0 |
| #ifndef NESTING |
| , &bootstrap_map |
| #endif |
| ); |
| } |
| bootstrap_map.l_relocated = 1; |
| |
| /* Please note that we don't allow profiling of this object and |
| therefore need not test whether we have to allocate the array |
| for the relocation results (as done in dl-reloc.c). */ |
| |
| /* Now life is sane; we can call functions and access global data. |
| Set up to use the operating system facilities, and find out from |
| the operating system's program loader where to find the program |
| header table in core. Put the rest of _dl_start into a separate |
| function, that way the compiler cannot put accesses to the GOT |
| before ELF_DYNAMIC_RELOCATE. */ |
| { |
| #ifdef DONT_USE_BOOTSTRAP_MAP |
| ElfW(Addr) entry = _dl_start_final (arg); |
| #else |
| ElfW(Addr) entry = _dl_start_final (arg, &info); |
| #endif |
| |
| #ifndef ELF_MACHINE_START_ADDRESS |
| # define ELF_MACHINE_START_ADDRESS(map, start) (start) |
| #endif |
| |
| return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry); |
| } |
| } |
| |
| |
| |
| /* Now life is peachy; we can do all normal operations. |
| On to the real work. */ |
| |
| /* Some helper functions. */ |
| |
| /* Arguments to relocate_doit. */ |
| struct relocate_args |
| { |
| struct link_map *l; |
| int reloc_mode; |
| }; |
| |
| struct map_args |
| { |
| /* Argument to map_doit. */ |
| const char *str; |
| struct link_map *loader; |
| int mode; |
| /* Return value of map_doit. */ |
| struct link_map *map; |
| }; |
| |
| struct dlmopen_args |
| { |
| const char *fname; |
| struct link_map *map; |
| }; |
| |
| struct lookup_args |
| { |
| const char *name; |
| struct link_map *map; |
| void *result; |
| }; |
| |
| /* Arguments to version_check_doit. */ |
| struct version_check_args |
| { |
| int doexit; |
| int dotrace; |
| }; |
| |
| static void |
| relocate_doit (void *a) |
| { |
| struct relocate_args *args = (struct relocate_args *) a; |
| |
| _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0); |
| } |
| |
| static void |
| map_doit (void *a) |
| { |
| struct map_args *args = (struct map_args *) a; |
| int type = (args->mode == __RTLD_OPENEXEC) ? lt_executable : lt_library; |
| args->map = _dl_map_object (args->loader, args->str, 0, type, 0, |
| args->mode, LM_ID_BASE); |
| } |
| |
| static void |
| dlmopen_doit (void *a) |
| { |
| struct dlmopen_args *args = (struct dlmopen_args *) a; |
| args->map = _dl_open (args->fname, 0, |
| (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT |
| | __RTLD_SECURE), |
| dl_main, LM_ID_NEWLM, _dl_argc, _dl_argv, |
| __environ); |
| } |
| |
| static void |
| lookup_doit (void *a) |
| { |
| struct lookup_args *args = (struct lookup_args *) a; |
| const ElfW(Sym) *ref = NULL; |
| args->result = NULL; |
| lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref, |
| args->map->l_local_scope, NULL, 0, |
| DL_LOOKUP_RETURN_NEWEST, NULL); |
| if (ref != NULL) |
| args->result = DL_SYMBOL_ADDRESS (l, ref); |
| } |
| |
| static void |
| version_check_doit (void *a) |
| { |
| struct version_check_args *args = (struct version_check_args *) a; |
| if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1, |
| args->dotrace) && args->doexit) |
| /* We cannot start the application. Abort now. */ |
| _exit (1); |
| } |
| |
| |
| static inline struct link_map * |
| find_needed (const char *name) |
| { |
| struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist; |
| unsigned int n = scope->r_nlist; |
| |
| while (n-- > 0) |
| if (_dl_name_match_p (name, scope->r_list[n])) |
| return scope->r_list[n]; |
| |
| /* Should never happen. */ |
| return NULL; |
| } |
| |
| static int |
| match_version (const char *string, struct link_map *map) |
| { |
| const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); |
| ElfW(Verdef) *def; |
| |
| #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF)) |
| if (map->l_info[VERDEFTAG] == NULL) |
| /* The file has no symbol versioning. */ |
| return 0; |
| |
| def = (ElfW(Verdef) *) ((char *) map->l_addr |
| + map->l_info[VERDEFTAG]->d_un.d_ptr); |
| while (1) |
| { |
| ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux); |
| |
| /* Compare the version strings. */ |
| if (strcmp (string, strtab + aux->vda_name) == 0) |
| /* Bingo! */ |
| return 1; |
| |
| /* If no more definitions we failed to find what we want. */ |
| if (def->vd_next == 0) |
| break; |
| |
| /* Next definition. */ |
| def = (ElfW(Verdef) *) ((char *) def + def->vd_next); |
| } |
| |
| return 0; |
| } |
| |
| static bool tls_init_tp_called; |
| |
| static void * |
| init_tls (void) |
| { |
| /* Number of elements in the static TLS block. */ |
| GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx); |
| |
| /* Do not do this twice. The audit interface might have required |
| the DTV interfaces to be set up early. */ |
| if (GL(dl_initial_dtv) != NULL) |
| return NULL; |
| |
| /* Allocate the array which contains the information about the |
| dtv slots. We allocate a few entries more than needed to |
| avoid the need for reallocation. */ |
| size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS; |
| |
| /* Allocate. */ |
| GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *) |
| calloc (sizeof (struct dtv_slotinfo_list) |
| + nelem * sizeof (struct dtv_slotinfo), 1); |
| /* No need to check the return value. If memory allocation failed |
| the program would have been terminated. */ |
| |
| struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo; |
| GL(dl_tls_dtv_slotinfo_list)->len = nelem; |
| GL(dl_tls_dtv_slotinfo_list)->next = NULL; |
| |
| /* Fill in the information from the loaded modules. No namespace |
| but the base one can be filled at this time. */ |
| assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL); |
| int i = 0; |
| for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL; |
| l = l->l_next) |
| if (l->l_tls_blocksize != 0) |
| { |
| /* This is a module with TLS data. Store the map reference. |
| The generation counter is zero. */ |
| slotinfo[i].map = l; |
| /* slotinfo[i].gen = 0; */ |
| ++i; |
| } |
| assert (i == GL(dl_tls_max_dtv_idx)); |
| |
| /* Compute the TLS offsets for the various blocks. */ |
| _dl_determine_tlsoffset (); |
| |
| /* Construct the static TLS block and the dtv for the initial |
| thread. For some platforms this will include allocating memory |
| for the thread descriptor. The memory for the TLS block will |
| never be freed. It should be allocated accordingly. The dtv |
| array can be changed if dynamic loading requires it. */ |
| void *tcbp = _dl_allocate_tls_storage (); |
| if (tcbp == NULL) |
| _dl_fatal_printf ("\ |
| cannot allocate TLS data structures for initial thread\n"); |
| |
| /* Store for detection of the special case by __tls_get_addr |
| so it knows not to pass this dtv to the normal realloc. */ |
| GL(dl_initial_dtv) = GET_DTV (tcbp); |
| |
| /* And finally install it for the main thread. */ |
| const char *lossage = TLS_INIT_TP (tcbp); |
| if (__glibc_unlikely (lossage != NULL)) |
| _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage); |
| tls_init_tp_called = true; |
| |
| return tcbp; |
| } |
| |
| static unsigned int |
| do_preload (const char *fname, struct link_map *main_map, const char *where) |
| { |
| const char *objname; |
| const char *err_str = NULL; |
| struct map_args args; |
| bool malloced; |
| |
| args.str = fname; |
| args.loader = main_map; |
| args.mode = __RTLD_SECURE; |
| |
| unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded; |
| |
| (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args); |
| if (__glibc_unlikely (err_str != NULL)) |
| { |
| _dl_error_printf ("\ |
| ERROR: ld.so: object '%s' from %s cannot be preloaded (%s): ignored.\n", |
| fname, where, err_str); |
| /* No need to call free, this is still before |
| the libc's malloc is used. */ |
| } |
| else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded) |
| /* It is no duplicate. */ |
| return 1; |
| |
| /* Nothing loaded. */ |
| return 0; |
| } |
| |
| #if defined SHARED && defined _LIBC_REENTRANT \ |
| && defined __rtld_lock_default_lock_recursive |
| static void |
| rtld_lock_default_lock_recursive (void *lock) |
| { |
| __rtld_lock_default_lock_recursive (lock); |
| } |
| |
| static void |
| rtld_lock_default_unlock_recursive (void *lock) |
| { |
| __rtld_lock_default_unlock_recursive (lock); |
| } |
| #endif |
| |
| |
| static void |
| security_init (void) |
| { |
| /* Set up the stack checker's canary. */ |
| uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random); |
| #ifdef THREAD_SET_STACK_GUARD |
| THREAD_SET_STACK_GUARD (stack_chk_guard); |
| #else |
| __stack_chk_guard = stack_chk_guard; |
| #endif |
| |
| /* Set up the pointer guard as well, if necessary. */ |
| uintptr_t pointer_chk_guard |
| = _dl_setup_pointer_guard (_dl_random, stack_chk_guard); |
| #ifdef THREAD_SET_POINTER_GUARD |
| THREAD_SET_POINTER_GUARD (pointer_chk_guard); |
| #endif |
| __pointer_chk_guard_local = pointer_chk_guard; |
| |
| /* We do not need the _dl_random value anymore. The less |
| information we leave behind, the better, so clear the |
| variable. */ |
| _dl_random = NULL; |
| } |
| |
| #include "setup-vdso.h" |
| |
| /* The library search path. */ |
| static const char *library_path attribute_relro; |
| /* The list preloaded objects. */ |
| static const char *preloadlist attribute_relro; |
| /* Nonzero if information about versions has to be printed. */ |
| static int version_info attribute_relro; |
