299601a1ef
2003-04-22 Jakub Jelinek <jakub@redhat.com> * include/link.h (NO_TLS_OFFSET): Define to 0 if not defined. * elf/dl-close.c (_dl_close): Use NO_TLS_OFFSET. * elf/dl-object.c (_dl_new_object): Initialize l_tls_offset to NO_TLS_OFFSET. * elf/rtld.c (_dl_start_final, _dl_start): Likewise. * elf/dl-reloc.c (CHECK_STATIC_TLS): Use NO_TLS_OFFSET. * sysdeps/generic/dl-tls.c (_dl_allocate_tls_init): Likewise. * sysdeps/powerpc/dl-tls.h (TLS_TPREL_VALUE): Don't subtract TLS_TCB_SIZE.
300 lines
10 KiB
C
300 lines
10 KiB
C
/* Relocate a shared object and resolve its references to other loaded objects.
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Copyright (C) 1995-2002, 2003 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <errno.h>
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#include <libintl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <ldsodefs.h>
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#include <sys/mman.h>
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#include <sys/param.h>
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#include <sys/types.h>
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#include "dynamic-link.h"
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/* Statistics function. */
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#ifdef SHARED
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# define bump_num_cache_relocations() ++GL(dl_num_cache_relocations)
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#else
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# define bump_num_cache_relocations() ((void) 0)
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#endif
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#ifdef USE_TLS
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/* We are trying to perform a static TLS relocation in MAP, but it was
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dynamically loaded. This can only work if there is enough surplus in
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the static TLS area already allocated for each running thread. If this
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object's TLS segment is too big to fit, we fail. If it fits,
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we set MAP->l_tls_offset and return. */
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void
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internal_function __attribute_noinline__
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_dl_allocate_static_tls (struct link_map *map)
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{
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size_t offset, used, check;
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# if TLS_TCB_AT_TP
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offset = roundup (GL(dl_tls_static_used) + map->l_tls_blocksize,
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map->l_tls_align);
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used = offset;
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check = offset + TLS_TCB_SIZE;
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# elif TLS_DTV_AT_TP
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offset = roundup (GL(dl_tls_static_used), map->l_tls_align);
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used = offset + map->l_tls_blocksize;
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check = used;
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/* dl_tls_static_used includes the TCB at the beginning. */
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# else
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# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
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# endif
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if (check > GL(dl_tls_static_size))
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{
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const char *errstring = N_("\
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shared object cannot be dlopen()ed: static TLS memory too small");
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INTUSE(_dl_signal_error) (0, (map)->l_name, NULL, errstring);
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}
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map->l_tls_offset = offset;
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GL(dl_tls_static_used) = used;
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}
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#endif
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void
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_dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
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int lazy, int consider_profiling)
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{
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struct textrels
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{
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caddr_t start;
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size_t len;
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int prot;
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struct textrels *next;
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} *textrels = NULL;
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/* Initialize it to make the compiler happy. */
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const char *errstring = NULL;
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if (l->l_relocated)
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return;
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/* If DT_BIND_NOW is set relocate all references in this object. We
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do not do this if we are profiling, of course. */
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if (!consider_profiling
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&& __builtin_expect (l->l_info[DT_BIND_NOW] != NULL, 0))
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lazy = 0;
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if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_RELOC, 0))
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INTUSE(_dl_debug_printf) ("\nrelocation processing: %s%s\n",
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l->l_name[0] ? l->l_name : rtld_progname,
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lazy ? " (lazy)" : "");
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/* DT_TEXTREL is now in level 2 and might phase out at some time.
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But we rewrite the DT_FLAGS entry to a DT_TEXTREL entry to make
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testing easier and therefore it will be available at all time. */
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if (__builtin_expect (l->l_info[DT_TEXTREL] != NULL, 0))
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{
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/* Bletch. We must make read-only segments writable
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long enough to relocate them. */
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const ElfW(Phdr) *ph;
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for (ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph)
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if (ph->p_type == PT_LOAD && (ph->p_flags & PF_W) == 0)
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{
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struct textrels *newp;
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newp = (struct textrels *) alloca (sizeof (*newp));
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newp->len = (((ph->p_vaddr + ph->p_memsz + GL(dl_pagesize) - 1)
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& ~(GL(dl_pagesize) - 1))
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- (ph->p_vaddr & ~(GL(dl_pagesize) - 1)));
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newp->start = ((ph->p_vaddr & ~(GL(dl_pagesize) - 1))
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+ (caddr_t) l->l_addr);
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if (__mprotect (newp->start, newp->len, PROT_READ|PROT_WRITE) < 0)
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{
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errstring = N_("cannot make segment writable for relocation");
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call_error:
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INTUSE(_dl_signal_error) (errno, l->l_name, NULL, errstring);
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}
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#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
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newp->prot = (PF_TO_PROT
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>> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
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#else
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newp->prot = 0;
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if (ph->p_flags & PF_R)
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newp->prot |= PROT_READ;
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if (ph->p_flags & PF_W)
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newp->prot |= PROT_WRITE;
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if (ph->p_flags & PF_X)
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newp->prot |= PROT_EXEC;
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#endif
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newp->next = textrels;
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textrels = newp;
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}
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}
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{
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/* Do the actual relocation of the object's GOT and other data. */
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/* String table object symbols. */
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const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
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/* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */
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#define RESOLVE_MAP(ref, version, r_type) \
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(ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \
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? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \
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&& elf_machine_type_class (r_type) == l->l_lookup_cache.type_class) \
