From d66e34cd423425c348bcc83df127dd19711b0b9a Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Tue, 2 May 1995 06:35:55 +0000 Subject: * sysdeps/mach/i386/sysdep.h (SNARF_ARGS, CALL_WITH_SP): Rewritten. * sysdeps/i386/dl-machine.h: New file. * sysdeps/stub/dl-machine.h: New file. * sysdeps/i386/dl-runtime.c: New file. * sysdeps/stub/dl-runtime.c: New file. * sysdeps/i386/elf/start.S: New file. * sysdeps/generic/dl-sysdep.c: New file. * sysdeps/mach/hurd/dl-sysdep.c: New file. --- elf/dl-reloc.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 elf/dl-reloc.c (limited to 'elf/dl-reloc.c') diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c new file mode 100644 index 0000000000..8efb3f04a6 --- /dev/null +++ b/elf/dl-reloc.c @@ -0,0 +1,115 @@ +/* Relocate a shared object and resolve its references to other loaded objects. +Copyright (C) 1995 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include +#include +#include +#include +#include +#include "dynamic-link.h" + + +void +_dl_relocate_object (struct link_map *l, int lazy) +{ + const size_t pagesize = getpagesize (); + + if (l->l_relocated) + return; + + if (l->l_info[DT_TEXTREL]) + { + /* Bletch. We must make read-only segments writable + long enough to relocate them. */ + const Elf32_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) + { + caddr_t mapstart = ((caddr_t) l->l_addr + + (ph->p_vaddr & ~(pagesize - 1))); + caddr_t mapend = ((caddr_t) l->l_addr + + ((ph->p_vaddr + ph->p_memsz + pagesize - 1) + & ~(pagesize - 1))); + if (mprotect (mapstart, mapend - mapstart, + PROT_READ|PROT_WRITE) < 0) + _dl_signal_error (errno, + "cannot make segment writable for relocation"); + } + } + + { + struct link_map *real_next, *scope; + + const char *strtab + = ((void *) l->l_addr + l->l_info[DT_STRTAB]->d_un.d_ptr); + + + Elf32_Addr resolve (const Elf32_Sym **ref) + { + return _dl_lookup_symbol (strtab + (*ref)->st_name, ref, scope); + } + + real_next = l->l_next; + if (l->l_info[DT_SYMBOLIC]) + { + l->l_prev->l_next = real_next; + l->l_next = _dl_loaded; + scope = l; + } + else + scope = _dl_loaded; + + elf_dynamic_relocate (l->l_info, l->l_addr, lazy, resolve); + + /* Restore list frobnication done above for DT_SYMBOLIC. */ + l->l_next = real_next; + l->l_prev->l_next = l; + } + + if (l->l_info[DT_JMPREL] && ! lazy) + /* Set up the PLT so its unrelocated entries will + jump to _dl_runtime_resolve, which will relocate them. */ + elf_machine_runtime_setup (l); + + l->l_relocated = 1; + + if (l->l_info[DT_TEXTREL]) + { + /* Undo the protection change we made before relocating. */ + const Elf32_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) + { + caddr_t mapstart = ((caddr_t) l->l_addr + + (ph->p_vaddr & ~(pagesize - 1))); + caddr_t mapend = ((caddr_t) l->l_addr + + ((ph->p_vaddr + ph->p_memsz + pagesize - 1) + & ~(pagesize - 1))); + int prot = 0; + if (ph->p_flags & PF_R) + prot |= PROT_READ; + if (ph->p_flags & PF_X) + prot |= PROT_EXEC; + if (mprotect (mapstart, mapend - mapstart, prot) < 0) + _dl_signal_error (errno, + "can't restore segment prot after reloc"); + } + } + +} -- cgit v1.2.3