272 lines
6.8 KiB
C
272 lines
6.8 KiB
C
/* Operating system support for run-time dynamic linker. Generic Unix version.
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Copyright (C) 1995, 1996, 1997, 1998 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 <elf.h>
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#include <entry.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 <fcntl.h>
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#include <link.h>
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#include <unistd.h>
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#include <stdio-common/_itoa.h>
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#include <dl-machine.h>
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#include <dl-procinfo.h>
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extern int _dl_argc;
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extern char **_dl_argv;
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extern char **_environ;
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extern size_t _dl_pagesize;
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extern const char *_dl_platform;
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extern unsigned long _dl_hwcap;
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extern size_t _dl_platformlen;
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extern void _end;
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extern void ENTRY_POINT (void);
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ElfW(Addr) _dl_base_addr;
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int __libc_enable_secure;
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int __libc_multiple_libcs; /* Defining this here avoids the inclusion
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of init-first. */
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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 *) cookie; \
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(argv) = (char **) 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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uid_t euid = 0;
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gid_t gid = 0;
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gid_t egid = 0;
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unsigned int seen;
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DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, _dl_argv, _environ, _dl_auxv);
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user_entry = (ElfW(Addr)) &ENTRY_POINT;
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_dl_platform = NULL; /* Default to nothing known about the platform. */
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seen = 0;
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#define M(type) (1 << (type))
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for (av = _dl_auxv; av->a_type != AT_NULL; seen |= M ((++av)->a_type))
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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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_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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case AT_BASE:
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_dl_base_addr = av->a_un.a_val;
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break;
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case AT_UID:
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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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gid = av->a_un.a_val;
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break;
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case AT_EUID:
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euid = av->a_un.a_val;
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break;
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case AT_EGID:
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egid = av->a_un.a_val;
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break;
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case AT_PLATFORM:
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_dl_platform = av->a_un.a_ptr;
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break;
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case AT_HWCAP:
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_dl_hwcap = av->a_un.a_val;
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break;
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}
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/* Linux doesn't provide us with any of these values on the stack
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when the dynamic linker is run directly as a program. */
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#define SEE(UID, uid) if ((seen & M (AT_##UID)) == 0) uid = __get##uid ()
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SEE (UID, uid);
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SEE (GID, gid);
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SEE (EUID, euid);
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SEE (EGID, egid);
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__libc_enable_secure = uid != euid || gid != egid;
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if (_dl_pagesize == 0)
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_dl_pagesize = __getpagesize ();
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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 (_dl_platform != NULL)
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_dl_platformlen = strlen (_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 (_dl_pagesize - ((&_end - (void *) 0) & (_dl_pagesize - 1)));
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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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_dl_sysdep_start_cleanup (void)
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{
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}
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void
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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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for (av = _dl_auxv; av->a_type != AT_NULL; ++av)
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switch (av->a_type)
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{
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case AT_PHDR:
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_dl_sysdep_message ("AT_PHDR: 0x",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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16, 0),
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"\n", NULL);
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break;
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case AT_PHNUM:
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_dl_sysdep_message ("AT_PHNUM: ",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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10, 0),
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"\n", NULL);
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break;
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case AT_PAGESZ:
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_dl_sysdep_message ("AT_PAGESZ: ",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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10, 0),
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"\n", NULL);
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break;
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case AT_ENTRY:
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_dl_sysdep_message ("AT_ENTRY: 0x",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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16, 0),
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"\n", NULL);
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break;
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case AT_BASE:
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_dl_sysdep_message ("AT_BASE: 0x",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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16, 0),
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"\n", NULL);
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break;
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case AT_UID:
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_dl_sysdep_message ("AT_UID: ",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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10, 0),
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"\n", NULL);
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break;
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case AT_GID:
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_dl_sysdep_message ("AT_GID: ",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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10, 0),
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"\n", NULL);
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break;
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case AT_EUID:
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_dl_sysdep_message ("AT_EUID: ",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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10, 0),
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"\n", NULL);
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break;
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case AT_EGID:
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_dl_sysdep_message ("AT_EGID: ",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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10, 0),
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"\n", NULL);
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break;
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case AT_PLATFORM:
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_dl_sysdep_message ("AT_PLATFORM: ", av->a_un.a_ptr, "\n", NULL);
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break;
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case AT_HWCAP:
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if (_dl_procinfo (av->a_un.a_val) < 0)
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_dl_sysdep_message ("AT_HWCAP: ",
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_itoa_word (av->a_un.a_val, buf + sizeof buf - 1,
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16, 0),
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"\n", NULL);
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break;
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}
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}
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/* Walk through the environment of the process and return all entries
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starting with `LD_'. */
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char *
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_dl_next_ld_env_entry (char ***position)
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{
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char **current = *position;
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char *result = NULL;
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if (current == NULL)
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/* We start over. */
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current = _environ;
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while (result == NULL && *current != NULL)
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{
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if ((*current)[0] == 'L' && (*current)[1] == 'D' && (*current)[2] == '_')
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result = *current;
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++current;
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}
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/* Save current position for next visit. */
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*position = current;
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return result;
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}
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