2785 lines
84 KiB
C
2785 lines
84 KiB
C
/* Run time dynamic linker.
|
||
Copyright (C) 1995-2017 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
|
||
|
||
/* 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);
|
||
|
||
#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,
|
||
#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;
|
||
}
|
||
|
||
static ElfW(Addr) __attribute_used__
|
||
_dl_start (void *arg)
|
||
{
|
||
#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 RESOLVE_MAP(sym, version, flags) (&bootstrap_map)
|
||
#include "dynamic-link.h"
|
||
|
||
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);
|
||
}
|
||
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, 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,
|
||
(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");
|
||
|
||
/* 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");
|
||
|
||
++_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, 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
|
||
{
|
||
/* 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;
|
||
++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;
|
||
|
||
/* 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;
|
||
|
||
/* 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. */
|
||
#ifdef HAVE_EHDR_START
|
||
extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden")));
|
||
rtld_ehdr = &__ehdr_start;
|
||
#else
|
||
rtld_ehdr = (void *) GL(dl_rtld_map).l_map_start;
|
||
#endif
|
||
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);
|
||
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. */
|
||
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 ("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 },
|
||
{ 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;
|
||
|
||
/* 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';
|
||
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;
|
||
|
||
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
|
||
}
|
||
}
|
||
|
||
/* The caller wants this information. */
|
||
*modep = mode;
|
||
|
||
/* 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
|
||
}
|