This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
2054 lines
52 KiB
C
2054 lines
52 KiB
C
/*
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* Copyright (c) 1993 Paul Kranenburg
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Paul Kranenburg.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/file.h>
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#include <sys/time.h>
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#include <sys/resource.h>
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#include <sys/errno.h>
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#include <sys/mman.h>
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#ifndef MAP_COPY
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#define MAP_COPY MAP_PRIVATE
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#endif
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#include <dlfcn.h>
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#include <err.h>
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#include <fcntl.h>
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#include <a.out.h>
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#include <stab.h>
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#include <stdio.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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#if __STDC__
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#include <stdarg.h>
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#else
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#include <varargs.h>
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#endif
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#include <link.h>
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#include "md.h"
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#include "shlib.h"
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#include "support.h"
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#include "dynamic.h"
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#ifndef MAP_ANON
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#define MAP_ANON 0
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#define anon_open() do { \
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if ((anon_fd = open("/dev/zero", O_RDWR, 0)) == -1) \
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err("open: %s", "/dev/zero"); \
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} while (0)
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#define anon_close() do { \
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(void)close(anon_fd); \
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anon_fd = -1; \
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} while (0)
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#else
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#define anon_open()
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#define anon_close()
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#endif
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/*
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* Structure for building a list of shared objects.
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*/
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struct so_list {
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struct so_map *sol_map; /* Link map for shared object */
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struct so_list *sol_next; /* Next entry in the list */
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};
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/*
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* Loader private data, hung off <so_map>->som_spd
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*/
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struct somap_private {
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int spd_version;
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struct so_map *spd_parent;
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struct so_list *spd_children;
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struct so_map *spd_prev;
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dev_t spd_dev;
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ino_t spd_ino;
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int spd_refcount;
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int spd_flags;
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#define RTLD_MAIN 0x01
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#define RTLD_RTLD 0x02
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#define RTLD_DL 0x04
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#define RTLD_INIT 0x08
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unsigned long a_text; /* text size, if known */
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unsigned long a_data; /* initialized data size */
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unsigned long a_bss; /* uninitialized data size */
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#ifdef SUN_COMPAT
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long spd_offset; /* Correction for Sun main programs */
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#endif
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};
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#define LM_PRIVATE(smp) ((struct somap_private *)(smp)->som_spd)
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#ifdef SUN_COMPAT
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#define LM_OFFSET(smp) (LM_PRIVATE(smp)->spd_offset)
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#else
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#define LM_OFFSET(smp) (0)
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#endif
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/* Base address for section_dispatch_table entries */
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#define LM_LDBASE(smp) (smp->som_addr + LM_OFFSET(smp))
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/* Start of text segment */
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#define LM_TXTADDR(smp) (smp->som_addr == (caddr_t)0 ? PAGSIZ : 0)
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/* Start of run-time relocation_info */
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#define LM_REL(smp) ((struct relocation_info *) \
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(smp->som_addr + LM_OFFSET(smp) + LD_REL((smp)->som_dynamic)))
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/* Start of symbols */
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#define LM_SYMBOL(smp, i) ((struct nzlist *) \
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(smp->som_addr + LM_OFFSET(smp) + LD_SYMBOL((smp)->som_dynamic) + \
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i * (LD_VERSION_NZLIST_P(smp->som_dynamic->d_version) ? \
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sizeof(struct nzlist) : sizeof(struct nlist))))
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/* Start of hash table */
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#define LM_HASH(smp) ((struct rrs_hash *) \
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((smp)->som_addr + LM_OFFSET(smp) + LD_HASH((smp)->som_dynamic)))
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/* Start of strings */
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#define LM_STRINGS(smp) ((char *) \
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((smp)->som_addr + LM_OFFSET(smp) + LD_STRINGS((smp)->som_dynamic)))
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/* Start of search paths */
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#define LM_PATHS(smp) ((char *) \
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((smp)->som_addr + LM_OFFSET(smp) + LD_PATHS((smp)->som_dynamic)))
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/* End of text */
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#define LM_ETEXT(smp) ((char *) \
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((smp)->som_addr + LM_TXTADDR(smp) + LD_TEXTSZ((smp)->som_dynamic)))
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/* Needed shared objects */
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#define LM_NEED(smp) ((struct sod *) \
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((smp)->som_addr + LM_TXTADDR(smp) + LD_NEED((smp)->som_dynamic)))
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/* PLT is in data segment, so don't use LM_OFFSET here */
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#define LM_PLT(smp) ((jmpslot_t *) \
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((smp)->som_addr + LD_PLT((smp)->som_dynamic)))
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/* Parent of link map */
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#define LM_PARENT(smp) (LM_PRIVATE(smp)->spd_parent)
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#ifndef RELOC_EXTERN_P
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#define RELOC_EXTERN_P(s) ((s)->r_extern)
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#endif
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#ifndef RELOC_SYMBOL
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#define RELOC_SYMBOL(s) ((s)->r_symbolnum)
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#endif
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#ifndef RELOC_PCREL_P
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#define RELOC_PCREL_P(s) ((s)->r_pcrel)
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#endif
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static char __main_progname[] = "main";
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static char *main_progname = __main_progname;
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static char us[] = "/usr/libexec/ld.so";
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char **environ;
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char *__progname;
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int errno;
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static uid_t uid, euid;
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static gid_t gid, egid;
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static int careful;
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static int anon_fd = -1;
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static char *ld_bind_now;
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static char *ld_library_path;
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static char *ld_preload;
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static char *ld_tracing;
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static char *ld_suppress_warnings;
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static char *ld_warn_non_pure_code;
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struct so_map *link_map_head;
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struct so_map *link_map_tail;
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struct rt_symbol *rt_symbol_head;
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static void *__dlopen __P((char *, int));
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static int __dlclose __P((void *));
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static void *__dlsym __P((void *, char *));
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static char *__dlerror __P((void));
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static void __dlexit __P((void));
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static struct ld_entry ld_entry = {
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__dlopen, __dlclose, __dlsym, __dlerror, __dlexit
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};
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void xprintf __P((char *, ...));
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static struct so_map *map_object __P(( char *,
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struct sod *,
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struct so_map *));
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static int map_preload __P((void));
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static int map_sods __P((struct so_map *));
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static int reloc_and_init __P((struct so_map *, int));
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static void unmap_object __P((struct so_map *, int));
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static struct so_map *alloc_link_map __P(( char *, struct sod *,
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struct so_map *, caddr_t,
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struct _dynamic *));
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static void free_link_map __P((struct so_map *));
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static inline int check_text_reloc __P(( struct relocation_info *,
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struct so_map *,
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caddr_t));
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static int reloc_map __P((struct so_map *, int));
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static void reloc_copy __P((struct so_map *));
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static void init_object __P((struct so_map *));
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static void init_sods __P((struct so_list *));
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static int call_map __P((struct so_map *, char *));
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static char *findhint __P((char *, int, int *));
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static char *rtfindlib __P((char *, int, int));
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static char *rtfindfile __P((char *));
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void binder_entry __P((void));
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long binder __P((jmpslot_t *));
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static struct nzlist *lookup __P((char *, struct so_map **, int));
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static inline struct rt_symbol *lookup_rts __P((char *));
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static struct rt_symbol *enter_rts __P((char *, long, int, caddr_t,
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long, struct so_map *));
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static void die __P((void));
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static void generror __P((char *, ...));
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static int maphints __P((void));
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static void unmaphints __P((void));
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static void ld_trace __P((struct so_map *));
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static void rt_readenv __P((void));
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static int hinthash __P((char *, int));
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int rtld __P((int, struct crt_ldso *, struct _dynamic *));
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static inline int
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strcmp (register const char *s1, register const char *s2)
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{
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while (*s1 == *s2++)
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if (*s1++ == 0)
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return (0);
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return (*(unsigned char *)s1 - *(unsigned char *)--s2);
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}
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#include "md-static-funcs.c"
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/*
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* Called from assembler stub that has set up crtp (passed from crt0)
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* and dp (our __DYNAMIC).
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*/
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int
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rtld(version, crtp, dp)
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int version;
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struct crt_ldso *crtp;
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struct _dynamic *dp;
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{
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struct relocation_info *reloc;
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struct relocation_info *reloc_limit; /* End+1 of relocation */
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struct so_debug *ddp;
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struct so_map *main_map;
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struct so_map *smp;
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char *add_paths;
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/* Check version */
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if (version != CRT_VERSION_BSD_2 &&
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version != CRT_VERSION_BSD_3 &&
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version != CRT_VERSION_BSD_4 &&
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version != CRT_VERSION_SUN)
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return -1;
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/* Fixup __DYNAMIC structure */
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(long)dp->d_un.d_sdt += crtp->crt_ba;
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/* Relocate ourselves */
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reloc = (struct relocation_info *) (LD_REL(dp) + crtp->crt_ba);
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reloc_limit =
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(struct relocation_info *) ((char *) reloc + LD_RELSZ(dp));
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while(reloc < reloc_limit) {
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/*
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* Objects linked with "-Bsymbolic" (in particular, ld.so
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* itself) can end up having unused relocation entries at
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* the end. These can be detected by the fact that they
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* have an address of 0.
