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This is Paul K's latest set of ld changes. A commit was necessary at this
[unix-history] / gnu / usr.bin / ld / rtld / rtld.c
/*
* Copyright (c) 1993 Paul Kranenburg
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Paul Kranenburg.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id: rtld.c,v 1.14 1994/01/14 11:47:00 jkh Exp $
*/
#include <machine/vmparam.h>
#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/errno.h>
#include <sys/mman.h>
#ifndef BSD
#define MAP_COPY MAP_PRIVATE
#define MAP_FILE 0
#define MAP_ANON 0
#endif
#include <fcntl.h>
#include <a.out.h>
#include <stab.h>
#include <string.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include "ld.h"
#ifndef BSD /* Need do better than this */
#define NEED_DEV_ZERO 1
#endif
/*
* Loader private data, hung off <so_map>->som_spd
*/
struct somap_private {
int spd_version;
struct so_map *spd_parent;
int spd_refcount;
int spd_flags;
#define RTLD_MAIN 1
#define RTLD_RTLD 2
#define RTLD_DL 4
#ifdef SUN_COMPAT
long spd_offset; /* Correction for Sun main programs */
#endif
};
#define LM_PRIVATE(smp) ((struct somap_private *)(smp)->som_spd)
#ifdef SUN_COMPAT
#define LM_OFFSET(smp) (LM_PRIVATE(smp)->spd_offset)
#else
#define LM_OFFSET(smp) (0)
#endif
/* Base address for section_dispatch_table entries */
#define LM_LDBASE(smp) (smp->som_addr + LM_OFFSET(smp))
/* Start of text segment */
#define LM_TXTADDR(smp) (smp->som_addr == (caddr_t)0 ? PAGSIZ : 0)
/* Start of run-time relocation_info */
#define LM_REL(smp) ((struct relocation_info *) \
(smp->som_addr + LM_OFFSET(smp) + LD_REL((smp)->som_dynamic)))
/* Start of symbols */
#define LM_SYMBOL(smp, i) ((struct nzlist *) \
(smp->som_addr + LM_OFFSET(smp) + LD_SYMBOL((smp)->som_dynamic) + \
i * (LD_VERSION_NZLIST_P(smp->som_dynamic->d_version) ? \
sizeof(struct nzlist) : sizeof(struct nlist))))
/* Start of hash table */
#define LM_HASH(smp) ((struct rrs_hash *) \
((smp)->som_addr + LM_OFFSET(smp) + LD_HASH((smp)->som_dynamic)))
/* Start of strings */
#define LM_STRINGS(smp) ((char *) \
((smp)->som_addr + LM_OFFSET(smp) + LD_STRINGS((smp)->som_dynamic)))
/* End of text */
#define LM_ETEXT(smp) ((char *) \
((smp)->som_addr + LM_TXTADDR(smp) + LD_TEXTSZ((smp)->som_dynamic)))
/* PLT is in data segment, so don't use LM_OFFSET here */
#define LM_PLT(smp) ((jmpslot_t *) \
((smp)->som_addr + LD_PLT((smp)->som_dynamic)))
/* Parent of link map */
#define LM_PARENT(smp) (LM_PRIVATE(smp)->spd_parent)
char **environ;
int errno;
static uid_t uid, euid;
static gid_t gid, egid;
static int careful;
static char *main_progname = "main";
struct so_map *link_map_head, *main_map;
struct so_map **link_map_tail = &link_map_head;
struct rt_symbol *rt_symbol_head;
static void *dlopen __P((char *, int));
static int dlclose __P((void *));
static void *dlsym __P((void *, char *));
static int dlctl __P((void *, int, void *));
static struct ld_entry ld_entry = {
dlopen, dlclose, dlsym, dlctl
};
void xprintf __P((char *, ...));
static void init_brk __P((void));
static void load_objects __P(( struct crt_ldso *,
struct _dynamic *));
static struct so_map *map_object __P((struct sod *, struct so_map *));
static struct so_map *alloc_link_map __P(( char *, struct sod *,
struct so_map *, caddr_t,
struct _dynamic *));
static void inline check_text_reloc __P(( struct relocation_info *,
struct so_map *,
caddr_t));
static void reloc_map __P((struct so_map *));
static void reloc_copy __P((struct so_map *));
static void init_map __P((struct so_map *, char *));
static char *rtfindlib __P((char *, int, int, int *));
void binder_entry __P((void));
long binder __P((jmpslot_t *));
static struct nzlist *lookup __P((char *, struct so_map **, int));
static inline struct rt_symbol *lookup_rts __P((char *));
static struct rt_symbol *enter_rts __P((char *, long, int, caddr_t,
long, struct so_map *));
static inline int
strcmp (register const char *s1, register const char *s2)
{
while (*s1 == *s2++)
if (*s1++ == 0)
return (0);
return (*(unsigned char *)s1 - *(unsigned char *)--s2);
}
#include "md-static-funcs.c"
/*
* Called from assembler stub that has set up crtp (passed from crt0)
* and dp (our __DYNAMIC).
