Date: Thu, 26 Sep 2019 18:56:41 +0000 (UTC) From: Ed Maste <emaste@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-releng@freebsd.org Subject: svn commit: r352769 - in releng/12.1: share/mk tools/build/options Message-ID: <201909261856.x8QIuf6Y078677@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: emaste Date: Thu Sep 26 18:56:41 2019 New Revision: 352769 URL: https://svnweb.freebsd.org/changeset/base/352769 Log: MFS r352752: Add a WITH_BIND_NOW build knob MFC r340186: Add a WITH_BIND_NOW build knob The linker's -z now flag sets the DF_BIND_NOW flag, which signals to the runtime loader that all relocation processing should be performed at process startup rather than on demand. In combination with lld's default of enabling relro this causes the GOT to be made read-only when the process starts, preventing straightforward GOT overwrite attacks. MFC r341429: disable BIND_NOW in libc, libthr, and rtld An issue remains with BIND_NOW and processes using threads. For now, restore libc's BIND_NOW disable, and also disable BIND_NOW in rtld and libthr. MFC r345625: revert r341429 "disable BIND_NOW in libc, libthr, and rtld" r345620 by kib@ fixed the rtld issue that caused a crash at startup during resolution of libc's ifuncs with BIND_NOW. MFC r345638: Revert change accidentally committed along with r345625 MFC r345640: Revert other accidentally committed part of r345625 Approved by: re (gjb) Sponsored by: The FreeBSD Foundation Added: releng/12.1/tools/build/options/WITHOUT_BIND_NOW - copied unchanged from r352752, stable/12/tools/build/options/WITHOUT_BIND_NOW releng/12.1/tools/build/options/WITH_BIND_NOW - copied unchanged from r352752, stable/12/tools/build/options/WITH_BIND_NOW Modified: releng/12.1/share/mk/bsd.lib.mk releng/12.1/share/mk/bsd.opts.mk releng/12.1/share/mk/bsd.prog.mk Directory Properties: releng/12.1/ (props changed) Modified: releng/12.1/share/mk/bsd.lib.mk ============================================================================== --- releng/12.1/share/mk/bsd.lib.mk Thu Sep 26 18:37:58 2019 (r352768) +++ releng/12.1/share/mk/bsd.lib.mk Thu Sep 26 18:56:41 2019 (r352769) @@ -69,6 +69,10 @@ TAGS+= package=${PACKAGE:Uruntime} TAG_ARGS= -T ${TAGS:[*]:S/ /,/g} .endif +# ELF hardening knobs +.if ${MK_BIND_NOW} != "no" +LDFLAGS+= -Wl,-znow +.endif .if ${MK_RETPOLINE} != "no" CFLAGS+= -mretpoline CXXFLAGS+= -mretpoline Modified: releng/12.1/share/mk/bsd.opts.mk ============================================================================== --- releng/12.1/share/mk/bsd.opts.mk Thu Sep 26 18:37:58 2019 (r352768) +++ releng/12.1/share/mk/bsd.opts.mk Thu Sep 26 18:56:41 2019 (r352769) @@ -69,6 +69,7 @@ __DEFAULT_YES_OPTIONS = \ WARNS __DEFAULT_NO_OPTIONS = \ + BIND_NOW \ CCACHE_BUILD \ CTF \ INSTALL_AS_USER \ Modified: releng/12.1/share/mk/bsd.prog.mk ============================================================================== --- releng/12.1/share/mk/bsd.prog.mk Thu Sep 26 18:37:58 2019 (r352768) +++ releng/12.1/share/mk/bsd.prog.mk Thu Sep 26 18:56:41 2019 (r352769) @@ -34,6 +34,10 @@ PROG= ${PROG_CXX} MK_DEBUG_FILES= no .endif +# ELF hardening knobs +.if ${MK_BIND_NOW} != "no" +LDFLAGS+= -Wl,-znow +.endif .if ${MK_PIE} != "no" && (!defined(NO_SHARED) || ${NO_SHARED:tl} == "no") CFLAGS+= -fPIE CXXFLAGS+= -fPIE Copied: releng/12.1/tools/build/options/WITHOUT_BIND_NOW (from r352752, stable/12/tools/build/options/WITHOUT_BIND_NOW) ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ releng/12.1/tools/build/options/WITHOUT_BIND_NOW Thu Sep 26 18:56:41 2019 (r352769, copy of r352752, stable/12/tools/build/options/WITHOUT_BIND_NOW) @@ -0,0 +1,5 @@ +.\" $FreeBSD$ +Do not build all binaries with the +.Dv DF_BIND_NOW +flag set. +Run-time relocation processing will be performed on demand. Copied: releng/12.1/tools/build/options/WITH_BIND_NOW (from r352752, stable/12/tools/build/options/WITH_BIND_NOW) ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ releng/12.1/tools/build/options/WITH_BIND_NOW Thu Sep 26 18:56:41 2019 (r352769, copy of r352752, stable/12/tools/build/options/WITH_BIND_NOW) @@ -0,0 +1,5 @@ +.\" $FreeBSD$ +Build all binaries with the +.Dv DF_BIND_NOW +flag set to indicate that the run-time loader should perform all relocation +processing at process startup rather than on demand.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201909261856.x8QIuf6Y078677>