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338 lines
12 KiB
C
338 lines
12 KiB
C
/* Inline functions for dynamic linking.
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Copyright (C) 1995-2002, 2003, 2004 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 <elf.h>
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#include <assert.h>
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#ifdef RESOLVE
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/* We pass reloc_addr as a pointer to void, as opposed to a pointer to
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ElfW(Addr), because not all architectures can assume that the
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relocated address is properly aligned, whereas the compiler is
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entitled to assume that a pointer to a type is properly aligned for
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the type. Even if we cast the pointer back to some other type with
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less strict alignment requirements, the compiler might still
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remember that the pointer was originally more aligned, thereby
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optimizing away alignment tests or using word instructions for
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copying memory, breaking the very code written to handle the
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unaligned cases. */
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auto void __attribute__((always_inline))
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elf_machine_rel (struct link_map *map, const ElfW(Rel) *reloc,
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const ElfW(Sym) *sym, const struct r_found_version *version,
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void *const reloc_addr);
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auto void __attribute__((always_inline))
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elf_machine_rela (struct link_map *map, const ElfW(Rela) *reloc,
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const ElfW(Sym) *sym, const struct r_found_version *version,
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void *const reloc_addr);
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auto void __attribute__((always_inline))
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elf_machine_rel_relative (ElfW(Addr) l_addr, const ElfW(Rel) *reloc,
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void *const reloc_addr);
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auto void __attribute__((always_inline))
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elf_machine_rela_relative (ElfW(Addr) l_addr, const ElfW(Rela) *reloc,
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void *const reloc_addr);
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# if ELF_MACHINE_NO_RELA || defined ELF_MACHINE_PLT_REL
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auto void __attribute__((always_inline))
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elf_machine_lazy_rel (struct link_map *map,
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ElfW(Addr) l_addr, const ElfW(Rel) *reloc);
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# else
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auto void __attribute__((always_inline))
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elf_machine_lazy_rel (struct link_map *map,
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ElfW(Addr) l_addr, const ElfW(Rela) *reloc);
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# endif
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#endif
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#include <dl-machine.h>
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#ifndef VERSYMIDX
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# define VERSYMIDX(sym) (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (sym))
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#endif
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/* Read the dynamic section at DYN and fill in INFO with indices DT_*. */
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#ifndef RESOLVE
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static
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#else
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auto
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#endif
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inline void __attribute__ ((unused, always_inline))
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elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp)
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{
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ElfW(Dyn) *dyn = l->l_ld;
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ElfW(Dyn) **info;
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#ifndef RTLD_BOOTSTRAP
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if (dyn == NULL)
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return;
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#endif
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info = l->l_info;
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while (dyn->d_tag != DT_NULL)
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{
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if (dyn->d_tag < DT_NUM)
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info[dyn->d_tag] = dyn;
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else if (dyn->d_tag >= DT_LOPROC &&
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dyn->d_tag < DT_LOPROC + DT_THISPROCNUM)
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info[dyn->d_tag - DT_LOPROC + DT_NUM] = dyn;
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else if ((Elf32_Word) DT_VERSIONTAGIDX (dyn->d_tag) < DT_VERSIONTAGNUM)
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info[VERSYMIDX (dyn->d_tag)] = dyn;
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else if ((Elf32_Word) DT_EXTRATAGIDX (dyn->d_tag) < DT_EXTRANUM)
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info[DT_EXTRATAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
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+ DT_VERSIONTAGNUM] = dyn;
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else if ((Elf32_Word) DT_VALTAGIDX (dyn->d_tag) < DT_VALNUM)
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info[DT_VALTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
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+ DT_VERSIONTAGNUM + DT_EXTRANUM] = dyn;
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else if ((Elf32_Word) DT_ADDRTAGIDX (dyn->d_tag) < DT_ADDRNUM)
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info[DT_ADDRTAGIDX (dyn->d_tag) + DT_NUM + DT_THISPROCNUM
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+ DT_VERSIONTAGNUM + DT_EXTRANUM + DT_VALNUM] = dyn;
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++dyn;
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}
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#define DL_RO_DYN_TEMP_CNT 8
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#ifndef DL_RO_DYN_SECTION
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/* Don't adjust .dynamic unnecessarily. */
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if (l->l_addr != 0)
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{
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ElfW(Addr) l_addr = l->l_addr;
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int cnt = 0;
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# define ADJUST_DYN_INFO(tag) \
