436 lines
12 KiB
C
436 lines
12 KiB
C
/* Operating system support for run-time dynamic linker. Generic Unix version.
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Copyright (C) 1995-1998, 2000, 2001, 2002 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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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 = 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;
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static ElfW(auxv_t) *_dl_auxv;
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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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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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uid_t uid = 0;
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gid_t gid = 0;
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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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unsigned int seen = 0;
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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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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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GL(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 = av->a_un.a_ptr;
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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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GL(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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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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case AT_PLATFORM:
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GL(dl_platform) = av->a_un.a_ptr;
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break;
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case AT_HWCAP:
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GL(dl_hwcap) = av->a_un.a_val;
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break;
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case AT_CLKTCK:
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GL(dl_clktck) = av->a_un.a_val;
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break;
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case AT_FPUCW:
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GL(dl_fpu_control) = av->a_un.a_val;
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break;
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}
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#ifdef DL_SYSDEP_OSCHECK
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DL_SYSDEP_OSCHECK (dl_fatal);
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#endif
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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 mattch 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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#ifndef HAVE_AUX_PAGESIZE
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if (GL(dl_pagesize) == 0)
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GL(dl_pagesize) = __getpagesize ();
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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 (GL(dl_platform) != NULL)
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GL(dl_platformlen) = strlen (GL(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 (GL(dl_pagesize) - ((&_end - (void *) 0) & (GL(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 { dec, hex, str } 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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};
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unsigned int idx = (unsigned int) (av->a_type - 2);
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assert (AT_NULL == 0);
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assert (AT_IGNORE == 1);
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if (idx < sizeof (auxvars) / sizeof (auxvars[0]))
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{
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if (av->a_type != AT_HWCAP || _dl_procinfo (av->a_un.a_val) < 0)
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{
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const char *val = av->a_un.a_ptr;
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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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}
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}
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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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unsigned long int masked = GL(dl_hwcap) & GL(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; (~((1UL << n) - 1) & masked) != 0; ++n)
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if ((masked & (1UL << n)) != 0)
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++cnt;
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if (cnt == 0)
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{
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/* If we have platform name and no important capability we only have
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the base directory to search. */
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result = (struct r_strlenpair *) malloc (sizeof (*result));
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if (result == NULL)
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{
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no_memory:
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INTUSE(_dl_signal_error) (ENOMEM, NULL, NULL,
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N_("cannot create capability list"));
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}
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result[0].str = (char *) result; /* Does not really matter. */
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result[0].len = 0;
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*sz = 1;
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return result;
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}
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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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for (n = 0; masked != 0; ++n)
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if ((masked & (1UL << 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 ^= 1UL << 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;
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temp[m].len = platform_len;
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++m;
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}
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assert (m == cnt);
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/* Determine the total size of all strings together. */
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if (cnt == 1)
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total = temp[0].len;
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else
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{
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total = (1UL << (cnt - 2)) * (temp[0].len + temp[cnt - 1].len + 2);
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for (n = 1; n + 1 < cnt; ++n)
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total += (1UL << (cnt - 3)) * (temp[n].len + 1);
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}
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/* The result structure: we use a very compressed way to store the
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various combinations of capability names. */
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*sz = 1 << cnt;
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result = (struct r_strlenpair *) malloc (*sz * sizeof (*result) + total);
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if (result == NULL)
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goto no_memory;
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if (cnt == 1)
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{
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result[0].str = (char *) (result + *sz);
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result[0].len = temp[0].len + 1;
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result[1].str = (char *) (result + *sz);
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result[1].len = 0;
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cp = __mempcpy ((char *) (result + *sz), temp[0].str, temp[0].len);
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*cp = '/';
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*sz = 2;
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*max_capstrlen = result[0].len;
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return result;
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}
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/* Fill in the information. This follows the following scheme
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(indeces from TEMP for four strings):
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entry #0: 0, 1, 2, 3 binary: 1111
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#1: 0, 1, 3 1101
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#2: 0, 2, 3 1011
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#3: 0, 3 1001
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This allows the representation of all possible combinations of
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capability names in the string. First generate the strings. */
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result[1].str = result[0].str = cp = (char *) (result + *sz);
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#define add(idx) \
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cp = __mempcpy (__mempcpy (cp, temp[idx].str, temp[idx].len), "/", 1);
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if (cnt == 2)
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{
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add (1);
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add (0);
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}
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else
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{
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n = 1 << cnt;
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do
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{
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n -= 2;
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/* We always add the last string. */
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add (cnt - 1);
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/* Add the strings which have the bit set in N. */
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for (m = cnt - 2; m > 0; --m)
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if ((n & (1 << m)) != 0)
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add (m);
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/* Always add the first string. */
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add (0);
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}
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while (n != 0);
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}
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#undef add
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/* Now we are ready to install the string pointers and length. */
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for (n = 0; n < (1UL << cnt); ++n)
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result[n].len = 0;
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n = cnt;
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do
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{
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size_t mask = 1 << --n;
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rp = result;
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for (m = 1 << cnt; m > 0; ++rp)
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if ((--m & mask) != 0)
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rp->len += temp[n].len + 1;
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}
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while (n != 0);
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/* The first half of the strings all include the first string. */
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n = (1 << cnt) - 2;
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rp = &result[2];
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while (n != (1UL << (cnt - 1)))
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{
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if ((--n & 1) != 0)
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rp[0].str = rp[-2].str + rp[-2].len;
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else
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rp[0].str = rp[-1].str;
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++rp;
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}
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/* The second have starts right after the first part of the string of
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corresponding entry in the first half. */
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do
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{
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rp[0].str = rp[-(1 << (cnt - 1))].str + temp[cnt - 1].len + 1;
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++rp;
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}
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while (--n != 0);
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/* The maximum string length. */
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*max_capstrlen = result[0].len;
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return result;
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}
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