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92effacf83
* elf/rtld.c (process_envvars): Place output files for profiling in SUID binaries in /var/profile.
1593 lines
47 KiB
C
1593 lines
47 KiB
C
/* Run time dynamic linker.
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Copyright (C) 1995-1999, 2000, 2001 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include <fcntl.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/mman.h> /* Check if MAP_ANON is defined. */
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#include <ldsodefs.h>
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#include <stdio-common/_itoa.h>
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#include <entry.h>
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#include <fpu_control.h>
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#include <hp-timing.h>
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#include <bits/libc-lock.h>
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#include "dynamic-link.h"
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#include "dl-librecon.h"
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#include <unsecvars.h>
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#include <assert.h>
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/* Helper function to handle errors while resolving symbols. */
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static void print_unresolved (int errcode, const char *objname,
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const char *errsting);
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/* Helper function to handle errors when a version is missing. */
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static void print_missing_version (int errcode, const char *objname,
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const char *errsting);
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/* Print the various times we collected. */
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static void print_statistics (void);
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/* This is a list of all the modes the dynamic loader can be in. */
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enum mode { normal, list, verify, trace };
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/* Process all environments variables the dynamic linker must recognize.
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Since all of them start with `LD_' we are a bit smarter while finding
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all the entries. */
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static void process_envvars (enum mode *modep, int *lazyp);
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int _dl_argc;
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char **_dl_argv;
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unsigned int _dl_skip_args; /* Nonzero if we were run directly. */
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int _dl_verbose;
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const char *_dl_platform;
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size_t _dl_platformlen;
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unsigned long _dl_hwcap;
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fpu_control_t _dl_fpu_control = _FPU_DEFAULT;
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struct r_search_path *_dl_search_paths;
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const char *_dl_profile;
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const char *_dl_profile_output;
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struct link_map *_dl_profile_map;
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int _dl_lazy;
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/* XXX I know about at least one case where we depend on the old weak
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behavior (it has to do with librt). Until we get DSO groups implemented
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we have to make this the default. Bummer. --drepper */
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#if 0
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int _dl_dynamic_weak;
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#else
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int _dl_dynamic_weak = 1;
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#endif
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int _dl_debug_libs;
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int _dl_debug_impcalls;
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int _dl_debug_bindings;
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int _dl_debug_symbols;
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int _dl_debug_versions;
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int _dl_debug_reloc;
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int _dl_debug_files;
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int _dl_debug_statistics;
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const char *_dl_inhibit_rpath; /* RPATH values which should be
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ignored. */
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const char *_dl_origin_path;
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int _dl_bind_not;
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/* This is a pointer to the map for the main object and through it to
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all loaded objects. */
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struct link_map *_dl_loaded;
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/* Number of object in the _dl_loaded list. */
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unsigned int _dl_nloaded;
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/* Pointer to the l_searchlist element of the link map of the main object. */
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struct r_scope_elem *_dl_main_searchlist;
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/* Copy of the content of `_dl_main_searchlist'. */
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struct r_scope_elem _dl_initial_searchlist;
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/* Array which is used when looking up in the global scope. */
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struct r_scope_elem *_dl_global_scope[2];
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/* During the program run we must not modify the global data of
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loaded shared object simultanously in two threads. Therefore we
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protect `_dl_open' and `_dl_close' in dl-close.c.
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This must be a recursive lock since the initializer function of
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the loaded object might as well require a call to this function.
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At this time it is not anymore a problem to modify the tables. */
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__libc_lock_define_initialized_recursive (, _dl_load_lock)
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/* Set nonzero during loading and initialization of executable and
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libraries, cleared before the executable's entry point runs. This
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must not be initialized to nonzero, because the unused dynamic
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linker loaded in for libc.so's "ld.so.1" dep will provide the
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definition seen by libc.so's initializer; that value must be zero,
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and will be since that dynamic linker's _dl_start and dl_main will
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never be called. */
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int _dl_starting_up;
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static void dl_main (const ElfW(Phdr) *phdr,
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ElfW(Word) phnum,
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ElfW(Addr) *user_entry);
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struct link_map _dl_rtld_map;
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struct libname_list _dl_rtld_libname;
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struct libname_list _dl_rtld_libname2;
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/* Variable for statistics. */
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#ifndef HP_TIMING_NONAVAIL
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static hp_timing_t rtld_total_time;
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static hp_timing_t relocate_time;
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static hp_timing_t load_time;
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#endif
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extern unsigned long int _dl_num_relocations; /* in dl-lookup.c */
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static ElfW(Addr) _dl_start_final (void *arg, struct link_map *bootstrap_map_p,
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hp_timing_t start_time);
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#ifdef RTLD_START
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RTLD_START
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#else
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#error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START"
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#endif
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static ElfW(Addr)
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_dl_start (void *arg)
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{
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struct link_map bootstrap_map;
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hp_timing_t start_time;
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size_t cnt;
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/* This #define produces dynamic linking inline functions for
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bootstrap relocation instead of general-purpose relocation. */
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#define RTLD_BOOTSTRAP
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#define RESOLVE_MAP(sym, version, flags) \
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((*(sym))->st_shndx == SHN_UNDEF ? 0 : &bootstrap_map)
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#define RESOLVE(sym, version, flags) \
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((*(sym))->st_shndx == SHN_UNDEF ? 0 : bootstrap_map.l_addr)
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#include "dynamic-link.h"
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if (HP_TIMING_INLINE && HP_TIMING_AVAIL)
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HP_TIMING_NOW (start_time);
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/* Partly clean the `bootstrap_map' structure up. Don't use `memset'
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since it might nor be built in or inlined and we cannot make function
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calls at this point. */
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for (cnt = 0;
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cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]);
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++cnt)
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bootstrap_map.l_info[cnt] = 0;
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/* Figure out the run-time load address of the dynamic linker itself. */
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bootstrap_map.l_addr = elf_machine_load_address ();
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/* Read our own dynamic section and fill in the info array. */
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bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
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elf_get_dynamic_info (&bootstrap_map);
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#ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
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ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
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#endif
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/* Relocate ourselves so we can do normal function calls and
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data access using the global offset table. */
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ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0);
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/* Please note that we don't allow profiling of this object and
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therefore need not test whether we have to allocate the array
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for the relocation results (as done in dl-reloc.c). */
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/* Now life is sane; we can call functions and access global data.