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? (bump_num_cache_relocations (), \
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(*ref) = l->l_lookup_cache.ret, \
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l->l_lookup_cache.value) \
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: ({ lookup_t _lr; \
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int _tc = elf_machine_type_class (r_type); \
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l->l_lookup_cache.type_class = _tc; \
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l->l_lookup_cache.sym = (*ref); \
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_lr = ((version) != NULL && (version)->hash != 0 \
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? INTUSE(_dl_lookup_versioned_symbol) (strtab \
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+ (*ref)->st_name, \
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l, (ref), scope, \
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(version), _tc, 0) \
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: INTUSE(_dl_lookup_symbol) (strtab + (*ref)->st_name, l, \
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(ref), scope, _tc, \
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DL_LOOKUP_ADD_DEPENDENCY)); \
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l->l_lookup_cache.ret = (*ref); \
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l->l_lookup_cache.value = _lr; })) \
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: l)
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#define RESOLVE(ref, version, r_type) \
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(ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \
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? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \
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&& elf_machine_type_class (r_type) == l->l_lookup_cache.type_class) \
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? (bump_num_cache_relocations (), \
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(*ref) = l->l_lookup_cache.ret, \
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l->l_lookup_cache.value) \
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: ({ lookup_t _lr; \
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int _tc = elf_machine_type_class (r_type); \
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l->l_lookup_cache.type_class = _tc; \
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l->l_lookup_cache.sym = (*ref); \
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_lr = ((version) != NULL && (version)->hash != 0 \
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? INTUSE(_dl_lookup_versioned_symbol) (strtab \
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+ (*ref)->st_name, \
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l, (ref), scope, \
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(version), _tc, 0) \
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: INTUSE(_dl_lookup_symbol) (strtab + (*ref)->st_name, l, \
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(ref), scope, _tc, \
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DL_LOOKUP_ADD_DEPENDENCY)); \
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l->l_lookup_cache.ret = (*ref); \
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l->l_lookup_cache.value = _lr; })) \
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: l->l_addr)
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/* This macro is used as a callback from elf_machine_rel{a,} when a
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static TLS reloc is about to be performed. Since (in dl-load.c) we
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permit dynamic loading of objects that might use such relocs, we
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have to check whether each use is actually doable. If the object
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whose TLS segment the reference resolves to was allocated space in
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the static TLS block at startup, then it's ok. Otherwise, we make
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an attempt to allocate it in surplus space on the fly. If that
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can't be done, we fall back to the error that DF_STATIC_TLS is
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intended to produce. */
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#define CHECK_STATIC_TLS(map, sym_map) \
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do { \
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if (__builtin_expect ((sym_map)->l_tls_offset == NO_TLS_OFFSET, 0)) \
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_dl_allocate_static_tls (sym_map); \
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} while (0)
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#include "dynamic-link.h"
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ELF_DYNAMIC_RELOCATE (l, lazy, consider_profiling);
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if (__builtin_expect (consider_profiling, 0))
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{
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/* Allocate the array which will contain the already found
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relocations. If the shared object lacks a PLT (for example
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if it only contains lead function) the l_info[DT_PLTRELSZ]
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will be NULL. */
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if (l->l_info[DT_PLTRELSZ] == NULL)
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{
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errstring = N_("%s: profiler found no PLTREL in object %s\n");
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fatal:
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_dl_fatal_printf (errstring,
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rtld_progname ?: "<program name unknown>",
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l->l_name);
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}
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l->l_reloc_result =
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(ElfW(Addr) *) calloc (sizeof (ElfW(Addr)),
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l->l_info[DT_PLTRELSZ]->d_un.d_val);
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if (l->l_reloc_result == NULL)
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{
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errstring = N_("\
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%s: profiler out of memory shadowing PLTREL of %s\n");
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goto fatal;
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}
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}
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}
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/* Mark the object so we know this work has been done. */
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l->l_relocated = 1;
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/* Undo the segment protection changes. */
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while (__builtin_expect (textrels != NULL, 0))
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{
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if (__mprotect (textrels->start, textrels->len, textrels->prot) < 0)
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{
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errstring = N_("cannot restore segment prot after reloc");
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goto call_error;
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}
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textrels = textrels->next;
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}
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}
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INTDEF (_dl_relocate_object)
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void
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internal_function __attribute_noinline__
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_dl_reloc_bad_type (struct link_map *map, unsigned int type, int plt)
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{
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extern const char INTUSE(_itoa_lower_digits)[] attribute_hidden;
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#define DIGIT(b) INTUSE(_itoa_lower_digits)[(b) & 0xf];
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/* XXX We cannot translate these messages. */
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static const char msg[2][32
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#if __ELF_NATIVE_CLASS == 64
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+ 6
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#endif
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] = { "unexpected reloc type 0x",
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"unexpected PLT reloc type 0x" };
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char msgbuf[sizeof (msg[0])];
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char *cp;
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cp = __stpcpy (msgbuf, msg[plt]);
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#if __ELF_NATIVE_CLASS == 64
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if (__builtin_expect(type > 0xff, 0))
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{
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*cp++ = DIGIT (type >> 28);
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*cp++ = DIGIT (type >> 24);
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*cp++ = DIGIT (type >> 20);
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*cp++ = DIGIT (type >> 16);
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*cp++ = DIGIT (type >> 12);
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*cp++ = DIGIT (type >> 8);
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}
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#endif
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*cp++ = DIGIT (type >> 4);
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*cp++ = DIGIT (type);
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*cp = '\0';
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INTUSE(_dl_signal_error) (0, map->l_name, NULL, msgbuf);
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}
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