sys-boot/grub:0 - Properly fix misoptimization by -fcombine-stack-adjustmemts (gcc-4.9+)

GCC assumes that it can combine stacks from outer "grub_stage2()"
and inner trampoline "doit()" functions (optimisation -fcombine-stack-adjustments).

But doit() function clobbers %esp in inline assebly statement as:

  asm volatile ("movl %%esp, %0\n\tmovl %1, %%esp\n"
               : "=&r" (realstack) : "r" (simstack));

which tricks gcc into computing invalid local variable offsets from current %esp value.

Fix by hinting gcc about %esp change in clobber list.

Thanks to slyfox for his debugging and patch!  This properly fixes bug 564890, allowing
for the -O0 hack to be removed.

Package-Manager: portage-2.2.24

2 files changed, 342 insertions, 0 deletions

diff --git a/sys-boot/grub/files/grub-0.97-Add-esp-to-list-of-clobbered-registers.patch b/sys-boot/grub/files/grub-0.97-Add-esp-to-list-of-clobbered-registers.patch
new file mode 100644
index 000000000000..c550aabd6167
--- /dev/null
+++ b/sys-boot/grub/files/grub-0.97-Add-esp-to-list-of-clobbered-registers.patch
@@ -0,0 +1,53 @@
+From 5a52ee4b5cd152fa4ccd1c1f938ce2eba652af52 Mon Sep 17 00:00:00 2001
+From: Sergei Trofimovich <slyfox@gentoo.org>
+Date: Mon, 14 Dec 2015 23:59:17 +0000
+Subject: [PATCH] Add %esp to list of clobbered registers
+
+GCC assumes that it can combine stacks from
+outer
+    grub_stage2()
+and inner
+    trampoline doit()
+functions (optimisation -fcombine-stack-adjustments).
+
+But doit() function clobbers %esp in inline
+assebly statement as:
+
+  asm volatile ("movl %%esp, %0\n\tmovl %1, %%esp\n"
+               : "=&r" (realstack) : "r" (simstack));
+
+which tricks gcc into computing invalid local variable
+offsets from current %esp value.
+
+Fix by hinting gcc about %esp change in clobber list.
+
+Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
+---
+ grub/asmstub.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/grub/asmstub.c b/grub/asmstub.c
+index 6354806..44b056f 100644
+--- a/grub/asmstub.c
++++ b/grub/asmstub.c
+@@ -174,7 +174,7 @@ grub_stage2 (void)
+     {
+       /* Make sure our stack lives in the simulated memory area. */
+       asm volatile ("movl %%esp, %0\n\tmovl %1, %%esp\n"
+-		    : "=&r" (realstack) : "r" (simstack));
++		    : "=&r" (realstack) : "r" (simstack) : "%esp");
+       
+       /* Do a setjmp here for the stop command.  */
+       if (! setjmp (env_for_exit))
+@@ -191,7 +191,7 @@ grub_stage2 (void)
+ 	}
+       
+       /* Replace our stack before we use any local variables. */
+-      asm volatile ("movl %0, %%esp\n" : : "r" (realstack));
++      asm volatile ("movl %0, %%esp\n" : : "r" (realstack) : "%esp");
+     }
+ 
+   assert (grub_scratch_mem == 0);
+-- 
+2.6.3
+
diff --git a/sys-boot/grub/grub-0.97-r17.ebuild b/sys-boot/grub/grub-0.97-r17.ebuild
new file mode 100644
index 000000000000..3b19b8e36c9b
--- /dev/null
+++ b/sys-boot/grub/grub-0.97-r17.ebuild
@@ -0,0 +1,289 @@
+# Copyright 1999-2015 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Id$
+
+# XXX: we need to review menu.lst vs grub.conf handling.  We've been converting