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Set up to use the operating system facilities, and find out from
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the operating system's program loader where to find the program
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header table in core. Put the rest of _dl_start into a separate
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function, that way the compiler cannot put accesses to the GOT
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before ELF_DYNAMIC_RELOCATE. */
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{
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ElfW(Addr) entry = _dl_start_final (arg, &bootstrap_map, start_time);
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#ifndef ELF_MACHINE_START_ADDRESS
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# define ELF_MACHINE_START_ADDRESS(map, start) (start)
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#endif
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return ELF_MACHINE_START_ADDRESS (_dl_loaded, entry);
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}
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}
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static ElfW(Addr)
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_dl_start_final (void *arg, struct link_map *bootstrap_map_p,
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hp_timing_t start_time)
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{
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/* The use of `alloca' here looks ridiculous but it helps. The goal
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is to avoid the function from being inlined. There is no official
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way to do this so we use this trick. gcc never inlines functions
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which use `alloca'. */
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ElfW(Addr) *start_addr = alloca (sizeof (ElfW(Addr)));
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if (HP_TIMING_AVAIL)
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{
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/* If it hasn't happen yet record the startup time. */
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if (! HP_TIMING_INLINE)
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HP_TIMING_NOW (start_time);
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/* Initialize the timing functions. */
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HP_TIMING_DIFF_INIT ();
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}
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/* Transfer data about ourselves to the permanent link_map structure. */
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_dl_rtld_map.l_addr = bootstrap_map_p->l_addr;
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_dl_rtld_map.l_ld = bootstrap_map_p->l_ld;
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_dl_rtld_map.l_opencount = 1;
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memcpy (_dl_rtld_map.l_info, bootstrap_map_p->l_info,
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sizeof _dl_rtld_map.l_info);
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_dl_setup_hash (&_dl_rtld_map);
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/* Don't bother trying to work out how ld.so is mapped in memory. */
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_dl_rtld_map.l_map_start = ~0;
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_dl_rtld_map.l_map_end = ~0;
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/* Call the OS-dependent function to set up life so we can do things like
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file access. It will call `dl_main' (below) to do all the real work
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of the dynamic linker, and then unwind our frame and run the user
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entry point on the same stack we entered on. */
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*start_addr = _dl_sysdep_start (arg, &dl_main);
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#ifndef HP_TIMING_NONAVAIL
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if (HP_TIMING_AVAIL)
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{
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hp_timing_t end_time;
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/* Get the current time. */
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HP_TIMING_NOW (end_time);
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/* Compute the difference. */
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HP_TIMING_DIFF (rtld_total_time, start_time, end_time);
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}
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#endif
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if (__builtin_expect (_dl_debug_statistics, 0))
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print_statistics ();
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return *start_addr;
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}
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/* Now life is peachy; we can do all normal operations.
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On to the real work. */
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void ENTRY_POINT (void);
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/* Some helper functions. */
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/* Arguments to relocate_doit. */
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struct relocate_args
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{
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struct link_map *l;
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int lazy;
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};
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struct map_args
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{
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/* Argument to map_doit. */
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char *str;
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/* Return value of map_doit. */
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struct link_map *main_map;
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};
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/* Arguments to version_check_doit. */
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struct version_check_args
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{
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int doexit;
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int dotrace;
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};
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static void
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relocate_doit (void *a)
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{
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struct relocate_args *args = (struct relocate_args *) a;
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_dl_relocate_object (args->l, args->l->l_scope,
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args->lazy, 0);
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}
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static void
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map_doit (void *a)
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{
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struct map_args *args = (struct map_args *) a;
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args->main_map = _dl_map_object (NULL, args->str, 0, lt_library, 0, 0);
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}
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static void
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version_check_doit (void *a)
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{
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struct version_check_args *args = (struct version_check_args *) a;
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if (_dl_check_all_versions (_dl_loaded, 1, args->dotrace) && args->doexit)
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/* We cannot start the application. Abort now. */
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_exit (1);
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}
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static inline struct link_map *
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find_needed (const char *name)
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{
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unsigned int n = _dl_loaded->l_searchlist.r_nlist;
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while (n-- > 0)
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if (_dl_name_match_p (name, _dl_loaded->l_searchlist.r_list[n]))
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return _dl_loaded->l_searchlist.r_list[n];
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/* Should never happen. */
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return NULL;
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}
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static int
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match_version (const char *string, struct link_map *map)
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{
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const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
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ElfW(Verdef) *def;
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#define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF))
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if (map->l_info[VERDEFTAG] == NULL)
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/* The file has no symbol versioning. */
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return 0;
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def = (ElfW(Verdef) *) ((char *) map->l_addr
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+ map->l_info[VERDEFTAG]->d_un.d_ptr);
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while (1)
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{
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ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux);
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/* Compare the version strings. */
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if (strcmp (string, strtab + aux->vda_name) == 0)
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/* Bingo! */
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return 1;
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/* If no more definitions we failed to find what we want. */
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if (def->vd_next == 0)
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break;
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/* Next definition. */
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def = (ElfW(Verdef) *) ((char *) def + def->vd_next);
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}
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return 0;
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}
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static const char *library_path; /* The library search path. */
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static const char *preloadlist; /* The list preloaded objects. */
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static int version_info; /* Nonzero if information about
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versions has to be printed. */
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static void
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dl_main (const ElfW(Phdr) *phdr,
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ElfW(Word) phnum,
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ElfW(Addr) *user_entry)
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{
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const ElfW(Phdr) *ph;
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enum mode mode;
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struct link_map **preloads;
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unsigned int npreloads;
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size_t file_size;
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char *file;
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int has_interp = 0;
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unsigned int i;
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int rtld_is_main = 0;
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#ifndef HP_TIMING_NONAVAIL
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hp_timing_t start;
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hp_timing_t stop;
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hp_timing_t diff;
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#endif
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/* Process the environment variable which control the behaviour. */
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process_envvars (&mode, &_dl_lazy);
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/* Set up a flag which tells we are just starting. */
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_dl_starting_up = 1;
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|
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if (*user_entry == (ElfW(Addr)) &ENTRY_POINT)
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{
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/* Ho ho. We are not the program interpreter! We are the program
|
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itself! This means someone ran ld.so as a command. Well, that
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might be convenient to do sometimes. We support it by
|
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interpreting the args like this:
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|
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ld.so PROGRAM ARGS...
