mirror of
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314 lines
8.0 KiB
C
314 lines
8.0 KiB
C
/* Support for dynamic linking code in static libc.
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Copyright (C) 1996-2002, 2003, 2004, 2005 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 Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the 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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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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/* This file defines some things that for the dynamic linker are defined in
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rtld.c and dl-sysdep.c in ways appropriate to bootstrap dynamic linking. */
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#include <errno.h>
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#include <libintl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <ldsodefs.h>
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#include <dl-machine.h>
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#include <bits/libc-lock.h>
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#include <dl-cache.h>
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#include <dl-librecon.h>
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#include <unsecvars.h>
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#include <hp-timing.h>
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extern char *__progname;
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char **_dl_argv = &__progname; /* This is checked for some error messages. */
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/* Name of the architecture. */
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const char *_dl_platform;
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size_t _dl_platformlen;
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int _dl_debug_mask;
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int _dl_lazy;
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ElfW(Addr) _dl_use_load_bias = -2;
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int _dl_dynamic_weak;
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/* If nonzero print warnings about problematic situations. */
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int _dl_verbose;
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/* We never do profiling. */
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const char *_dl_profile;
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const char *_dl_profile_output;
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/* Names of shared object for which the RUNPATHs and RPATHs should be
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ignored. */
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const char *_dl_inhibit_rpath;
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/* The map for the object we will profile. */
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struct link_map *_dl_profile_map;
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/* This is the address of the last stack address ever used. */
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void *__libc_stack_end;
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/* Path where the binary is found. */
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const char *_dl_origin_path;
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/* Nonzero if runtime lookup should not update the .got/.plt. */
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int _dl_bind_not;
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/* Namespace information. */
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struct link_namespaces _dl_ns[DL_NNS];
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/* Incremented whenever something may have been added to dl_loaded. */
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unsigned long long _dl_load_adds;
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/* Fake scope. In dynamically linked binaries this is the scope of the
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main application but here we don't have something like this. So
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create a fake scope containing nothing. */
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struct r_scope_elem _dl_initial_searchlist;
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#ifndef HAVE_INLINED_SYSCALLS
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/* Nonzero during startup. */
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int _dl_starting_up = 1;
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#endif
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/* Get architecture specific initializer. */
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#include <dl-procinfo.c>
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/* We expect less than a second for relocation. */
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#ifdef HP_SMALL_TIMING_AVAIL
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# undef HP_TIMING_AVAIL
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# define HP_TIMING_AVAIL HP_SMALL_TIMING_AVAIL
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#endif
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/* Initial value of the CPU clock. */
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#ifndef HP_TIMING_NONAVAIL
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hp_timing_t _dl_cpuclock_offset;
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#endif
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#ifdef USE_TLS
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void (*_dl_init_static_tls) (struct link_map *) = &_dl_nothread_init_static_tls;
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#endif
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size_t _dl_pagesize;
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unsigned int _dl_osversion;
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/* All known directories in sorted order. */
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struct r_search_path_elem *_dl_all_dirs;
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/* All directories after startup. */
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struct r_search_path_elem *_dl_init_all_dirs;
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/* The object to be initialized first. */
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struct link_map *_dl_initfirst;
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/* Descriptor to write debug messages to. */
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int _dl_debug_fd = STDERR_FILENO;
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int _dl_correct_cache_id = _DL_CACHE_DEFAULT_ID;
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ElfW(Phdr) *_dl_phdr;
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size_t _dl_phnum;
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uint64_t _dl_hwcap __attribute__ ((nocommon));
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/* Prevailing state of the stack, PF_X indicating it's executable. */
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ElfW(Word) _dl_stack_flags = PF_R|PF_W|PF_X;
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/* If loading a shared object requires that we make the stack executable
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when it was not, we do it by calling this function.
