uclibc-ng/ldso/ldso/ldso.c

/* vi: set sw=4 ts=4: */
/*
 * Program to load an ELF binary on a linux system, and run it
 * after resolving ELF shared library symbols
 *
 * Copyright (C) 2005 by Joakim Tjernlund
 * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
 * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
 *				David Engel, Hongjiu Lu and Mitch D'Souza
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. The name of the above contributors may not be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "ldso.h"
#include "unsecvars.h"

/* Pull in common debug code */
#include "dl-debug.c"

#define ALLOW_ZERO_PLTGOT

#if defined(USE_TLS) && USE_TLS
#include "dl-tls.c"
#endif

/* Pull in the value of _dl_progname */
#include LDSO_ELFINTERP

/* Global variables used within the shared library loader */
char *_dl_library_path         = NULL;	/* Where we look for libraries */
char *_dl_preload              = NULL;	/* Things to be loaded before the libs */
char *_dl_ldsopath             = NULL;	/* Location of the shared lib loader */
int _dl_errno                  = 0;	/* We can't use the real errno in ldso */
size_t _dl_pagesize            = 0;	/* Store the page size for use later */
struct r_debug *_dl_debug_addr = NULL;	/* Used to communicate with the gdb debugger */
void *(*_dl_malloc_function) (size_t size) = NULL;
void (*_dl_free_function) (void *p) = NULL;

static int _dl_secure = 1; /* Are we dealing with setuid stuff? */

#ifdef __SUPPORT_LD_DEBUG__
char *_dl_debug           = NULL;
char *_dl_debug_symbols   = NULL;
char *_dl_debug_move      = NULL;
char *_dl_debug_reloc     = NULL;
char *_dl_debug_detail    = NULL;
char *_dl_debug_nofixups  = NULL;
char *_dl_debug_bindings  = NULL;
int   _dl_debug_file      = 2;
#endif

/* Needed for standalone execution. */
unsigned long attribute_hidden _dl_skip_args = 0;
const char *_dl_progname = UCLIBC_LDSO;      /* The name of the executable being run */
#include "dl-startup.c"
#include "dl-symbols.c"
#include "dl-array.c"

/*
 * This stub function is used by some debuggers.  The idea is that they
 * can set an internal breakpoint on it, so that we are notified when the
 * address mapping is changed in some way.
 */
void _dl_debug_state(void);
rtld_hidden_proto(_dl_debug_state, noinline);
void _dl_debug_state(void)
{
	/* Make sure GCC doesn't recognize this function as pure, to avoid
	 * having the calls optimized away.
	 */
	__asm__("");
}
rtld_hidden_def(_dl_debug_state);

static unsigned char *_dl_malloc_addr = NULL;	/* Lets _dl_malloc use the already allocated memory page */
static unsigned char *_dl_mmap_zero   = NULL;	/* Also used by _dl_malloc */

static struct elf_resolve **init_fini_list;
static unsigned int nlist; /* # items in init_fini_list */
extern void _start(void);

#ifdef __UCLIBC_HAS_SSP__
# include <dl-osinfo.h>
uintptr_t stack_chk_guard;
# ifndef THREAD_SET_STACK_GUARD
/* Only exported for architectures that don't store the stack guard canary
 * in local thread area.  */
uintptr_t __stack_chk_guard attribute_relro;
#  ifdef __UCLIBC_HAS_SSP_COMPAT__
strong_alias(__stack_chk_guard,__guard)
#  endif
# elif __UCLIBC_HAS_SSP_COMPAT__
uintptr_t __guard attribute_relro;
# endif
#endif

char *_dl_getenv(const char *symbol, char **envp)
{
	char *pnt;
	const char *pnt1;

	while ((pnt = *envp++)) {
		pnt1 = symbol;
		while (*pnt && *pnt == *pnt1)
			pnt1++, pnt++;
		if (!*pnt || *pnt != '=' || *pnt1)
			continue;
		return pnt + 1;
	}
	return 0;
}

