mirror of
https://sourceware.org/git/glibc.git
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0e077a7eea
* elf/rtld.c [!__ASSUME_AT_EXECFN] (process_envvars): Don't handle LD_ORIGIN_PATH. * elf/dl-sysdep.c (_dl_sysdep_start): Handle AT_EXECFN. * elf/dl-support.c: Define _dl_execfn. Don't define _dl_origin_path if __ASSUME_AT_EXECFN is defined. (_dl_aux_init): Handle AT_EXECFN. * sysdeps/unix/sysv/linux/kernel-features.h: Define __ASSUME_AT_EXECFN for 2.6.27 and up. * sysdeps/generic/ldsodefs.h (rtld_global_ro): Add _dl_execfn. Don't define _dl_origin_path if __ASSUME_AT_EXECFN is defined. * sysdeps/unix/sysv/linux/dl-origin.c (_dl_get_origin): Use _dl_execfn if available and avoid compatibility code if __ASSUME_AT_EXECFN is defined.
585 lines
16 KiB
C
585 lines
16 KiB
C
/* Operating system support for run-time dynamic linker. Generic Unix version.
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Copyright (C) 1995-1998, 2000-2007, 2008 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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#include <assert.h>
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#include <elf.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <libintl.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/types.h>
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#include <sys/stat.h>
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#include <sys/mman.h>
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#include <ldsodefs.h>
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#include <stdio-common/_itoa.h>
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#include <fpu_control.h>
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#include <entry.h>
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#include <dl-machine.h>
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#include <dl-procinfo.h>
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#include <dl-osinfo.h>
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#include <hp-timing.h>
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#include <tls.h>
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#ifdef _DL_FIRST_PLATFORM
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# define _DL_FIRST_EXTRA (_DL_FIRST_PLATFORM + _DL_PLATFORMS_COUNT)
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#else
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# define _DL_FIRST_EXTRA _DL_HWCAP_COUNT
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#endif
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extern char **_environ attribute_hidden;
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extern void _end attribute_hidden;
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/* Protect SUID program against misuse of file descriptors. */
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extern void __libc_check_standard_fds (void);
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#ifdef NEED_DL_BASE_ADDR
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ElfW(Addr) _dl_base_addr;
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#endif
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int __libc_enable_secure attribute_relro = 0;
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INTVARDEF(__libc_enable_secure)
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int __libc_multiple_libcs = 0; /* Defining this here avoids the inclusion
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of init-first. */
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/* This variable contains the lowest stack address ever used. */
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void *__libc_stack_end attribute_relro = NULL;
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rtld_hidden_data_def(__libc_stack_end)
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static ElfW(auxv_t) *_dl_auxv attribute_relro;
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#ifndef DL_FIND_ARG_COMPONENTS
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# define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \
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do { \
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void **_tmp; \
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(argc) = *(long int *) cookie; \
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(argv) = (char **) ((long int *) cookie + 1); \
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(envp) = (argv) + (argc) + 1; \
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for (_tmp = (void **) (envp); *_tmp; ++_tmp) \
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continue; \
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(auxp) = (void *) ++_tmp; \
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} while (0)
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#endif
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#ifndef DL_STACK_END
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# define DL_STACK_END(cookie) ((void *) (cookie))
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#endif
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ElfW(Addr)
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_dl_sysdep_start (void **start_argptr,
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void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
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ElfW(Addr) *user_entry))
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{
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const ElfW(Phdr) *phdr = NULL;
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ElfW(Word) phnum = 0;
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ElfW(Addr) user_entry;
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ElfW(auxv_t) *av;
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#ifdef HAVE_AUX_SECURE
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# define set_seen(tag) (tag) /* Evaluate for the side effects. */
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# define set_seen_secure() ((void) 0)
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#else
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uid_t uid = 0;
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gid_t gid = 0;
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unsigned int seen = 0;
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# define set_seen_secure() (seen = -1)
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# ifdef HAVE_AUX_XID
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# define set_seen(tag) (tag) /* Evaluate for the side effects. */
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# else
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# define M(type) (1 << (type))
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# define set_seen(tag) seen |= M ((tag)->a_type)
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# endif
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#endif
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#ifdef NEED_DL_SYSINFO
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uintptr_t new_sysinfo = 0;
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#endif
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__libc_stack_end = DL_STACK_END (start_argptr);
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DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, INTUSE(_dl_argv), _environ,
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_dl_auxv);
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user_entry = (ElfW(Addr)) ENTRY_POINT;
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GLRO(dl_platform) = NULL; /* Default to nothing known about the platform. */
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for (av = _dl_auxv; av->a_type != AT_NULL; set_seen (av++))
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switch (av->a_type)
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{
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case AT_PHDR:
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phdr = (void *) av->a_un.a_val;