+#      all systems to grub.conf (and symlinking menu.lst to grub.conf), but
+#      we never updated any of the source code (it still all wants menu.lst),
+#      and there is no indication that upstream is making the transition.
+
+# If you need to roll a new grub-static distfile, here is how.
+# - Robin H. Johnson <robbat2@gentoo.org> - 29 Nov 2010
+# FEATURES='-noauto -noinfo -nodoc -noman -splitdebug nostrip' \
+# USE='static -ncurses -netboot -custom-cflags' \
+# PORTAGE_COMPRESS=true GRUB_STATIC_PACKAGE_BUILDING=1 ebuild \
+# grub-${PVR}.ebuild clean package && \
+# qtbz2 -s -j ${PKGDIR}/${CAT}/${PF}.tbz2 && \
+# mv ${PF}.tar.bz2 ${DISTDIR}/grub-static-${PVR}.tar.bz2
+
+EAPI="5"
+
+inherit eutils mount-boot toolchain-funcs linux-info flag-o-matic autotools pax-utils multiprocessing
+
+PATCHVER="1.14" # Should match the revision ideally
+DESCRIPTION="GNU GRUB Legacy boot loader"
+HOMEPAGE="https://www.gnu.org/software/grub/"
+SRC_URI="mirror://gentoo/${P}.tar.gz
+	mirror://gnu-alpha/${PN}/${P}.tar.gz
+	mirror://gentoo/splash.xpm.gz
+	mirror://gentoo/${P}-patches-${PATCHVER}.tar.bz2"
+
+LICENSE="GPL-2"
+SLOT="0"
+KEYWORDS="~amd64 ~x86 ~x86-fbsd"
+IUSE="custom-cflags ncurses netboot static"
+
+LIB_DEPEND="ncurses? ( >=sys-libs/ncurses-5.9-r3:0[static-libs(+),abi_x86_32(-)] )"
+RDEPEND="!static? ( ${LIB_DEPEND//[static-libs(+),/=[} )"
+DEPEND="${RDEPEND}
+	static? ( ${LIB_DEPEND} )"
+
+pkg_setup() {
+	case $(tc-arch) in
+	amd64) CONFIG_CHECK='~IA32_EMULATION' check_extra_config ;;
+	esac
+}
+
+src_prepare() {
+	# Grub will not handle a kernel larger than EXTENDED_MEMSIZE Mb as
+	# discovered in bug 160801. We can change this, however, using larger values
+	# for this variable means that Grub needs more memory to run and boot. For a
+	# kernel of size N, Grub needs (N+1)*2.  Advanced users should set a custom
+	# value in make.conf, it is possible to make kernels ~16Mb in size, but it
+	# needs the kitchen sink built-in.
+	local t="custom"
+	if [[ -z ${GRUB_MAX_KERNEL_SIZE} ]] ; then
+		case $(tc-arch) in
+		amd64) GRUB_MAX_KERNEL_SIZE=9 ;;
+		x86)   GRUB_MAX_KERNEL_SIZE=5 ;;
+		esac
+		t="default"
+	fi
+	einfo "Grub will support the ${t} maximum kernel size of ${GRUB_MAX_KERNEL_SIZE} Mb (GRUB_MAX_KERNEL_SIZE)"
+
+	sed -i \
+		-e "/^#define.*EXTENDED_MEMSIZE/s,3,${GRUB_MAX_KERNEL_SIZE},g" \
+		"${S}"/grub/asmstub.c \
+		|| die
+
+	EPATCH_SUFFIX="patch" epatch "${WORKDIR}"/patch
+	# bug 564890, 566638
+	epatch "${FILESDIR}"/grub-0.97-Add-esp-to-list-of-clobbered-registers.patch
+
+	rm -f "${S}"/aclocal.m4 # seems to keep bug 418287 away
+	eautoreconf
+}
+
+src_configure() {
+	filter-flags -fPIE #168834
+
+	use amd64 && multilib_toolchain_setup x86
+
+	unset BLOCK_SIZE #73499
+
+	### i686-specific code in the boot loader is a bad idea; disabling to ensure
+	### at least some compatibility if the hard drive is moved to an older or
+	### incompatible system.
+
+	# grub-0.95 added -fno-stack-protector detection, to disable ssp for stage2,
+	# but the objcopy's (faulty) test fails if -fstack-protector is default.