void _dl_unsetenv(const char *symbol, char **envp)
{
	char *pnt;
	const char *pnt1;
	char **newenvp = envp;

	for (pnt = *envp; pnt; pnt = *++envp) {
		pnt1 = symbol;
		while (*pnt && *pnt == *pnt1)
			pnt1++, pnt++;
		if (!*pnt || *pnt != '=' || *pnt1)
			*newenvp++ = *envp;
	}
	*newenvp++ = *envp;
	return;
}

static int _dl_suid_ok(void)
{
	__kernel_uid_t uid, euid;
	__kernel_gid_t gid, egid;

	uid = _dl_getuid();
	euid = _dl_geteuid();
	gid = _dl_getgid();
	egid = _dl_getegid();

	if (uid == euid && gid == egid) {
		return 1;
	}
	return 0;
}

void *_dl_malloc(size_t size)
{
	void *retval;

#if 0
	_dl_debug_early("request for %d bytes\n", size);
#endif

	if (_dl_malloc_function)
		return (*_dl_malloc_function) (size);

	if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
		size_t rounded_size;

		/* Since the above assumes we get a full page even if
		   we request less than that, make sure we request a
		   full page, since uClinux may give us less than than
		   a full page.  We might round even
		   larger-than-a-page sizes, but we end up never
		   reusing _dl_mmap_zero/_dl_malloc_addr in that case,
		   so we don't do it.

		   The actual page size doesn't really matter; as long
		   as we're self-consistent here, we're safe.  */
		if (size < _dl_pagesize)
			rounded_size = (size + ADDR_ALIGN) & _dl_pagesize;
		else
			rounded_size = size;

		_dl_debug_early("mmapping more memory\n");
		_dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
				PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_UNINITIALIZE, -1, 0);
		if (_dl_mmap_check_error(_dl_mmap_zero)) {
			_dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
			_dl_exit(20);
		}
	}
	retval = _dl_malloc_addr;
	_dl_malloc_addr += size;

	/*
	 * Align memory to DL_MALLOC_ALIGN byte boundary.  Some
	 * platforms require this, others simply get better
	 * performance.
	 */
	_dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
	return retval;
}

static void *_dl_zalloc(size_t size)
{
	void *p = _dl_malloc(size);
	if (p)
		_dl_memset(p, 0, size);
	return p;
}

void _dl_free(void *p)
{
	if (_dl_free_function)
		(*_dl_free_function) (p);
}

#if defined(USE_TLS) && USE_TLS
void *_dl_memalign(size_t __boundary, size_t __size)
{
	void *result;
	int i = 0;
	size_t delta;
	size_t rounded = 0;

	if (_dl_memalign_function)
		return (*_dl_memalign_function) (__boundary, __size);

	while (rounded < __boundary) {
		rounded = (1 << i++);
	}

	delta = (((size_t) _dl_malloc_addr + __size) & (rounded - 1));

	if ((result = _dl_malloc(rounded - delta)) == NULL)
		return result;

	result = _dl_malloc(__size);

	return result;
}
#endif

static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
{
	unsigned int i;
	struct elf_resolve * tpnt;

	for (i = 0; i < nlist; ++i) {
		tpnt = init_fini_list[i];
		if (tpnt->init_flag & FINI_FUNCS_CALLED)
			continue;
		tpnt->init_flag |= FINI_FUNCS_CALLED;
		_dl_run_fini_array(tpnt);
		if (tpnt->dynamic_info[DT_FINI]) {
			void (*dl_elf_func) (void);

			dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
			_dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
			DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
		}
	}
}

