347 lines
11 KiB
C
347 lines
11 KiB
C
/* Relocate a shared object and resolve its references to other loaded objects.
|
|
Copyright (C) 1995-2002, 2003 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <errno.h>
|
|
#include <libintl.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <ldsodefs.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/param.h>
|
|
#include <sys/types.h>
|
|
#include "dynamic-link.h"
|
|
|
|
/* Statistics function. */
|
|
#ifdef SHARED
|
|
# define bump_num_cache_relocations() ++GL(dl_num_cache_relocations)
|
|
#else
|
|
# define bump_num_cache_relocations() ((void) 0)
|
|
#endif
|
|
|
|
|
|
#ifdef USE_TLS
|
|
/* We are trying to perform a static TLS relocation in MAP, but it was
|
|
dynamically loaded. This can only work if there is enough surplus in
|
|
the static TLS area already allocated for each running thread. If this
|
|
object's TLS segment is too big to fit, we fail. If it fits,
|
|
we set MAP->l_tls_offset and return.
|
|
This function intentionally does not return any value but signals error
|
|
directly, as static TLS should be rare and code handling it should
|
|
not be inlined as much as possible. */
|
|
void
|
|
internal_function __attribute_noinline__
|
|
_dl_allocate_static_tls (struct link_map *map)
|
|
{
|
|
size_t offset;
|
|
size_t used;
|
|
size_t check;
|
|
size_t freebytes;
|
|
size_t n;
|
|
size_t blsize;
|
|
|
|
/* If the alignment requirements are too high fail. */
|
|
if (map->l_tls_align > GL(dl_tls_static_align))
|
|
{
|
|
fail:
|
|
INTUSE(_dl_signal_error) (0, map->l_name, NULL, N_("\
|
|
cannot allocate memory in static TLS block"));
|
|
}
|
|
|
|
# if TLS_TCB_AT_TP
|
|
freebytes = GL(dl_tls_static_size) - GL(dl_tls_static_used) - TLS_TCB_SIZE;
|
|
|
|
blsize = map->l_tls_blocksize + map->l_tls_firstbyte_offset;
|
|
if (freebytes < blsize)
|
|
goto fail;
|
|
|
|
n = (freebytes - blsize) / map->l_tls_align;
|
|
|
|
offset = GL(dl_tls_static_used) + (freebytes - n * map->l_tls_align
|
|
- map->l_tls_firstbyte_offset);
|
|
|
|
map->l_tls_offset = GL(dl_tls_static_used) = offset;
|
|
# elif TLS_DTV_AT_TP
|
|
offset = roundup (GL(dl_tls_static_used), map->l_tls_align);
|
|
used = offset + map->l_tls_blocksize;
|
|
check = used;
|
|
/* dl_tls_static_used includes the TCB at the beginning. */
|
|
|
|
if (check > GL(dl_tls_static_size))
|
|
goto fail;
|
|
|
|
map->l_tls_offset = offset;
|
|
GL(dl_tls_static_used) = used;
|
|
# else
|
|
# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
|
|
# endif
|
|
|
|
if (map->l_relocated)
|
|
GL(dl_init_static_tls) (map);
|
|
else
|
|
map->l_need_tls_init = 1;
|
|
}
|
|
|
|
/* Initialize static TLS area and DTV for current (only) thread.
|
|
libpthread implementations should provide their own hook
|
|
to handle all threads. */
|
|
void
|
|
_dl_nothread_init_static_tls (struct link_map *map)
|
|
{
|
|
# if TLS_TCB_AT_TP
|
|
void *dest = (char *) THREAD_SELF - map->l_tls_offset;
|
|
# elif TLS_DTV_AT_TP
|
|
void *dest = (char *) THREAD_SELF + map->l_tls_offset + TLS_PRE_TCB_SIZE;
|
|
# else
|
|
# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
|
|
# endif
|
|
|
|
/* Fill in the DTV slot so that a later LD/GD access will find it. */
|
|
THREAD_DTV ()[map->l_tls_modid].pointer = dest;
|
|
|
|
/* Initialize the memory. */
|
|
memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size),
|
|
'\0', map->l_tls_blocksize - map->l_tls_initimage_size);
|
|
}
|
|
#endif
|
|
|
|
|
|
void
|
|
_dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
|
|
int lazy, int consider_profiling)
|
|
{
|
|
struct textrels
|
|
{
|
|
caddr_t start;
|
|
size_t len;
|
|
int prot;
|
|
struct textrels *next;
|
|
} *textrels = NULL;
|
|
/* Initialize it to make the compiler happy. */
|
|
const char *errstring = NULL;
|
|
|
|
if (l->l_relocated)
|
|
return;
|
|
|
|
/* If DT_BIND_NOW is set relocate all references in this object. We
|
|
do not do this if we are profiling, of course. */
|
|
if (!consider_profiling
|
|
&& __builtin_expect (l->l_info[DT_BIND_NOW] != NULL, 0))
|
|
lazy = 0;
|
|
|
|
if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_RELOC, 0))
|
|
INTUSE(_dl_debug_printf) ("\nrelocation processing: %s%s\n",
|
|
l->l_name[0] ? l->l_name : rtld_progname,
|
|
lazy ? " (lazy)" : "");
|
|
|
|
/* DT_TEXTREL is now in level 2 and might phase out at some time.