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*/
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if(reloc->r_address == 0) /* We're done */
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break;
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md_relocate_simple(reloc, crtp->crt_ba,
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reloc->r_address + crtp->crt_ba);
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++reloc;
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}
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if (version >= CRT_VERSION_BSD_4)
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__progname = crtp->crt_ldso;
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if (version >= CRT_VERSION_BSD_3)
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main_progname = crtp->crt_prog;
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/* Some buggy versions of crt0.o have crt_ldso filled in as NULL. */
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if (__progname == NULL)
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__progname = us;
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/* Fill in some fields in _DYNAMIC or crt structure */
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if (version >= CRT_VERSION_BSD_4)
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crtp->crt_ldentry = &ld_entry; /* crt */
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else
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crtp->crt_dp->d_entry = &ld_entry; /* _DYNAMIC */
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/* Setup out (private) environ variable */
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environ = crtp->crt_ep;
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/* Get user and group identifiers */
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uid = getuid(); euid = geteuid();
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gid = getgid(); egid = getegid();
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careful = (uid != euid) || (gid != egid);
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rt_readenv();
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anon_open();
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/* Make a link map entry for the main program */
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main_map = alloc_link_map(main_progname,
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(struct sod *) NULL, (struct so_map *) NULL,
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(caddr_t) 0, crtp->crt_dp);
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LM_PRIVATE(main_map)->spd_refcount++;
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LM_PRIVATE(main_map)->spd_flags |= RTLD_MAIN;
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/* Make a link map entry for ourselves */
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smp = alloc_link_map(us,
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(struct sod *) NULL, (struct so_map *) NULL,
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(caddr_t) crtp->crt_ba, dp);
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LM_PRIVATE(smp)->spd_refcount++;
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LM_PRIVATE(smp)->spd_flags |= RTLD_RTLD;
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/*
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* Setup the executable's run path
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*/
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if (version >= CRT_VERSION_BSD_4) {
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add_paths = LM_PATHS(main_map);
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if (add_paths)
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add_search_path(add_paths);
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}
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/*
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* Setup the directory search list for findshlib. We use only
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* the standard search path. Any extra directories from
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* LD_LIBRARY_PATH are searched explicitly, in rtfindlib.
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*/
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std_search_path();
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/* Map in LD_PRELOADs before the main program's shared objects so we
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can intercept those calls */
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if (ld_preload != NULL) {
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if(map_preload() == -1) /* Failed */
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die();
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}
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/* Map all the shared objects that the main program depends upon */
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if(map_sods(main_map) == -1)
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die();
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if(ld_tracing) { /* We're done */
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ld_trace(link_map_head);
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exit(0);
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}
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crtp->crt_dp->d_un.d_sdt->sdt_loaded = link_map_head->som_next;
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/* Relocate and initialize all mapped objects */
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if(reloc_and_init(main_map, ld_bind_now != NULL) == -1) /* Failed */
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die();
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ddp = crtp->crt_dp->d_debug;
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ddp->dd_cc = rt_symbol_head;
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if (ddp->dd_in_debugger) {
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caddr_t addr = (caddr_t)((long)crtp->crt_bp & (~(PAGSIZ - 1)));
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|
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/* Set breakpoint for the benefit of debuggers */
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if (mprotect(addr, PAGSIZ,
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PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
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err(1, "Cannot set breakpoint (%s)", main_progname);
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}
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md_set_breakpoint((long)crtp->crt_bp, (long *)&ddp->dd_bpt_shadow);
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if (mprotect(addr, PAGSIZ, PROT_READ|PROT_EXEC) == -1) {
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err(1, "Cannot re-protect breakpoint (%s)",
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main_progname);
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}
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ddp->dd_bpt_addr = crtp->crt_bp;
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if (link_map_head)
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ddp->dd_sym_loaded = 1;
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}
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|
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/* Close the hints file */
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unmaphints();
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|
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/* Close our file descriptor */
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(void)close(crtp->crt_ldfd);
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anon_close();
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return LDSO_VERSION_HAS_DLEXIT;
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}
|
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|
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void
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ld_trace(smp)
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struct so_map *smp;
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{
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char *fmt1, *fmt2, *fmt, *main_local;
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int c;
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if ((main_local = getenv("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
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main_local = "";
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|
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if ((fmt1 = getenv("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
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fmt1 = "\t-l%o.%m => %p (%x)\n";
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|
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if ((fmt2 = getenv("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
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fmt2 = "\t%o (%x)\n";
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|
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for (; smp; smp = smp->som_next) {
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struct sod *sodp;
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char *name, *path;
|
|
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if ((sodp = smp->som_sod) == NULL)
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continue;
|
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name = (char *)sodp->sod_name;
|
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if (LM_PARENT(smp))
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name += (long)LM_LDBASE(LM_PARENT(smp));
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|
|
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if ((path = smp->som_path) == NULL)
|
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path = "not found";
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|
|
|
fmt = sodp->sod_library ? fmt1 : fmt2;
|
|
while ((c = *fmt++) != '\0') {
|
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switch (c) {
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default:
|
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putchar(c);
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continue;
|
|
case '\\':
|
|
switch (c = *fmt) {
|
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case '\0':
|
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continue;
|
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case 'n':
|
|
putchar('\n');
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break;
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case 't':
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putchar('\t');
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break;
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}
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break;
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|
case '%':
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|
switch (c = *fmt) {
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case '\0':
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continue;
|
|
case '%':
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|
default:
|
|
putchar(c);
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break;
|
|
case 'A':
|
|
printf("%s", main_local);
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|
break;
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|
case 'a':
|
|
printf("%s", main_progname);
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|
break;
|
|
case 'o':
|
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printf("%s", name);
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break;
|
|
case 'm':
|
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printf("%d", sodp->sod_major);
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|
break;
|
|
case 'n':
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printf("%d", sodp->sod_minor);
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|
break;
|
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case 'p':
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printf("%s", path);
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break;
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case 'x':
|
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printf("%p", smp->som_addr);
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break;
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}
|
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break;
|
|
}
|
|
++fmt;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Allocate a new link map and return a pointer to it.
|
|
*
|
|
* PATH is the pathname of the shared object.
|
|
*
|
|
* SODP is a pointer to the shared object dependency structure responsible
|
|
* for causing the new object to be loaded. PARENT is the shared object
|
|
* into which SODP points. Both can be NULL if the new object is not
|
|
* being loaded as a result of a shared object dependency.
|
|
*
|
|
* ADDR is the address at which the object has been mapped. DP is a pointer
|
|
* to its _dynamic structure.
|
|
*/
|
|
static struct so_map *
|
|
alloc_link_map(path, sodp, parent, addr, dp)
|
|
char *path;
|
|
struct sod *sodp;
|
|
struct so_map *parent;
|
|
caddr_t addr;
|
|
struct _dynamic *dp;
|
|
{
|
|
struct so_map *smp;
|
|
struct somap_private *smpp;
|
|
size_t smp_size;
|
|
|
|
#ifdef DEBUG /* { */
|
|
xprintf("alloc_link_map: \"%s\" at %p\n", path, addr);
|
|
#endif /* } */
|
|
|
|
/*
|
|
* Allocate so_map and private area with a single malloc. Round
|
|
* up the size of so_map so the private area is aligned.
|
|
*/
|
|
smp_size = ((((sizeof(struct so_map)) + sizeof (void *) - 1) /
|
|
sizeof (void *)) * sizeof (void *));
|
|
|
|
smp = (struct so_map *)xmalloc(smp_size +
|
|
sizeof (struct somap_private));
|
|
smpp = (struct somap_private *) (((caddr_t) smp) + smp_size);
|
|
|
|
/* Link the new entry into the list of link maps */
|
|
smp->som_next = NULL;
|
|
smpp->spd_prev = link_map_tail;
|
|
if(link_map_tail == NULL) /* First link map entered into list */
|
|
link_map_head = link_map_tail = smp;
|
|
else { /* Append to end of list */
|
|
link_map_tail->som_next = smp;
|
|
link_map_tail = smp;
|
|
}
|
|
|
|
smp->som_addr = addr;
|
|
smp->som_path = path ? strdup(path) : NULL;
|
|
smp->som_sod = sodp;
|
|
smp->som_dynamic = dp;
|
|
smp->som_spd = (caddr_t)smpp;
|
|
|
|
smpp->spd_refcount = 0;
|
|
smpp->spd_flags = 0;
|
|
smpp->spd_parent = parent;
|
|
smpp->spd_children = NULL;
|
|
smpp->a_text = 0;
|
|
smpp->a_data = 0;
|
|
smpp->a_bss = 0;
|
|
#ifdef SUN_COMPAT
|
|
smpp->spd_offset =
|
|
(addr==0 && dp && dp->d_version==LD_VERSION_SUN) ? PAGSIZ : 0;
|
|
#endif
|
|
return smp;
|
|
}
|
|
|
|
/*
|
|
* Remove the specified link map entry from the list of link maps, and free
|
|
* the associated storage.