+	# create a cache telling configure that objcopy is ok, and add -C to econf
+	# to make use of the cache.
+	#
+	# CFLAGS has to be undefined running econf, else -fno-stack-protector detection fails.
+	# STAGE2_CFLAGS is not allowed to be used on emake command-line, it overwrites
+	# -fno-stack-protector detected by configure, removed from netboot's emake.
+	use custom-cflags || unset CFLAGS
+
+	tc-ld-disable-gold #439082 #466536 #526348
+
+	export grub_cv_prog_objcopy_absolute=yes #79734
+	use static && append-ldflags -static
+
+	if use amd64 && use static ; then
+		if [[ -n ${GRUB_STATIC_PACKAGE_BUILDING} ]] ; then
+			eerror "You have set GRUB_STATIC_PACKAGE_BUILDING. This"
+			eerror "is specifically intended for building the tarballs for the"
+			eerror "grub-static package via USE='static -ncurses'."
+			eerror "All bets are now off."
+		fi
+	fi
+
+	multijob_init
+
+	# build the net-bootable grub first, but only if "netboot" is set
+	if use netboot ; then
+		(
+		multijob_child_init
+		mkdir -p "${WORKDIR}"/netboot
+		pushd "${WORKDIR}"/netboot >/dev/null
+		ECONF_SOURCE=${S} \
+		econf \
+			--libdir=/lib \
+			--datadir=/usr/lib/grub \
+			--exec-prefix=/ \
+			--disable-auto-linux-mem-opt \
+			--enable-diskless \
+			--enable-{3c{5{03,07,09,29,95},90x},cs89x0,davicom,depca,eepro{,100}} \
+			--enable-{epic100,exos205,ni5210,lance,ne2100,ni{50,65}10,natsemi} \
+			--enable-{ne,ns8390,wd,otulip,rtl8139,sis900,sk-g16,smc9000,tiara} \
+			--enable-{tulip,via-rhine,w89c840}
+		popd >/dev/null
+		) &
+		multijob_post_fork
+	fi
+
+	# Now build the regular grub
+	# Note that FFS and UFS2 support are broken for now - stage1_5 files too big
+	econf \
+		--libdir=/lib \
+		--datadir=/usr/lib/grub \
+		--exec-prefix=/ \
+		--disable-auto-linux-mem-opt \
+		$(use_with ncurses curses)
+
+	# sanity check due to common failure
+	use ncurses && ! grep -qs "HAVE_LIBCURSES.*1" config.h && die "USE=ncurses but curses not found"
+
+	multijob_finish
+}
+
+src_compile() {
+	use netboot && emake -C "${WORKDIR}"/netboot w89c840_o_CFLAGS="-O"
+	emake
+}
+
+src_test() {
+	# non-default block size also give false pass/fails.
+	unset BLOCK_SIZE
+	emake -j1 check
+}
+
+src_install() {
+	default
+	if use netboot ; then
+		exeinto /usr/lib/grub/${CHOST}
+		doexe "${WORKDIR}"/netboot/stage2/{nbgrub,pxegrub}
+		newexe "${WORKDIR}"/netboot/stage2/stage2 stage2.netboot
+	fi
+
+	pax-mark -m "${D}"/sbin/grub #330745
+
+	newdoc docs/menu.lst grub.conf.sample
+	dodoc "${FILESDIR}"/grub.conf.gentoo
+
+	[[ -n ${GRUB_STATIC_PACKAGE_BUILDING} ]] && \
+		mv "${D}"/usr/share/doc/{${PF},grub-static-${PF/grub-}}
+
+	insinto /usr/share/grub
+	doins "${DISTDIR}"/splash.xpm.gz
+}
+
+setup_boot_dir() {
+	local boot_dir=$1
+	local dir=${boot_dir}
+
+	mkdir -p "${dir}"
+	[[ ! -L ${dir}/boot ]] && ln -s . "${dir}/boot"
+	dir="${dir}/grub"
+	if [[ ! -e ${dir} ]] ; then
+		mkdir "${dir}" || die
+	fi
+
+	# change menu.lst to grub.conf
+	if [[ ! -e ${dir}/grub.conf ]] && [[ -e ${dir}/menu.lst ]] ; then
+		mv -f "${dir}"/menu.lst "${dir}"/grub.conf
+		ewarn "*** IMPORTANT NOTE: menu.lst has been renamed to grub.conf"
+		echo
+	fi
+