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break;
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case AT_PHNUM:
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phnum = av->a_un.a_val;
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break;
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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_ENTRY:
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user_entry = av->a_un.a_val;
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break;
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#ifdef NEED_DL_BASE_ADDR
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case AT_BASE:
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_dl_base_addr = av->a_un.a_val;
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break;
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#endif
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#ifndef HAVE_AUX_SECURE
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case AT_UID:
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case AT_EUID:
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uid ^= av->a_un.a_val;
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break;
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case AT_GID:
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case AT_EGID:
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gid ^= av->a_un.a_val;
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break;
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#endif
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case AT_SECURE:
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#ifndef HAVE_AUX_SECURE
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seen = -1;
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#endif
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INTUSE(__libc_enable_secure) = av->a_un.a_val;
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break;
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case AT_PLATFORM:
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GLRO(dl_platform) = (void *) 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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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_FPUCW:
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GLRO(dl_fpu_control) = 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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new_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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GLRO(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_EXECFN:
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GLRO(dl_execfn) = (void *) av->a_un.a_val;
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break;
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#ifdef DL_PLATFORM_AUXV
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DL_PLATFORM_AUXV
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#endif
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}
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#ifndef HAVE_AUX_SECURE
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if (seen != -1)
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{
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/* Fill in the values we have not gotten from the kernel through the
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auxiliary vector. */
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# ifndef HAVE_AUX_XID
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# define SEE(UID, var, uid) \
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if ((seen & M (AT_##UID)) == 0) var ^= __get##uid ()
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SEE (UID, uid, uid);
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SEE (EUID, uid, euid);
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SEE (GID, gid, gid);
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SEE (EGID, gid, egid);
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# endif
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/* If one of the two pairs of IDs does not match this is a setuid
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or setgid run. */
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INTUSE(__libc_enable_secure) = uid | gid;
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}
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#endif
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#ifndef HAVE_AUX_PAGESIZE
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if (GLRO(dl_pagesize) == 0)
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GLRO(dl_pagesize) = __getpagesize ();
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#endif
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#if defined NEED_DL_SYSINFO
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/* Only set the sysinfo value if we also have the vsyscall DSO. */
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if (GLRO(dl_sysinfo_dso) != 0 && new_sysinfo)
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GLRO(dl_sysinfo) = new_sysinfo;
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#endif
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#ifdef DL_SYSDEP_INIT
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DL_SYSDEP_INIT;
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#endif
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#ifdef DL_PLATFORM_INIT
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DL_PLATFORM_INIT;
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#endif
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/* Determine the length of the platform name. */
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if (GLRO(dl_platform) != NULL)
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GLRO(dl_platformlen) = strlen (GLRO(dl_platform));
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if (__sbrk (0) == &_end)
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/* The dynamic linker was run as a program, and so the initial break
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starts just after our bss, at &_end. The malloc in dl-minimal.c
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will consume the rest of this page, so tell the kernel to move the
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break up that far. When the user program examines its break, it
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will see this new value and not clobber our data. */
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__sbrk (GLRO(dl_pagesize)
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- ((&_end - (void *) 0) & (GLRO(dl_pagesize) - 1)));
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/* If this is a SUID program we make sure that FDs 0, 1, and 2 are
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allocated. If necessary we are doing it ourself. If it is not
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possible we stop the program. */
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if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
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__libc_check_standard_fds ();
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(*dl_main) (phdr, phnum, &user_entry);
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return user_entry;
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}
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void
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internal_function
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_dl_sysdep_start_cleanup (void)
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{
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}
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void
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internal_function
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_dl_show_auxv (void)
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{
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char buf[64];