*/
int
rtld(version, crtp, dp)
int version;
struct crt_ldso *crtp;
struct _dynamic *dp;
{
int n;
int nreloc; /* # of ld.so relocations */
struct relocation_info *reloc;
char **envp;
struct so_debug *ddp;
struct so_map *smp;
/* Check version */
if ( version != CRT_VERSION_BSD_2 &&
version != CRT_VERSION_BSD_3 &&
version != CRT_VERSION_SUN)
return -1;
/* Fixup __DYNAMIC structure */
(long)dp->d_un.d_sdt += crtp->crt_ba;
/* Divide by hand to avoid possible use of library division routine */
for ( nreloc = 0, n = LD_RELSZ(dp);
n > 0;
n -= sizeof(struct relocation_info) ) nreloc++;
/* Relocate ourselves */
for ( reloc = (struct relocation_info *)(LD_REL(dp) + crtp->crt_ba);
nreloc;
nreloc--, reloc++) {
register long addr = reloc->r_address + crtp->crt_ba;
md_relocate_simple(reloc, crtp->crt_ba, addr);
}
progname = "ld.so";
if (version >= CRT_VERSION_BSD_3)
main_progname = crtp->crt_prog;
/* Setup out (private) environ variable */
environ = crtp->crt_ep;
/* Get user and group identifiers */
uid = getuid(); euid = geteuid();
gid = getgid(); egid = getegid();
careful = (uid != euid) || (gid != egid);
if (careful) {
unsetenv("LD_LIBRARY_PATH");
unsetenv("LD_PRELOAD");
unsetenv("LD_RUN_PATH"); /* In case we ever implement this */
}
/* Setup directory search */
std_search_dirs(getenv("LD_LIBRARY_PATH"));
/* Load required objects into the process address space */
load_objects(crtp, dp);
/* Relocate all loaded objects according to their RRS segments */
for (smp = link_map_head; smp; smp = smp->som_next) {
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
continue;
reloc_map(smp);
}
/* Copy any relocated initialized data. */
for (smp = link_map_head; smp; smp = smp->som_next) {
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
continue;
reloc_copy(smp);
}
/* Call any object initialization routines. */
for (smp = link_map_head; smp; smp = smp->som_next) {
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
continue;
init_map(smp, ".init");
}
/* Fill in some field in main's __DYNAMIC structure */
crtp->crt_dp->d_entry = &ld_entry;
crtp->crt_dp->d_un.d_sdt->sdt_loaded = link_map_head->som_next;
ddp = crtp->crt_dp->d_debug;
ddp->dd_cc = rt_symbol_head;
if (ddp->dd_in_debugger) {
caddr_t addr = (caddr_t)((long)crtp->crt_bp & (~(PAGSIZ - 1)));
/* Set breakpoint for the benefit of debuggers */
if (mprotect(addr, PAGSIZ,
PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
perror("mprotect"),
fatal("Cannot set breakpoint (%s)\n", main_progname);
}
md_set_breakpoint(crtp->crt_bp, &ddp->dd_bpt_shadow);
if (mprotect(addr, PAGSIZ, PROT_READ|PROT_EXEC) == -1) {
perror("mprotect");
}
ddp->dd_bpt_addr = crtp->crt_bp;
if (link_map_head)
ddp->dd_sym_loaded = 1;
}
/* Close our file descriptor */
(void)close(crtp->crt_ldfd);
return 0;
}
static void
load_objects(crtp, dp)
struct crt_ldso *crtp;
struct _dynamic *dp;
{
struct so_map *smp;
int tracing = (int)getenv("LD_TRACE_LOADED_OBJECTS");
/* Handle LD_PRELOAD's here */
/* Make an entry for the main program */
smp = alloc_link_map(main_progname, (struct sod *)0, (struct so_map *)0,
(caddr_t)0, crtp->crt_dp);
LM_PRIVATE(smp)->spd_refcount++;
LM_PRIVATE(smp)->spd_flags |= RTLD_MAIN;
/* Make an entry for ourselves */
smp = alloc_link_map("/usr/libexec/ld.so", (struct sod *)0, (struct so_map *)0,
(caddr_t)crtp->crt_ba, dp);
LM_PRIVATE(smp)->spd_refcount++;
LM_PRIVATE(smp)->spd_flags |= RTLD_RTLD;
for (smp = link_map_head; smp; smp = smp->som_next) {
struct sod *sodp;
long next = 0;
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
continue;
if (smp->som_dynamic)
next = LD_NEED(smp->som_dynamic);
while (next) {
struct so_map *newmap;
sodp = (struct sod *)(LM_LDBASE(smp) + next);
if ((newmap = map_object(sodp, smp)) == NULL) {
if (!tracing) {
char *name = (char *)
(sodp->sod_name + LM_LDBASE(smp));
char *fmt = sodp->sod_library ?