|
|
But we rewrite the DT_FLAGS entry to a DT_TEXTREL entry to make
|
|
testing easier and therefore it will be available at all time. */
|
|
if (__builtin_expect (l->l_info[DT_TEXTREL] != NULL, 0))
|
|
{
|
|
/* Bletch. We must make read-only segments writable
|
|
long enough to relocate them. */
|
|
const ElfW(Phdr) *ph;
|
|
for (ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph)
|
|
if (ph->p_type == PT_LOAD && (ph->p_flags & PF_W) == 0)
|
|
{
|
|
struct textrels *newp;
|
|
|
|
newp = (struct textrels *) alloca (sizeof (*newp));
|
|
newp->len = (((ph->p_vaddr + ph->p_memsz + GL(dl_pagesize) - 1)
|
|
& ~(GL(dl_pagesize) - 1))
|
|
- (ph->p_vaddr & ~(GL(dl_pagesize) - 1)));
|
|
newp->start = ((ph->p_vaddr & ~(GL(dl_pagesize) - 1))
|
|
+ (caddr_t) l->l_addr);
|
|
|
|
if (__mprotect (newp->start, newp->len, PROT_READ|PROT_WRITE) < 0)
|
|
{
|
|
errstring = N_("cannot make segment writable for relocation");
|
|
call_error:
|
|
INTUSE(_dl_signal_error) (errno, l->l_name, NULL, errstring);
|
|
}
|
|
|
|
#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
|
|
newp->prot = (PF_TO_PROT
|
|
>> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
|
|
#else
|
|
newp->prot = 0;
|
|
if (ph->p_flags & PF_R)
|
|
newp->prot |= PROT_READ;
|
|
if (ph->p_flags & PF_W)
|
|
newp->prot |= PROT_WRITE;
|
|
if (ph->p_flags & PF_X)
|
|
newp->prot |= PROT_EXEC;
|
|
#endif
|
|
newp->next = textrels;
|
|
textrels = newp;
|
|
}
|
|
}
|
|
|
|
{
|
|
/* Do the actual relocation of the object's GOT and other data. */
|
|
|
|
/* String table object symbols. */
|
|
const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
|
|
|
|
/* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */
|
|
#define RESOLVE_MAP(ref, version, r_type) \
|
|
(ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \
|
|
? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \
|
|
&& elf_machine_type_class (r_type) == l->l_lookup_cache.type_class) \
|
|
? (bump_num_cache_relocations (), \
|
|
(*ref) = l->l_lookup_cache.ret, \
|
|
l->l_lookup_cache.value) \
|
|
: ({ lookup_t _lr; \
|
|
int _tc = elf_machine_type_class (r_type); \
|
|
l->l_lookup_cache.type_class = _tc; \
|
|
l->l_lookup_cache.sym = (*ref); \
|
|
_lr = ((version) != NULL && (version)->hash != 0 \
|
|
? INTUSE(_dl_lookup_versioned_symbol) (strtab \
|
|
+ (*ref)->st_name, \
|
|
l, (ref), scope, \
|
|
(version), _tc, 0) \
|
|
: INTUSE(_dl_lookup_symbol) (strtab + (*ref)->st_name, l, \
|
|
(ref), scope, _tc, \
|
|
DL_LOOKUP_ADD_DEPENDENCY)); \
|
|
l->l_lookup_cache.ret = (*ref); \
|
|
l->l_lookup_cache.value = _lr; })) \
|
|
: l)
|
|
#define RESOLVE(ref, version, r_type) \
|
|
(ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \
|
|
? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \
|
|
&& elf_machine_type_class (r_type) == l->l_lookup_cache.type_class) \
|
|
? (bump_num_cache_relocations (), \
|
|
(*ref) = l->l_lookup_cache.ret, \
|
|
l->l_lookup_cache.value) \
|
|
: ({ lookup_t _lr; \
|
|
int _tc = elf_machine_type_class (r_type); \
|
|
l->l_lookup_cache.type_class = _tc; \
|
|
l->l_lookup_cache.sym = (*ref); \
|
|
_lr = ((version) != NULL && (version)->hash != 0 \
|
|
? INTUSE(_dl_lookup_versioned_symbol) (strtab \
|
|
+ (*ref)->st_name, \
|
|
l, (ref), scope, \
|
|
(version), _tc, 0) \
|
|
: INTUSE(_dl_lookup_symbol) (strtab + (*ref)->st_name, l, \