|
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|
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The first argument is the name of a file containing an ELF
|
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executable we will load and run with the following arguments.
|
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To simplify life here, PROGRAM is searched for using the
|
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normal rules for shared objects, rather than $PATH or anything
|
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like that. We just load it and use its entry point; we don't
|
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pay attention to its PT_INTERP command (we are the interpreter
|
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ourselves). This is an easy way to test a new ld.so before
|
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installing it. */
|
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rtld_is_main = 1;
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|
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/* Note the place where the dynamic linker actually came from. */
|
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_dl_rtld_map.l_name = _dl_argv[0];
|
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|
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while (_dl_argc > 1)
|
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if (! strcmp (_dl_argv[1], "--list"))
|
||
{
|
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mode = list;
|
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_dl_lazy = -1; /* This means do no dependency analysis. */
|
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|
||
++_dl_skip_args;
|
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--_dl_argc;
|
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++_dl_argv;
|
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}
|
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else if (! strcmp (_dl_argv[1], "--verify"))
|
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{
|
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mode = verify;
|
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|
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++_dl_skip_args;
|
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--_dl_argc;
|
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++_dl_argv;
|
||
}
|
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else if (! strcmp (_dl_argv[1], "--library-path") && _dl_argc > 2)
|
||
{
|
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library_path = _dl_argv[2];
|
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|
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_dl_skip_args += 2;
|
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_dl_argc -= 2;
|
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_dl_argv += 2;
|
||
}
|
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else if (! strcmp (_dl_argv[1], "--inhibit-rpath") && _dl_argc > 2)
|
||
{
|
||
_dl_inhibit_rpath = _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_sysdep_fatal ("\
|
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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\
|
||
--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",
|
||
NULL);
|
||
|
||
++_dl_skip_args;
|
||
--_dl_argc;
|
||
++_dl_argv;
|
||
|
||
/* Initialize the data structures for the search paths for shared
|
||
objects. */
|
||
_dl_init_paths (library_path);
|
||
|
||
if (__builtin_expect (mode, normal) == verify)
|
||
{
|
||
const char *objname;
|
||
const char *err_str = NULL;
|
||
struct map_args args;
|
||
|
||
args.str = _dl_argv[0];
|
||
(void) _dl_catch_error (&objname, &err_str, map_doit, &args);
|
||
if (__builtin_expect (err_str != NULL, 0))
|
||
{
|
||
if (err_str != _dl_out_of_memory)
|
||
free ((char *) err_str);
|
||
_exit (EXIT_FAILURE);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
HP_TIMING_NOW (start);
|
||
_dl_map_object (NULL, _dl_argv[0], 0, lt_library, 0, 0);
|
||
HP_TIMING_NOW (stop);
|
||
|
||
HP_TIMING_DIFF (load_time, start, stop);
|
||
}
|
||
|
||
phdr = _dl_loaded->l_phdr;
|
||
phnum = _dl_loaded->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. */
|
||
_dl_loaded->l_name = (char *) "";
|
||
*user_entry = _dl_loaded->l_entry;
|
||
}
|
||
else
|
||
{
|
||
/* Create a link_map for the executable itself.