void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
			  ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
			  char **argv
			  DL_GET_READY_TO_RUN_EXTRA_PARMS)
{
	ElfW(Addr) app_mapaddr = 0;
	ElfW(Phdr) *ppnt;
	ElfW(Dyn) *dpnt;
	char *lpntstr;
	unsigned int i;
	int unlazy = 0, trace_loaded_objects = 0;
	struct dyn_elf *rpnt;
	struct elf_resolve *tcurr;
	struct elf_resolve *tpnt1;
	struct elf_resolve app_tpnt_tmp;
	struct elf_resolve *app_tpnt = &app_tpnt_tmp;
	struct r_debug *debug_addr;
	unsigned long *lpnt;
	unsigned long *_dl_envp;		/* The environment address */
	ElfW(Addr) relro_addr = 0;
	size_t relro_size = 0;
	struct stat st;
#if defined(USE_TLS) && USE_TLS
	void *tcbp = NULL;
#endif

	/* Wahoo!!! We managed to make a function call!  Get malloc
	 * setup so we can use _dl_dprintf() to print debug noise
	 * instead of the SEND_STDERR macros used in dl-startup.c */

	_dl_memset(app_tpnt, 0, sizeof(*app_tpnt));

	/* Store the page size for later use */
	_dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
	/* Make it so _dl_malloc can use the page of memory we have already
	 * allocated.  We shouldn't need to grab any more memory.  This must
	 * be first since things like _dl_dprintf() use _dl_malloc()...
	 */
	_dl_malloc_addr = (unsigned char *)_dl_pagesize;
	_dl_mmap_zero = 0;

	/* Wahoo!!! */
	_dl_debug_early("Cool, ldso survived making function calls\n");

	/* Now we have done the mandatory linking of some things.  We are now
	 * free to start using global variables, since these things have all
	 * been fixed up by now.  Still no function calls outside of this
	 * library, since the dynamic resolver is not yet ready.
	 */
	if (argv[0]) {
		_dl_progname = argv[0];
	}

	if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
		_dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
		_dl_exit(1);
	}

	/* Start to build the tables of the modules that are required for
	 * this beast to run.  We start with the basic executable, and then
	 * go from there.  Eventually we will run across ourself, and we
	 * will need to properly deal with that as well.
	 */
	rpnt = NULL;
	if (_dl_getenv("LD_BIND_NOW", envp))
		unlazy = RTLD_NOW;

	/* Now we need to figure out what kind of options are selected.
	 * Note that for SUID programs we ignore the settings in
	 * LD_LIBRARY_PATH.
	 */
	if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
	    (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
	     auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
	     auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
		_dl_secure = 0;
		_dl_preload = _dl_getenv("LD_PRELOAD", envp);
		_dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
	} else {
		static const char unsecure_envvars[] =
#ifdef EXTRA_UNSECURE_ENVVARS
			EXTRA_UNSECURE_ENVVARS
#endif
			UNSECURE_ENVVARS;
		const char *nextp;
		_dl_secure = 1;

		nextp = unsecure_envvars;
		do {
			_dl_unsetenv (nextp, envp);
			/* We could use rawmemchr but this need not be fast.  */
			nextp = _dl_strchr(nextp, '\0') + 1;
		} while (*nextp != '\0');
		_dl_preload = NULL;
		_dl_library_path = NULL;
		/* SUID binaries can be exploited if they do LAZY relocation. */
		unlazy = RTLD_NOW;
	}

#if defined(USE_TLS) && USE_TLS
	_dl_error_catch_tsd = &_dl_initial_error_catch_tsd;
	_dl_init_static_tls = &_dl_nothread_init_static_tls;
#endif

#ifdef __UCLIBC_HAS_SSP__
	/* Set up the stack checker's canary.  */
	stack_chk_guard = _dl_setup_stack_chk_guard ();
# ifdef THREAD_SET_STACK_GUARD
	THREAD_SET_STACK_GUARD (stack_chk_guard);
#  ifdef __UCLIBC_HAS_SSP_COMPAT__
	__guard = stack_chk_guard;
#  endif
# else
	__stack_chk_guard = stack_chk_guard;
# endif
#endif