|
|
(ref), scope, _tc, \
|
|
DL_LOOKUP_ADD_DEPENDENCY)); \
|
|
l->l_lookup_cache.ret = (*ref); \
|
|
l->l_lookup_cache.value = _lr; })) \
|
|
: l->l_addr)
|
|
|
|
/* This macro is used as a callback from elf_machine_rel{a,} when a
|
|
static TLS reloc is about to be performed. Since (in dl-load.c) we
|
|
permit dynamic loading of objects that might use such relocs, we
|
|
have to check whether each use is actually doable. If the object
|
|
whose TLS segment the reference resolves to was allocated space in
|
|
the static TLS block at startup, then it's ok. Otherwise, we make
|
|
an attempt to allocate it in surplus space on the fly. If that
|
|
can't be done, we fall back to the error that DF_STATIC_TLS is
|
|
intended to produce. */
|
|
#define CHECK_STATIC_TLS(map, sym_map) \
|
|
do { \
|
|
if (__builtin_expect ((sym_map)->l_tls_offset == NO_TLS_OFFSET, 0)) \
|
|
_dl_allocate_static_tls (sym_map); \
|
|
} while (0)
|
|
|
|
#include "dynamic-link.h"
|
|
|
|
ELF_DYNAMIC_RELOCATE (l, lazy, consider_profiling);
|
|
|
|
if (__builtin_expect (consider_profiling, 0))
|
|
{
|
|
/* Allocate the array which will contain the already found
|
|
relocations. If the shared object lacks a PLT (for example
|
|
if it only contains lead function) the l_info[DT_PLTRELSZ]
|
|
will be NULL. */
|
|
if (l->l_info[DT_PLTRELSZ] == NULL)
|
|
{
|
|
errstring = N_("%s: profiler found no PLTREL in object %s\n");
|
|
fatal:
|
|
_dl_fatal_printf (errstring,
|
|
rtld_progname ?: "<program name unknown>",
|
|
l->l_name);
|
|
}
|
|
|
|
l->l_reloc_result =
|
|
(ElfW(Addr) *) calloc (sizeof (ElfW(Addr)),
|
|
l->l_info[DT_PLTRELSZ]->d_un.d_val);
|
|
if (l->l_reloc_result == NULL)
|
|
{
|
|
errstring = N_("\
|
|
%s: profiler out of memory shadowing PLTREL of %s\n");
|
|
goto fatal;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Mark the object so we know this work has been done. */
|
|
l->l_relocated = 1;
|
|
|
|
/* Undo the segment protection changes. */
|
|
while (__builtin_expect (textrels != NULL, 0))
|
|
{
|
|
if (__mprotect (textrels->start, textrels->len, textrels->prot) < 0)
|
|
{
|
|
errstring = N_("cannot restore segment prot after reloc");
|
|
goto call_error;
|
|
}
|
|
|
|
textrels = textrels->next;
|
|
}
|
|
}
|
|
INTDEF (_dl_relocate_object)
|
|
|
|
|
|
void
|
|
internal_function __attribute_noinline__
|
|
_dl_reloc_bad_type (struct link_map *map, unsigned int type, int plt)
|
|
{
|
|
extern const char INTUSE(_itoa_lower_digits)[] attribute_hidden;
|
|
#define DIGIT(b) INTUSE(_itoa_lower_digits)[(b) & 0xf];
|
|
|
|
/* XXX We cannot translate these messages. */
|
|
static const char msg[2][32
|
|
#if __ELF_NATIVE_CLASS == 64
|
|
+ 6
|
|
#endif
|
|
] = { "unexpected reloc type 0x",
|
|
"unexpected PLT reloc type 0x" };
|
|
char msgbuf[sizeof (msg[0])];
|
|
char *cp;
|
|
|
|
cp = __stpcpy (msgbuf, msg[plt]);
|
|
#if __ELF_NATIVE_CLASS == 64
|
|
if (__builtin_expect(type > 0xff, 0))
|
|
{
|
|
*cp++ = DIGIT (type >> 28);
|
|
*cp++ = DIGIT (type >> 24);
|
|
*cp++ = DIGIT (type >> 20);
|
|
*cp++ = DIGIT (type >> 16);
|
|
*cp++ = DIGIT (type >> 12);
|
|
*cp++ = DIGIT (type >> 8);
|
|
}
|
|
#endif
|
|
*cp++ = DIGIT (type >> 4);
|
|
*cp++ = DIGIT (type);
|
|
*cp = '\0';
|
|
|
|
INTUSE(_dl_signal_error) (0, map->l_name, NULL, msgbuf);
|
|
}
|