|
|
*/
|
|
static void
|
|
free_link_map(smp)
|
|
struct so_map *smp;
|
|
{
|
|
struct somap_private *smpp = LM_PRIVATE(smp);
|
|
|
|
#ifdef DEBUG /* { */
|
|
xprintf("free_link_map: \"%s\"\n", smp->som_path);
|
|
#endif /* } */
|
|
|
|
if(smpp->spd_prev == NULL) /* Removing first entry in list */
|
|
link_map_head = smp->som_next;
|
|
else /* Update link of previous entry */
|
|
smpp->spd_prev->som_next = smp->som_next;
|
|
|
|
if(smp->som_next == NULL) /* Removing last entry in list */
|
|
link_map_tail = smpp->spd_prev;
|
|
else /* Update back link of next entry */
|
|
LM_PRIVATE(smp->som_next)->spd_prev = smpp->spd_prev;
|
|
|
|
free(smp->som_path);
|
|
free(smp);
|
|
}
|
|
|
|
/*
|
|
* Map the shared object specified by PATH into memory, if it is not
|
|
* already mapped. Increment the object's reference count, and return a
|
|
* pointer to its link map.
|
|
*
|
|
* As a special case, if PATH is NULL, it is taken to refer to the main
|
|
* program.
|
|
*
|
|
* SODP is a pointer to the shared object dependency structure that caused
|
|
* this object to be requested. PARENT is a pointer to the link map of
|
|
* the shared object containing that structure. For a shared object not
|
|
* being mapped as a result of a shared object dependency, these pointers
|
|
* should be NULL. An example of this is a shared object that is explicitly
|
|
* loaded via dlopen().
|
|
*
|
|
* The return value is a pointer to the link map for the requested object.
|
|
* If the operation failed, the return value is NULL. In that case, an
|
|
* error message can be retrieved by calling dlerror().
|
|
*/
|
|
static struct so_map *
|
|
map_object(path, sodp, parent)
|
|
char *path;
|
|
struct sod *sodp;
|
|
struct so_map *parent;
|
|
{
|
|
struct so_map *smp;
|
|
struct stat statbuf;
|
|
|
|
if(path == NULL) /* Special case for the main program itself */
|
|
smp = link_map_head;
|
|
else {
|
|
/*
|
|
* Check whether the shared object is already mapped.
|
|
* We check first for an exact match by pathname. That
|
|
* will detect the usual case. If no match is found by
|
|
* pathname, then stat the file, and check for a match by
|
|
* device and inode. That will detect the less common case
|
|
* involving multiple links to the same library.
|
|
*/
|
|
for(smp = link_map_head; smp != NULL; smp = smp->som_next) {
|
|
if(!(LM_PRIVATE(smp)->spd_flags & (RTLD_MAIN|RTLD_RTLD))
|
|
&& smp->som_path != NULL
|
|
&& strcmp(smp->som_path, path) == 0)
|
|
break;
|
|
}
|
|
if(smp == NULL) { /* Check for a match by device and inode */
|
|
if (stat(path, &statbuf) == -1) {
|
|
generror ("cannot stat \"%s\" : %s",
|
|
path, strerror(errno));
|
|
return NULL;
|
|
}
|
|
for (smp = link_map_head; smp != NULL;
|
|
smp = smp->som_next) {
|
|
struct somap_private *smpp = LM_PRIVATE(smp);
|
|
|
|
if (!(smpp->spd_flags & (RTLD_MAIN | RTLD_RTLD))
|
|
&& smpp->spd_ino == statbuf.st_ino
|
|
&& smpp->spd_dev == statbuf.st_dev)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (smp == NULL) { /* We must map the object */
|
|
struct _dynamic *dp;
|
|
int fd;
|
|
caddr_t addr;
|
|
struct exec hdr;
|
|
struct somap_private *smpp;
|
|
|
|
if ((fd = open(path, O_RDONLY, 0)) == -1) {
|
|
generror ("open failed for \"%s\" : %s",
|
|
path, strerror (errno));
|
|
return NULL;
|
|
}
|
|
|
|
if (read(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
|
|
generror ("header read failed for \"%s\"", path);
|
|
(void)close(fd);
|
|
return NULL;
|
|
}
|
|
|
|
if (N_BADMAG(hdr)) {
|
|
generror ("bad magic number in \"%s\"", path);
|
|
(void)close(fd);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Map the entire address space of the object. It is
|
|
* tempting to map just the text segment at first, in
|
|
* order to avoid having to use mprotect to change the
|
|
* protections of the data segment. But that would not
|
|
* be correct. Mmap might find a group of free pages
|
|
* large enough to hold the text segment, but not large
|
|
* enough for the entire object. When we then mapped
|
|
* in the data and BSS segments, they would either be
|
|
* non-contiguous with the text segment (if we didn't
|
|
* specify MAP_FIXED), or they would map over some
|
|
* previously mapped region (if we did use MAP_FIXED).
|
|
* The only way we can be sure of getting a contigous
|
|
* region that is large enough is to map the entire
|
|
* region at once.
|
|
*/
|
|
if ((addr = mmap(0, hdr.a_text + hdr.a_data + hdr.a_bss,
|
|
PROT_READ|PROT_EXEC,
|
|
MAP_COPY, fd, 0)) == (caddr_t)-1) {
|
|
generror ("mmap failed for \"%s\" : %s",
|
|
path, strerror (errno));
|
|
(void)close(fd);
|
|
return NULL;
|
|
}
|
|
|
|
(void)close(fd);
|
|
|
|
/* Change the data segment to writable */
|
|
if (mprotect(addr + hdr.a_text, hdr.a_data,
|
|
PROT_READ|PROT_WRITE|PROT_EXEC) != 0) {
|
|
generror ("mprotect failed for \"%s\" : %s",
|
|
path, strerror (errno));
|
|
(void)munmap(addr, hdr.a_text + hdr.a_data + hdr.a_bss);
|
|
return NULL;
|
|
}
|
|
|
|
/* Map in pages of zeros for the BSS segment */
|
|
if (mmap(addr + hdr.a_text + hdr.a_data, hdr.a_bss,
|
|
PROT_READ|PROT_WRITE|PROT_EXEC,
|
|
MAP_ANON|MAP_COPY|MAP_FIXED,
|
|
anon_fd, 0) == (caddr_t)-1) {
|
|
generror ("mmap failed for \"%s\" : %s",
|
|
path, strerror (errno));
|
|
(void)munmap(addr, hdr.a_text + hdr.a_data + hdr.a_bss);
|
|
return NULL;
|
|
}
|
|
|
|
/* Assume _DYNAMIC is the first data item */
|
|
dp = (struct _dynamic *)(addr+hdr.a_text);
|
|
|
|
/* Fixup __DYNAMIC structure */
|
|
(long)dp->d_un.d_sdt += (long)addr;
|
|
|
|
smp = alloc_link_map(path, sodp, parent, addr, dp);
|
|
|
|
/* save segment sizes for unmap. */
|
|
smpp = LM_PRIVATE(smp);
|
|
smpp->a_text = hdr.a_text;
|
|
smpp->a_data = hdr.a_data;
|
|
smpp->a_bss = hdr.a_bss;
|
|
|
|
/*
|
|
* Save the device and inode, so we can detect multiple links
|
|
* to the same library. Note, if we reach this point, then
|
|
* statbuf is guaranteed to have been filled in.
|
|
*/
|
|
smpp->spd_dev = statbuf.st_dev;
|
|
smpp->spd_ino = statbuf.st_ino;
|
|
}
|
|
|
|
LM_PRIVATE(smp)->spd_refcount++;
|
|
if(LM_PRIVATE(smp)->spd_refcount == 1) { /* First use of object */
|
|
/*
|
|
* Recursively map all of the shared objects that this
|
|
* one depends upon.
|
|
*/
|
|
if(map_sods(smp) == -1) { /* Failed */
|
|
unmap_object(smp, 0); /* Clean up */
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
return smp;
|
|
}
|
|
|
|
/*
|
|
* Map all the shared libraries named in the LD_PRELOAD environment
|
|
* variable.
|
|
*
|
|
* Returns 0 on success, -1 on failure. On failure, an error message can
|
|
* be gotten via dlerror().