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It returns an errno code or zero on success. */
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int (*_dl_make_stack_executable_hook) (void **) internal_function
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= _dl_make_stack_executable;
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#ifdef NEED_DL_SYSINFO
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/* Needed for improved syscall handling on at least x86/Linux. */
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uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT;
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#endif
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#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
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/* Address of the ELF headers in the vsyscall page. */
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const ElfW(Ehdr) *_dl_sysinfo_dso;
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#endif
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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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__rtld_lock_define_initialized_recursive (, _dl_load_lock)
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#ifdef HAVE_AUX_VECTOR
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int _dl_clktck;
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void
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internal_function
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_dl_aux_init (ElfW(auxv_t) *av)
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{
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int seen = 0;
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uid_t uid = 0;
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gid_t gid = 0;
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for (; av->a_type != AT_NULL; ++av)
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switch (av->a_type)
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{
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case AT_PAGESZ:
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GLRO(dl_pagesize) = av->a_un.a_val;
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break;
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case AT_CLKTCK:
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GLRO(dl_clktck) = av->a_un.a_val;
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break;
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case AT_PHDR:
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GL(dl_phdr) = (void *) av->a_un.a_val;
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break;
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case AT_PHNUM:
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GL(dl_phnum) = av->a_un.a_val;
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break;
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case AT_HWCAP:
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GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
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break;
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#ifdef NEED_DL_SYSINFO
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case AT_SYSINFO:
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GL(dl_sysinfo) = av->a_un.a_val;
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break;
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#endif
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#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
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case AT_SYSINFO_EHDR:
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GL(dl_sysinfo_dso) = (void *) av->a_un.a_val;
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break;
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#endif
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case AT_UID:
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uid ^= av->a_un.a_val;
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seen |= 1;
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break;
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case AT_EUID:
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uid ^= av->a_un.a_val;
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seen |= 2;
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break;
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case AT_GID:
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gid ^= av->a_un.a_val;
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seen |= 4;
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break;
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case AT_EGID:
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gid ^= av->a_un.a_val;
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seen |= 8;
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break;
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case AT_SECURE:
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seen = -1;
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__libc_enable_secure = av->a_un.a_val;
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__libc_enable_secure_decided = 1;
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break;
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}
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if (seen == 0xf)
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{
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__libc_enable_secure = uid != 0 || gid != 0;
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__libc_enable_secure_decided = 1;
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}
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}
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#endif
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void
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internal_function
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_dl_non_dynamic_init (void)
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{
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if (HP_TIMING_AVAIL)
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HP_TIMING_NOW (_dl_cpuclock_offset);
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if (!_dl_pagesize)
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_dl_pagesize = __getpagesize ();
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_dl_verbose = *(getenv ("LD_WARN") ?: "") == '\0' ? 0 : 1;
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/* Initialize the data structures for the search paths for shared
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objects. */
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_dl_init_paths (getenv ("LD_LIBRARY_PATH"));
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_dl_lazy = *(getenv ("LD_BIND_NOW") ?: "") == '\0';
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_dl_bind_not = *(getenv ("LD_BIND_NOT") ?: "") != '\0';
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_dl_dynamic_weak = *(getenv ("LD_DYNAMIC_WEAK") ?: "") == '\0';
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_dl_profile_output = getenv ("LD_PROFILE_OUTPUT");
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if (_dl_profile_output == NULL || _dl_profile_output[0] == '\0')
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_dl_profile_output
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= &"/var/tmp\0/var/profile"[__libc_enable_secure ? 9 : 0];
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if (__libc_enable_secure)
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{
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static const char unsecure_envvars[] =
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UNSECURE_ENVVARS
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#ifdef EXTRA_UNSECURE_ENVVARS
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EXTRA_UNSECURE_ENVVARS
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#endif
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;
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const char *cp = unsecure_envvars;
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while (cp < unsecure_envvars + sizeof (unsecure_envvars))
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{
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__unsetenv (cp);
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cp = (const char *) __rawmemchr (cp, '\0') + 1;
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}
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if (__access ("/etc/suid-debug", F_OK) != 0)
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__unsetenv ("MALLOC_CHECK_");
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}
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#ifdef DL_PLATFORM_INIT
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DL_PLATFORM_INIT;
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#endif
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#ifdef DL_OSVERSION_INIT
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DL_OSVERSION_INIT;
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#endif
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/* Now determine the length of the platform string. */
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if (_dl_platform != NULL)
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_dl_platformlen = strlen (_dl_platform);
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/* Scan for a program header telling us the stack is nonexecutable. */
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if (_dl_phdr != NULL)
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for (uint_fast16_t i = 0; i < _dl_phnum; ++i)
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if (_dl_phdr[i].p_type == PT_GNU_STACK)
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{
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_dl_stack_flags = _dl_phdr[i].p_flags;
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break;
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}
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}
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const struct r_strlenpair *
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internal_function
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_dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz,
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size_t *max_capstrlen)
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{
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static struct r_strlenpair result;
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static char buf[1];
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result.str = buf; /* Does not really matter. */
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result.len = 0;
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*sz = 1;
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return &result;
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}
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#ifdef DL_SYSINFO_IMPLEMENTATION
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DL_SYSINFO_IMPLEMENTATION
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#endif
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