From owner-svn-src-head@FreeBSD.ORG Mon Jan 30 19:52:18 2012 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 00CBF106566B; Mon, 30 Jan 2012 19:52:18 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id E3A098FC0C; Mon, 30 Jan 2012 19:52:17 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.4/8.14.4) with ESMTP id q0UJqHA7000135; Mon, 30 Jan 2012 19:52:17 GMT (envelope-from kib@svn.freebsd.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.4/8.14.4/Submit) id q0UJqHTs000131; Mon, 30 Jan 2012 19:52:17 GMT (envelope-from kib@svn.freebsd.org) Message-Id: <201201301952.q0UJqHTs000131@svn.freebsd.org> From: Konstantin Belousov Date: Mon, 30 Jan 2012 19:52:17 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r230784 - head/libexec/rtld-elf X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 30 Jan 2012 19:52:18 -0000 Author: kib Date: Mon Jan 30 19:52:17 2012 New Revision: 230784 URL: http://svn.freebsd.org/changeset/base/230784 Log: Add support for GNU RELRO. Submitted by: John Marino MFC after: 2 weeks Modified: head/libexec/rtld-elf/map_object.c head/libexec/rtld-elf/rtld.c head/libexec/rtld-elf/rtld.h Modified: head/libexec/rtld-elf/map_object.c ============================================================================== --- head/libexec/rtld-elf/map_object.c Mon Jan 30 19:50:13 2012 (r230783) +++ head/libexec/rtld-elf/map_object.c Mon Jan 30 19:52:17 2012 (r230784) @@ -84,6 +84,8 @@ map_object(int fd, const char *path, con Elf_Addr bss_vlimit; caddr_t bss_addr; Elf_Word stack_flags; + Elf_Addr relro_page; + size_t relro_size; hdr = get_elf_header(fd, path); if (hdr == NULL) @@ -100,6 +102,8 @@ map_object(int fd, const char *path, con nsegs = -1; phdyn = phinterp = phtls = NULL; phdr_vaddr = 0; + relro_page = 0; + relro_size = 0; segs = alloca(sizeof(segs[0]) * hdr->e_phnum); stack_flags = RTLD_DEFAULT_STACK_PF_EXEC | PF_R | PF_W; while (phdr < phlimit) { @@ -134,6 +138,11 @@ map_object(int fd, const char *path, con case PT_GNU_STACK: stack_flags = phdr->p_flags; break; + + case PT_GNU_RELRO: + relro_page = phdr->p_vaddr; + relro_size = phdr->p_memsz; + break; } ++phdr; @@ -269,6 +278,9 @@ map_object(int fd, const char *path, con obj->tlsinit = mapbase + phtls->p_vaddr; } obj->stack_flags = stack_flags; + obj->relro_page = obj->relocbase + trunc_page(relro_page); + obj->relro_size = round_page(relro_size); + return obj; } Modified: head/libexec/rtld-elf/rtld.c ============================================================================== --- head/libexec/rtld-elf/rtld.c Mon Jan 30 19:50:13 2012 (r230783) +++ head/libexec/rtld-elf/rtld.c Mon Jan 30 19:52:17 2012 (r230784) @@ -1114,6 +1114,11 @@ digest_phdr(const Elf_Phdr *phdr, int ph case PT_GNU_STACK: obj->stack_flags = ph->p_flags; break; + + case PT_GNU_RELRO: + obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); + obj->relro_size = round_page(ph->p_memsz); + break; } } if (nsegs < 1) { @@ -2007,6 +2012,14 @@ relocate_objects(Obj_Entry *first, bool if (reloc_jmpslots(obj, lockstate) == -1) return -1; + if (obj->relro_size > 0) { + if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) { + _rtld_error("%s: Cannot enforce relro protection: %s", + obj->path, strerror(errno)); + return -1; + } + } + /* * Set up the magic number and version in the Obj_Entry. These * were checked in the crt1.o from the original ElfKit, so we Modified: head/libexec/rtld-elf/rtld.h ============================================================================== --- head/libexec/rtld-elf/rtld.h Mon Jan 30 19:50:13 2012 (r230783) +++ head/libexec/rtld-elf/rtld.h Mon Jan 30 19:52:17 2012 (r230784) @@ -168,6 +168,9 @@ typedef struct Struct_Obj_Entry { size_t tlsoffset; /* Offset of static TLS block for this module */ size_t tlsalign; /* Alignment of static TLS block */ + caddr_t relro_page; + size_t relro_size; + /* Items from the dynamic section. */ Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ const Elf_Rel *rel; /* Relocation entries */