| |
| /* The LD_PRELOAD environment variable gives list of libraries |
| separated by white space or colons that are loaded before the |
| executable's dependencies and prepended to the global scope list. |
| (If the binary is running setuid all elements containing a '/' are |
| ignored since it is insecure.) Return the number of preloads |
| performed. */ |
| unsigned int |
| handle_ld_preload (const char *preloadlist, struct link_map *main_map) |
| { |
| unsigned int npreloads = 0; |
| const char *p = preloadlist; |
| char fname[SECURE_PATH_LIMIT]; |
| |
| while (*p != '\0') |
| { |
| /* Split preload list at space/colon. */ |
| size_t len = strcspn (p, " :"); |
| if (len > 0 && len < sizeof (fname)) |
| { |
| memcpy (fname, p, len); |
| fname[len] = '\0'; |
| } |
| else |
| fname[0] = '\0'; |
| |
| /* Skip over the substring and the following delimiter. */ |
| p += len; |
| if (*p != '\0') |
| ++p; |
| |
| if (dso_name_valid_for_suid (fname)) |
| npreloads += do_preload (fname, main_map, "LD_PRELOAD"); |
| } |
| return npreloads; |
| } |
| |
| static void |
| dl_main (const ElfW(Phdr) *phdr, |
| ElfW(Word) phnum, |
| ElfW(Addr) *user_entry, |
| ElfW(auxv_t) *auxv) |
| { |
| const ElfW(Phdr) *ph; |
| enum mode mode; |
| struct link_map *main_map; |
| size_t file_size; |
| char *file; |
| bool has_interp = false; |
| unsigned int i; |
| bool prelinked = false; |
| bool rtld_is_main = false; |
| #ifndef HP_TIMING_NONAVAIL |
| hp_timing_t start; |
| hp_timing_t stop; |
| hp_timing_t diff; |
| #endif |
| void *tcbp = NULL; |
| |
| GL(dl_init_static_tls) = &_dl_nothread_init_static_tls; |
| |
| #if defined SHARED && defined _LIBC_REENTRANT \ |
| && defined __rtld_lock_default_lock_recursive |
| GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive; |
| GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive; |
| #endif |
| |
| /* The explicit initialization here is cheaper than processing the reloc |
| in the _rtld_local definition's initializer. */ |
| GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable; |
| |
| /* Process the environment variable which control the behaviour. */ |
| process_envvars (&mode); |
| |
| #ifndef HAVE_INLINED_SYSCALLS |
| /* Set up a flag which tells we are just starting. */ |
| _dl_starting_up = 1; |
| #endif |
| |
| if (*user_entry == (ElfW(Addr)) ENTRY_POINT) |
| { |
| /* Ho ho. We are not the program interpreter! We are the program |
| itself! This means someone ran ld.so as a command. Well, that |
| might be convenient to do sometimes. We support it by |
| interpreting the args like this: |
| |
| ld.so PROGRAM ARGS... |
| |
| The first argument is the name of a file containing an ELF |
| executable we will load and run with the following arguments. |
| To simplify life here, PROGRAM is searched for using the |
| normal rules for shared objects, rather than $PATH or anything |
| like that. We just load it and use its entry point; we don't |
| pay attention to its PT_INTERP command (we are the interpreter |
| ourselves). This is an easy way to test a new ld.so before |
| installing it. */ |
| rtld_is_main = true; |
| |
| /* Note the place where the dynamic linker actually came from. */ |
| GL(dl_rtld_map).l_name = rtld_progname; |
| |
| while (_dl_argc > 1) |
| if (! strcmp (_dl_argv[1], "--list")) |
| { |
| mode = list; |
| GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */ |
| |
| ++_dl_skip_args; |
| --_dl_argc; |
| ++_dl_argv; |
| } |
| else if (! strcmp (_dl_argv[1], "--verify")) |
| { |
| mode = verify; |
| |
| ++_dl_skip_args; |
| --_dl_argc; |
| ++_dl_argv; |
| } |
| else if (! strcmp (_dl_argv[1], "--inhibit-cache")) |
| { |
| GLRO(dl_inhibit_cache) = 1; |
| ++_dl_skip_args; |
| --_dl_argc; |
| ++_dl_argv; |
| } |
| else if (! strcmp (_dl_argv[1], "--library-path") |
| && _dl_argc > 2) |
| { |
| library_path = _dl_argv[2]; |
| |
| _dl_skip_args += 2; |
| _dl_argc -= 2; |
| _dl_argv += 2; |
| } |
| else if (! strcmp (_dl_argv[1], "--inhibit-rpath") |
| && _dl_argc > 2) |
| { |
| GLRO(dl_inhibit_rpath) = _dl_argv[2]; |
| |
| _dl_skip_args += 2; |
| _dl_argc -= 2; |
| _dl_argv += 2; |
| } |
| else if (! strcmp (_dl_argv[1], "--audit") && _dl_argc > 2) |
| { |
| process_dl_audit (_dl_argv[2]); |
| |
| _dl_skip_args += 2; |
| _dl_argc -= 2; |
| _dl_argv += 2; |
| } |
| else |
| break; |
| |
| /* If we have no further argument the program was called incorrectly. |
| Grant the user some education. */ |
| if (_dl_argc < 2) |
| _dl_fatal_printf ("\ |
| Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ |
| You have invoked `ld.so', the helper program for shared library executables.\n\ |
| This program usually lives in the file `/lib/ld.so', and special directives\n\ |
| in executable files using ELF shared libraries tell the system's program\n\ |
| loader to load the helper program from this file. This helper program loads\n\ |
| the shared libraries needed by the program executable, prepares the program\n\ |
| to run, and runs it. You may invoke this helper program directly from the\n\ |
| command line to load and run an ELF executable file; this is like executing\n\ |
| that file itself, but always uses this helper program from the file you\n\ |
| specified, instead of the helper program file specified in the executable\n\ |
| file you run. This is mostly of use for maintainers to test new versions\n\ |
| of this helper program; chances are you did not intend to run this program.\n\ |
| \n\ |
| --list list all dependencies and how they are resolved\n\ |
| --verify verify that given object really is a dynamically linked\n\ |
| object we can handle\n\ |
| --inhibit-cache Do not use " LD_SO_CACHE "\n\ |
| --library-path PATH use given PATH instead of content of the environment\n\ |
| variable LD_LIBRARY_PATH\n\ |
| --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\ |
| in LIST\n\ |
| --audit LIST use objects named in LIST as auditors\n"); |
| |
| set_exec_origin_dir (_dl_argv[1]); |
| |
| ++_dl_skip_args; |
| --_dl_argc; |
| ++_dl_argv; |
| |
| /* The initialization of _dl_stack_flags done below assumes the |
| executable's PT_GNU_STACK may have been honored by the kernel, and |
| so a PT_GNU_STACK with PF_X set means the stack started out with |
| execute permission. However, this is not really true if the |
| dynamic linker is the executable the kernel loaded. For this |
| case, we must reinitialize _dl_stack_flags to match the dynamic |
| linker itself. If the dynamic linker was built with a |
| PT_GNU_STACK, then the kernel may have loaded us with a |
| nonexecutable stack that we will have to make executable when we |
| load the program below unless it has a PT_GNU_STACK indicating |
| nonexecutable stack is ok. */ |
| |
| for (ph = phdr; ph < &phdr[phnum]; ++ph) |
| if (ph->p_type == PT_GNU_STACK) |
| { |
| GL(dl_stack_flags) = ph->p_flags; |
| break; |
| } |
| |
| if (__builtin_expect (mode, normal) == verify) |
| { |
| const char *objname; |
| const char *err_str = NULL; |
| struct map_args args; |
| bool malloced; |
| |
| args.str = rtld_progname; |
| args.loader = NULL; |
| args.mode = __RTLD_OPENEXEC; |
| (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, |
| &args); |
| if (__glibc_unlikely (err_str != NULL)) |
| /* We don't free the returned string, the programs stops |
| anyway. */ |
| _exit (EXIT_FAILURE); |
| } |
| else |
| { |
| HP_TIMING_NOW (start); |
| _dl_map_object (NULL, rtld_progname, 0, lt_executable, 0, |
| __RTLD_OPENEXEC, LM_ID_BASE); |
| HP_TIMING_NOW (stop); |
| |
| HP_TIMING_DIFF (load_time, start, stop); |
| } |
| |
| /* Now the map for the main executable is available. */ |
| main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded; |
| |
| if (__builtin_expect (mode, normal) == normal |
| && GL(dl_rtld_map).l_info[DT_SONAME] != NULL |
| && main_map->l_info[DT_SONAME] != NULL |
| && strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) |
| + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val, |
| (const char *) D_PTR (main_map, l_info[DT_STRTAB]) |
| + main_map->l_info[DT_SONAME]->d_un.d_val) == 0) |
| _dl_fatal_printf ("loader cannot load itself\n"); |
| |
| phdr = main_map->l_phdr; |
| phnum = main_map->l_phnum; |
| /* We overwrite here a pointer to a malloc()ed string. But since |
| the malloc() implementation used at this point is the dummy |
| implementations which has no real free() function it does not |
| makes sense to free the old string first. */ |
| main_map->l_name = (char *) ""; |
| *user_entry = main_map->l_entry; |
| |
| #ifdef HAVE_AUX_VECTOR |
| /* Adjust the on-stack auxiliary vector so that it looks like the |
| binary was executed directly. */ |
| for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++) |
| switch (av->a_type) |
| { |
| case AT_PHDR: |
| av->a_un.a_val = (uintptr_t) phdr; |
| break; |
| case AT_PHNUM: |
| av->a_un.a_val = phnum; |
| break; |
| case AT_ENTRY: |
| av->a_un.a_val = *user_entry; |
| break; |
| case AT_EXECFN: |
| av->a_un.a_val = (uintptr_t) _dl_argv[0]; |
| break; |
| } |
| #endif |
| } |
| else |
| { |
| set_exec_origin_dir (get_at_execfn (auxv)); |
| |
| /* Create a link_map for the executable itself. |
| This will be what dlopen on "" returns. */ |
| main_map = _dl_new_object ((char *) "", "", lt_executable, NULL, |
| __RTLD_OPENEXEC, LM_ID_BASE); |
| assert (main_map != NULL); |
| main_map->l_phdr = phdr; |
| main_map->l_phnum = phnum; |
| main_map->l_entry = *user_entry; |
| |
| /* Even though the link map is not yet fully initialized we can add |