|
|
*/
|
|
static int
|
|
map_preload __P((void)) {
|
|
char *ld_name = ld_preload;
|
|
char *name;
|
|
|
|
while ((name = strsep(&ld_name, ":")) != NULL) {
|
|
char *path = NULL;
|
|
struct so_map *smp = NULL;
|
|
|
|
if (*name != '\0') {
|
|
path = (strchr(name, '/') != NULL) ? strdup(name) :
|
|
rtfindfile(name);
|
|
}
|
|
if (path == NULL) {
|
|
generror("Can't find LD_PRELOAD shared"
|
|
" library \"%s\"", name);
|
|
} else {
|
|
smp = map_object(path, (struct sod *) NULL,
|
|
(struct so_map *) NULL);
|
|
free(path);
|
|
}
|
|
if (ld_name != NULL)
|
|
*(ld_name - 1) = ':';
|
|
if (smp == NULL) {
|
|
/*
|
|
* We don't bother to unmap already-loaded libraries
|
|
* on failure, because in that case the program is
|
|
* about to die anyway.
|
|
*/
|
|
return -1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Map all of the shared objects that a given object depends upon. PARENT is
|
|
* a pointer to the link map for the shared object whose dependencies are
|
|
* to be mapped.
|
|
*
|
|
* Returns 0 on success. Returns -1 on failure. In that case, an error
|
|
* message can be retrieved by calling dlerror().
|
|
*/
|
|
static int
|
|
map_sods(parent)
|
|
struct so_map *parent;
|
|
{
|
|
struct somap_private *parpp = LM_PRIVATE(parent);
|
|
struct so_list **soltail = &parpp->spd_children;
|
|
long next = LD_NEED(parent->som_dynamic);
|
|
|
|
while(next != 0) {
|
|
struct sod *sodp =
|
|
(struct sod *) (LM_LDBASE(parent) + next);
|
|
char *name =
|
|
(char *) (LM_LDBASE(parent) + sodp->sod_name);
|
|
char *path = NULL;
|
|
struct so_map *smp = NULL;
|
|
|
|
if(sodp->sod_library) {
|
|
path = rtfindlib(name, sodp->sod_major,
|
|
sodp->sod_minor);
|
|
if(path == NULL && !ld_tracing) {
|
|
generror ("Can't find shared library"
|
|
" \"lib%s.so.%d.%d\"", name,
|
|
sodp->sod_major, sodp->sod_minor);
|
|
}
|
|
} else {
|
|
if(careful && name[0] != '/') {
|
|
generror("Shared library path must start"
|
|
" with \"/\" for \"%s\"", name);
|
|
} else
|
|
path = strdup(name);
|
|
}
|
|
|
|
if(path != NULL) {
|
|
smp = map_object(path, sodp, parent);
|
|
free(path);
|
|
}
|
|
|
|
if(smp != NULL) {
|
|
struct so_list *solp = (struct so_list *)
|
|
xmalloc(sizeof(struct so_list));
|
|
solp->sol_map = smp;
|
|
solp->sol_next = NULL;
|
|
*soltail = solp;
|
|
soltail = &solp->sol_next;
|
|
} else if(ld_tracing) {
|
|
/*
|
|
* Allocate a dummy map entry so that we will get the
|
|
* "not found" message.
|
|
*/
|
|
(void)alloc_link_map(NULL, sodp, parent, 0, 0);
|
|
} else /* Give up */
|
|
break;
|
|
|
|
next = sodp->sod_next;
|
|
}
|
|
|
|
if(next != 0) {
|
|
/*
|
|
* Oh drat, we have to clean up a mess.
|
|
*
|
|
* We failed to load a shared object that we depend upon.
|
|
* So now we have to unload any dependencies that we had
|
|
* already successfully loaded prior to the error.
|
|
*
|
|
* Cleaning up doesn't matter so much for the initial
|
|
* loading of the program, since any failure is going to
|
|
* terminate the program anyway. But it is very important
|
|
* to clean up properly when something is being loaded
|
|
* via dlopen().
|
|
*/
|
|
struct so_list *solp;
|
|
|
|
while((solp = parpp->spd_children) != NULL) {
|
|
unmap_object(solp->sol_map, 0);
|
|
parpp->spd_children = solp->sol_next;
|
|
free(solp);
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Relocate and initialize the tree of shared objects rooted at the given
|
|
* link map entry. Returns 0 on success, or -1 on failure. On failure,
|
|
* an error message can be retrieved via dlerror().
|
|
*/
|
|
static int
|
|
reloc_and_init(root, bind_now)
|
|
struct so_map *root;
|
|
int bind_now;
|
|
{
|
|
struct so_map *smp;
|
|
|
|
/*
|
|
* Relocate all newly-loaded objects. We avoid recursion for this
|
|
* step by taking advantage of a few facts. This function is called
|
|
* only when there are in fact some newly-loaded objects to process.
|
|
* Furthermore, all newly-loaded objects will have their link map
|
|
* entries at the end of the link map list. And, the root of the
|
|
* tree of objects just loaded will have been the first to be loaded
|
|
* and therefore the first new object in the link map list. Finally,
|
|
* we take advantage of the fact that we can relocate the newly-loaded
|
|
* objects in any order.
|
|
*
|
|
* All these facts conspire to let us simply loop over the tail
|
|
* portion of the link map list, relocating each object so
|
|
* encountered.
|
|
*/
|
|
for(smp = root; smp != NULL; smp = smp->som_next) {
|
|
if(!(LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)) {
|
|
if(reloc_map(smp, bind_now) < 0)
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy any relocated initialized data. Again, we can just loop
|
|
* over the appropriate portion of the link map list.
|
|
*/
|
|
for(smp = root; smp != NULL; smp = smp->som_next) {
|
|
if(!(LM_PRIVATE(smp)->spd_flags & RTLD_RTLD))
|
|
reloc_copy(smp);
|
|
}
|
|
|
|
/*
|
|
* Call any object initialization routines.
|
|
*
|
|
* Here, the order is very important, and we cannot simply loop
|
|
* over the newly-loaded objects as we did before. Rather, we
|
|
* have to initialize the tree of new objects depth-first, and
|
|
* process the sibling objects at each level in reverse order
|
|
* relative to the dependency list.
|
|
*
|
|
* Here is the reason we initialize depth-first. If an object
|
|
* depends on one or more other objects, then the objects it
|
|
* depends on should be initialized first, before the parent
|
|
* object itself. For it is possible that the parent's
|
|
* initialization routine will need the services provided by the
|
|
* objects it depends on -- and those objects had better already
|
|
* be initialized.
|
|
*
|
|
* We initialize the objects at each level of the tree in reverse
|
|
* order for a similar reason. When an object is linked with
|
|
* several libraries, it is common for routines in the earlier
|
|
* libraries to call routines in the later libraries. So, again,
|
|
* the later libraries need to be initialized first.
|
|
*
|
|
* The upshot of these rules is that we have to use recursion to
|
|
* get the libraries initialized in the best order. But the
|
|
* recursion is never likely to be very deep.
|
|
*/
|
|
init_object(root);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Remove a reference to the shared object specified by SMP. If no
|
|
* references remain, unmap the object and, recursively, its descendents.
|
|
* This function also takes care of calling the finalization routines for
|
|
* objects that are removed.
|
|
*
|
|
* If KEEP is true, then the actual calls to munmap() are skipped,
|
|
* and the object is kept in memory. That is used only for finalization,
|
|
* from dlexit(), when the program is exiting. There are two reasons
|
|
* for it. First, the program is exiting and there is no point in
|
|
* spending the time to explicitly unmap its shared objects. Second,
|
|
* even after dlexit() has been called, there are still a couple of
|
|
* calls that are made to functions in libc. (This is really a bug
|
|
* in crt0.) So libc and the main program, at least, must remain
|
|
* mapped in that situation.
|
|
*
|
|
* Under no reasonable circumstances should this function fail. If
|
|
* anything goes wrong, we consider it an internal error, and report
|
|
* it with err().
|
|
*/
|
|
static void
|
|
unmap_object(smp, keep)
|
|
struct so_map *smp;
|
|
int keep;
|
|
{
|
|
struct somap_private *smpp = LM_PRIVATE(smp);
|
|
|
|
smpp->spd_refcount--;
|
|
if(smpp->spd_refcount == 0) { /* Finished with this object */
|
|
struct so_list *solp;
|
|
|
|
if(smpp->spd_flags & RTLD_INIT) { /* Was initialized */
|
|
/*
|
|
* Call the object's finalization routine. For
|
|
* backward compatibility, we first try to call
|
|
* ".fini". If that does not exist, we call
|
|
* "__fini".