"%s: lib%s.so.%d.%d: %s\n" :
"%s: %s: %s\n";
fatal(fmt, main_progname, name,
sodp->sod_major,
sodp->sod_minor,
strerror(errno));
}
newmap = alloc_link_map(NULL, sodp, smp, 0, 0);
}
LM_PRIVATE(newmap)->spd_refcount++;
next = sodp->sod_next;
}
}
if (! tracing)
return;
for (smp = link_map_head; smp; smp = smp->som_next) {
struct sod *sodp;
char *name, *path;
if ((sodp = smp->som_sod) == NULL)
continue;
name = sodp->sod_name + LM_LDBASE(LM_PARENT(smp));
if ((path = smp->som_path) == NULL)
path = "not found";
if (sodp->sod_library)
printf("\t-l%s.%d => %s (%#x)\n", name,
sodp->sod_major, path, smp->som_addr);
else
printf("\t%s => %s (%#x)\n", name, path, smp->som_addr);
}
exit(0);
}
/*
* Allocate a new link map for an shared object NAME loaded at ADDR as a
* result of the presence of link object LOP in the link map PARENT.
*/
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;
smpp = (struct somap_private *)xmalloc(sizeof(struct somap_private));
smp = (struct so_map *)xmalloc(sizeof(struct so_map));
smp->som_next = NULL;
*link_map_tail = smp;
link_map_tail = &smp->som_next;
smp->som_addr = addr;
smp->som_path = path;
smp->som_sod = sodp;
smp->som_dynamic = dp;
smp->som_spd = (caddr_t)smpp;
/*XXX*/ if (addr == 0) main_map = smp;
smpp->spd_refcount = 0;
smpp->spd_flags = 0;
smpp->spd_parent = parent;
#ifdef SUN_COMPAT
smpp->spd_offset =
(addr==0 && dp && dp->d_version==LD_VERSION_SUN) ? PAGSIZ : 0;
#endif
return smp;
}
/*
* Map object identified by link object LOP which was found
* in link map LMP.