|
||
This will be what dlopen on "" returns. */
|
||
_dl_new_object ((char *) "", "", lt_executable, NULL);
|
||
if (_dl_loaded == NULL)
|
||
_dl_sysdep_fatal ("cannot allocate memory for link map\n", NULL);
|
||
_dl_loaded->l_phdr = phdr;
|
||
_dl_loaded->l_phnum = phnum;
|
||
_dl_loaded->l_entry = *user_entry;
|
||
|
||
/* 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. */
|
||
}
|
||
|
||
/* It is not safe to load stuff after the main program. */
|
||
_dl_loaded->l_map_end = ~0;
|
||
/* Perhaps the executable has no PT_LOAD header entries at all. */
|
||
_dl_loaded->l_map_start = ~0;
|
||
|
||
/* 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. */
|
||
_dl_loaded->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. */
|
||
_dl_loaded->l_ld = (void *) _dl_loaded->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 *) _dl_loaded->l_addr
|
||
+ ph->p_vaddr);
|
||
/* _dl_rtld_libname.next = NULL; Already zero. */
|
||
_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 (_dl_rtld_map.l_ld == NULL)
|
||
{
|
||
char *p = strrchr (_dl_rtld_libname.name, '/');
|
||
if (p)
|
||
{
|
||
_dl_rtld_libname2.name = p+1;
|
||
/* _dl_rtld_libname2.next = NULL; Already zero. */
|
||
_dl_rtld_libname.next = &_dl_rtld_libname2;
|
||
}
|
||
}
|
||
|
||
has_interp = 1;
|
||
break;
|
||
case PT_LOAD:
|
||
/* Remember where the main program starts in memory. */
|
||
{
|
||
ElfW(Addr) mapstart;
|
||
mapstart = _dl_loaded->l_addr + (ph->p_vaddr & ~(ph->p_align - 1));
|
||
if (_dl_loaded->l_map_start > mapstart)
|
||
_dl_loaded->l_map_start = mapstart;
|
||
}
|
||
break;
|
||
}
|
||
if (! _dl_rtld_map.l_libname && _dl_rtld_map.l_name)
|
||
{
|
||
/* We were invoked directly, so the program might not have a
|
||
PT_INTERP. */
|
||
_dl_rtld_libname.name = _dl_rtld_map.l_name;
|
||
/* _dl_rtld_libname.next = NULL; Alread zero. */
|
||
_dl_rtld_map.l_libname = &_dl_rtld_libname;
|
||
}
|
||
else
|
||
assert (_dl_rtld_map.l_libname); /* How else did we get here? */
|
||
|
||
if (! rtld_is_main)
|
||
{
|
||
/* Extract the contents of the dynamic section for easy access. */
|
||
elf_get_dynamic_info (_dl_loaded);
|
||
if (_dl_loaded->l_info[DT_HASH])
|
||
/* Set up our cache of pointers into the hash table. */
|
||
_dl_setup_hash (_dl_loaded);
|
||
}
|
||
|
||
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 (_dl_loaded->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);
|
||
}
|
||
|
||
if (! rtld_is_main)
|
||
/* Initialize the data structures for the search paths for shared
|
||
objects. */
|
||
_dl_init_paths (library_path);
|
||
|
||
/* 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 (! _dl_rtld_map.l_name)
|
||
/* If not invoked directly, the dynamic linker shared object file was
|
||
found by the PT_INTERP name. */
|
||
_dl_rtld_map.l_name = (char *) _dl_rtld_map.l_libname->name;
|
||
_dl_rtld_map.l_type = lt_library;
|
||
_dl_loaded->l_next = &_dl_rtld_map;
|
||
_dl_rtld_map.l_prev = _dl_loaded;
|
||
++_dl_nloaded;
|
||
|
||
/* 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. */
|
||
preloads = NULL;
|
||
npreloads = 0;
|
||
|
||
if (__builtin_expect (preloadlist != NULL, 0))
|
||
{
|
||
/* 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. */
|
||
char *list = strdupa (preloadlist);
|
||
char *p;
|
||
|
||
HP_TIMING_NOW (start);
|
||
|
||
while ((p = strsep (&list, " :")) != NULL)
|
||
if (p[0] != '\0'
|
||
&& (__builtin_expect (! __libc_enable_secure, 1)
|
||
|| strchr (p, '/') == NULL))
|
||
{
|
||
struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
|
||
lt_library, 0, 0);
|
||
if (++new_map->l_opencount == 1)
|
||
/* It is no duplicate. */
|
||
++npreloads;
|
||
}
|
||
|
||
HP_TIMING_NOW (stop);
|
||
HP_TIMING_DIFF (diff, start, stop);
|
||
HP_TIMING_ACCUM_NT (load_time, diff);
|
||
}
|
||
|
||
/* Read the contents of the file. */
|
||
file = _dl_sysdep_read_whole_file ("/etc/ld.so.preload", &file_size,
|
||
PROT_READ | PROT_WRITE);
|
||
if (__builtin_expect (file != NULL, 0))
|
||
{
|
||
/* 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')
|
||
{
|
||
struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
|
||
lt_library, 0, 0);
|
||
if (++new_map->l_opencount == 1)
|
||
/* It is no duplicate. */
|
||
++npreloads;
|
||
}
|
||
}
|
||
|
||
if (problem != NULL)
|
||
{
|
||
char *p = strndupa (problem, file_size - (problem - file));
|
||
struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
|
||
lt_library, 0, 0);
|
||
if (++new_map->l_opencount == 1)
|
||
/* It is no duplicate. */
|
||
++npreloads;
|
||
}
|
||
|
||
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 (__builtin_expect (npreloads, 0) != 0)
|
||
{
|
||
/* Set up PRELOADS with a vector of the preloaded libraries. */
|
||
struct link_map *l;
|
||
preloads = __alloca (npreloads * sizeof preloads[0]);
|
||
l = _dl_rtld_map.l_next; /* End of the chain before preloads. */
|
||
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 (_dl_loaded, preloads, npreloads, mode == trace);
|
||
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 and set the open
|
||
counter. */
|
||
for (i = _dl_loaded->l_searchlist.r_nlist; i > 0; )
|
||
{
|
||
--i;
|
||
_dl_loaded->l_searchlist.r_list[i]->l_global = 1;
|
||
++_dl_loaded->l_searchlist.r_list[i]->l_opencount;
|
||
}
|
||
|
||
#ifndef MAP_ANON
|
||
/* We are done mapping things, so close the zero-fill descriptor. */