|
|
*/
|
|
if(call_map(smp, ".fini") == -1)
|
|
call_map(smp, "__fini");
|
|
}
|
|
|
|
/* Recursively unreference the object's descendents */
|
|
while((solp = smpp->spd_children) != NULL) {
|
|
unmap_object(solp->sol_map, keep);
|
|
smpp->spd_children = solp->sol_next;
|
|
free(solp);
|
|
}
|
|
|
|
if(!keep) { /* Unmap the object from memory */
|
|
if(munmap(smp->som_addr,
|
|
smpp->a_text + smpp->a_data + smpp->a_bss) < 0)
|
|
err(1, "internal error 1: munmap failed");
|
|
|
|
/* Unlink and free the object's link map entry */
|
|
free_link_map(smp);
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline int
|
|
check_text_reloc(r, smp, addr)
|
|
struct relocation_info *r;
|
|
struct so_map *smp;
|
|
caddr_t addr;
|
|
{
|
|
char *sym;
|
|
|
|
if (addr >= LM_ETEXT(smp))
|
|
return 0;
|
|
|
|
if (RELOC_EXTERN_P(r))
|
|
sym = LM_STRINGS(smp) +
|
|
LM_SYMBOL(smp, RELOC_SYMBOL(r))->nz_strx;
|
|
else
|
|
sym = "";
|
|
|
|
if (!ld_suppress_warnings && ld_warn_non_pure_code)
|
|
warnx("warning: non pure code in %s at %x (%s)",
|
|
smp->som_path, r->r_address, sym);
|
|
|
|
if (smp->som_write == 0 &&
|
|
mprotect(smp->som_addr + LM_TXTADDR(smp),
|
|
LD_TEXTSZ(smp->som_dynamic),
|
|
PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
|
|
generror ("mprotect failed for \"%s\" : %s",
|
|
smp->som_path, strerror (errno));
|
|
return -1;
|
|
}
|
|
|
|
smp->som_write = 1;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
reloc_map(smp, bind_now)
|
|
struct so_map *smp;
|
|
int bind_now;
|
|
{
|
|
/*
|
|
* Caching structure for reducing the number of calls to
|
|
* lookup() during relocation.
|
|
*
|
|
* While relocating a given shared object, the dynamic linker
|
|
* maintains a caching vector that is directly indexed by
|
|
* the symbol number in the relocation entry. The first time
|
|
* a given symbol is looked up, the caching vector is
|
|
* filled in with a pointer to the symbol table entry, and
|
|
* a pointer to the so_map of the shared object in which the
|
|
* symbol was defined. On subsequent uses of the same symbol,
|
|
* that information is retrieved directly from the caching
|
|
* vector, without calling lookup() again.
|
|
*
|
|
* A symbol that is referenced in a relocation entry is
|
|
* typically referenced in many relocation entries, so this
|
|
* caching reduces the number of calls to lookup()
|
|
* dramatically. The overall improvement in the speed of
|
|
* dynamic linking is also dramatic -- as much as a factor
|
|
* of three for programs that use many shared libaries.
|
|
*/
|
|
struct cacheent {
|
|
struct nzlist *np; /* Pointer to symbol entry */
|
|
struct so_map *src_map; /* Shared object that defined symbol */
|
|
};
|
|
|
|
struct _dynamic *dp = smp->som_dynamic;
|
|
struct relocation_info *r = LM_REL(smp);
|
|
struct relocation_info *rend = r + LD_RELSZ(dp)/sizeof(*r);
|
|
long symbolbase = (long)LM_SYMBOL(smp, 0);
|
|
char *stringbase = LM_STRINGS(smp);
|
|
int symsize = LD_VERSION_NZLIST_P(dp->d_version) ?
|
|
sizeof(struct nzlist) :
|
|
sizeof(struct nlist);
|
|
long numsyms = LD_STABSZ(dp) / symsize;
|
|
size_t cachebytes = numsyms * sizeof(struct cacheent);
|
|
struct cacheent *symcache =
|
|
(struct cacheent *) alloca(cachebytes);
|
|
|
|
if(symcache == NULL) {
|
|
generror("Cannot allocate symbol caching vector for %s",
|
|
smp->som_path);
|
|
return -1;
|
|
}
|
|
bzero(symcache, cachebytes);
|
|
|
|
if (LD_PLTSZ(dp))
|
|
md_fix_jmpslot(LM_PLT(smp),
|
|
(long)LM_PLT(smp), (long)binder_entry);
|
|
|
|
for (; r < rend; r++) {
|
|
char *sym;
|
|
caddr_t addr;
|
|
|
|
/*
|
|
* Objects linked with "-Bsymbolic" can end up having unused
|
|
* relocation entries at the end. These can be detected by
|
|
* the fact that they have an address of 0.
|
|
*/
|
|
if(r->r_address == 0) /* Finished relocating this object */
|
|
break;
|
|
|
|
addr = smp->som_addr + r->r_address;
|
|
if (check_text_reloc(r, smp, addr) < 0)
|
|
return -1;
|
|
|
|
if (RELOC_EXTERN_P(r)) {
|
|
struct so_map *src_map = NULL;
|
|
struct nzlist *p, *np;
|
|
long relocation;
|
|
|
|
if (RELOC_JMPTAB_P(r) && !bind_now)
|
|
continue;
|
|
|
|
p = (struct nzlist *)
|
|
(symbolbase + symsize * RELOC_SYMBOL(r));
|
|
|
|
if (p->nz_type == (N_SETV + N_EXT))
|
|
src_map = smp;
|
|
|
|
sym = stringbase + p->nz_strx;
|
|
|
|
/*
|
|
* Look up the symbol, checking the caching
|
|
* vector first.
|
|
*/
|
|
np = symcache[RELOC_SYMBOL(r)].np;
|
|
if(np != NULL) /* Symbol already cached */
|
|
src_map = symcache[RELOC_SYMBOL(r)].src_map;
|
|
else { /* Symbol not cached yet */
|
|
np = lookup(sym, &src_map, RELOC_JMPTAB_P(r));
|
|
/*
|
|
* Record the needed information about
|
|
* the symbol in the caching vector,
|
|
* so that we won't have to call
|
|
* lookup the next time we encounter
|
|
* the symbol.
|
|
*/
|
|
symcache[RELOC_SYMBOL(r)].np = np;
|
|
symcache[RELOC_SYMBOL(r)].src_map = src_map;
|
|
}
|
|
|
|
if (np == NULL) {
|
|
generror ("Undefined symbol \"%s\" in %s:%s",
|
|
sym, main_progname, smp->som_path);
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Found symbol definition.
|
|
* If it's in a link map, adjust value
|
|
* according to the load address of that map.
|
|
* Otherwise it's a run-time allocated common
|
|
* whose value is already up-to-date.
|
|
*/
|
|
relocation = np->nz_value;
|
|
if (src_map)
|
|
relocation += (long)src_map->som_addr;
|
|
|
|
if (RELOC_JMPTAB_P(r)) {
|
|
md_bind_jmpslot(relocation, addr);
|
|
continue;
|
|
}
|
|
|
|
relocation += md_get_addend(r, addr);
|
|
|
|
if (RELOC_PCREL_P(r))
|
|
relocation -= (long)smp->som_addr;
|
|
|
|
if (RELOC_COPY_P(r) && src_map) {
|
|
(void)enter_rts(sym,
|
|
(long)addr,
|
|
N_DATA + N_EXT,
|
|
src_map->som_addr + np->nz_value,
|
|
np->nz_size, src_map);
|
|
continue;
|
|
}
|
|
|
|
md_relocate(r, relocation, addr, 0);
|
|
} else {
|
|
md_relocate(r,
|
|
#ifdef SUN_COMPAT
|
|
md_get_rt_segment_addend(r, addr)
|
|
#else
|
|
md_get_addend(r, addr)
|
|
#endif
|
|
+ (long)smp->som_addr, addr, 0);
|
|
}
|
|
|
|
}
|
|
|
|
if (smp->som_write) {
|
|
if (mprotect(smp->som_addr + LM_TXTADDR(smp),
|
|
LD_TEXTSZ(smp->som_dynamic),
|
|
PROT_READ|PROT_EXEC) == -1) {
|
|
generror ("mprotect failed for \"%s\" : %s",
|
|
smp->som_path, strerror (errno));
|
|
return -1;
|
|
}
|
|
smp->som_write = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
reloc_copy(smp)
|
|
struct so_map *smp;
|
|
{
|
|
struct rt_symbol *rtsp;
|
|
|
|
for (rtsp = rt_symbol_head; rtsp; rtsp = rtsp->rt_next)
|
|
if ((rtsp->rt_smp == NULL || rtsp->rt_smp == smp) &&
|
|
rtsp->rt_sp->nz_type == N_DATA + N_EXT) {
|
|
bcopy(rtsp->rt_srcaddr, (caddr_t)rtsp->rt_sp->nz_value,
|
|
rtsp->rt_sp->nz_size);
|
|
}
|
|
}
|
|
|
|
static void
|
|
init_object(smp)
|
|
struct so_map *smp;
|
|
{
|
|
struct somap_private *smpp = LM_PRIVATE(smp);
|
|
|
|
if(!(smpp->spd_flags & RTLD_INIT)) { /* Not initialized yet */
|
|
smpp->spd_flags |= RTLD_INIT;
|
|
|
|
/* Make sure all the children are initialized */
|
|
if(smpp->spd_children != NULL)
|
|
init_sods(smpp->spd_children);
|
|
|
|
if(call_map(smp, ".init") == -1)
|
|
call_map(smp, "__init");
|
|
}
|
|
}
|
|
|
|
static void
|
|
init_sods(solp)
|
|
struct so_list *solp;
|
|
{
|
|
/* Recursively initialize the rest of the list */
|
|
if(solp->sol_next != NULL)
|
|
init_sods(solp->sol_next);
|
|
|
|
/* Initialize the first element of the list */
|
|
init_object(solp->sol_map);
|
|
}
|
|
|
|
|
|
/*
|
|
* Call a function in a given shared object. SMP is the shared object, and
|
|
* SYM is the name of the function.