+	if [[ ! -e ${dir}/menu.lst ]]; then
+		einfo "Linking from new grub.conf name to menu.lst"
+		ln -snf grub.conf "${dir}"/menu.lst
+	fi
+
+	if [[ -e ${dir}/stage2 ]] ; then
+		mv "${dir}"/stage2{,.old}
+		ewarn "*** IMPORTANT NOTE: you must run grub and install"
+		ewarn "the new version's stage1 to your MBR.  Until you do,"
+		ewarn "stage1 and stage2 will still be the old version, but"
+		ewarn "later stages will be the new version, which could"
+		ewarn "cause problems such as an unbootable system."
+		ewarn
+		ewarn "This means you must use either grub-install or perform"
+		ewarn "root/setup manually."
+		ewarn
+		ewarn "For more help, see the handbook:"
+		ewarn "https://www.gentoo.org/doc/en/handbook/handbook-${ARCH}.xml?part=1&chap=10#grub-install-auto"
+		echo
+	fi
+
+	einfo "Copying files from /lib/grub and /usr/share/grub to ${dir}"
+	for x in \
+		"${ROOT}"/lib*/grub/*/* \
+		"${ROOT}"/usr/share/grub/* ; do
+		[[ -f ${x} ]] && cp -p "${x}" "${dir}"/
+	done
+
+	if [[ ! -e ${dir}/grub.conf ]] ; then
+		s="${ROOT}/usr/share/doc/${PF}/grub.conf.gentoo"
+		[[ -e "${s}" ]] && cat "${s}" >${dir}/grub.conf
+		[[ -e "${s}.gz" ]] && zcat "${s}.gz" >${dir}/grub.conf
+		[[ -e "${s}.bz2" ]] && bzcat "${s}.bz2" >${dir}/grub.conf
+	fi
+
+	# Per bug 218599, we support grub.conf.install for users that want to run a
+	# specific set of Grub setup commands rather than the default ones.
+	grub_config=${dir}/grub.conf.install
+	[[ -e ${grub_config} ]] || grub_config=${dir}/grub.conf
+	if [[ -e ${grub_config} ]] ; then
+		egrep \
+			-v '^[[:space:]]*(#|$|default|fallback|initrd|password|splashimage|timeout|title)' \
+			"${grub_config}" | \
+		/sbin/grub --batch \
+			--device-map="${dir}"/device.map \
+			> /dev/null
+	fi
+
+	# the grub default commands silently piss themselves if
+	# the default file does not exist ahead of time
+	if [[ ! -e ${dir}/default ]] ; then
+		grub-set-default --root-directory="${boot_dir}" default
+	fi
+	einfo "Grub has been installed to ${boot_dir} successfully."
+}
+
+pkg_postinst() {
+	mount-boot_mount_boot_partition
+
+	if [[ -n ${DONT_MOUNT_BOOT} ]]; then
+		elog "WARNING: you have DONT_MOUNT_BOOT in effect, so you must apply"
+		elog "the following instructions for your /boot!"
+		elog "Neglecting to do so may cause your system to fail to boot!"
+		elog
+	else
+		setup_boot_dir "${ROOT}"/boot
+		# Trailing output because if this is run from pkg_postinst, it gets mixed into
+		# the other output.
+		einfo ""
+	fi
+	elog "To interactively install grub files to another device such as a USB"
+	elog "stick, just run the following and specify the directory as prompted:"
+	elog "   emerge --config =${PF}"
+	elog "Alternately, you can export GRUB_ALT_INSTALLDIR=/path/to/use to tell"
+	elog "grub where to install in a non-interactive way."
+
+	# needs to be after we call setup_boot_dir
+	mount-boot_pkg_postinst
+}
+
+pkg_config() {
+	local dir
+	if [ ! -d "${GRUB_ALT_INSTALLDIR}" ]; then
+		einfo "Enter the directory where you want to setup grub:"
+		read dir
+	else
+		dir="${GRUB_ALT_INSTALLDIR}"
+	fi
+	setup_boot_dir "${dir}"
+}