*/
static struct so_map *
map_object(sodp, smp)
struct sod *sodp;
struct so_map *smp;
{
struct _dynamic *dp;
char *path, *name = (char *)(sodp->sod_name + LM_LDBASE(smp));
int fd;
caddr_t addr;
struct exec hdr;
int usehints = 0;
struct so_map *p;
if (sodp->sod_library) {
usehints = 1;
again:
path = rtfindlib(name, sodp->sod_major,
sodp->sod_minor, &usehints);
if (path == NULL) {
errno = ENOENT;
return NULL;
}
} else {
if (careful && *name != '/') {
errno = EACCES;
return NULL;
}
path = name;
}
/* Check if already loaded */
for (p = link_map_head; p; p = p->som_next)
if (p->som_path && strcmp(p->som_path, path) == 0)
break;
if (p != NULL)
return p;
if ((fd = open(path, O_RDONLY, 0)) == -1) {
if (usehints) {
usehints = 0;
goto again;
}
return NULL;
}
if (read(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
(void)close(fd);
/*errno = x;*/
return NULL;
}
if (N_BADMAG(hdr)) {
(void)close(fd);
errno = EFTYPE;
return NULL;
}
if ((addr = mmap(0, hdr.a_text + hdr.a_data,
PROT_READ|PROT_EXEC,
MAP_FILE|MAP_COPY, fd, 0)) == (caddr_t)-1) {
(void)close(fd);
return NULL;
}
if (mmap(addr + hdr.a_text, hdr.a_data,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_FILE|MAP_FIXED|MAP_COPY,
fd, hdr.a_text) == (caddr_t)-1) {
(void)close(fd);
return NULL;
}
(void)close(fd);
fd = -1;
#ifdef NEED_DEV_ZERO
if ((fd = open("/dev/zero", O_RDWR, 0)) == -1)
perror("/dev/zero");
#endif
if (hdr.a_bss && mmap(addr + hdr.a_text + hdr.a_data, hdr.a_bss,
PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_ANON|MAP_FIXED|MAP_COPY,
fd, hdr.a_text + hdr.a_data) == (caddr_t)-1)
return NULL;
#ifdef NEED_DEV_ZERO
close(fd);
#endif
/* 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;
return alloc_link_map(path, sodp, smp, addr, dp);
}
static void inline
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;
if (RELOC_EXTERN_P(r))
sym = LM_STRINGS(smp) +
LM_SYMBOL(smp, RELOC_SYMBOL(r))->nz_strx;
else
sym = "";
if (getenv("LD_WARN_NON_PURE_CODE") != NULL)
fprintf(stderr,
"ld.so: warning: non pure code in %s at %x (%s)\n",
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) {
perror("mprotect"),
fatal("Cannot enable writes to %s:%s\n",
main_progname, smp->som_path);
}
smp->som_write = 1;
}
static void
reloc_map(smp)
struct so_map *smp;
{
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);
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 = smp->som_addr + r->r_address;
check_text_reloc(r, smp, addr);
if (RELOC_EXTERN_P(r)) {
struct so_map *src_map = NULL;
struct nzlist *p, *np;
long relocation = md_get_addend(r, addr);
if (RELOC_LAZY_P(r))
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;
np = lookup(sym, &src_map, 0/*XXX-jumpslots!*/);
if (np == NULL)
fatal("Undefined symbol \"%s\" in %s:%s\n",
sym, main_progname, smp->som_path);
/*
* 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_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) {
perror("mprotect"),
fatal("Cannot disable writes to %s:%s\n",
main_progname, smp->som_path);
}
smp->som_write = 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_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))();
}
/*
* 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 int inline
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)
;
/* 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 = LD_BUCKETS(smp->som_dynamic);
long hashval = 0;
struct rrs_hash *hp;
char *cp;
struct nzlist *np;
/* Some local caching */
long symbolbase;
struct rrs_hash *hashbase;
char *stringbase;
int symsize;
if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
continue;
if (*src_map && smp != *src_map)
continue;
/*
* Compute bucket in which the symbol might be found.
*/
for (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_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)
fatal("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)
fatal("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;
static struct hints_bucket *hbuckets;
static char *hstrtab;
#define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1)
static void
maphints()
{
caddr_t addr;
long msize;
int fd;
if ((fd = open(_PATH_LD_HINTS, O_RDONLY, 0)) == -1) {
hheader = (struct hints_header *)-1;
return;
}
msize = PAGSIZ;
addr = mmap(0, msize, PROT_READ, MAP_FILE|MAP_COPY, fd, 0);
if (addr == (caddr_t)-1) {