	/* At this point we are now free to examine the user application,
	 * and figure out which libraries are supposed to be called.  Until
	 * we have this list, we will not be completely ready for dynamic
	 * linking.
	 */

	/* Find the runtime load address of the main executable.  This may be
	 * different from what the ELF header says for ET_DYN/PIE executables.
	 */
	{
		unsigned int idx;
		ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;

		for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
			if (phdr->p_type == PT_PHDR) {
				DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
				break;
			}

		if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
			_dl_debug_early("Position Independent Executable: "
					"app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
	}

	/*
	 * This is used by gdb to locate the chain of shared libraries that are
	 * currently loaded.
	 */
	debug_addr = _dl_zalloc(sizeof(struct r_debug));

	ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
	for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
		if (ppnt->p_type == PT_GNU_RELRO) {
			relro_addr = ppnt->p_vaddr;
			relro_size = ppnt->p_memsz;
		}
		if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
			app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
		}
		if (ppnt->p_type == PT_DYNAMIC) {
			dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
			_dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
#ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
			/* Ugly, ugly.  We need to call mprotect to change the
			 * protection of the text pages so that we can do the
			 * dynamic linking.  We can set the protection back
			 * again once we are done.
			 */
			_dl_debug_early("calling mprotect on the application program\n");
			/* Now cover the application program. */
			if (app_tpnt->dynamic_info[DT_TEXTREL]) {
				ElfW(Phdr) *ppnt_outer = ppnt;
				ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
				for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
					if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
						_dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
							     (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & ADDR_ALIGN) +
							     (unsigned long) ppnt->p_filesz,
							     PROT_READ | PROT_WRITE | PROT_EXEC);
				}
				ppnt = ppnt_outer;
			}
#else
			if (app_tpnt->dynamic_info[DT_TEXTREL]) {
				_dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
				_dl_exit(1);
			}
#endif

#ifndef ALLOW_ZERO_PLTGOT
			/* make sure it's really there. */
			if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
				continue;
#endif
			/* OK, we have what we need - slip this one into the list. */
			app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
					app_tpnt->dynamic_info,
					(unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
					ppnt->p_filesz);
			_dl_loaded_modules->libtype = elf_executable;
			_dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
			_dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
			_dl_symbol_tables = rpnt = _dl_zalloc(sizeof(struct dyn_elf));
			rpnt->dyn = _dl_loaded_modules;
			app_tpnt->mapaddr = app_mapaddr;
			app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
			app_tpnt->usage_count++;
			app_tpnt->symbol_scope = _dl_symbol_tables;
			lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
#ifdef ALLOW_ZERO_PLTGOT
			if (lpnt)
#endif
				INIT_GOT(lpnt, _dl_loaded_modules);
		}

		/* OK, fill this in - we did not have this before */
		if (ppnt->p_type == PT_INTERP) {
			tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
#ifdef __LDSO_SEARCH_INTERP_PATH__
			{
				char *ptmp;
				/* Store the path where the shared lib loader was found
				 * for later use
				 */
				_dl_ldsopath = _dl_strdup(tpnt->libname);
				ptmp = _dl_strrchr(_dl_ldsopath, '/');
				if (ptmp != _dl_ldsopath)
					*ptmp = '\0';
			}
			_dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
#endif
		}

		/* Discover any TLS sections if the target supports them. */
		if (ppnt->p_type == PT_TLS) {
#if defined(USE_TLS) && USE_TLS
			if (ppnt->p_memsz > 0) {
				app_tpnt->l_tls_blocksize = ppnt->p_memsz;
				app_tpnt->l_tls_align = ppnt->p_align;
				if (ppnt->p_align == 0)
					app_tpnt->l_tls_firstbyte_offset = 0;
				else
					app_tpnt->l_tls_firstbyte_offset =
						(ppnt->p_vaddr & (ppnt->p_align - 1));
				app_tpnt->l_tls_initimage_size = ppnt->p_filesz;
				app_tpnt->l_tls_initimage = (void *) ppnt->p_vaddr;