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ElfW(auxv_t) *av;
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/* Terminate string. */
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buf[63] = '\0';
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/* The following code assumes that the AT_* values are encoded
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starting from 0 with AT_NULL, 1 for AT_IGNORE, and all other values
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close by (otherwise the array will be too large). In case we have
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to support a platform where these requirements are not fulfilled
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some alternative implementation has to be used. */
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for (av = _dl_auxv; av->a_type != AT_NULL; ++av)
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{
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static const struct
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{
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const char label[20];
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enum { unknown = 0, dec, hex, str, ignore } form;
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} auxvars[] =
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{
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[AT_EXECFD - 2] = { "AT_EXECFD: ", dec },
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[AT_PHDR - 2] = { "AT_PHDR: 0x", hex },
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[AT_PHENT - 2] = { "AT_PHENT: ", dec },
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[AT_PHNUM - 2] = { "AT_PHNUM: ", dec },
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[AT_PAGESZ - 2] = { "AT_PAGESZ: ", dec },
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[AT_BASE - 2] = { "AT_BASE: 0x", hex },
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[AT_FLAGS - 2] = { "AT_FLAGS: 0x", hex },
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[AT_ENTRY - 2] = { "AT_ENTRY: 0x", hex },
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[AT_NOTELF - 2] = { "AT_NOTELF: ", hex },
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[AT_UID - 2] = { "AT_UID: ", dec },
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[AT_EUID - 2] = { "AT_EUID: ", dec },
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[AT_GID - 2] = { "AT_GID: ", dec },
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[AT_EGID - 2] = { "AT_EGID: ", dec },
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[AT_PLATFORM - 2] = { "AT_PLATFORM: ", str },
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[AT_HWCAP - 2] = { "AT_HWCAP: ", hex },
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[AT_CLKTCK - 2] = { "AT_CLKTCK: ", dec },
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[AT_FPUCW - 2] = { "AT_FPUCW: ", hex },
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[AT_DCACHEBSIZE - 2] = { "AT_DCACHEBSIZE: 0x", hex },
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[AT_ICACHEBSIZE - 2] = { "AT_ICACHEBSIZE: 0x", hex },
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[AT_UCACHEBSIZE - 2] = { "AT_UCACHEBSIZE: 0x", hex },
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[AT_IGNOREPPC - 2] = { "AT_IGNOREPPC", ignore },
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[AT_SECURE - 2] = { "AT_SECURE: ", dec },
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[AT_SYSINFO - 2] = { "AT_SYSINFO: 0x", hex },
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[AT_SYSINFO_EHDR - 2] = { "AT_SYSINFO_EHDR: 0x", hex },
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};
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unsigned int idx = (unsigned int) (av->a_type - 2);
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if ((unsigned int) av->a_type < 2u || auxvars[idx].form == ignore)
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continue;
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assert (AT_NULL == 0);
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assert (AT_IGNORE == 1);
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if (av->a_type == AT_HWCAP)
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{
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/* This is handled special. */
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if (_dl_procinfo (av->a_un.a_val) == 0)
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continue;
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}
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if (idx < sizeof (auxvars) / sizeof (auxvars[0])
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&& auxvars[idx].form != unknown)
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{
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const char *val = (char *) av->a_un.a_val;
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if (__builtin_expect (auxvars[idx].form, dec) == dec)
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val = _itoa ((unsigned long int) av->a_un.a_val,
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buf + sizeof buf - 1, 10, 0);
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else if (__builtin_expect (auxvars[idx].form, hex) == hex)
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val = _itoa ((unsigned long int) av->a_un.a_val,
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buf + sizeof buf - 1, 16, 0);
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_dl_printf ("%s%s\n", auxvars[idx].label, val);
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continue;
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}
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/* Unknown value: print a generic line. */
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char buf2[17];
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buf[sizeof (buf2) - 1] = '\0';
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const char *val2 = _itoa ((unsigned long int) av->a_un.a_val,
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buf2 + sizeof buf2 - 1, 16, 0);
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const char *val = _itoa ((unsigned long int) av->a_type,
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buf + sizeof buf - 1, 16, 0);
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_dl_printf ("AT_??? (0x%s): 0x%s\n", val, val2);
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}
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}
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/* Return an array of useful/necessary hardware capability names. */
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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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/* Determine how many important bits are set. */
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uint64_t masked = GLRO(dl_hwcap) & GLRO(dl_hwcap_mask);
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size_t cnt = platform != NULL;
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size_t n, m;
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size_t total;
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struct r_strlenpair *temp;
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struct r_strlenpair *result;
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struct r_strlenpair *rp;
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char *cp;
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/* Count the number of bits set in the masked value. */
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for (n = 0; (~((1ULL << n) - 1) & masked) != 0; ++n)
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if ((masked & (1ULL << n)) != 0)
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++cnt;
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#if (defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO) && defined SHARED
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/* The system-supplied DSO can contain a note of type 2, vendor "GNU".