|
||
__close (_dl_zerofd);
|
||
_dl_zerofd = -1;
|
||
#endif
|
||
|
||
/* Remove _dl_rtld_map from the chain. */
|
||
_dl_rtld_map.l_prev->l_next = _dl_rtld_map.l_next;
|
||
if (_dl_rtld_map.l_next)
|
||
_dl_rtld_map.l_next->l_prev = _dl_rtld_map.l_prev;
|
||
|
||
if (__builtin_expect (_dl_rtld_map.l_opencount, 2) > 1)
|
||
{
|
||
/* 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. */
|
||
i = 1;
|
||
while (_dl_loaded->l_searchlist.r_list[i] != &_dl_rtld_map)
|
||
++i;
|
||
_dl_rtld_map.l_prev = _dl_loaded->l_searchlist.r_list[i - 1];
|
||
if (__builtin_expect (mode, normal) == normal)
|
||
_dl_rtld_map.l_next = (i + 1 < _dl_loaded->l_searchlist.r_nlist
|
||
? _dl_loaded->l_searchlist.r_list[i + 1]
|
||
: NULL);
|
||
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. */
|
||
_dl_rtld_map.l_next = _dl_rtld_map.l_prev->l_next;
|
||
|
||
assert (_dl_rtld_map.l_prev->l_next == _dl_rtld_map.l_next);
|
||
_dl_rtld_map.l_prev->l_next = &_dl_rtld_map;
|
||
if (_dl_rtld_map.l_next)
|
||
{
|
||
assert (_dl_rtld_map.l_next->l_prev == _dl_rtld_map.l_prev);
|
||
_dl_rtld_map.l_next->l_prev = &_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);
|
||
}
|
||
|
||
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. */
|
||
if (! _dl_loaded->l_info[DT_NEEDED])
|
||
_dl_sysdep_message ("\t", "statically linked\n", NULL);
|
||
else
|
||
{
|
||
struct link_map *l;
|
||
|
||
for (l = _dl_loaded->l_next; l; l = l->l_next)
|
||
if (l->l_faked)
|
||
/* The library was not found. */
|
||
_dl_sysdep_message ("\t", l->l_libname->name, " => not found\n",
|
||
NULL);
|
||
else
|
||
{
|
||
char buf[20], *bp;
|
||
buf[sizeof buf - 1] = '\0';
|
||
bp = _itoa_word (l->l_addr, &buf[sizeof buf - 1], 16, 0);
|
||
while ((size_t) (&buf[sizeof buf - 1] - bp)
|
||
< sizeof l->l_addr * 2)
|
||
*--bp = '0';
|
||
_dl_sysdep_message ("\t", l->l_libname->name, " => ",
|
||
l->l_name, " (0x", bp, ")\n", NULL);
|
||
}
|
||
}
|
||
|
||
if (__builtin_expect (mode, trace) != trace)
|
||
for (i = 1; i < _dl_argc; ++i)
|
||
{
|
||
const ElfW(Sym) *ref = NULL;
|
||
ElfW(Addr) loadbase;
|
||
lookup_t result;
|
||
char buf[20], *bp;
|
||
|
||
result = _dl_lookup_symbol (_dl_argv[i], _dl_loaded,
|
||
&ref, _dl_loaded->l_scope,
|
||
ELF_MACHINE_JMP_SLOT, 1);
|
||
|
||
loadbase = LOOKUP_VALUE_ADDRESS (result);
|
||
|
||
buf[sizeof buf - 1] = '\0';
|
||
bp = _itoa_word (ref->st_value, &buf[sizeof buf - 1], 16, 0);
|
||
while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2)
|
||
*--bp = '0';
|
||
_dl_sysdep_message (_dl_argv[i], " found at 0x", bp, NULL);
|
||
buf[sizeof buf - 1] = '\0';
|
||
bp = _itoa_word (loadbase, &buf[sizeof buf - 1], 16, 0);
|
||
while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2)
|
||
*--bp = '0';
|
||
_dl_sysdep_message (" in object at 0x", bp, "\n", NULL);
|
||
}
|
||
else
|
||
{
|
||
if (_dl_lazy >= 0)
|
||
{
|
||
/* We have to do symbol dependency testing. */
|
||
struct relocate_args args;
|
||
struct link_map *l;
|
||
|
||
args.lazy = _dl_lazy;
|
||
|
||
l = _dl_loaded;
|
||
while (l->l_next)
|
||
l = l->l_next;
|
||
do
|
||
{
|
||
if (l != &_dl_rtld_map && ! l->l_faked)
|
||
{
|
||
args.l = l;
|
||
_dl_receive_error (print_unresolved, relocate_doit,
|
||
&args);
|
||
}
|
||
l = l->l_prev;
|
||
} while (l);
|
||
}
|
||
|
||
#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 = _dl_loaded;
|
||
|
||
for (map = _dl_loaded; 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_sysdep_message ("\n\tVersion information:\n", NULL);
|
||
first = 0;
|
||
}
|
||
|
||
_dl_sysdep_message ("\t", (map->l_name[0]
|
||
? map->l_name : _dl_argv[0]),
|
||
":\n", NULL);
|
||
|
||
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;
|
||
|
||
_dl_sysdep_message ("\t\t",
|
||
strtab + ent->vn_file,
|
||
" (", strtab + aux->vna_name,
|
||
") ",
|
||
(aux->vna_flags
|
||
& VER_FLG_WEAK
|
||
? "[WEAK] " : ""),
|
||
"=> ", NULL);
|
||
|
||
if (needed != NULL
|
||
&& match_version (strtab+aux->vna_name, needed))
|
||
fname = needed->l_name;
|
||
|
||
_dl_sysdep_message (fname ?: "not found", "\n",
|
||
NULL);
|
||
|
||
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);
|
||
}
|
||
|
||
{
|
||
/* 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). */
|
||
|
||
struct link_map *l;
|
||
int consider_profiling = _dl_profile != NULL;
|
||
#ifndef HP_TIMING_NONAVAIL
|
||
hp_timing_t start;
|
||
hp_timing_t stop;
|
||
hp_timing_t add;
|
||
#endif
|
||
|
||
/* If we are profiling we also must do lazy reloaction. */
|
||
_dl_lazy |= consider_profiling;
|
||
|
||
l = _dl_loaded;
|
||
while (l->l_next)
|
||
l = l->l_next;
|
||
|
||
HP_TIMING_NOW (start);
|
||
do
|
||
{
|
||
/* 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;
|
||
}
|
||
|
||
if (l != &_dl_rtld_map)
|
||
_dl_relocate_object (l, l->l_scope, _dl_lazy, consider_profiling);
|
||
|
||
l = l->l_prev;
|
||
}
|
||
while (l);
|
||
HP_TIMING_NOW (stop);
|
||
|
||
HP_TIMING_DIFF (relocate_time, start, stop);
|
||
|
||
/* 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 ();
|
||
|
||
/* 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 (__builtin_expect (_dl_profile_map != NULL, 0))
|
||
/* We must prepare the profiling. */
|
||
_dl_start_profile (_dl_profile_map, _dl_profile_output);
|
||
|
||
if (_dl_rtld_map.l_opencount > 1)
|
||
{
|
||
/* There was an explicit ref to the dynamic linker as a shared lib.