| it to the map list since there are no possible users running yet. */ |
| _dl_add_to_namespace_list (main_map, LM_ID_BASE); |
| assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded); |
| |
| /* At this point we are in a bit of trouble. We would have to |
| fill in the values for l_dev and l_ino. But in general we |
| do not know where the file is. We also do not handle AT_EXECFD |
| even if it would be passed up. |
| |
| We leave the values here defined to 0. This is normally no |
| problem as the program code itself is normally no shared |
| object and therefore cannot be loaded dynamically. Nothing |
| prevent the use of dynamic binaries and in these situations |
| we might get problems. We might not be able to find out |
| whether the object is already loaded. But since there is no |
| easy way out and because the dynamic binary must also not |
| have an SONAME we ignore this program for now. If it becomes |
| a problem we can force people using SONAMEs. */ |
| |
| /* We delay initializing the path structure until we got the dynamic |
| information for the program. */ |
| } |
| |
| main_map->l_map_end = 0; |
| main_map->l_text_end = 0; |
| /* Perhaps the executable has no PT_LOAD header entries at all. */ |
| main_map->l_map_start = ~0; |
| /* And it was opened directly. */ |
| ++main_map->l_direct_opencount; |
| |
| /* Scan the program header table for the dynamic section. */ |
| for (ph = phdr; ph < &phdr[phnum]; ++ph) |
| switch (ph->p_type) |
| { |
| case PT_PHDR: |
| /* Find out the load address. */ |
| main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr; |
| break; |
| case PT_DYNAMIC: |
| /* This tells us where to find the dynamic section, |
| which tells us everything we need to do. */ |
| main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr; |
| break; |
| case PT_INTERP: |
| /* This "interpreter segment" was used by the program loader to |
| find the program interpreter, which is this program itself, the |
| dynamic linker. We note what name finds us, so that a future |
| dlopen call or DT_NEEDED entry, for something that wants to link |
| against the dynamic linker as a shared library, will know that |
| the shared object is already loaded. */ |
| _dl_rtld_libname.name = ((const char *) main_map->l_addr |
| + ph->p_vaddr); |
| /* _dl_rtld_libname.next = NULL; Already zero. */ |
| GL(dl_rtld_map).l_libname = &_dl_rtld_libname; |
| |
| /* Ordinarilly, we would get additional names for the loader from |
| our DT_SONAME. This can't happen if we were actually linked as |
| a static executable (detect this case when we have no DYNAMIC). |
| If so, assume the filename component of the interpreter path to |
| be our SONAME, and add it to our name list. */ |
| if (GL(dl_rtld_map).l_ld == NULL) |
| { |
| const char *p = NULL; |
| const char *cp = _dl_rtld_libname.name; |
| |
| /* Find the filename part of the path. */ |
| while (*cp != '\0') |
| if (*cp++ == '/') |
| p = cp; |
| |
| if (p != NULL) |
| { |
| _dl_rtld_libname2.name = p; |
| /* _dl_rtld_libname2.next = NULL; Already zero. */ |
| _dl_rtld_libname.next = &_dl_rtld_libname2; |
| } |
| } |
| |
| has_interp = true; |
| break; |
| case PT_LOAD: |
| { |
| ElfW(Addr) mapstart; |
| ElfW(Addr) allocend; |
| |
| /* Remember where the main program starts in memory. */ |
| mapstart = (main_map->l_addr |
| + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1))); |
| if (main_map->l_map_start > mapstart) |
| main_map->l_map_start = mapstart; |
| |
| /* Also where it ends. */ |
| allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz; |
| if (main_map->l_map_end < allocend) |
| main_map->l_map_end = allocend; |
| if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end) |
| main_map->l_text_end = allocend; |
| } |
| break; |
| |
| case PT_TLS: |
| if (ph->p_memsz > 0) |
| { |
| /* Note that in the case the dynamic linker we duplicate work |
| here since we read the PT_TLS entry already in |
| _dl_start_final. But the result is repeatable so do not |
| check for this special but unimportant case. */ |
| main_map->l_tls_blocksize = ph->p_memsz; |
| main_map->l_tls_align = ph->p_align; |
| if (ph->p_align == 0) |
| main_map->l_tls_firstbyte_offset = 0; |
| else |
| main_map->l_tls_firstbyte_offset = (ph->p_vaddr |
| & (ph->p_align - 1)); |
| main_map->l_tls_initimage_size = ph->p_filesz; |
| main_map->l_tls_initimage = (void *) ph->p_vaddr; |
| |
| /* This image gets the ID one. */ |
| GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1; |
| } |
| break; |
| |
| case PT_GNU_STACK: |
| GL(dl_stack_flags) = ph->p_flags; |
| break; |
| |
| case PT_GNU_RELRO: |
| main_map->l_relro_addr = ph->p_vaddr; |
| main_map->l_relro_size = ph->p_memsz; |
| break; |
| } |
| |
| /* Adjust the address of the TLS initialization image in case |
| the executable is actually an ET_DYN object. */ |
| if (main_map->l_tls_initimage != NULL) |
| main_map->l_tls_initimage |
| = (char *) main_map->l_tls_initimage + main_map->l_addr; |
| if (! main_map->l_map_end) |
| main_map->l_map_end = ~0; |
| if (! main_map->l_text_end) |
| main_map->l_text_end = ~0; |
| if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name) |
| { |
| /* We were invoked directly, so the program might not have a |
| PT_INTERP. */ |
| _dl_rtld_libname.name = GL(dl_rtld_map).l_name; |
| /* _dl_rtld_libname.next = NULL; Already zero. */ |
| GL(dl_rtld_map).l_libname = &_dl_rtld_libname; |
| } |
| else |
| assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */ |
| |
| /* If the current libname is different from the SONAME, add the |
| latter as well. */ |
| if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL |
| && strcmp (GL(dl_rtld_map).l_libname->name, |
| (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) |
| + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0) |
| { |
| static struct libname_list newname; |
| newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) |
| + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr); |
| newname.next = NULL; |
| newname.dont_free = 1; |
| |
| assert (GL(dl_rtld_map).l_libname->next == NULL); |
| GL(dl_rtld_map).l_libname->next = &newname; |
| } |
| /* The ld.so must be relocated since otherwise loading audit modules |
| will fail since they reuse the very same ld.so. */ |
| assert (GL(dl_rtld_map).l_relocated); |
| |
| if (! rtld_is_main) |
| { |
| /* Extract the contents of the dynamic section for easy access. */ |
| elf_get_dynamic_info (main_map, NULL); |
| /* Set up our cache of pointers into the hash table. */ |
| _dl_setup_hash (main_map); |
| } |
| |
| if (__builtin_expect (mode, normal) == verify) |
| { |
| /* We were called just to verify that this is a dynamic |
| executable using us as the program interpreter. Exit with an |
| error if we were not able to load the binary or no interpreter |
| is specified (i.e., this is no dynamically linked binary. */ |
| if (main_map->l_ld == NULL) |
| _exit (1); |
| |
| /* We allow here some platform specific code. */ |
| #ifdef DISTINGUISH_LIB_VERSIONS |
| DISTINGUISH_LIB_VERSIONS; |
| #endif |
| _exit (has_interp ? 0 : 2); |
| } |
| |
| struct link_map **first_preload = &GL(dl_rtld_map).l_next; |
| /* Set up the data structures for the system-supplied DSO early, |
| so they can influence _dl_init_paths. */ |
| setup_vdso (main_map, &first_preload); |
| |
| #ifdef DL_SYSDEP_OSCHECK |
| DL_SYSDEP_OSCHECK (_dl_fatal_printf); |
| #endif |
| |
| /* Initialize the data structures for the search paths for shared |
| objects. */ |
| _dl_init_paths (library_path); |
| |
| /* Initialize _r_debug. */ |
| struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr, |
| LM_ID_BASE); |
| r->r_state = RT_CONSISTENT; |
| |
| /* Put the link_map for ourselves on the chain so it can be found by |
| name. Note that at this point the global chain of link maps contains |
| exactly one element, which is pointed to by dl_loaded. */ |
| if (! GL(dl_rtld_map).l_name) |
| /* If not invoked directly, the dynamic linker shared object file was |
| found by the PT_INTERP name. */ |
| GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name; |
| GL(dl_rtld_map).l_type = lt_library; |
| main_map->l_next = &GL(dl_rtld_map); |
| GL(dl_rtld_map).l_prev = main_map; |
| _dl_hash_add_object (&GL(dl_rtld_map)); |
| ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded; |
| ++GL(dl_load_adds); |
| |
| /* If LD_USE_LOAD_BIAS env variable has not been seen, default |
| to not using bias for non-prelinked PIEs and libraries |
| and using it for executables or prelinked PIEs or libraries. */ |
| if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2) |
| GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0; |
| |
| /* Starting from binutils-2.23, the linker will define the magic symbol |
| __ehdr_start to point to our own ELF header if it is visible in a |
| segment that also includes the phdrs. If that's not available, we use |
| the old method that assumes the beginning of the file is part of the |
| lowest-addressed PT_LOAD segment. */ |
| extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden"))); |
| |
| /* Set up the program header information for the dynamic linker |
| itself. It is needed in the dl_iterate_phdr callbacks. */ |
| const ElfW(Ehdr) *rtld_ehdr = &__ehdr_start; |
| assert (rtld_ehdr->e_ehsize == sizeof *rtld_ehdr); |
| assert (rtld_ehdr->e_phentsize == sizeof (ElfW(Phdr))); |
| |
| const ElfW(Phdr) *rtld_phdr = (const void *) rtld_ehdr + rtld_ehdr->e_phoff; |