|
|
*
|
|
* Returns 0 on success, or -1 if the symbol was not found. Failure is not
|
|
* necessarily an error condition, so no error message is generated.
|
|
*/
|
|
static int
|
|
call_map(smp, sym)
|
|
struct so_map *smp;
|
|
char *sym;
|
|
{
|
|
struct so_map *src_map = smp;
|
|
struct nzlist *np;
|
|
|
|
np = lookup(sym, &src_map, 1);
|
|
if (np) {
|
|
(*(void (*)())(src_map->som_addr + np->nz_value))();
|
|
return 0;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Run-time common symbol table.
|
|
*/
|
|
|
|
#define RTC_TABSIZE 57
|
|
static struct rt_symbol *rt_symtab[RTC_TABSIZE];
|
|
|
|
/*
|
|
* Compute hash value for run-time symbol table
|
|
*/
|
|
static inline int
|
|
hash_string(key)
|
|
char *key;
|
|
{
|
|
register char *cp;
|
|
register int k;
|
|
|
|
cp = key;
|
|
k = 0;
|
|
while (*cp)
|
|
k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;
|
|
|
|
return k;
|
|
}
|
|
|
|
/*
|
|
* Lookup KEY in the run-time common symbol table.
|
|
*/
|
|
|
|
static inline struct rt_symbol *
|
|
lookup_rts(key)
|
|
char *key;
|
|
{
|
|
register int hashval;
|
|
register struct rt_symbol *rtsp;
|
|
|
|
/* Determine which bucket. */
|
|
|
|
hashval = hash_string(key) % RTC_TABSIZE;
|
|
|
|
/* Search the bucket. */
|
|
|
|
for (rtsp = rt_symtab[hashval]; rtsp; rtsp = rtsp->rt_link)
|
|
if (strcmp(key, rtsp->rt_sp->nz_name) == 0)
|
|
return rtsp;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct rt_symbol *
|
|
enter_rts(name, value, type, srcaddr, size, smp)
|
|
char *name;
|
|
long value;
|
|
int type;
|
|
caddr_t srcaddr;
|
|
long size;
|
|
struct so_map *smp;
|
|
{
|
|
register int hashval;
|
|
register struct rt_symbol *rtsp, **rpp;
|
|
|
|
/* Determine which bucket */
|
|
hashval = hash_string(name) % RTC_TABSIZE;
|
|
|
|
/* Find end of bucket */
|
|
for (rpp = &rt_symtab[hashval]; *rpp; rpp = &(*rpp)->rt_link)
|
|
continue;
|
|
|
|
/* Allocate new common symbol */
|
|
rtsp = (struct rt_symbol *)malloc(sizeof(struct rt_symbol));
|
|
rtsp->rt_sp = (struct nzlist *)malloc(sizeof(struct nzlist));
|
|
rtsp->rt_sp->nz_name = strdup(name);
|
|
rtsp->rt_sp->nz_value = value;
|
|
rtsp->rt_sp->nz_type = type;
|
|
rtsp->rt_sp->nz_size = size;
|
|
rtsp->rt_srcaddr = srcaddr;
|
|
rtsp->rt_smp = smp;
|
|
rtsp->rt_link = NULL;
|
|
|
|
/* Link onto linear list as well */
|
|
rtsp->rt_next = rt_symbol_head;
|
|
rt_symbol_head = rtsp;
|
|
|
|
*rpp = rtsp;
|
|
|
|
return rtsp;
|
|
}
|
|
|
|
|
|
/*
|
|
* Lookup NAME in the link maps. The link map producing a definition
|
|
* is returned in SRC_MAP. If SRC_MAP is not NULL on entry the search is
|
|
* confined to that map. If STRONG is set, the symbol returned must
|
|
* have a proper type (used by binder()).
|
|
*/
|
|
static struct nzlist *
|
|
lookup(name, src_map, strong)
|
|
char *name;
|
|
struct so_map **src_map; /* IN/OUT */
|
|
int strong;
|
|
{
|
|
long common_size = 0;
|
|
struct so_map *smp;
|
|
struct rt_symbol *rtsp;
|
|
|
|
if ((rtsp = lookup_rts(name)) != NULL)
|
|
return rtsp->rt_sp;
|
|
|
|
/*
|
|
* Search all maps for a definition of NAME
|
|
*/
|
|
for (smp = link_map_head; smp; smp = smp->som_next) {
|
|
int buckets;
|
|
long hashval;
|
|
struct rrs_hash *hp;
|
|
char *cp;
|
|
struct nzlist *np;
|
|
|
|
/* Some local caching */
|
|
long symbolbase;
|
|
struct rrs_hash *hashbase;
|
|
char *stringbase;
|
|
int symsize;
|
|
|
|
if (*src_map && smp != *src_map)
|
|
continue;
|
|
|
|
if ((buckets = LD_BUCKETS(smp->som_dynamic)) == 0)
|
|
continue;
|
|
|
|
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
|
|
continue;
|
|
|
|
restart:
|
|
/*
|
|
* Compute bucket in which the symbol might be found.
|
|
*/
|
|
for (hashval = 0, cp = name; *cp; cp++)
|
|
hashval = (hashval << 1) + *cp;
|
|
|
|
hashval = (hashval & 0x7fffffff) % buckets;
|
|
|
|
hashbase = LM_HASH(smp);
|
|
hp = hashbase + hashval;
|
|
if (hp->rh_symbolnum == -1)
|
|
/* Nothing in this bucket */
|
|
continue;
|
|
|
|
symbolbase = (long)LM_SYMBOL(smp, 0);
|
|
stringbase = LM_STRINGS(smp);
|
|
symsize = LD_VERSION_NZLIST_P(smp->som_dynamic->d_version)?
|
|
sizeof(struct nzlist) :
|
|
sizeof(struct nlist);
|
|
while (hp) {
|
|
np = (struct nzlist *)
|
|
(symbolbase + hp->rh_symbolnum * symsize);
|
|
cp = stringbase + np->nz_strx;
|
|
if (strcmp(cp, name) == 0)
|
|
break;
|
|
if (hp->rh_next == 0)
|
|
hp = NULL;
|
|
else
|
|
hp = hashbase + hp->rh_next;
|
|
}
|
|
if (hp == NULL)
|
|
/* Nothing in this bucket */
|
|
continue;
|
|
|
|
/*
|
|
* We have a symbol with the name we're looking for.
|
|
*/
|
|
if (np->nz_type == N_INDR+N_EXT) {
|
|
/*
|
|
* Next symbol gives the aliased name. Restart
|
|
* search with new name and confine to this map.
|
|
*/
|
|
name = stringbase + (++np)->nz_strx;
|
|
*src_map = smp;
|
|
goto restart;
|
|
}
|
|
|
|
if (np->nz_value == 0)
|
|
/* It's not a definition */
|
|
continue;
|
|
|
|
if (np->nz_type == N_UNDF+N_EXT && np->nz_value != 0) {
|
|
if (np->nz_other == AUX_FUNC) {
|
|
/* It's a weak function definition */
|
|
if (strong)
|
|
continue;
|
|
} else {
|
|
/* It's a common, note value and continue search */
|
|
if (common_size < np->nz_value)
|
|
common_size = np->nz_value;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
*src_map = smp;
|
|
return np;
|
|
}
|
|
|
|
if (common_size == 0)
|
|
/* Not found */
|
|
return NULL;
|
|
|
|
/*
|
|
* It's a common, enter into run-time common symbol table.