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do \
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if (info[tag] != NULL) \
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{ \
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if (temp) \
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{ \
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temp[cnt].d_tag = info[tag]->d_tag; \
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temp[cnt].d_un.d_ptr = info[tag]->d_un.d_ptr + l_addr; \
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info[tag] = temp + cnt++; \
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} \
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else \
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info[tag]->d_un.d_ptr += l_addr; \
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} \
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while (0)
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ADJUST_DYN_INFO (DT_HASH);
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ADJUST_DYN_INFO (DT_PLTGOT);
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ADJUST_DYN_INFO (DT_STRTAB);
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ADJUST_DYN_INFO (DT_SYMTAB);
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# if ! ELF_MACHINE_NO_RELA
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ADJUST_DYN_INFO (DT_RELA);
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# endif
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# if ! ELF_MACHINE_NO_REL
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ADJUST_DYN_INFO (DT_REL);
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# endif
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ADJUST_DYN_INFO (DT_JMPREL);
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ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM));
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# undef ADJUST_DYN_INFO
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assert (cnt <= DL_RO_DYN_TEMP_CNT);
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}
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#endif
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if (info[DT_PLTREL] != NULL)
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{
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#if ELF_MACHINE_NO_RELA
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assert (info[DT_PLTREL]->d_un.d_val == DT_REL);
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#elif ELF_MACHINE_NO_REL
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assert (info[DT_PLTREL]->d_un.d_val == DT_RELA);
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#else
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assert (info[DT_PLTREL]->d_un.d_val == DT_REL
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|| info[DT_PLTREL]->d_un.d_val == DT_RELA);
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#endif
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}
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#if ! ELF_MACHINE_NO_RELA
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if (info[DT_RELA] != NULL)
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assert (info[DT_RELAENT]->d_un.d_val == sizeof (ElfW(Rela)));
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# endif
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# if ! ELF_MACHINE_NO_REL
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if (info[DT_REL] != NULL)
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assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
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#endif
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#ifdef RTLD_BOOTSTRAP
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/* Only the bind now flags are allowed. */
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assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL
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|| info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val == DF_1_NOW);
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assert (info[DT_FLAGS] == NULL
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|| info[DT_FLAGS]->d_un.d_val == DF_BIND_NOW);
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/* Flags must not be set for ld.so. */
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assert (info[DT_RUNPATH] == NULL);
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assert (info[DT_RPATH] == NULL);
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#else
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if (info[DT_FLAGS] != NULL)
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{
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/* Flags are used. Translate to the old form where available.
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Since these l_info entries are only tested for NULL pointers it
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is ok if they point to the DT_FLAGS entry. */
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l->l_flags = info[DT_FLAGS]->d_un.d_val;
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if (l->l_flags & DF_SYMBOLIC)
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info[DT_SYMBOLIC] = info[DT_FLAGS];
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if (l->l_flags & DF_TEXTREL)
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info[DT_TEXTREL] = info[DT_FLAGS];
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if (l->l_flags & DF_BIND_NOW)
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info[DT_BIND_NOW] = info[DT_FLAGS];
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}
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if (info[VERSYMIDX (DT_FLAGS_1)] != NULL)
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{
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l->l_flags_1 = info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val;
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if (l->l_flags_1 & DF_1_NOW)
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info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)];
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}
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if (info[DT_RUNPATH] != NULL)
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/* If both RUNPATH and RPATH are given, the latter is ignored. */
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info[DT_RPATH] = NULL;
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#endif
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}
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#ifdef RESOLVE
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# ifdef RTLD_BOOTSTRAP
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# define ELF_DURING_STARTUP (1)
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# else
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# define ELF_DURING_STARTUP (0)
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# endif
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/* Get the definitions of `elf_dynamic_do_rel' and `elf_dynamic_do_rela'.
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These functions are almost identical, so we use cpp magic to avoid
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duplicating their code. It cannot be done in a more general function
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because we must be able to completely inline. */
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/* On some machines, notably SPARC, DT_REL* includes DT_JMPREL in its
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range. Note that according to the ELF spec, this is completely legal!