hheader = (struct hints_header *)-1;
return;
}
hheader = (struct hints_header *)addr;
if (HH_BADMAG(*hheader)) {
munmap(addr, msize);
hheader = (struct hints_header *)-1;
return;
}
if (hheader->hh_version != LD_HINTS_VERSION_1) {
munmap(addr, msize);
hheader = (struct hints_header *)-1;
return;
}
if (hheader->hh_ehints > msize) {
if (mmap(addr+msize, hheader->hh_ehints - msize,
PROT_READ, MAP_FILE|MAP_COPY|MAP_FIXED,
fd, msize) != (caddr_t)(addr+msize)) {
munmap((caddr_t)hheader, msize);
hheader = (struct hints_header *)-1;
return;
}
}
close(fd);
hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab);
hstrtab = (char *)(addr + hheader->hh_strtab);
}
int
hinthash(cp, vmajor, vminor)
char *cp;
int vmajor, vminor;
{
int k = 0;
while (*cp)
k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;
k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff;
k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff;
return k;
}
#undef major
#undef minor
static char *
findhint(name, major, minor, preferred_path)
char *name;
int major, minor;
char *preferred_path;
{
struct hints_bucket *bp;
bp = hbuckets + (hinthash(name, major, minor) % hheader->hh_nbucket);
while (1) {
/* Sanity check */
if (bp->hi_namex >= hheader->hh_strtab_sz) {
fprintf(stderr, "Bad name index: %#x\n", bp->hi_namex);
break;
}
if (bp->hi_pathx >= hheader->hh_strtab_sz) {
fprintf(stderr, "Bad path index: %#x\n", bp->hi_pathx);
break;
}
if (strcmp(name, hstrtab + bp->hi_namex) == 0) {
/* It's `name', check version numbers */
if (bp->hi_major == major &&
(bp->hi_ndewey < 2 || bp->hi_minor == minor)) {
if (preferred_path == NULL ||
strcmp(preferred_path,
hstrtab + bp->hi_pathx) == 0) {
return 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;
}
static char *
rtfindlib(name, major, minor, usehints)
char *name;
int major, minor;
int *usehints;
{
char *hint;
char *cp, *ld_path = getenv("LD_LIBRARY_PATH");
if (hheader == NULL)
maphints();
if (!HINTS_VALID || !(*usehints)) {
*usehints = 0;
return (char *)findshlib(name, &major, &minor, 0);
}
if (ld_path != NULL) {
/* Prefer paths from LD_LIBRARY_PATH */
while ((cp = strsep(&ld_path, ":")) != NULL) {
hint = findhint(name, major, minor, cp);
if (ld_path)
*(ld_path-1) = ':';
if (hint)
return hint;
}
} else {
/* No LD_LIBRARY_PATH, check default */
hint = findhint(name, major, minor, NULL);
if (hint)
return hint;
}
/* No hints available for name */
*usehints = 0;
return (char *)findshlib(name, &major, &minor, 0);
}
static struct somap_private dlmap_private = {
0,
(struct so_map *)0,
0,
#ifdef SUN_COMPAT
0,
#endif
};
static struct so_map dlmap = {
(caddr_t)0,
"internal",
(struct so_map *)0,
(struct sod *)0,
(caddr_t)0,
(u_int)0,
(struct _dynamic *)0,
(caddr_t)&dlmap_private
};
static int dlerrno;
static void *
dlopen(name, mode)
char *name;
int mode;
{
struct sod *sodp;
struct so_map *smp;
/*
* A NULL argument returns the current set of mapped objects.
*/
if (name == NULL)
return link_map_head;
if ((sodp = (struct sod *)malloc(sizeof(struct sod))) == NULL) {
dlerrno = ENOMEM;
return NULL;
}
sodp->sod_name = (long)name;
sodp->sod_library = 0;
sodp->sod_major = sodp->sod_minor = 0;
if ((smp = map_object(sodp, &dlmap)) == NULL) {
#ifdef DEBUG
xprintf("%s: %s\n", name, strerror(errno));
#endif
dlerrno = errno;
return NULL;
}
if (LM_PRIVATE(smp)->spd_refcount++ == 0) {
LM_PRIVATE(smp)->spd_flags |= RTLD_DL;
reloc_map(smp);
reloc_copy(smp);
init_map(smp, ".init");
init_map(smp, "_init");
}
return smp;
}
static int
dlclose(fd)
void *fd;
{
struct so_map *smp = (struct so_map *)fd;
#ifdef DEBUG
xprintf("dlclose(%s): refcount = %d\n", smp->som_path, LM_PRIVATE(smp)->spd_refcount);
#endif
if (--LM_PRIVATE(smp)->spd_refcount != 0)
return 0;
/* Dismantle shared object map and descriptor */
init_map(smp, "_fini");
#if 0
unmap_object(smp);
free(smp->som_sod);
free(smp);
#endif
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 (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 int
dlctl(fd, cmd, arg)
void *fd, *arg;
int cmd;
{
switch (cmd) {
case DL_GETERRNO:
*(int *)arg = dlerrno;
return 0;
default:
dlerrno = EOPNOTSUPP;
return -1;
}
return 0;
}
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
vsprintf(buf, fmt, ap);
(void)write(1, buf, strlen(buf));
va_end(ap);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.