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This gives us a list of names to treat as fake hwcap bits. */
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const char *dsocaps = NULL;
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size_t dsocapslen = 0;
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if (GLRO(dl_sysinfo_map) != NULL)
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{
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const ElfW(Phdr) *const phdr = GLRO(dl_sysinfo_map)->l_phdr;
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const ElfW(Word) phnum = GLRO(dl_sysinfo_map)->l_phnum;
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for (uint_fast16_t i = 0; i < phnum; ++i)
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if (phdr[i].p_type == PT_NOTE)
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{
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const ElfW(Addr) start = (phdr[i].p_vaddr
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+ GLRO(dl_sysinfo_map)->l_addr);
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const struct
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{
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ElfW(Word) vendorlen;
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ElfW(Word) datalen;
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ElfW(Word) type;
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} *note = (const void *) start;
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while ((ElfW(Addr)) (note + 1) - start < phdr[i].p_memsz)
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{
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#define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
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if (note->type == 2
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&& note->vendorlen == sizeof "GNU"
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&& !memcmp ((note + 1), "GNU", sizeof "GNU")
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&& note->datalen > 2 * sizeof (ElfW(Word)) + 2)
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{
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const ElfW(Word) *p = ((const void *) (note + 1)
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+ ROUND (sizeof "GNU"));
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cnt += *p++;
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++p; /* Skip mask word. */
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dsocaps = (const char *) p;
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dsocapslen = note->datalen - sizeof *p * 2;
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break;
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}
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note = ((const void *) (note + 1)
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+ ROUND (note->vendorlen) + ROUND (note->datalen));
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#undef ROUND
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}
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if (dsocaps != NULL)
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break;
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}
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}
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#endif
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/* For TLS enabled builds always add 'tls'. */
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++cnt;
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/* Create temporary data structure to generate result table. */
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temp = (struct r_strlenpair *) alloca (cnt * sizeof (*temp));
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m = 0;
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#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
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if (dsocaps != NULL)
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{
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const ElfW(Word) mask = ((const ElfW(Word) *) dsocaps)[-1];
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GLRO(dl_hwcap) |= (uint64_t) mask << _DL_FIRST_EXTRA;
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size_t len;
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for (const char *p = dsocaps; p < dsocaps + dsocapslen; p += len + 1)
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{
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uint_fast8_t bit = *p++;
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len = strlen (p);
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/* Skip entries that are not enabled in the mask word. */