				/* This image gets the ID one.  */
				_dl_tls_max_dtv_idx = app_tpnt->l_tls_modid = 1;

			}
			_dl_debug_early("Found TLS header for appplication program\n");
			break;
#else
			_dl_dprintf(_dl_debug_file, "Program uses unsupported TLS data!\n");
			_dl_exit(1);
#endif
		}
	}
	app_tpnt->relro_addr = relro_addr;
	app_tpnt->relro_size = relro_size;

#if defined(USE_TLS) && USE_TLS
	/*
	 * Adjust the address of the TLS initialization image in
	 * case the executable is actually an ET_DYN object.
	 */
	if (app_tpnt->l_tls_initimage != NULL) {
		app_tpnt->l_tls_initimage =
			(char *) app_tpnt->l_tls_initimage + app_tpnt->loadaddr;
		_dl_debug_early("Relocated TLS initial image from %x to %x (size = %x)\n",
			(unsigned int)app_tpnt->l_tls_initimage,
			app_tpnt->l_tls_initimage, app_tpnt->l_tls_initimage_size);
	}
#endif

#ifdef __SUPPORT_LD_DEBUG__
	_dl_debug = _dl_getenv("LD_DEBUG", envp);
	if (_dl_debug) {
		if (_dl_strstr(_dl_debug, "all")) {
			_dl_debug_detail = _dl_debug_move = _dl_debug_symbols
				= _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
		} else {
			_dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
			_dl_debug_move     = _dl_strstr(_dl_debug, "move");
			_dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
			_dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
			_dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
			_dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
		}
	}

	{
		const char *dl_debug_output;

		dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);

		if (dl_debug_output) {
			char tmp[22], *tmp1, *filename;
			int len1, len2;

			_dl_memset(tmp, 0, sizeof(tmp));
			tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());

			len1 = _dl_strlen(dl_debug_output);
			len2 = _dl_strlen(tmp1);

			filename = _dl_malloc(len1 + len2 + 2);

			if (filename) {
				_dl_strcpy (filename, dl_debug_output);
				filename[len1] = '.';
				_dl_strcpy (&filename[len1+1], tmp1);

				_dl_debug_file = _dl_open(filename, O_WRONLY|O_CREAT, 0644);
				if (_dl_debug_file < 0) {
					_dl_debug_file = 2;
					_dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
				}
			}
		}
	}
#endif

	if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
		trace_loaded_objects++;
	}

#ifndef __LDSO_LDD_SUPPORT__
	if (trace_loaded_objects) {
		_dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
		_dl_exit(1);
	}
#endif

	/*
	 * OK, fix one more thing - set up debug_addr so it will point
	 * to our chain.  Later we may need to fill in more fields, but this
	 * should be enough for now.
	 */
	debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
	debug_addr->r_version = 1;
	debug_addr->r_ldbase = (ElfW(Addr)) DL_LOADADDR_BASE(load_addr);
	debug_addr->r_brk = (unsigned long) &_dl_debug_state;
	_dl_debug_addr = debug_addr;

	/* Do not notify the debugger until the interpreter is in the list */

	/* OK, we now have the application in the list, and we have some
	 * basic stuff in place.  Now search through the list for other shared
	 * libraries that should be loaded, and insert them on the list in the
	 * correct order.
	 */

	_dl_map_cache();

	if (_dl_preload) {
		char c, *str, *str2;

		str = _dl_preload;
		while (*str == ':' || *str == ' ' || *str == '\t')
			str++;

		while (*str) {
			str2 = str;
			while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
				str2++;
			c = *str2;
			*str2 = '\0';

			if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
				_dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);

				tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
				if (!tpnt1) {
#ifdef __LDSO_LDD_SUPPORT__
					if (trace_loaded_objects)
						_dl_dprintf(1, "\t%s => not found\n", str);
					else
#endif
					{
						_dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
						_dl_exit(15);
					}
				} else {
					tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;