|
||
Re-relocate ourselves with user-controlled symbol definitions. */
|
||
HP_TIMING_NOW (start);
|
||
_dl_relocate_object (&_dl_rtld_map, _dl_loaded->l_scope, 0, 0);
|
||
HP_TIMING_NOW (stop);
|
||
HP_TIMING_DIFF (add, start, stop);
|
||
HP_TIMING_ACCUM_NT (relocate_time, add);
|
||
}
|
||
}
|
||
|
||
/* Now set up the variable which helps the assembler startup code. */
|
||
_dl_main_searchlist = &_dl_loaded->l_searchlist;
|
||
_dl_global_scope[0] = &_dl_loaded->l_searchlist;
|
||
|
||
/* Safe the information about the original global scope list since
|
||
we need it in the memory handling later. */
|
||
_dl_initial_searchlist = *_dl_main_searchlist;
|
||
|
||
{
|
||
/* Initialize _r_debug. */
|
||
struct r_debug *r = _dl_debug_initialize (_dl_rtld_map.l_addr);
|
||
struct link_map *l;
|
||
|
||
l = _dl_loaded;
|
||
|
||
#ifdef ELF_MACHINE_DEBUG_SETUP
|
||
|
||
/* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */
|
||
|
||
ELF_MACHINE_DEBUG_SETUP (l, r);
|
||
ELF_MACHINE_DEBUG_SETUP (&_dl_rtld_map, r);
|
||
|
||
#else
|
||
|
||
if (l->l_info[DT_DEBUG])
|
||
/* There is a DT_DEBUG entry in the dynamic section. Fill it in
|
||
with the run-time address of the r_debug structure */
|
||
l->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 (_dl_rtld_map.l_info[DT_DEBUG])
|
||
_dl_rtld_map.l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
|
||
|
||
#endif
|
||
|
||
/* Notify the debugger that all objects are now mapped in. */
|
||
r->r_state = RT_ADD;
|
||
_dl_debug_state ();
|
||
}
|
||
|
||
#ifndef 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 = _dl_argv[0] ?: "<main program>";
|
||
_dl_sysdep_error (errstring, " (", objname, ")\n", NULL);
|
||
}
|
||
|
||
/* 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_sysdep_error (_dl_argv[0] ?: "<program name unknown>", ": ",
|
||
objname, ": ", errstring, "\n", NULL);
|
||
}
|
||
|
||
/* Nonzero if any of the debugging options is enabled. */
|
||
static int any_debug;
|
||
|
||
/* Process the string given as the parameter which explains which debugging
|
||
options are enabled. */
|
||
static void
|
||
process_dl_debug (const char *dl_debug)
|
||
{
|
||
size_t len;
|
||
#define separators " ,:"
|
||
do
|
||
{
|
||
len = 0;
|
||
/* Skip separating white spaces and commas. */
|
||
dl_debug += strspn (dl_debug, separators);
|
||
if (*dl_debug != '\0')
|
||
{
|
||
len = strcspn (dl_debug, separators);
|
||
|
||
switch (len)
|
||
{
|
||
case 3:
|
||
/* This option is not documented since it is not generally
|
||
useful. */
|
||
if (memcmp (dl_debug, "all", 3) == 0)
|
||
{
|
||
_dl_debug_libs = 1;
|
||
_dl_debug_impcalls = 1;
|
||
_dl_debug_reloc = 1;
|
||
_dl_debug_files = 1;
|
||
_dl_debug_symbols = 1;
|
||
_dl_debug_bindings = 1;
|
||
_dl_debug_versions = 1;
|
||
any_debug = 1;
|
||
continue;
|
||
}
|
||
break;
|
||
|
||
case 4:
|
||
if (memcmp (dl_debug, "help", 4) == 0)
|
||
{
|
||
_dl_sysdep_message ("\
|
||
Valid options for the LD_DEBUG environment variable are:\n\
|
||
\n\
|
||
bindings display information about symbol binding\n\
|
||
files display processing of files and libraries\n\
|
||
help display this help message and exit\n\
|
||
libs display library search paths\n\
|
||
reloc display relocation processing\n\
|
||
statistics display relocation statistics\n\
|
||
symbols display symbol table processing\n\
|
||
versions display version dependencies\n\
|
||
\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",
|
||
NULL);
|
||
_exit (0);
|
||
}
|
||
|
||
if (memcmp (dl_debug, "libs", 4) == 0)
|
||
{
|
||
_dl_debug_libs = 1;
|
||
_dl_debug_impcalls = 1;
|
||
any_debug = 1;
|
||
continue;
|
||
}
|
||
break;
|
||
|
||
case 5:
|
||
if (memcmp (dl_debug, "reloc", 5) == 0)
|
||
{
|
||
_dl_debug_reloc = 1;
|
||
_dl_debug_impcalls = 1;
|
||
any_debug = 1;
|
||
continue;
|
||
}
|
||
|
||
if (memcmp (dl_debug, "files", 5) == 0)
|
||
{
|
||
_dl_debug_files = 1;
|
||
_dl_debug_impcalls = 1;
|
||
any_debug = 1;
|
||
continue;
|
||
}
|
||
break;
|
||
|
||
case 7:
|
||
if (memcmp (dl_debug, "symbols", 7) == 0)