|
|
*/
|
|
rtsp = enter_rts(name, (long)calloc(1, common_size),
|
|
N_UNDF + N_EXT, 0, common_size, NULL);
|
|
|
|
#if DEBUG
|
|
xprintf("Allocating common: %s size %d at %#x\n", name, common_size,
|
|
rtsp->rt_sp->nz_value);
|
|
#endif
|
|
|
|
return rtsp->rt_sp;
|
|
}
|
|
|
|
/*
|
|
* This routine is called from the jumptable to resolve
|
|
* procedure calls to shared objects.
|
|
*/
|
|
long
|
|
binder(jsp)
|
|
jmpslot_t *jsp;
|
|
{
|
|
struct so_map *smp, *src_map = NULL;
|
|
long addr;
|
|
char *sym;
|
|
struct nzlist *np;
|
|
int index;
|
|
|
|
/*
|
|
* Find the PLT map that contains JSP.
|
|
*/
|
|
for (smp = link_map_head; smp; smp = smp->som_next) {
|
|
if (LM_PLT(smp) < jsp &&
|
|
jsp < LM_PLT(smp) + LD_PLTSZ(smp->som_dynamic)/sizeof(*jsp))
|
|
break;
|
|
}
|
|
|
|
if (smp == NULL)
|
|
errx(1, "Call to binder from unknown location: %#x\n", jsp);
|
|
|
|
index = jsp->reloc_index & JMPSLOT_RELOC_MASK;
|
|
|
|
/* Get the local symbol this jmpslot refers to */
|
|
sym = LM_STRINGS(smp) +
|
|
LM_SYMBOL(smp,RELOC_SYMBOL(&LM_REL(smp)[index]))->nz_strx;
|
|
|
|
np = lookup(sym, &src_map, 1);
|
|
if (np == NULL)
|
|
errx(1, "Undefined symbol \"%s\" called from %s:%s at %#x",
|
|
sym, main_progname, smp->som_path, jsp);
|
|
|
|
/* Fixup jmpslot so future calls transfer directly to target */
|
|
addr = np->nz_value;
|
|
if (src_map)
|
|
addr += (long)src_map->som_addr;
|
|
|
|
md_fix_jmpslot(jsp, (long)jsp, addr);
|
|
|
|
#if DEBUG
|
|
xprintf(" BINDER: %s located at = %#x in %s\n", sym, addr,
|
|
src_map->som_path);
|
|
#endif
|
|
return addr;
|
|
}
|
|
|
|
static struct hints_header *hheader; /* NULL means not mapped */
|
|
static struct hints_bucket *hbuckets;
|
|
static char *hstrtab;
|
|
|
|
/*
|
|
* Map the hints file into memory, if it is not already mapped. Returns
|
|
* 0 on success, or -1 on failure.
|
|
*/
|
|
static int
|
|
maphints __P((void))
|
|
{
|
|
static int hints_bad; /* TRUE if hints are unusable */
|
|
static int paths_added;
|
|
int hfd;
|
|
struct hints_header hdr;
|
|
caddr_t addr;
|
|
|
|
if (hheader != NULL) /* Already mapped */
|
|
return 0;
|
|
|
|
if (hints_bad) /* Known to be corrupt or unavailable */
|
|
return -1;
|
|
|
|
if ((hfd = open(_PATH_LD_HINTS, O_RDONLY, 0)) == -1) {
|
|
hints_bad = 1;
|
|
return -1;
|
|
}
|
|
|
|
/* Read the header and check it */
|
|
|
|
if (read(hfd, &hdr, sizeof hdr) != sizeof hdr ||
|
|
HH_BADMAG(hdr) ||
|
|
(hdr.hh_version != LD_HINTS_VERSION_1 &&
|
|
hdr.hh_version != LD_HINTS_VERSION_2)) {
|
|
close(hfd);
|
|
hints_bad = 1;
|
|
return -1;
|
|
}
|
|
|
|
/* Map the hints into memory */
|
|
|
|
addr = mmap(0, hdr.hh_ehints, PROT_READ, MAP_SHARED, hfd, 0);
|
|
if (addr == (caddr_t)-1) {
|
|
close(hfd);
|
|
hints_bad = 1;
|
|
return -1;
|
|
}
|
|
|
|
close(hfd);
|
|
|
|
hheader = (struct hints_header *)addr;
|
|
hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab);
|
|
hstrtab = (char *)(addr + hheader->hh_strtab);
|
|
/* pluck out the system ldconfig path */
|
|
if (hheader->hh_version >= LD_HINTS_VERSION_2 && !paths_added) {
|
|
add_search_path(hstrtab + hheader->hh_dirlist);
|
|
paths_added = 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unmap the hints file, if it is currently mapped.
|
|
*/
|
|
static void
|
|
unmaphints()
|
|
{
|
|
if (hheader != NULL) {
|
|
munmap((caddr_t)hheader, hheader->hh_ehints);
|
|
hheader = NULL;
|
|
}
|
|
}
|
|
|
|
int
|
|
hinthash(cp, vmajor)
|
|
char *cp;
|
|
int vmajor;
|
|
{
|
|
int k = 0;
|
|
|
|
while (*cp)
|
|
k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;
|
|
|
|
k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff;
|
|
|
|
return k;
|
|
}
|
|
|
|
#undef major
|
|
#undef minor
|
|
|
|
/*
|
|
* Search for a library in the hints generated by ldconfig. On success,
|
|
* returns the full pathname of the matching library. This string is
|
|
* always dynamically allocated on the heap.
|
|
*
|
|
* Returns the minor number of the matching library via the pointer
|
|
* argument MINORP.
|
|
*
|
|
* Returns NULL if the library cannot be found.
|
|
*/
|
|
static char *
|
|
findhint(name, major, minorp)
|
|
char *name;
|
|
int major;
|
|
int *minorp;
|
|
{
|
|
struct hints_bucket *bp =
|
|
hbuckets + (hinthash(name, major) % hheader->hh_nbucket);
|
|
|
|
while (1) {
|
|
/* Sanity check */
|
|
if (bp->hi_namex >= hheader->hh_strtab_sz) {
|
|
warnx("Bad name index: %#x\n", bp->hi_namex);
|
|
break;
|
|
}
|
|
if (bp->hi_pathx >= hheader->hh_strtab_sz) {
|
|
warnx("Bad path index: %#x\n", bp->hi_pathx);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We accept the current hints entry if its name matches
|
|
* and its major number matches. We don't have to search
|
|
* for the best minor number, because that was already
|
|
* done by "ldconfig" when it built the hints file.
|
|
*/
|
|
if (strcmp(name, hstrtab + bp->hi_namex) == 0 &&
|
|
bp->hi_major == major) {
|
|
*minorp = bp->hi_ndewey >= 2 ? bp->hi_minor : -1;
|
|
return strdup(hstrtab + bp->hi_pathx);
|
|
}
|
|
|
|
if (bp->hi_next == -1)
|
|
break;
|
|
|
|
/* Move on to next in bucket */
|
|
bp = &hbuckets[bp->hi_next];
|
|
}
|
|
|
|
/* No hints available for name */
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Search for the given shared library. On success, returns a string
|
|
* containing the full pathname for the library. This string is always
|
|
* dynamically allocated on the heap.
|
|
*
|
|
* Returns NULL if the library cannot be found.
|
|
*/
|
|
static char *
|
|
rtfindlib(name, major, minor)
|
|
char *name;
|
|
int major, minor;
|
|
{
|
|
char *ld_path = ld_library_path;
|
|
char *path = NULL;
|
|
int realminor = -1;
|
|
|
|
if (ld_path != NULL) { /* First, search the directories in ld_path */
|
|
/*
|
|
* There is no point in trying to use the hints file for this.
|
|
*/
|
|
char *dir;
|
|
|
|
while (path == NULL && (dir = strsep(&ld_path, ":")) != NULL) {
|
|
path = search_lib_dir(dir, name, &major, &realminor, 0);
|
|
if (ld_path != NULL)
|
|
*(ld_path - 1) = ':';
|
|
}
|
|
}
|
|
|
|
if (path == NULL && maphints() == 0) /* Search the hints file */
|
|
path = findhint(name, major, &realminor);
|
|
|
|
if (path == NULL) /* Search the standard directories */
|
|
path = findshlib(name, &major, &realminor, 0);
|
|
|
|
if (path != NULL && realminor < minor && !ld_suppress_warnings) {
|
|
warnx("warning: %s: minor version %d"
|
|
" older than expected %d, using it anyway",
|
|
path, realminor, minor);
|
|
}
|
|
|
|
return path;
|
|
}
|
|
|
|
/*
|
|
* Search for the given shared library file. This is similar to rtfindlib,
|
|
* except that the argument is the actual name of the desired library file.
|
|
* Thus there is no need to worry about version numbers. The return value
|
|
* is a string containing the full pathname for the library. This string
|
|
* is always dynamically allocated on the heap.
|
|
*
|
|
* Returns NULL if the library cannot be found.
