From ed20b3d9cc5ce78fd71f32c47b2eb7a897c7a25d Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 13 Jan 2004 08:36:54 +0000 Subject: Update. 2004-01-13 Ulrich Drepper * Makeconfig: Define relro-LDFLAGS if have-z-relro==yes. Add it to LDFLAGS.so and LDFLAGS-rtld. (+link): Add relro-LDFLAGS. * Makeconfig (shlib.lds): Place __libc_subfreeres, __libc_atexit, and __libc_thread_subfreeres sections after .jcr section. * config.make.in: Add have-z-relro. * configure.in: Add check for -z relro option. * include/link.h (struct link_map): Add relro_addr and relro_size members. * elf/dl-load.c (_dl_map_object_from_fd): Recognize PT_GNU_RELRO. * elf/dl-reloc.c (_dl_relocate_object): At the end, make relro part of loaded segments read-only. * elf/elf.h: Define PT_GNU_RELRO. * elf/rtld.c (_dl_start): Recognize PT_GNU_RELRO of ld.so. (dl_main): Recognize PT_GNU_RELRO of the application. Call _dl_debug_initialize and initialize l_info[DT_DEBUG] before relocations. --- elf/dl-reloc.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'elf/dl-reloc.c') diff --git a/elf/dl-reloc.c b/elf/dl-reloc.c index e5abba41dd..21d1871c6d 100644 --- a/elf/dl-reloc.c +++ b/elf/dl-reloc.c @@ -1,5 +1,5 @@ /* Relocate a shared object and resolve its references to other loaded objects. - Copyright (C) 1995-2002, 2003 Free Software Foundation, Inc. + Copyright (C) 1995-2002, 2003, 2004 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 @@ -307,6 +307,24 @@ _dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[], textrels = textrels->next; } + + /* In case we can protect the data now that the relocations are + done, do it. */ + if (l->l_relro_size != 0) + { + ElfW(Addr) start = ((l->l_addr + l->l_relro_addr) + & ~(GL(dl_pagesize) - 1)); + ElfW(Addr) end = ((l->l_addr + l->l_relro_addr + l->l_relro_size) + & ~(GL(dl_pagesize) - 1)); + + if (start != end + && __mprotect ((void *) start, end - start, PROT_READ) < 0) + { + errstring = N_("\ +cannot apply additional memory protection after relocation"); + goto call_error; + } + } } INTDEF (_dl_relocate_object) -- cgit 1.4.1