|
||
{
|
||
_dl_debug_symbols = 1;
|
||
_dl_debug_impcalls = 1;
|
||
any_debug = 1;
|
||
continue;
|
||
}
|
||
break;
|
||
|
||
case 8:
|
||
if (memcmp (dl_debug, "bindings", 8) == 0)
|
||
{
|
||
_dl_debug_bindings = 1;
|
||
_dl_debug_impcalls = 1;
|
||
any_debug = 1;
|
||
continue;
|
||
}
|
||
|
||
if (memcmp (dl_debug, "versions", 8) == 0)
|
||
{
|
||
_dl_debug_versions = 1;
|
||
_dl_debug_impcalls = 1;
|
||
any_debug = 1;
|
||
continue;
|
||
}
|
||
break;
|
||
|
||
case 10:
|
||
if (memcmp (dl_debug, "statistics", 10) == 0)
|
||
{
|
||
_dl_debug_statistics = 1;
|
||
continue;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
{
|
||
/* Display a warning and skip everything until next separator. */
|
||
char *startp = strndupa (dl_debug, len);
|
||
_dl_sysdep_error ("warning: debug option `", startp,
|
||
"' unknown; try LD_DEBUG=help\n", NULL);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
while (*(dl_debug += len) != '\0');
|
||
}
|
||
|
||
/* 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, int *lazyp)
|
||
{
|
||
char **runp = NULL;
|
||
char *envline;
|
||
enum mode mode = normal;
|
||
int bind_now = 0;
|
||
char *debug_output = NULL;
|
||
|
||
/* This is the default place for profiling data file. */
|
||
_dl_profile_output = __libc_enable_secure ? "/var/profile" : "/var/tmp";
|
||
|
||
while ((envline = _dl_next_ld_env_entry (&runp)) != NULL)
|
||
{
|
||
size_t len = strcspn (envline, "=");
|
||
|
||
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. */
|
||
break;
|
||
|
||
switch (len - 3)
|
||
{
|
||
case 4:
|
||
/* Warning level, verbose or not. */
|
||
if (memcmp (&envline[3], "WARN", 4) == 0)
|
||
_dl_verbose = envline[8] != '\0';
|
||
break;
|
||
|
||
case 5:
|
||
/* Debugging of the dynamic linker? */
|
||
if (memcmp (&envline[3], "DEBUG", 5) == 0)
|
||
process_dl_debug (&envline[9]);
|
||
break;
|
||
|
||
case 7:
|
||
/* Print information about versions. */
|
||
if (memcmp (&envline[3], "VERBOSE", 7) == 0)
|
||
{
|
||
version_info = envline[11] != '\0';
|
||
break;
|
||
}
|
||
|
||
/* List of objects to be preloaded. */
|
||
if (memcmp (&envline[3], "PRELOAD", 7) == 0)
|
||
{
|
||
preloadlist = &envline[11];
|
||
break;
|
||
}
|
||
|
||
/* Which shared object shall be profiled. */
|
||
if (memcmp (&envline[3], "PROFILE", 7) == 0)
|
||
_dl_profile = &envline[11];
|
||
break;
|
||
|
||
case 8:
|
||
/* Do we bind early? */
|
||
if (memcmp (&envline[3], "BIND_NOW", 8) == 0)
|
||
{
|
||
bind_now = envline[12] != '\0';
|
||
break;
|
||
}
|
||
if (memcmp (&envline[3], "BIND_NOT", 8) == 0)
|
||
_dl_bind_not = envline[12] != '\0';
|
||
break;
|
||
|
||
case 9:
|
||
/* Test whether we want to see the content of the auxiliary
|
||
array passed up from the kernel. */
|
||
if (memcmp (&envline[3], "SHOW_AUXV", 9) == 0)
|
||
_dl_show_auxv ();
|
||
break;
|
||
|
||
case 10:
|
||
/* Mask for the important hardware capabilities. */
|
||
if (memcmp (&envline[3], "HWCAP_MASK", 10) == 0)
|
||
_dl_hwcap_mask = strtoul (&envline[14], NULL, 0);
|
||
break;
|
||
|
||
case 11:
|
||
/* Path where the binary is found. */
|
||
if (!__libc_enable_secure
|
||
&& memcmp (&envline[3], "ORIGIN_PATH", 11) == 0)
|
||
_dl_origin_path = &envline[15];
|
||
break;
|
||
|
||
case 12:
|
||
/* The library search path. */
|
||
if (memcmp (&envline[3], "LIBRARY_PATH", 12) == 0)
|
||
{
|
||
library_path = &envline[16];
|
||
break;
|
||
}
|
||
|
||
/* Where to place the profiling data file. */
|
||
if (memcmp (&envline[3], "DEBUG_OUTPUT", 12) == 0)
|
||
{
|
||
debug_output = &envline[16];
|
||
break;
|
||
}
|
||
|
||
if (memcmp (&envline[3], "DYNAMIC_WEAK", 12) == 0)
|
||
_dl_dynamic_weak = 1;
|
||
break;
|
||
|
||
case 14:
|
||
/* Where to place the profiling data file. */
|
||
if (!__libc_enable_secure
|
||
&& memcmp (&envline[3], "PROFILE_OUTPUT", 14) == 0)
|
||
{
|
||
_dl_profile_output = &envline[18];
|
||
if (*_dl_profile_output == '\0')
|
||
_dl_profile_output = "/var/tmp";
|
||
}
|
||
break;
|
||
|
||
case 20:
|
||
/* The mode of the dynamic linker can be set. */
|
||