|
|
*/
|
|
static char *
|
|
rtfindfile(name)
|
|
char *name;
|
|
{
|
|
char *ld_path = ld_library_path;
|
|
char *path = NULL;
|
|
|
|
if (ld_path != NULL) { /* First, search the directories in ld_path */
|
|
char *dir;
|
|
|
|
while (path == NULL && (dir = strsep(&ld_path, ":")) != NULL) {
|
|
struct stat sb;
|
|
|
|
path = concat(dir, "/", name);
|
|
if (lstat(path, &sb) == -1) { /* Does not exist */
|
|
free(path);
|
|
path = NULL;
|
|
}
|
|
if (ld_path != NULL)
|
|
*(ld_path - 1) = ':';
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We don't search the hints file. It is organized around major
|
|
* and minor version numbers, so it is not suitable for finding
|
|
* a specific file name.
|
|
*/
|
|
|
|
if (path == NULL) /* Search the standard directories */
|
|
path = find_lib_file(name);
|
|
|
|
return path;
|
|
}
|
|
|
|
/*
|
|
* Buffer for error messages and a pointer that is set to point to the buffer
|
|
* when a error occurs. It acts as a last error flag, being set to NULL
|
|
* after an error is returned.
|
|
*/
|
|
#define DLERROR_BUF_SIZE 512
|
|
static char dlerror_buf [DLERROR_BUF_SIZE];
|
|
static char *dlerror_msg = NULL;
|
|
|
|
|
|
static void *
|
|
__dlopen(path, mode)
|
|
char *path;
|
|
int mode;
|
|
{
|
|
struct so_map *old_tail = link_map_tail;
|
|
struct so_map *smp;
|
|
int bind_now = mode == RTLD_NOW;
|
|
|
|
/*
|
|
* path == NULL is handled by map_object()
|
|
*/
|
|
|
|
anon_open();
|
|
|
|
/* Map the object, and the objects on which it depends */
|
|
smp = map_object(path, (struct sod *) NULL, (struct so_map *) NULL);
|
|
if(smp == NULL) /* Failed */
|
|
return NULL;
|
|
LM_PRIVATE(smp)->spd_flags |= RTLD_DL;
|
|
|
|
/* Relocate and initialize all newly-mapped objects */
|
|
if(link_map_tail != old_tail) { /* We have mapped some new objects */
|
|
if(reloc_and_init(smp, bind_now) == -1) /* Failed */
|
|
return NULL;
|
|
}
|
|
|
|
unmaphints();
|
|
anon_close();
|
|
|
|
return smp;
|
|
}
|
|
|
|
static int
|
|
__dlclose(fd)
|
|
void *fd;
|
|
{
|
|
struct so_map *smp = (struct so_map *)fd;
|
|
struct so_map *scanp;
|
|
|
|
#ifdef DEBUG
|
|
xprintf("dlclose(%s): refcount = %d\n", smp->som_path,
|
|
LM_PRIVATE(smp)->spd_refcount);
|
|
#endif
|
|
/* Check the argument for validity */
|
|
for(scanp = link_map_head; scanp != NULL; scanp = scanp->som_next)
|
|
if(scanp == smp) /* We found the map in the list */
|
|
break;
|
|
if(scanp == NULL || !(LM_PRIVATE(smp)->spd_flags & RTLD_DL)) {
|
|
generror("Invalid argument to dlclose");
|
|
return -1;
|
|
}
|
|
|
|
unmap_object(smp, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void *
|
|
__dlsym(fd, sym)
|
|
void *fd;
|
|
char *sym;
|
|
{
|
|
struct so_map *smp = (struct so_map *)fd, *src_map = NULL;
|
|
struct nzlist *np;
|
|
long addr;
|
|
|
|
/*
|
|
* Restrict search to passed map if dlopen()ed.
|
|
*/
|
|
if (smp != NULL && LM_PRIVATE(smp)->spd_flags & RTLD_DL)
|
|
src_map = smp;
|
|
|
|
np = lookup(sym, &src_map, 1);
|
|
if (np == NULL)
|
|
return NULL;
|
|
|
|
/* Fixup jmpslot so future calls transfer directly to target */
|
|
addr = np->nz_value;
|
|
if (src_map)
|
|
addr += (long)src_map->som_addr;
|
|
|
|
return (void *)addr;
|
|
}
|
|
|
|
static char *
|
|
__dlerror __P((void))
|
|
{
|
|
char *err;
|
|
|
|
err = dlerror_msg;
|
|
dlerror_msg = NULL; /* Next call will return NULL */
|
|
|
|
return err;
|
|
}
|
|
|
|
static void
|
|
__dlexit __P((void))
|
|
{
|
|
#ifdef DEBUG
|
|
xprintf("__dlexit called\n");
|
|
#endif
|
|
|
|
unmap_object(link_map_head, 1);
|
|
}
|
|
|
|
/*
|
|
* Print the current error message and exit with failure status.
|
|
*/
|
|
static void
|
|
die __P((void))
|
|
{
|
|
char *msg;
|
|
|
|
fprintf(stderr, "ld.so failed");
|
|
if ((msg = __dlerror()) != NULL)
|
|
fprintf(stderr, ": %s", msg);
|
|
putc('\n', stderr);
|
|
_exit(1);
|
|
}
|
|
|
|
|
|
/*
|
|
* Generate an error message that can be later be retrieved via dlerror.
|
|
*/
|
|
static void
|
|
#if __STDC__
|
|
generror(char *fmt, ...)
|
|
#else
|
|
generror(fmt, va_alist)
|
|
char *fmt;
|
|
#endif
|
|
{
|
|
va_list ap;
|
|
#if __STDC__
|
|
va_start(ap, fmt);
|
|
#else
|
|
va_start(ap);
|
|
#endif
|
|
vsnprintf (dlerror_buf, DLERROR_BUF_SIZE, fmt, ap);
|
|
dlerror_msg = dlerror_buf;
|
|
|
|
va_end(ap);
|
|
}
|
|
|
|
void
|
|
#if __STDC__
|
|
xprintf(char *fmt, ...)
|
|
#else
|
|
xprintf(fmt, va_alist)
|
|
char *fmt;
|
|
#endif
|
|
{
|
|
char buf[256];
|
|
va_list ap;
|
|
#if __STDC__
|
|
va_start(ap, fmt);
|
|
#else
|
|
va_start(ap);
|
|
#endif
|
|
|
|
vsnprintf(buf, sizeof(buf), fmt, ap);
|
|
(void)write(1, buf, strlen(buf));
|
|
va_end(ap);
|
|
}
|
|
|
|
/*
|
|
* rt_readenv() etc.
|
|
*
|
|
* Do a sweep over the environment once only, pick up what
|
|
* looks interesting.
|
|
*
|
|
* This is pretty obscure, but is relatively simple. Simply
|
|
* look at each environment variable, if it starts with "LD_" then
|
|
* look closer at it. If it's in our table, set the variable
|
|
* listed. effectively, this is like:
|
|
* ld_preload = careful ? NULL : getenv("LD_PRELOAD");
|
|
* except that the environment is scanned once only to pick up all
|
|
* known variables, rather than scanned multiple times for each
|
|
* variable.
|
|
*
|
|
* If an environment variable of interest is set to the empty string, we
|
|
* treat it as if it were unset.
|
|
*/
|
|
|
|
#define L(n, u, v) { n, sizeof(n) - 1, u, v },
|
|
struct env_scan_tab {
|
|
char *name;
|
|
int len;
|
|
int unsafe;
|
|
char **value;
|
|
} scan_tab[] = {
|
|
L("LD_LIBRARY_PATH=", 1, &ld_library_path)
|
|
L("LD_PRELOAD=", 1, &ld_preload)
|
|
L("LD_TRACE_LOADED_OBJECTS=", 0, &ld_tracing)
|
|
L("LD_BIND_NOW=", 0, &ld_bind_now)
|
|
L("LD_SUPPRESS_WARNINGS=", 0, &ld_suppress_warnings)
|
|
L("LD_WARN_NON_PURE_CODE=", 0, &ld_warn_non_pure_code)
|
|
{ NULL, 0, NULL }
|
|
};
|
|
#undef L
|
|
|
|
static void
|
|
rt_readenv()
|
|
{
|
|
char **p = environ;
|
|
char *v;
|
|
struct env_scan_tab *t;
|
|
|
|
/* for each string in the environment... */
|
|
while ((v = *p++)) {
|
|
|
|
/* check for LD_xxx */
|
|
if (v[0] != 'L' || v[1] != 'D' || v[2] != '_')
|
|
continue;
|
|
|
|
for (t = scan_tab; t->name; t++) {
|
|
if (careful && t->unsafe)
|
|
continue; /* skip for set[ug]id */
|
|
if (strncmp(t->name, v, t->len) == 0) {
|
|
if (*(v + t->len) != '\0') /* Not empty */
|
|
*t->value = v + t->len;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|