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if (__builtin_expect (mask & ((ElfW(Word)) 1 << bit), 1))
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{
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temp[m].str = p;
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temp[m].len = len;
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++m;
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}
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else
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--cnt;
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}
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}
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#endif
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for (n = 0; masked != 0; ++n)
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if ((masked & (1ULL << n)) != 0)
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{
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temp[m].str = _dl_hwcap_string (n);
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temp[m].len = strlen (temp[m].str);
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masked ^= 1ULL << n;
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++m;
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}
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if (platform != NULL)
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{
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temp[m].str = platform;
|
|
temp[m].len = platform_len;
|
|
++m;
|
|
}
|
|
|
|
temp[m].str = "tls";
|
|
temp[m].len = 3;
|
|
++m;
|
|
|
|
assert (m == cnt);
|
|
|
|
/* Determine the total size of all strings together. */
|
|
if (cnt == 1)
|
|
total = temp[0].len + 1;
|
|
else
|
|
{
|
|
total = temp[0].len + temp[cnt - 1].len + 2;
|
|
if (cnt > 2)
|
|
{
|
|
total <<= 1;
|
|
for (n = 1; n + 1 < cnt; ++n)
|
|
total += temp[n].len + 1;
|
|
if (cnt > 3
|
|
&& (cnt >= sizeof (size_t) * 8
|
|
|| total + (sizeof (*result) << 3)
|
|
>= (1UL << (sizeof (size_t) * 8 - cnt + 3))))
|
|
_dl_signal_error (ENOMEM, NULL, NULL,
|
|
N_("cannot create capability list"));
|
|
|
|
total <<= cnt - 3;
|
|
}
|
|
}
|
|
|
|
/* The result structure: we use a very compressed way to store the
|
|
various combinations of capability names. */
|
|
*sz = 1 << cnt;
|
|
result = (struct r_strlenpair *) malloc (*sz * sizeof (*result) + total);
|
|
if (result == NULL)
|
|
_dl_signal_error (ENOMEM, NULL, NULL,
|
|
N_("cannot create capability list"));
|
|
|
|
if (cnt == 1)
|
|
{
|
|
result[0].str = (char *) (result + *sz);
|
|
result[0].len = temp[0].len + 1;
|
|
result[1].str = (char *) (result + *sz);
|
|
result[1].len = 0;
|
|
cp = __mempcpy ((char *) (result + *sz), temp[0].str, temp[0].len);
|
|
*cp = '/';
|
|
*sz = 2;
|
|
*max_capstrlen = result[0].len;
|
|
|
|
return result;
|
|
}
|
|
|
|
/* Fill in the information. This follows the following scheme
|
|
(indeces from TEMP for four strings):
|
|
entry #0: 0, 1, 2, 3 binary: 1111
|
|
#1: 0, 1, 3 1101
|
|
#2: 0, 2, 3 1011
|
|
#3: 0, 3 1001
|
|
This allows the representation of all possible combinations of
|
|
capability names in the string. First generate the strings. */
|
|
result[1].str = result[0].str = cp = (char *) (result + *sz);
|
|
#define add(idx) \
|
|
cp = __mempcpy (__mempcpy (cp, temp[idx].str, temp[idx].len), "/", 1);
|
|
if (cnt == 2)
|
|
{
|
|
add (1);
|
|
add (0);
|
|
}
|
|
else
|
|
{
|
|
n = 1 << (cnt - 1);
|
|
do
|
|
{
|
|
n -= 2;
|
|
|
|
/* We always add the last string. */
|
|
add (cnt - 1);
|
|
|
|
/* Add the strings which have the bit set in N. */
|
|
for (m = cnt - 2; m > 0; --m)
|
|
if ((n & (1 << m)) != 0)
|
|
add (m);
|
|
|
|
/* Always add the first string. */
|
|
add (0);
|
|
}
|
|
while (n != 0);
|
|
}
|
|
#undef add
|
|
|
|
/* Now we are ready to install the string pointers and length. */
|
|
for (n = 0; n < (1UL << cnt); ++n)
|
|
result[n].len = 0;
|
|
n = cnt;
|
|
do
|
|
{
|
|
size_t mask = 1 << --n;
|
|
|
|
rp = result;
|
|
for (m = 1 << cnt; m > 0; ++rp)
|
|
if ((--m & mask) != 0)
|
|
rp->len += temp[n].len + 1;
|
|
}
|
|
while (n != 0);
|
|
|
|
/* The first half of the strings all include the first string. */
|
|
n = (1 << cnt) - 2;
|
|
rp = &result[2];
|
|
while (n != (1UL << (cnt - 1)))
|
|
{
|
|
if ((--n & 1) != 0)
|
|
rp[0].str = rp[-2].str + rp[-2].len;
|
|
else
|
|
rp[0].str = rp[-1].str;
|
|
++rp;
|
|
}
|
|
|
|
/* The second half starts right after the first part of the string of
|
|
the corresponding entry in the first half. */
|
|
do
|
|
{
|
|
rp[0].str = rp[-(1 << (cnt - 1))].str + temp[cnt - 1].len + 1;
|
|
++rp;
|
|
}
|
|
while (--n != 0);
|
|
|
|
/* The maximum string length. */
|
|
*max_capstrlen = result[0].len;
|
|
|
|
return result;
|
|
}
|