if (memcmp (&envline[3], "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
|
||
}
|
||
}
|
||
|
||
/* Extra security for SUID binaries. Remove all dangerous environment
|
||
variables. */
|
||
if (__libc_enable_secure)
|
||
{
|
||
static const char *unsecure_envvars[] =
|
||
{
|
||
UNSECURE_ENVVARS,
|
||
#ifdef EXTRA_UNSECURE_ENVVARS
|
||
EXTRA_UNSECURE_ENVVARS
|
||
#endif
|
||
};
|
||
size_t cnt;
|
||
|
||
if (preloadlist != NULL)
|
||
unsetenv ("LD_PRELOAD");
|
||
if (library_path != NULL)
|
||
unsetenv ("LD_LIBRARY_PATH");
|
||
if (_dl_origin_path != NULL)
|
||
unsetenv ("LD_ORIGIN_PATH");
|
||
if (debug_output != NULL)
|
||
unsetenv ("LD_DEBUG_OUTPUT");
|
||
if (_dl_profile != NULL)
|
||
unsetenv ("LD_PROFILE");
|
||
|
||
for (cnt = 0;
|
||
cnt < sizeof (unsecure_envvars) / sizeof (unsecure_envvars[0]);
|
||
++cnt)
|
||
unsetenv (unsecure_envvars[cnt]);
|
||
|
||
if (__access ("/etc/suid-debug", F_OK) != 0)
|
||
unsetenv ("MALLOC_CHECK_");
|
||
}
|
||
|
||
/* The name of the object to profile cannot be empty. */
|
||
if (_dl_profile != NULL && *_dl_profile == '\0')
|
||
_dl_profile = NULL;
|
||
|
||
/* 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. */
|
||
if (any_debug && debug_output != NULL && !__libc_enable_secure)
|
||
{
|
||
#ifdef O_NOFOLLOW
|
||
const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW;
|
||
#else
|
||
const int flags = O_WRONLY | O_APPEND | O_CREAT;
|
||
#endif
|
||
size_t name_len = strlen (debug_output);
|
||
char buf[name_len + 12];
|
||
char *startp;
|
||
|
||
buf[name_len + 11] = '\0';
|
||
startp = _itoa_word (__getpid (), &buf[name_len + 11], 10, 0);
|
||
*--startp = '.';
|
||
startp = memcpy (startp - name_len, debug_output, name_len);
|
||
|
||
_dl_debug_fd = __open (startp, flags, 0666);
|
||
if (_dl_debug_fd == -1)
|
||
/* We use standard output if opening the file failed. */
|
||
_dl_debug_fd = STDOUT_FILENO;
|
||
}
|
||
|
||
/* LAZY is determined by the environment variable LD_WARN and
|
||
LD_BIND_NOW if we trace the binary. */
|
||
if (__builtin_expect (mode, normal) == trace)
|
||
*lazyp = _dl_verbose ? !bind_now : -1;
|
||
else
|
||
*lazyp = !bind_now;
|
||
|
||
*modep = mode;
|
||
}
|
||
|
||
|
||
/* Print the various times we collected. */
|
||
static void
|
||
print_statistics (void)
|
||
{
|
||
char buf[200];
|
||
#ifndef HP_TIMING_NONAVAIL
|
||
char *cp;
|
||
char *wp;
|
||
|
||
/* Total time rtld used. */
|
||
if (HP_TIMING_AVAIL)
|
||
{
|
||
HP_TIMING_PRINT (buf, sizeof (buf), rtld_total_time);
|
||
_dl_debug_message (1, "\nruntime linker statistics:\n"
|
||
" total startup time in dynamic loader: ",
|
||
buf, "\n", NULL);
|
||
}
|
||
|
||
/* Print relocation statistics. */
|
||
if (HP_TIMING_AVAIL)
|
||
{
|
||
HP_TIMING_PRINT (buf, sizeof (buf), relocate_time);
|
||
_dl_debug_message (1, " time needed for relocation: ", buf,
|
||
NULL);
|
||
cp = _itoa_word ((1000 * relocate_time) / rtld_total_time,
|
||
buf + sizeof (buf), 10, 0);
|
||
wp = buf;
|
||
switch (buf + sizeof (buf) - cp)
|
||
{
|
||
case 3:
|
||
*wp++ = *cp++;
|
||
case 2:
|
||
*wp++ = *cp++;
|
||
case 1:
|
||
*wp++ = '.';
|
||
*wp++ = *cp++;
|
||
}
|
||
*wp = '\0';
|
||
_dl_debug_message (0, " (", buf, "%)\n", NULL);
|
||
}
|
||
#endif
|
||
buf[sizeof (buf) - 1] = '\0';
|
||
_dl_debug_message (1, " number of relocations: ",
|
||
_itoa_word (_dl_num_relocations,
|
||
buf + sizeof (buf) - 1, 10, 0),
|
||
"\n", NULL);
|
||
|
||
#ifndef HP_TIMING_NONAVAIL
|
||
/* Time spend while loading the object and the dependencies. */
|
||
if (HP_TIMING_AVAIL)
|
||
{
|
||
HP_TIMING_PRINT (buf, sizeof (buf), load_time);
|
||
_dl_debug_message (1, " time needed to load objects: ", buf,
|
||
NULL);
|
||
cp = _itoa_word ((1000 * load_time) / rtld_total_time,
|
||
buf + sizeof (buf), 10, 0);
|
||
wp = buf;
|
||
switch (buf + sizeof (buf) - cp)
|
||
{
|
||
case 3:
|
||
*wp++ = *cp++;
|
||
case 2:
|
||
*wp++ = *cp++;
|
||
case 1:
|
||
*wp++ = '.';
|
||
*wp++ = *cp++;
|
||
}
|
||
*wp = '\0';
|
||
_dl_debug_message (0, " (", buf, "%)\n", NULL);
|
||
}
|
||
#endif
|
||
}
|