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But conditionally define things so that on machines we know this will
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not happen we do something more optimal. */
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# ifdef ELF_MACHINE_PLTREL_OVERLAP
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# define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, do_lazy, test_rel) \
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do { \
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struct { ElfW(Addr) start, size; int lazy; } ranges[3]; \
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int ranges_index; \
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\
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ranges[0].lazy = ranges[2].lazy = 0; \
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ranges[1].lazy = 1; \
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ranges[0].size = ranges[1].size = ranges[2].size = 0; \
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\
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if ((map)->l_info[DT_##RELOC]) \
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{ \
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ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \
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ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
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} \
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\
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if ((do_lazy) \
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&& (map)->l_info[DT_PLTREL] \
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&& (!test_rel || (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)) \
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{ \
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ranges[1].start = D_PTR ((map), l_info[DT_JMPREL]); \
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ranges[1].size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
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ranges[2].start = ranges[1].start + ranges[1].size; \
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ranges[2].size = ranges[0].start + ranges[0].size - ranges[2].start; \
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ranges[0].size = ranges[1].start - ranges[0].start; \
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} \
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\
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for (ranges_index = 0; ranges_index < 3; ++ranges_index) \
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elf_dynamic_do_##reloc ((map), \
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ranges[ranges_index].start, \
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ranges[ranges_index].size, \
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ranges[ranges_index].lazy); \
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} while (0)
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# else
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# define _ELF_DYNAMIC_DO_RELOC(RELOC, reloc, map, do_lazy, test_rel) \
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do { \
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struct { ElfW(Addr) start, size; int lazy; } ranges[2]; \
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ranges[0].lazy = 0; \
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ranges[0].size = ranges[1].size = 0; \
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ranges[0].start = 0; \
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\
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if ((map)->l_info[DT_##RELOC]) \
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{ \
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ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \
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ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
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} \
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if ((map)->l_info[DT_PLTREL] \
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&& (!test_rel || (map)->l_info[DT_PLTREL]->d_un.d_val == DT_##RELOC)) \
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{ \
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ElfW(Addr) start = D_PTR ((map), l_info[DT_JMPREL]); \
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\
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if (! ELF_DURING_STARTUP \
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&& ((do_lazy) \
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/* This test does not only detect whether the relocation \
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sections are in the right order, it also checks whether \
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there is a DT_REL/DT_RELA section. */ \
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|| ranges[0].start + ranges[0].size != start)) \
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{ \
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ranges[1].start = start; \
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ranges[1].size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
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ranges[1].lazy = (do_lazy); \
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} \
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else \
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{ \
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/* Combine processing the sections. */ \
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assert (ranges[0].start + ranges[0].size == start); \
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ranges[0].size += (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
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} \
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} \
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\
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if (ELF_DURING_STARTUP) \
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elf_dynamic_do_##reloc ((map), ranges[0].start, ranges[0].size, 0); \
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else \
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{ \
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int ranges_index; \
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for (ranges_index = 0; ranges_index < 2; ++ranges_index) \
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elf_dynamic_do_##reloc ((map), \
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ranges[ranges_index].start, \
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ranges[ranges_index].size, \
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ranges[ranges_index].lazy); \
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} \
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} while (0)
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# endif
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# if ELF_MACHINE_NO_REL || ELF_MACHINE_NO_RELA
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# define _ELF_CHECK_REL 0
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# else
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# define _ELF_CHECK_REL 1
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# endif
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# if ! ELF_MACHINE_NO_REL
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# include "do-rel.h"
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# define ELF_DYNAMIC_DO_REL(map, lazy) \
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_ELF_DYNAMIC_DO_RELOC (REL, rel, map, lazy, _ELF_CHECK_REL)
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# else
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# define ELF_DYNAMIC_DO_REL(map, lazy) /* Nothing to do. */
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# endif
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# if ! ELF_MACHINE_NO_RELA
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# define DO_RELA
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# include "do-rel.h"
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# define ELF_DYNAMIC_DO_RELA(map, lazy) \
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_ELF_DYNAMIC_DO_RELOC (RELA, rela, map, lazy, _ELF_CHECK_REL)
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# else
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# define ELF_DYNAMIC_DO_RELA(map, lazy) /* Nothing to do. */
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# endif
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/* This can't just be an inline function because GCC is too dumb
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to inline functions containing inlines themselves. */
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# define ELF_DYNAMIC_RELOCATE(map, lazy, consider_profile) \
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do { \
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int edr_lazy = elf_machine_runtime_setup ((map), (lazy), \
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(consider_profile)); \
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ELF_DYNAMIC_DO_REL ((map), edr_lazy); \
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ELF_DYNAMIC_DO_RELA ((map), edr_lazy); \
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} while (0)
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#endif
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