					_dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);

#ifdef __LDSO_LDD_SUPPORT__
					if (trace_loaded_objects &&
					    tpnt1->usage_count == 1) {
						/* This is a real hack to make
						 * ldd not print the library
						 * itself when run on a
						 * library.
						 */
						if (_dl_strcmp(_dl_progname, str) != 0)
							_dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
								    DL_LOADADDR_BASE(tpnt1->loadaddr));
					}
#endif
				}
			}

			*str2 = c;
			str = str2;
			while (*str == ':' || *str == ' ' || *str == '\t')
				str++;
		}
	}

#ifdef __LDSO_PRELOAD_FILE_SUPPORT__
	do {
		struct stat st;
		char *preload;
		int fd;
		char c, *cp, *cp2;

		if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
			break;
		}

		if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
			_dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
				    _dl_progname, LDSO_PRELOAD);
			break;
		}

		preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
					     PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		_dl_close(fd);
		if (preload == (caddr_t) -1) {
			_dl_dprintf(_dl_debug_file, "%s:%i: can't map '%s'\n",
				    _dl_progname, __LINE__, LDSO_PRELOAD);
			break;
		}

		/* convert all separators and comments to spaces */
		for (cp = preload; *cp; /*nada */ ) {
			if (*cp == ':' || *cp == '\t' || *cp == '\n') {
				*cp++ = ' ';
			} else if (*cp == '#') {
				do {
					*cp++ = ' ';
				} while (*cp != '\n' && *cp != '\0');
			} else {
				cp++;
			}
		}

		/* find start of first library */
		for (cp = preload; *cp && *cp == ' '; cp++)
			/*nada */ ;

		while (*cp) {
			/* find end of library */
			for (cp2 = cp; *cp && *cp != ' '; cp++)
				/*nada */ ;
			c = *cp;
			*cp = '\0';

			_dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);

			tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
			if (!tpnt1) {
#ifdef __LDSO_LDD_SUPPORT__
				if (trace_loaded_objects)
					_dl_dprintf(1, "\t%s => not found\n", cp2);
				else
#endif
				{
					_dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
					_dl_exit(15);
				}
			} else {
				tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;

				_dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);

#ifdef __LDSO_LDD_SUPPORT__
				if (trace_loaded_objects &&
				    tpnt1->usage_count == 1) {
					_dl_dprintf(1, "\t%s => %s (%x)\n",
						    cp2, tpnt1->libname,
						    DL_LOADADDR_BASE(tpnt1->loadaddr));
				}
#endif
			}

			/* find start of next library */
			*cp = c;
			for ( /*nada */ ; *cp && *cp == ' '; cp++)
				/*nada */ ;
		}

		_dl_munmap(preload, st.st_size + 1);
	} while (0);
#endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */

	nlist = 0;
	for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
		ElfW(Dyn) *this_dpnt;

		nlist++;
		for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
			if (this_dpnt->d_tag == DT_NEEDED) {
				char *name;
				struct init_fini_list *tmp;

				lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
				name = _dl_get_last_path_component(lpntstr);
				if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
					continue;

				_dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);

				if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects)))	{
#ifdef __LDSO_LDD_SUPPORT__
					if (trace_loaded_objects) {
						_dl_dprintf(1, "\t%s => not found\n", lpntstr);
						continue;
					} else
#endif
					{
						_dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
						_dl_exit(16);
					}
				}

				tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
				tmp->tpnt = tpnt1;
				tmp->next = tcurr->init_fini;
				tcurr->init_fini = tmp;

				tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;

				_dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);

#ifdef __LDSO_LDD_SUPPORT__
				if (trace_loaded_objects &&
				    tpnt1->usage_count == 1) {
					_dl_dprintf(1, "\t%s => %s (%x)\n",
						    lpntstr, tpnt1->libname,
						    DL_LOADADDR_BASE(tpnt1->loadaddr));
				}
#endif
			}
		}
	}
	_dl_unmap_cache();