| |
| GL(dl_rtld_map).l_phdr = rtld_phdr; |
| GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum; |
| |
| |
| /* PT_GNU_RELRO is usually the last phdr. */ |
| size_t cnt = rtld_ehdr->e_phnum; |
| while (cnt-- > 0) |
| if (rtld_phdr[cnt].p_type == PT_GNU_RELRO) |
| { |
| GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr; |
| GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz; |
| break; |
| } |
| |
| /* Add the dynamic linker to the TLS list if it also uses TLS. */ |
| if (GL(dl_rtld_map).l_tls_blocksize != 0) |
| /* Assign a module ID. Do this before loading any audit modules. */ |
| GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid (); |
| |
| /* If we have auditing DSOs to load, do it now. */ |
| bool need_security_init = true; |
| if (__glibc_unlikely (audit_list != NULL) |
| || __glibc_unlikely (audit_list_string != NULL)) |
| { |
| struct audit_ifaces *last_audit = NULL; |
| struct audit_list_iter al_iter; |
| audit_list_iter_init (&al_iter); |
| |
| /* Since we start using the auditing DSOs right away we need to |
| initialize the data structures now. */ |
| tcbp = init_tls (); |
| |
| /* Initialize security features. We need to do it this early |
| since otherwise the constructors of the audit libraries will |
| use different values (especially the pointer guard) and will |
| fail later on. */ |
| security_init (); |
| need_security_init = false; |
| |
| while (true) |
| { |
| const char *name = audit_list_iter_next (&al_iter); |
| if (name == NULL) |
| break; |
| |
| int tls_idx = GL(dl_tls_max_dtv_idx); |
| |
| /* Now it is time to determine the layout of the static TLS |
| block and allocate it for the initial thread. Note that we |
| always allocate the static block, we never defer it even if |
| no DF_STATIC_TLS bit is set. The reason is that we know |
| glibc will use the static model. */ |
| struct dlmopen_args dlmargs; |
| dlmargs.fname = name; |
| dlmargs.map = NULL; |
| |
| const char *objname; |
| const char *err_str = NULL; |
| bool malloced; |
| (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit, |
| &dlmargs); |
| if (__glibc_unlikely (err_str != NULL)) |
| { |
| not_loaded: |
| _dl_error_printf ("\ |
| ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n", |
| name, err_str); |
| if (malloced) |
| free ((char *) err_str); |
| } |
| else |
| { |
| struct lookup_args largs; |
| largs.name = "la_version"; |
| largs.map = dlmargs.map; |
| |
| /* Check whether the interface version matches. */ |
| (void) _dl_catch_error (&objname, &err_str, &malloced, |
| lookup_doit, &largs); |
| |
| unsigned int (*laversion) (unsigned int); |
| unsigned int lav; |
| if (err_str == NULL |
| && (laversion = largs.result) != NULL |
| && (lav = laversion (LAV_CURRENT)) > 0 |
| && lav <= LAV_CURRENT) |
| { |
| /* Allocate structure for the callback function pointers. |
| This call can never fail. */ |
| union |
| { |
| struct audit_ifaces ifaces; |
| #define naudit_ifaces 8 |
| void (*fptr[naudit_ifaces]) (void); |
| } *newp = malloc (sizeof (*newp)); |
| |
| /* Names of the auditing interfaces. All in one |
| long string. */ |
| static const char audit_iface_names[] = |
| "la_activity\0" |
| "la_objsearch\0" |
| "la_objopen\0" |
| "la_preinit\0" |
| #if __ELF_NATIVE_CLASS == 32 |
| "la_symbind32\0" |
| #elif __ELF_NATIVE_CLASS == 64 |
| "la_symbind64\0" |
| #else |
| # error "__ELF_NATIVE_CLASS must be defined" |
| #endif |
| #define STRING(s) __STRING (s) |
| "la_" STRING (ARCH_LA_PLTENTER) "\0" |
| "la_" STRING (ARCH_LA_PLTEXIT) "\0" |
| "la_objclose\0"; |
| unsigned int cnt = 0; |
| const char *cp = audit_iface_names; |
| do |
| { |
| largs.name = cp; |
| (void) _dl_catch_error (&objname, &err_str, &malloced, |
| lookup_doit, &largs); |
| |
| /* Store the pointer. */ |
| if (err_str == NULL && largs.result != NULL) |
| { |
| newp->fptr[cnt] = largs.result; |
| |
| /* The dynamic linker link map is statically |
| allocated, initialize the data now. */ |
| GL(dl_rtld_map).l_audit[cnt].cookie |
| = (intptr_t) &GL(dl_rtld_map); |
| } |
| else |
| newp->fptr[cnt] = NULL; |
| ++cnt; |
| |
| cp = (char *) rawmemchr (cp, '\0') + 1; |
| } |
| while (*cp != '\0'); |
| assert (cnt == naudit_ifaces); |
| |
| /* Now append the new auditing interface to the list. */ |
| newp->ifaces.next = NULL; |
| if (last_audit == NULL) |
| last_audit = GLRO(dl_audit) = &newp->ifaces; |
| else |
| last_audit = last_audit->next = &newp->ifaces; |
| ++GLRO(dl_naudit); |
| |
| /* Mark the DSO as being used for auditing. */ |
| dlmargs.map->l_auditing = 1; |
| } |
| else |
| { |
| /* We cannot use the DSO, it does not have the |
| appropriate interfaces or it expects something |
| more recent. */ |
| #ifndef NDEBUG |
| Lmid_t ns = dlmargs.map->l_ns; |
| #endif |
| _dl_close (dlmargs.map); |
| |
| /* Make sure the namespace has been cleared entirely. */ |
| assert (GL(dl_ns)[ns]._ns_loaded == NULL); |
| assert (GL(dl_ns)[ns]._ns_nloaded == 0); |
| |
| GL(dl_tls_max_dtv_idx) = tls_idx; |
| goto not_loaded; |
| } |
| } |
| } |
| |
| /* If we have any auditing modules, announce that we already |
| have two objects loaded. */ |
| if (__glibc_unlikely (GLRO(dl_naudit) > 0)) |
| { |
| struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) }; |
| |
| for (unsigned int outer = 0; outer < 2; ++outer) |
| { |
| struct audit_ifaces *afct = GLRO(dl_audit); |
| for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) |
| { |
| if (afct->objopen != NULL) |
| { |
| ls[outer]->l_audit[cnt].bindflags |
| = afct->objopen (ls[outer], LM_ID_BASE, |
| &ls[outer]->l_audit[cnt].cookie); |
| |
| ls[outer]->l_audit_any_plt |
| |= ls[outer]->l_audit[cnt].bindflags != 0; |
| } |
| |
| afct = afct->next; |
| } |
| } |
| } |
| } |
| |
| /* Keep track of the currently loaded modules to count how many |
| non-audit modules which use TLS are loaded. */ |
| size_t count_modids = _dl_count_modids (); |
| |
| /* Set up debugging before the debugger is notified for the first time. */ |
| #ifdef ELF_MACHINE_DEBUG_SETUP |
| /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ |
| ELF_MACHINE_DEBUG_SETUP (main_map, r); |
| ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r); |
| #else |
| if (main_map->l_info[DT_DEBUG] != NULL) |
| /* There is a DT_DEBUG entry in the dynamic section. Fill it in |
| with the run-time address of the r_debug structure */ |
| main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; |
| |
| /* Fill in the pointer in the dynamic linker's own dynamic section, in |
| case you run gdb on the dynamic linker directly. */ |
| if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL) |
| GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; |
| #endif |
| |
| /* We start adding objects. */ |
| r->r_state = RT_ADD; |
| _dl_debug_state (); |
| LIBC_PROBE (init_start, 2, LM_ID_BASE, r); |
| |
| /* Auditing checkpoint: we are ready to signal that the initial map |
| is being constructed. */ |
| if (__glibc_unlikely (GLRO(dl_naudit) > 0)) |
| { |
| struct audit_ifaces *afct = GLRO(dl_audit); |
| for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) |
| { |
| if (afct->activity != NULL) |
| afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD); |
| |
| afct = afct->next; |
| } |
| } |
| |
| /* We have two ways to specify objects to preload: via environment |
| variable and via the file /etc/ld.so.preload. The latter can also |
| be used when security is enabled. */ |
| assert (*first_preload == NULL); |
| struct link_map **preloads = NULL; |
| unsigned int npreloads = 0; |
| |
| if (__glibc_unlikely (preloadlist != NULL)) |
| { |
| HP_TIMING_NOW (start); |
| npreloads += handle_ld_preload (preloadlist, main_map); |
| HP_TIMING_NOW (stop); |
| HP_TIMING_DIFF (diff, start, stop); |
| HP_TIMING_ACCUM_NT (load_time, diff); |
| } |
| |
| /* There usually is no ld.so.preload file, it should only be used |
| for emergencies and testing. So the open call etc should usually |
| fail. Using access() on a non-existing file is faster than using |
| open(). So we do this first. If it succeeds we do almost twice |
| the work but this does not matter, since it is not for production |
| use. */ |
| static const char preload_file[] = "/etc/ld.so.preload"; |
| if (__glibc_unlikely (__access (preload_file, R_OK) == 0)) |
| { |
| /* Read the contents of the file. */ |
| file = _dl_sysdep_read_whole_file (preload_file, &file_size, |
| PROT_READ | PROT_WRITE); |
| if (__glibc_unlikely (file != MAP_FAILED)) |
| { |
| /* Parse the file. It contains names of libraries to be loaded, |
| separated by white spaces or `:'. It may also contain |
| comments introduced by `#'. */ |
| char *problem; |
| char *runp; |
| size_t rest; |
| |
| /* Eliminate comments. */ |
| runp = file; |
| rest = file_size; |
| while (rest > 0) |
| { |
| char *comment = memchr (runp, '#', rest); |
| if (comment == NULL) |
| break; |
| |
| rest -= comment - runp; |
| do |
| *comment = ' '; |
| while (--rest > 0 && *++comment != '\n'); |
| } |
| |
| /* We have one problematic case: if we have a name at the end of |
| the file without a trailing terminating characters, we cannot |
| place the \0. Handle the case separately. */ |
| if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' |
| && file[file_size - 1] != '\n' && file[file_size - 1] != ':') |
| { |
| problem = &file[file_size]; |
| while (problem > file && problem[-1] != ' ' |
| && problem[-1] != '\t' |
| && problem[-1] != '\n' && problem[-1] != ':') |