	--nlist; /* Exclude the application. */
	init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
	i = 0;
	for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
		init_fini_list[i++] = tcurr;
	}

	/* Sort the INIT/FINI list in dependency order. */
	for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
		unsigned int j, k;

		for (j = 0; init_fini_list[j] != tcurr; ++j)
			/* Empty */;
		for (k = j + 1; k < nlist; ++k) {
			struct init_fini_list *runp = init_fini_list[k]->init_fini;

			for (; runp; runp = runp->next) {
				if (runp->tpnt == tcurr) {
					struct elf_resolve *here = init_fini_list[k];
					_dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
					for (i = (k - j); i; --i)
						init_fini_list[i+j] = init_fini_list[i+j-1];
					init_fini_list[j] = here;
					++j;
					break;
				}
			}
		}
	}
#ifdef __SUPPORT_LD_DEBUG__
	if (_dl_debug) {
		_dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
		for (i = 0; i < nlist; i++) {
			struct init_fini_list *tmp;

			_dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
				    init_fini_list[i]->libname);
			tmp = init_fini_list[i]->init_fini;
			for (; tmp; tmp = tmp->next)
				_dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
			_dl_dprintf(_dl_debug_file, "\n");
		}
	}
#endif

	/*
	 * If the program interpreter is not in the module chain, add it.
	 * This will be required for dlopen to be able to access the internal
	 * functions in the dynamic linker and to relocate the interpreter
	 * again once all libs are loaded.
	 */
	if (tpnt) {
		ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
		ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
		int j;

		tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
					      tpnt->dynamic_info,
					      (unsigned long)tpnt->dynamic_addr,
					      0);

		if (_dl_stat(tpnt->libname, &st) >= 0) {
			tpnt->st_dev = st.st_dev;
			tpnt->st_ino = st.st_ino;
		}
		tpnt->n_phent = epnt->e_phnum;
		tpnt->ppnt = myppnt;
		for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
			if (myppnt->p_type ==  PT_GNU_RELRO) {
				tpnt->relro_addr = myppnt->p_vaddr;
				tpnt->relro_size = myppnt->p_memsz;
				break;
			}
		}
		tpnt->libtype = program_interpreter;
		tpnt->usage_count++;
		tpnt->symbol_scope = _dl_symbol_tables;
		if (rpnt) {
			rpnt->next = _dl_zalloc(sizeof(struct dyn_elf));
			rpnt->next->prev = rpnt;
			rpnt = rpnt->next;
		} else {
			rpnt = _dl_zalloc(sizeof(struct dyn_elf));
		}
		rpnt->dyn = tpnt;
		tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
#ifdef RERELOCATE_LDSO
		/* Only rerelocate functions for now. */
		tpnt->init_flag = RELOCS_DONE;
		lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
# ifdef ALLOW_ZERO_PLTGOT
		if (tpnt->dynamic_info[DT_PLTGOT])
# endif
			INIT_GOT(lpnt, tpnt);
#else
		tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
#endif
		tpnt = NULL;
	}

#ifdef __LDSO_LDD_SUPPORT__
	/* End of the line for ldd.... */
	if (trace_loaded_objects) {
		_dl_dprintf(1, "\t%s => %s (%x)\n",
			    rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
			    rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
		_dl_exit(0);
	}
#endif

#if defined(USE_TLS) && USE_TLS
	/* 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) {
		_dl_debug_early("Calling init_tls()!\n");
		tcbp = init_tls ();
	}
#endif

	_dl_debug_early("Beginning relocation fixups\n");

#ifdef __mips__
	/*
	 * Relocation of the GOT entries for MIPS have to be done
	 * after all the libraries have been loaded.
	 */
	_dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
#endif