| --problem; |
| |
| if (problem > file) |
| problem[-1] = '\0'; |
| } |
| else |
| { |
| problem = NULL; |
| file[file_size - 1] = '\0'; |
| } |
| |
| HP_TIMING_NOW (start); |
| |
| if (file != problem) |
| { |
| char *p; |
| runp = file; |
| while ((p = strsep (&runp, ": \t\n")) != NULL) |
| if (p[0] != '\0') |
| npreloads += do_preload (p, main_map, preload_file); |
| } |
| |
| if (problem != NULL) |
| { |
| char *p = strndupa (problem, file_size - (problem - file)); |
| |
| npreloads += do_preload (p, main_map, preload_file); |
| } |
| |
| HP_TIMING_NOW (stop); |
| HP_TIMING_DIFF (diff, start, stop); |
| HP_TIMING_ACCUM_NT (load_time, diff); |
| |
| /* We don't need the file anymore. */ |
| __munmap (file, file_size); |
| } |
| } |
| |
| if (__glibc_unlikely (*first_preload != NULL)) |
| { |
| /* Set up PRELOADS with a vector of the preloaded libraries. */ |
| struct link_map *l = *first_preload; |
| preloads = __alloca (npreloads * sizeof preloads[0]); |
| i = 0; |
| do |
| { |
| preloads[i++] = l; |
| l = l->l_next; |
| } while (l); |
| assert (i == npreloads); |
| } |
| |
| /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD |
| specified some libraries to load, these are inserted before the actual |
| dependencies in the executable's searchlist for symbol resolution. */ |
| HP_TIMING_NOW (start); |
| _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0); |
| |
| /* We have now finished loading every required (linked-in) object. |
| Set up the position hash if needed. */ |
| _dl_fill_position_hash (main_map); |
| |
| HP_TIMING_NOW (stop); |
| HP_TIMING_DIFF (diff, start, stop); |
| HP_TIMING_ACCUM_NT (load_time, diff); |
| |
| /* Mark all objects as being in the global scope. */ |
| for (i = main_map->l_searchlist.r_nlist; i > 0; ) |
| main_map->l_searchlist.r_list[--i]->l_global = 1; |
| |
| /* Remove _dl_rtld_map from the chain. */ |
| GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next; |
| if (GL(dl_rtld_map).l_next != NULL) |
| GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev; |
| |
| for (i = 1; i < main_map->l_searchlist.r_nlist; ++i) |
| if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map)) |
| break; |
| |
| bool rtld_multiple_ref = false; |
| if (__glibc_likely (i < main_map->l_searchlist.r_nlist)) |
| { |
| /* Some DT_NEEDED entry referred to the interpreter object itself, so |
| put it back in the list of visible objects. We insert it into the |
| chain in symbol search order because gdb uses the chain's order as |
| its symbol search order. */ |
| rtld_multiple_ref = true; |
| |
| GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1]; |
| if (__builtin_expect (mode, normal) == normal) |
| { |
| GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist |
| ? main_map->l_searchlist.r_list[i + 1] |
| : NULL); |
| #ifdef NEED_DL_SYSINFO_DSO |
| if (GLRO(dl_sysinfo_map) != NULL |
| && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map) |
| && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map)) |
| GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map); |
| #endif |
| } |
| else |
| /* In trace mode there might be an invisible object (which we |
| could not find) after the previous one in the search list. |
| In this case it doesn't matter much where we put the |
| interpreter object, so we just initialize the list pointer so |
| that the assertion below holds. */ |
| GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next; |
| |
| assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next); |
| GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map); |
| if (GL(dl_rtld_map).l_next != NULL) |
| { |
| assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev); |
| GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map); |
| } |
| } |
| |
| /* Now let us see whether all libraries are available in the |
| versions we need. */ |
| { |
| struct version_check_args args; |
| args.doexit = mode == normal; |
| args.dotrace = mode == trace; |
| _dl_receive_error (print_missing_version, version_check_doit, &args); |
| } |
| |
| /* We do not initialize any of the TLS functionality unless any of the |
| initial modules uses TLS. This makes dynamic loading of modules with |
| TLS impossible, but to support it requires either eagerly doing setup |
| now or lazily doing it later. Doing it now makes us incompatible with |
| an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever |
| used. Trying to do it lazily is too hairy to try when there could be |
| multiple threads (from a non-TLS-using libpthread). */ |
| bool was_tls_init_tp_called = tls_init_tp_called; |
| if (tcbp == NULL) |
| tcbp = init_tls (); |
| |
| if (__glibc_likely (need_security_init)) |
| /* Initialize security features. But only if we have not done it |
| earlier. */ |
| security_init (); |
| |
| if (__builtin_expect (mode, normal) != normal) |
| { |
| /* We were run just to list the shared libraries. It is |
| important that we do this before real relocation, because the |
| functions we call below for output may no longer work properly |
| after relocation. */ |
| struct link_map *l; |
| |
| if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) |
| { |
| struct r_scope_elem *scope = &main_map->l_searchlist; |
| |
| for (i = 0; i < scope->r_nlist; i++) |
| { |
| l = scope->r_list [i]; |
| if (l->l_faked) |
| { |
| _dl_printf ("\t%s => not found\n", l->l_libname->name); |
| continue; |
| } |
| if (_dl_name_match_p (GLRO(dl_trace_prelink), l)) |
| GLRO(dl_trace_prelink_map) = l; |
| _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)", |
| DSO_FILENAME (l->l_libname->name), |
| DSO_FILENAME (l->l_name), |
| (int) sizeof l->l_map_start * 2, |
| (size_t) l->l_map_start, |
| (int) sizeof l->l_addr * 2, |
| (size_t) l->l_addr); |
| |
| if (l->l_tls_modid) |
| _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid, |
| (int) sizeof l->l_tls_offset * 2, |
| (size_t) l->l_tls_offset); |
| else |
| _dl_printf ("\n"); |
| } |
| } |
| else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) |
| { |
| /* Look through the dependencies of the main executable |
| and determine which of them is not actually |
| required. */ |
| struct link_map *l = main_map; |
| |
| /* Relocate the main executable. */ |
| struct relocate_args args = { .l = l, |
| .reloc_mode = ((GLRO(dl_lazy) |
| ? RTLD_LAZY : 0) |
| | __RTLD_NOIFUNC) }; |
| _dl_receive_error (print_unresolved, relocate_doit, &args); |
| |
| /* This loop depends on the dependencies of the executable to |
| correspond in number and order to the DT_NEEDED entries. */ |
| ElfW(Dyn) *dyn = main_map->l_ld; |
| bool first = true; |
| while (dyn->d_tag != DT_NULL) |
| { |
| if (dyn->d_tag == DT_NEEDED) |
| { |
| l = l->l_next; |
| #ifdef NEED_DL_SYSINFO_DSO |
| /* Skip the VDSO since it's not part of the list |
| of objects we brought in via DT_NEEDED entries. */ |
| if (l == GLRO(dl_sysinfo_map)) |
| l = l->l_next; |
| #endif |
| if (!l->l_used) |
| { |
| if (first) |
| { |
| _dl_printf ("Unused direct dependencies:\n"); |
| first = false; |
| } |
| |
| _dl_printf ("\t%s\n", l->l_name); |
| } |
| } |
| |
| ++dyn; |
| } |
| |
| _exit (first != true); |
| } |
| else if (! main_map->l_info[DT_NEEDED]) |
| _dl_printf ("\tstatically linked\n"); |
| else |
| { |
| for (l = main_map->l_next; l; l = l->l_next) |
| if (l->l_faked) |
| /* The library was not found. */ |
| _dl_printf ("\t%s => not found\n", l->l_libname->name); |
| else if (strcmp (l->l_libname->name, l->l_name) == 0) |
| _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name, |
| (int) sizeof l->l_map_start * 2, |
| (size_t) l->l_map_start); |
| else |
| _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name, |
| l->l_name, (int) sizeof l->l_map_start * 2, |
| (size_t) l->l_map_start); |
| } |
| |
| if (__builtin_expect (mode, trace) != trace) |
| for (i = 1; i < (unsigned int) _dl_argc; ++i) |
| { |
| const ElfW(Sym) *ref = NULL; |
| ElfW(Addr) loadbase; |
| lookup_t result; |
| |
| result = _dl_lookup_symbol_x (_dl_argv[i], main_map, |
| &ref, main_map->l_scope, |
| NULL, ELF_RTYPE_CLASS_PLT, |
| DL_LOOKUP_ADD_DEPENDENCY, NULL); |
| |
| loadbase = LOOKUP_VALUE_ADDRESS (result); |
| |
| _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n", |
| _dl_argv[i], |
| (int) sizeof ref->st_value * 2, |
| (size_t) ref->st_value, |
| (int) sizeof loadbase * 2, (size_t) loadbase); |
| } |
| else |
| { |
| /* If LD_WARN is set, warn about undefined symbols. */ |
| if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose)) |
| { |
| /* We have to do symbol dependency testing. */ |
| struct relocate_args args; |
| unsigned int i; |
| |
| args.reloc_mode = ((GLRO(dl_lazy) ? RTLD_LAZY : 0) |
| | __RTLD_NOIFUNC); |
| |
| i = main_map->l_searchlist.r_nlist; |
| while (i-- > 0) |
| { |
| struct link_map *l = main_map->l_initfini[i]; |
| if (l != &GL(dl_rtld_map) && ! l->l_faked) |
| { |
| args.l = l; |
| _dl_receive_error (print_unresolved, relocate_doit, |
| &args); |
| } |
| } |
| |
| if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) |
| && rtld_multiple_ref) |
| { |
| /* Mark the link map as not yet relocated again. */ |
| GL(dl_rtld_map).l_relocated = 0; |
| _dl_relocate_object (&GL(dl_rtld_map), |
| main_map->l_scope, __RTLD_NOIFUNC, 0); |
| } |
| } |
| #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED)) |
| if (version_info) |
| { |
| /* Print more information. This means here, print information |
| about the versions needed. */ |
| int first = 1; |
| struct link_map *map; |
| |
| for (map = main_map; map != NULL; map = map->l_next) |
| { |
| const char *strtab; |
| ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG]; |
| ElfW(Verneed) *ent; |
| |
| if (dyn == NULL) |
| continue; |
| |
| strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); |
| ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); |
| |
| if (first) |
| { |
| _dl_printf ("\n\tVersion information:\n"); |
| first = 0; |
| } |
| |
| _dl_printf ("\t%s:\n", DSO_FILENAME (map->l_name)); |
| |
| while (1) |
| { |
| ElfW(Vernaux) *aux; |
| struct link_map *needed; |
| |
| needed = find_needed (strtab + ent->vn_file); |
| aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); |
| |
| while (1) |
| { |
| const char *fname = NULL; |
| |
| if (needed != NULL |
| && match_version (strtab + aux->vna_name, |
| needed)) |
| fname = needed->l_name; |
| |
| _dl_printf ("\t\t%s (%s) %s=> %s\n", |
| strtab + ent->vn_file, |
| strtab + aux->vna_name, |
| aux->vna_flags & VER_FLG_WEAK |
| ? "[WEAK] " : "", |
| fname ?: "not found"); |
| |
| if (aux->vna_next == 0) |
| /* No more symbols. */ |
| break; |
| |
| /* Next symbol. */ |
| aux = (ElfW(Vernaux) *) ((char *) aux |
| + aux->vna_next); |
| } |
| |
| if (ent->vn_next == 0) |
| /* No more dependencies. */ |
| break; |
| |
| /* Next dependency. */ |
| ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); |
| } |
| } |
| } |
| } |
| |
| _exit (0); |
| } |
| |
| if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)] |
| && ! __builtin_expect (GLRO(dl_profile) != NULL, 0) |
| && ! __builtin_expect (GLRO(dl_dynamic_weak), 0)) |
| { |
| ElfW(Lib) *liblist, *liblistend; |
| struct link_map **r_list, **r_listend, *l; |
| const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]); |
| |
| assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL); |
| liblist = (ElfW(Lib) *) |
| main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr; |
| liblistend = (ElfW(Lib) *) |
| ((char *) liblist + |
| main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val); |
| r_list = main_map->l_searchlist.r_list; |
| r_listend = r_list + main_map->l_searchlist.r_nlist; |
| |
| for (; r_list < r_listend && liblist < liblistend; r_list++) |
| { |
| l = *r_list; |
| |
| if (l == main_map) |
| continue; |
| |
| /* If the library is not mapped where it should, fail. */ |
| if (l->l_addr) |
| break; |
| |
| /* Next, check if checksum matches. */ |
| if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL |
| || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val |
| != liblist->l_checksum) |
| break; |
| |
| if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL |
| || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val |
| != liblist->l_time_stamp) |
| break; |
| |
| if (! _dl_name_match_p (strtab + liblist->l_name, l)) |
| break; |
| |
| ++liblist; |
| } |
| |
| |
| if (r_list == r_listend && liblist == liblistend) |
| prelinked = true; |
| |
| if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)) |
| _dl_debug_printf ("\nprelink checking: %s\n", |
| prelinked ? "ok" : "failed"); |
| } |
| |
| |
| /* Now set up the variable which helps the assembler startup code. */ |
| GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist; |
| |
| /* Save the information about the original global scope list since |
| we need it in the memory handling later. */ |
| GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist; |
| |
| /* Remember the last search directory added at startup, now that |
| malloc will no longer be the one from dl-minimal.c. As a side |
| effect, this marks ld.so as initialized, so that the rtld_active |
| function returns true from now on. */ |
| GLRO(dl_init_all_dirs) = GL(dl_all_dirs); |
| |
| /* Print scope information. */ |
| if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES)) |
| { |
| _dl_debug_printf ("\nInitial object scopes\n"); |
| |
| for (struct link_map *l = main_map; l != NULL; l = l->l_next) |
| _dl_show_scope (l, 0); |
| } |
| |
| if (prelinked) |
| { |
| if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL) |
| { |
| ElfW(Rela) *conflict, *conflictend; |
| #ifndef HP_TIMING_NONAVAIL |
| hp_timing_t start; |
| hp_timing_t stop; |
| #endif |
| |
| HP_TIMING_NOW (start); |
| assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL); |
| conflict = (ElfW(Rela) *) |
| main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr; |
| conflictend = (ElfW(Rela) *) |
| ((char *) conflict |
| + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val); |
| _dl_resolve_conflicts (main_map, conflict, conflictend); |
| HP_TIMING_NOW (stop); |
| HP_TIMING_DIFF (relocate_time, start, stop); |
| } |
| |
| |
| /* Mark all the objects so we know they have been already relocated. */ |
| for (struct link_map *l = main_map; l != NULL; l = l->l_next) |
| { |
| l->l_relocated = 1; |
| if (l->l_relro_size) |
| _dl_protect_relro (l); |
| |
| /* Add object to slot information data if necessasy. */ |
| if (l->l_tls_blocksize != 0 && tls_init_tp_called) |
| _dl_add_to_slotinfo (l); |
| } |
| } |
| else |
| { |
| /* Now we have all the objects loaded. Relocate them all except for |
| the dynamic linker itself. We do this in reverse order so that copy |
| relocs of earlier objects overwrite the data written by later |
| objects. We do not re-relocate the dynamic linker itself in this |
| loop because that could result in the GOT entries for functions we |
| call being changed, and that would break us. It is safe to relocate |
| the dynamic linker out of order because it has no copy relocs (we |
| know that because it is self-contained). */ |
| |
| int consider_profiling = GLRO(dl_profile) != NULL; |
| #ifndef HP_TIMING_NONAVAIL |
| hp_timing_t start; |
| hp_timing_t stop; |
| #endif |
| |
| /* If we are profiling we also must do lazy reloaction. */ |
| GLRO(dl_lazy) |= consider_profiling; |
| |
| HP_TIMING_NOW (start); |
| unsigned i = main_map->l_searchlist.r_nlist; |
| while (i-- > 0) |
| { |
| struct link_map *l = main_map->l_initfini[i]; |
| |
| /* While we are at it, help the memory handling a bit. We have to |
| mark some data structures as allocated with the fake malloc() |
| implementation in ld.so. */ |
| struct libname_list *lnp = l->l_libname->next; |
| |
| while (__builtin_expect (lnp != NULL, 0)) |
| { |
| lnp->dont_free = 1; |
| lnp = lnp->next; |
| } |
| /* Also allocated with the fake malloc(). */ |
| l->l_free_initfini = 0; |
| |
| if (l != &GL(dl_rtld_map)) |
| _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0, |
| consider_profiling); |
| |
| /* Add object to slot information data if necessasy. */ |
| if (l->l_tls_blocksize != 0 && tls_init_tp_called) |
| _dl_add_to_slotinfo (l); |
| } |
| HP_TIMING_NOW (stop); |
| |
| HP_TIMING_DIFF (relocate_time, start, stop); |
| |
| /* Now enable profiling if needed. Like the previous call, |
| this has to go here because the calls it makes should use the |
| rtld versions of the functions (particularly calloc()), but it |
| needs to have _dl_profile_map set up by the relocator. */ |
| if (__glibc_unlikely (GL(dl_profile_map) != NULL)) |
| /* We must prepare the profiling. */ |
| _dl_start_profile (); |
| } |
| |
| if ((!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0) |
| || count_modids != _dl_count_modids ()) |
| ++GL(dl_tls_generation); |
| |
| /* Now that we have completed relocation, the initializer data |
| for the TLS blocks has its final values and we can copy them |
| into the main thread's TLS area, which we allocated above. |
| Note: thread-local variables must only be accessed after completing |
| the next step. */ |
| _dl_allocate_tls_init (tcbp); |
| |
| /* And finally install it for the main thread. */ |
| if (! tls_init_tp_called) |
| { |
| const char *lossage = TLS_INIT_TP (tcbp); |
| if (__glibc_unlikely (lossage != NULL)) |
| _dl_fatal_printf ("cannot set up thread-local storage: %s\n", |
| lossage); |
| } |
| |
| /* Make sure no new search directories have been added. */ |
| assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs)); |
| |
| if (! prelinked && rtld_multiple_ref) |
| { |
| /* There was an explicit ref to the dynamic linker as a shared lib. |
| Re-relocate ourselves with user-controlled symbol definitions. |
| |
| We must do this after TLS initialization in case after this |
| re-relocation, we might call a user-supplied function |
| (e.g. calloc from _dl_relocate_object) that uses TLS data. */ |
| |
| #ifndef HP_TIMING_NONAVAIL |
| hp_timing_t start; |
| hp_timing_t stop; |
| hp_timing_t add; |
| #endif |
| |
| HP_TIMING_NOW (start); |
| /* Mark the link map as not yet relocated again. */ |
| GL(dl_rtld_map).l_relocated = 0; |
| _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0); |
| HP_TIMING_NOW (stop); |
| HP_TIMING_DIFF (add, start, stop); |
| HP_TIMING_ACCUM_NT (relocate_time, add); |
| } |
| |
| /* Do any necessary cleanups for the startup OS interface code. |
| We do these now so that no calls are made after rtld re-relocation |
| which might be resolved to different functions than we expect. |
| We cannot do this before relocating the other objects because |
| _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */ |
| _dl_sysdep_start_cleanup (); |
| |
| #ifdef SHARED |
| /* Auditing checkpoint: we have added all objects. */ |
| if (__glibc_unlikely (GLRO(dl_naudit) > 0)) |
| { |
| struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded; |
| /* Do not call the functions for any auditing object. */ |