	/*
	 * OK, now all of the kids are tucked into bed in their proper
	 * addresses.  Now we go through and look for REL and RELA records that
	 * indicate fixups to the GOT tables.  We need to do this in reverse
	 * order so that COPY directives work correctly.
	 */
	if (_dl_symbol_tables)
		if (_dl_fixup(_dl_symbol_tables, unlazy))
			_dl_exit(-1);

	for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
		if (tpnt->relro_size)
			_dl_protect_relro (tpnt);
	}

#if defined(USE_TLS) && USE_TLS
	if (!was_tls_init_tp_called && _dl_tls_max_dtv_idx > 0)
		++_dl_tls_generation;

	_dl_debug_early("Calling _dl_allocate_tls_init()!\n");

	/* 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.  */
	_dl_allocate_tls_init (tcbp);

	/* And finally install it for the main thread.  If ld.so itself uses
	   TLS we know the thread pointer was initialized earlier.  */
	if (! tls_init_tp_called) {
		const char *lossage = (char *) TLS_INIT_TP (tcbp, USE___THREAD);
		if (__builtin_expect (lossage != NULL, 0)) {
			_dl_debug_early("cannot set up thread-local storage: %s\n", lossage);
			_dl_exit(30);
		}
	}
#endif /* USE_TLS */

	/* OK, at this point things are pretty much ready to run.  Now we need
	 * to touch up a few items that are required, and then we can let the
	 * user application have at it.  Note that the dynamic linker itself
	 * is not guaranteed to be fully dynamicly linked if we are using
	 * ld.so.1, so we have to look up each symbol individually.
	 */

	_dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0, NULL);
	if (_dl_envp)
		*_dl_envp = (unsigned long) envp;

#ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
	{
		unsigned int j;
		ElfW(Phdr) *myppnt;

		/* We had to set the protections of all pages to R/W for
		 * dynamic linking.  Set text pages back to R/O.
		 */
		for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
			for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
				if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
					_dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
							(myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
				}
			}
		}

	}
#endif
	/* Notify the debugger we have added some objects. */
	_dl_debug_addr->r_state = RT_ADD;
	_dl_debug_state();

	/* Run pre-initialization functions for the executable.  */
	_dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
			      _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
			      _dl_loaded_modules->loadaddr);

	/* Run initialization functions for loaded objects.  For the
	   main executable, they will be run from __uClibc_main.  */
	for (i = nlist; i; --i) {
		tpnt = init_fini_list[i-1];
		tpnt->init_fini = NULL; /* Clear, since alloca was used */
		if (tpnt->init_flag & INIT_FUNCS_CALLED)
			continue;
		tpnt->init_flag |= INIT_FUNCS_CALLED;

		if (tpnt->dynamic_info[DT_INIT]) {
			void (*dl_elf_func) (void);

			dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);

			_dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);

			DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
		}

		_dl_run_init_array(tpnt);
	}

	/* Find the real malloc function and make ldso functions use that from now on */
	_dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
			_dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);

#if defined(USE_TLS) && USE_TLS
	/* Find the real functions and make ldso functions use them from now on */
	_dl_calloc_function = (void* (*)(size_t, size_t)) (intptr_t)
		_dl_find_hash(__C_SYMBOL_PREFIX__ "calloc", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);

	_dl_realloc_function = (void* (*)(void *, size_t)) (intptr_t)
		_dl_find_hash(__C_SYMBOL_PREFIX__ "realloc", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);

	_dl_free_function = (void (*)(void *)) (intptr_t)
		_dl_find_hash(__C_SYMBOL_PREFIX__ "free", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);

	_dl_memalign_function = (void* (*)(size_t, size_t)) (intptr_t)
		_dl_find_hash(__C_SYMBOL_PREFIX__ "memalign", _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT, NULL);

#endif

	/* Notify the debugger that all objects are now mapped in.  */
	_dl_debug_addr->r_state = RT_CONSISTENT;
	_dl_debug_state();
}

#include "dl-hash.c"
#include "dl-elf.c"