| if (head->l_auditing == 0) |
| { |
| struct audit_ifaces *afct = GLRO(dl_audit); |
| for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) |
| { |
| if (afct->activity != NULL) |
| afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT); |
| |
| afct = afct->next; |
| } |
| } |
| } |
| #endif |
| |
| /* Notify the debugger all new objects are now ready to go. We must re-get |
| the address since by now the variable might be in another object. */ |
| r = _dl_debug_initialize (0, LM_ID_BASE); |
| r->r_state = RT_CONSISTENT; |
| _dl_debug_state (); |
| LIBC_PROBE (init_complete, 2, LM_ID_BASE, r); |
| |
| #if defined USE_LDCONFIG && !defined MAP_COPY |
| /* We must munmap() the cache file. */ |
| _dl_unload_cache (); |
| #endif |
| |
| /* Once we return, _dl_sysdep_start will invoke |
| the DT_INIT functions and then *USER_ENTRY. */ |
| } |
| |
| /* This is a little helper function for resolving symbols while |
| tracing the binary. */ |
| static void |
| print_unresolved (int errcode __attribute__ ((unused)), const char *objname, |
| const char *errstring) |
| { |
| if (objname[0] == '\0') |
| objname = RTLD_PROGNAME; |
| _dl_error_printf ("%s (%s)\n", errstring, objname); |
| } |
| |
| /* This is a little helper function for resolving symbols while |
| tracing the binary. */ |
| static void |
| print_missing_version (int errcode __attribute__ ((unused)), |
| const char *objname, const char *errstring) |
| { |
| _dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME, |
| objname, errstring); |
| } |
| |
| /* Nonzero if any of the debugging options is enabled. */ |
| static int any_debug attribute_relro; |
| |
| /* Process the string given as the parameter which explains which debugging |
| options are enabled. */ |
| static void |
| process_dl_debug (const char *dl_debug) |
| { |
| /* When adding new entries make sure that the maximal length of a name |
| is correctly handled in the LD_DEBUG_HELP code below. */ |
| static const struct |
| { |
| unsigned char len; |
| const char name[10]; |
| const char helptext[41]; |
| unsigned short int mask; |
| } debopts[] = |
| { |
| #define LEN_AND_STR(str) sizeof (str) - 1, str |
| { LEN_AND_STR ("libs"), "display library search paths", |
| DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS }, |
| { LEN_AND_STR ("reloc"), "display relocation processing", |
| DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS }, |
| { LEN_AND_STR ("files"), "display progress for input file", |
| DL_DEBUG_FILES | DL_DEBUG_IMPCALLS }, |
| { LEN_AND_STR ("symbols"), "display symbol table processing", |
| DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS }, |
| { LEN_AND_STR ("bindings"), "display information about symbol binding", |
| DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS }, |
| { LEN_AND_STR ("versions"), "display version dependencies", |
| DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS }, |
| { LEN_AND_STR ("scopes"), "display scope information", |
| DL_DEBUG_SCOPES }, |
| { LEN_AND_STR ("tls"), "display thread-local storage processing", |
| DL_DEBUG_TLS }, |
| { LEN_AND_STR ("fastload"), "display fastload information", |
| DL_DEBUG_FASTLOAD }, |
| { LEN_AND_STR ("all"), "all previous options combined", |
| DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS |
| | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS |
| | DL_DEBUG_SCOPES | DL_DEBUG_FASTLOAD }, |
| { LEN_AND_STR ("statistics"), "display relocation statistics", |
| DL_DEBUG_STATISTICS }, |
| { LEN_AND_STR ("unused"), "determined unused DSOs", |
| DL_DEBUG_UNUSED }, |
| { LEN_AND_STR ("help"), "display this help message and exit", |
| DL_DEBUG_HELP }, |
| }; |
| #define ndebopts (sizeof (debopts) / sizeof (debopts[0])) |
| |
| /* Skip separating white spaces and commas. */ |
| while (*dl_debug != '\0') |
| { |
| if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':') |
| { |
| size_t cnt; |
| size_t len = 1; |
| |
| while (dl_debug[len] != '\0' && dl_debug[len] != ' ' |
| && dl_debug[len] != ',' && dl_debug[len] != ':') |
| ++len; |
| |
| for (cnt = 0; cnt < ndebopts; ++cnt) |
| if (debopts[cnt].len == len |
| && memcmp (dl_debug, debopts[cnt].name, len) == 0) |
| { |
| GLRO(dl_debug_mask) |= debopts[cnt].mask; |
| any_debug = 1; |
| break; |
| } |
| |
| if (cnt == ndebopts) |
| { |
| /* Display a warning and skip everything until next |
| separator. */ |
| char *copy = strndupa (dl_debug, len); |
| _dl_error_printf ("\ |
| warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy); |
| } |
| |
| dl_debug += len; |
| continue; |
| } |
| |
| ++dl_debug; |
| } |
| |
| if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) |
| { |
| /* In order to get an accurate picture of whether a particular |
| DT_NEEDED entry is actually used we have to process both |
| the PLT and non-PLT relocation entries. */ |
| GLRO(dl_lazy) = 0; |
| } |
| |
| if (GLRO(dl_debug_mask) & DL_DEBUG_HELP) |
| { |
| size_t cnt; |
| |
| _dl_printf ("\ |
| Valid options for the LD_DEBUG environment variable are:\n\n"); |
| |
| for (cnt = 0; cnt < ndebopts; ++cnt) |
| _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name, |
| " " + debopts[cnt].len - 3, |
| debopts[cnt].helptext); |
| |
| _dl_printf ("\n\ |
| To direct the debugging output into a file instead of standard output\n\ |
| a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n"); |
| _exit (0); |
| } |
| } |
| |
| static void |
| process_dl_audit (char *str) |
| { |
| /* The parameter is a colon separated list of DSO names. */ |
| char *p; |
| |
| while ((p = (strsep) (&str, ":")) != NULL) |
| if (dso_name_valid_for_suid (p)) |
| { |
| /* This is using the local malloc, not the system malloc. The |
| memory can never be freed. */ |
| struct audit_list *newp = malloc (sizeof (*newp)); |
| newp->name = p; |
| |
| if (audit_list == NULL) |
| audit_list = newp->next = newp; |
| else |
| { |
| newp->next = audit_list->next; |
| audit_list = audit_list->next = newp; |
| } |
| } |
| } |
| |
| /* Process all environments variables the dynamic linker must recognize. |
| Since all of them start with `LD_' we are a bit smarter while finding |
| all the entries. */ |
| extern char **_environ attribute_hidden; |
| |
| |
| static void |
| process_envvars (enum mode *modep) |
| { |
| char **runp = _environ; |
| char *envline; |
| enum mode mode = normal; |
| char *debug_output = NULL; |
| |
| /* Enable async-signal-safe TLS by default. */ |
| GLRO(dl_async_signal_safe) = 1; |
| |
| /* This is the default place for profiling data file. */ |
| GLRO(dl_profile_output) |
| = &"/var/tmp\0/var/profile"[__libc_enable_secure ? 9 : 0]; |
| |
| while ((envline = _dl_next_ld_env_entry (&runp)) != NULL) |
| { |
| size_t len = 0; |
| |
| while (envline[len] != '\0' && envline[len] != '=') |
| ++len; |
| |
| if (envline[len] != '=') |
| /* This is a "LD_" variable at the end of the string without |
| a '=' character. Ignore it since otherwise we will access |
| invalid memory below. */ |
| continue; |
| |
| switch (len) |
| { |
| case 4: |
| /* Warning level, verbose or not. */ |
| if (memcmp (envline, "WARN", 4) == 0) |
| GLRO(dl_verbose) = envline[5] != '\0'; |
| #if 0 /* enable to get runtime control over async signal safety */ |
| if (memcmp (envline, "SAFE", 4) == 0) |
| GLRO(dl_async_signal_safe) = 1; |
| #endif |
| break; |
| |
| case 5: |
| /* Debugging of the dynamic linker? */ |
| if (memcmp (envline, "DEBUG", 5) == 0) |
| { |
| process_dl_debug (&envline[6]); |
| break; |
| } |
| if (memcmp (envline, "AUDIT", 5) == 0) |
| audit_list_string = &envline[6]; |
| break; |
| #if 0 /* enable to get runtime control over async signal safety */ |
| case 6: |
| if (memcmp (envline, "UNSAFE", 6) == 0) |
| GLRO(dl_async_signal_safe) = 0; |
| break; |
| #endif |
| case 7: |
| /* Print information about versions. */ |
| if (memcmp (envline, "VERBOSE", 7) == 0) |
| { |
| version_info = envline[8] != '\0'; |
| break; |
| } |
| |
| /* List of objects to be preloaded. */ |
| if (memcmp (envline, "PRELOAD", 7) == 0) |
| { |
| preloadlist = &envline[8]; |
| break; |
| } |
| |
| /* Which shared object shall be profiled. */ |
| if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0') |
| GLRO(dl_profile) = &envline[8]; |
| break; |
| |
| case 8: |
| /* Do we bind early? */ |
| if (memcmp (envline, "BIND_NOW", 8) == 0) |
| { |
| GLRO(dl_lazy) = envline[9] == '\0'; |
| break; |
| } |
| if (memcmp (envline, "BIND_NOT", 8) == 0) |
| GLRO(dl_bind_not) = envline[9] != '\0'; |
| break; |
| |
| case 9: |
| /* Test whether we want to see the content of the auxiliary |
| array passed up from the kernel. */ |
| if (!__libc_enable_secure |
| && memcmp (envline, "SHOW_AUXV", 9) == 0) |
| _dl_show_auxv (); |
| break; |
| |
| #if !HAVE_TUNABLES |
| case 10: |
| /* Mask for the important hardware capabilities. */ |
| if (!__libc_enable_secure |
| && memcmp (envline, "HWCAP_MASK", 10) == 0) |
| GLRO(dl_hwcap_mask) = _dl_strtoul (&envline[11], NULL); |
| break; |
| #endif |
| |
| case 11: |
| /* Path where the binary is found. */ |
| if (!__libc_enable_secure |
| && memcmp (envline, "ORIGIN_PATH", 11) == 0) |
| GLRO(dl_origin_path) = &envline[12]; |
| break; |
| |
| case 12: |
| /* The library search path. */ |
| if (!__libc_enable_secure |
| && memcmp (envline, "LIBRARY_PATH", 12) == 0) |
| { |
| library_path = &envline[13]; |
| break; |
| } |
| |
| /* Where to place the profiling data file. */ |
| if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0) |
| { |
| debug_output = &envline[13]; |
| break; |
| } |
| |
| if (!__libc_enable_secure |
| && memcmp (envline, "DYNAMIC_WEAK", 12) == 0) |
| GLRO(dl_dynamic_weak) = 1; |
| break; |
| |
| case 13: |
| /* We might have some extra environment variable with length 13 |
| to handle. */ |
| #ifdef EXTRA_LD_ENVVARS_13 |
| EXTRA_LD_ENVVARS_13 |
| #endif |
| if (!__libc_enable_secure |
| && memcmp (envline, "USE_LOAD_BIAS", 13) == 0) |
| { |
| GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0; |
| break; |
| } |
| break; |
| |
| case 14: |
| /* Where to place the profiling data file. */ |
| if (!__libc_enable_secure |
| && memcmp (envline, "PROFILE_OUTPUT", 14) == 0 |
| && envline[15] != '\0') |
| GLRO(dl_profile_output) = &envline[15]; |
| break; |
| |
| case 16: |
| /* The mode of the dynamic linker can be set. */ |
| if (memcmp (envline, "TRACE_PRELINKING", 16) == 0) |
| { |
| mode = trace; |
| GLRO(dl_verbose) = 1; |
| GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK; |
| GLRO(dl_trace_prelink) = &envline[17]; |
| } |
| break; |
| |
| case 20: |
| /* The mode of the dynamic linker can be set. */ |
| if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0) |
| mode = trace; |
| break; |
| |
| /* We might have some extra environment variable to handle. This |
| is tricky due to the pre-processing of the length of the name |
| in the switch statement here. The code here assumes that added |
| environment variables have a different length. */ |
| #ifdef EXTRA_LD_ENVVARS |
| EXTRA_LD_ENVVARS |
| #endif |
| } |
| |
| /* Handle all fastload-related env vars here. This may duplicate |
| effort with the switch table above, but it localizes changes |
| made by the fastload patch. On Linux, the '15' case is used |
| by another environment variable (LIBRARY_VERSION) and much |
| change would be needed to add support adding a variable of |
| that length with the existing style. */ |
| switch (len) |
| { |
| case 15: |
| if (memcmp (envline, "FASTLOAD_CUTOFF", 15) == 0) |
| GLRO(dl_position_hash_cutoff) |
| = _dl_strtoul (&envline[16], NULL);; |
| break; |
| } |
| } |
| |
| /* The caller wants this information. */ |
| *modep = mode; |
| |
| #if 0 /* enable this to help debug async-safe TLS */ |
| if (GLRO(dl_debug_mask)) |
| { |
| if (GLRO(dl_async_signal_safe)) |
| _dl_printf ("TLS is async-signal-safe\n"); |
| else |
| _dl_printf ("TLS is NOT async-signal-safe\n"); |
| } |
| #endif /* for async-safe TLS */ |
| |
| /* Extra security for SUID binaries. Remove all dangerous environment |
| variables. */ |
| if (__builtin_expect (__libc_enable_secure, 0)) |
| { |
| static const char unsecure_envvars[] = |
| #ifdef EXTRA_UNSECURE_ENVVARS |
| EXTRA_UNSECURE_ENVVARS |
| #endif |
| UNSECURE_ENVVARS; |
| const char *nextp; |
| |
| nextp = unsecure_envvars; |
| do |
| { |
| unsetenv (nextp); |
| /* We could use rawmemchr but this need not be fast. */ |
| nextp = (char *) (strchr) (nextp, '\0') + 1; |
| } |
| while (*nextp != '\0'); |
| |
| if (__access ("/etc/suid-debug", F_OK) != 0) |
| { |
| #if !HAVE_TUNABLES |
| unsetenv ("MALLOC_CHECK_"); |
| #endif |
| GLRO(dl_debug_mask) = 0; |
| } |
| |
| if (mode != normal) |
| _exit (5); |
| } |
| /* If we have to run the dynamic linker in debugging mode and the |
| LD_DEBUG_OUTPUT environment variable is given, we write the debug |
| messages to this file. */ |
| else if (any_debug && debug_output != NULL) |
| { |
| const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW; |
| size_t name_len = strlen (debug_output); |
| char buf[name_len + 12]; |
| char *startp; |
| |
| buf[name_len + 11] = '\0'; |
| startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0); |
| *--startp = '.'; |
| startp = memcpy (startp - name_len, debug_output, name_len); |
| |
| GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE); |
| if (GLRO(dl_debug_fd) == -1) |
| /* We use standard output if opening the file failed. */ |
| GLRO(dl_debug_fd) = STDOUT_FILENO; |
| } |
| } |
| |
| |
| /* Print the various times we collected. */ |
| static void |
| __attribute ((noinline)) |
| print_statistics (hp_timing_t *rtld_total_timep) |
| { |
| #ifndef HP_TIMING_NONAVAIL |
| char buf[200]; |
| char *cp; |
| char *wp; |
| |
| /* Total time rtld used. */ |
| if (HP_SMALL_TIMING_AVAIL) |
| { |
| HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep); |
| _dl_debug_printf ("\nruntime linker statistics:\n" |
| " total startup time in dynamic loader: %s\n", buf); |
| |
| /* Print relocation statistics. */ |
| char pbuf[30]; |
| HP_TIMING_PRINT (buf, sizeof (buf), relocate_time); |
| cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep, |
| pbuf + sizeof (pbuf), 10, 0); |
| wp = pbuf; |
| switch (pbuf + sizeof (pbuf) - cp) |
| { |
| case 3: |
| *wp++ = *cp++; |
| case 2: |
| *wp++ = *cp++; |
| case 1: |
| *wp++ = '.'; |
| *wp++ = *cp++; |
| } |
| *wp = '\0'; |
| _dl_debug_printf ("\ |
| time needed for relocation: %s (%s%%)\n", buf, pbuf); |
| } |
| #endif |
| |
| unsigned long int num_relative_relocations = 0; |
| for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns) |
| { |
| if (GL(dl_ns)[ns]._ns_loaded == NULL) |
| continue; |
| |
| struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist; |
| |
| for (unsigned int i = 0; i < scope->r_nlist; i++) |
| { |
| struct link_map *l = scope->r_list [i]; |
| |
| if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)]) |
| num_relative_relocations |
| += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val; |
| #ifndef ELF_MACHINE_REL_RELATIVE |
| /* Relative relocations are processed on these architectures if |
| library is loaded to different address than p_vaddr or |
| if not prelinked. */ |
| if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)]) |
| && l->l_info[VERSYMIDX (DT_RELACOUNT)]) |
| #else |
| /* On e.g. IA-64 or Alpha, relative relocations are processed |
| only if library is loaded to different address than p_vaddr. */ |
| if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)]) |
| #endif |
| num_relative_relocations |
| += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val; |
| } |
| } |
| |
| _dl_debug_printf (" number of relocations: %lu\n" |
| " number of relocations from cache: %lu\n" |
| " number of relative relocations: %lu\n", |
| GL(dl_num_relocations), |
| GL(dl_num_cache_relocations), |
| num_relative_relocations); |
| |
| #ifndef HP_TIMING_NONAVAIL |
| /* Time spend while loading the object and the dependencies. */ |
| if (HP_SMALL_TIMING_AVAIL) |
| { |
| char pbuf[30]; |
| HP_TIMING_PRINT (buf, sizeof (buf), load_time); |
| cp = _itoa ((1000ULL * load_time) / *rtld_total_timep, |
| pbuf + sizeof (pbuf), 10, 0); |
| wp = pbuf; |
| switch (pbuf + sizeof (pbuf) - cp) |
| { |
| case 3: |
| *wp++ = *cp++; |
| case 2: |
| *wp++ = *cp++; |
| case 1: |
| *wp++ = '.'; |
| *wp++ = *cp++; |
| } |
| *wp = '\0'; |
| _dl_debug_printf ("\ |
| time needed to load objects: %s (%s%%)\n", |
| buf, pbuf); |
| } |
| #endif |
| } |
| |
| /* Given file path, return an absolute directory path. |
| Examples: in: "/foo/bar/a.out", out: "/foo/bar/"; |
| in: "./a.out", out: "/dot/resolved/to/full/path/./". */ |
| static char * |
| get_directory (const char *file_path) |
| { |
| assert (file_path != NULL); |
| |
| /* Find the end of the directory substring in file_path. */ |
| size_t path_len = strlen (file_path); |
| while (path_len > 0 && file_path[path_len - 1] != '/') |
| --path_len; |
| |
| /* Allocate space and set the path prefix according to whether or not |
| this is an absolute path. */ |
| char *dest; |
| char *full_dir_path; |
| if (file_path[0] == '/') |
| { |
| full_dir_path = malloc (path_len + 1); |
| assert (full_dir_path != NULL); |
| dest = full_dir_path; |
| } |
| else |
| { |
| /* For a relative path, we need to include space for the largest |
| possible current path, a joining '/', the relevant part of |
| file_path, and a trailing '\0'. */ |
| full_dir_path = malloc (PATH_MAX + path_len + 2); |
| assert (full_dir_path != NULL); |
| |
| char *status = __getcwd (full_dir_path, PATH_MAX); |
| assert (status != NULL); |
| |
| dest = __rawmemchr (full_dir_path, '\0'); |
| if (dest[-1] != '/') |
| *dest++ = '/'; |
| } |
| |
| if (path_len > 0) |
| dest = __mempcpy (dest, file_path, path_len); |
| *dest = '\0'; |
| |
| return full_dir_path; |
| } |
| |
| /* Set GLRO(google_exec_origin_dir). */ |
| static void |
| set_exec_origin_dir (const char *exe_path) |
| { |
| assert (GLRO(google_exec_origin_dir) == NULL); |
| |
| if (GLRO(dl_origin_path) != NULL) |
| GLRO(google_exec_origin_dir) = strdup (GLRO(dl_origin_path)); |
| else if (exe_path != NULL) |
| GLRO(google_exec_origin_dir) = get_directory (exe_path); |
| } |
| |
| /* Iterate over auxv, find AT_EXECFN if any. */ |
| static char * |
| get_at_execfn (ElfW(auxv_t) *auxv) |
| { |
| assert (auxv != NULL); |
| |
| for (; auxv->a_type != AT_NULL; ++auxv) |
| if (auxv->a_type == AT_EXECFN) |
| return (char *) auxv->a_un.a_val; |
| |
| return NULL; |
| } |
| |
| #ifndef NESTING |
| char *dummy1 = (char *)elf_get_dynamic_info; |
| # if ! ELF_MACHINE_NO_REL |
| char *dummy2 = (char *)elf_machine_rel; |
| char *dummy3 = (char *)elf_machine_rel_relative; |
| #endif |
| # if ! ELF_MACHINE_NO_RELA |
| char *dummy4 = (char *)elf_machine_rela; |
| char *dummy5 = (char *)elf_machine_rela_relative; |
| #endif |
| # if ELF_MACHINE_NO_RELA || defined ELF_MACHINE_PLT_REL |
| char *dummy6 = (char *)elf_machine_lazy_rel; |
| #endif |
| #endif |