Commit 16c36f88 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: deb-pkg: use build ID instead of debug link for dbg package 



There are two ways of managing separate debug info files:

 [1] The executable contains the .gnu_debuglink section, which specifies
     the name and the CRC of the separate debug info file.

 [2] The executable contains a build ID, and the corresponding debug info
     file is placed in the .build-id directory.

We could do both, but the former, which 'make deb-pkg' currently does,
results in complicated installation steps because we need to manually
strip the debug sections, create debug links, and re-sign the modules.
Besides, it is not working with module compression.

This commit abandons the approach [1], and instead opts for [2].

Debian kernel commit de26137e2a9f ("Drop not needed extra step to add
debug links") also stopped adding debug links.

Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
parent 5e73758b

scripts/package/builddeb

+13 −19
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ install_linux_image () { 
		${MAKE} -f ${srctree}/Makefile INSTALL_DTBS_PATH="${pdir}/usr/lib/linux-image-${KERNELRELEASE}" dtbs_install

	fi



	${MAKE} -f ${srctree}/Makefile INSTALL_MOD_PATH="${pdir}" modules_install

	${MAKE} -f ${srctree}/Makefile INSTALL_MOD_PATH="${pdir}" INSTALL_MOD_STRIP=1 modules_install

	rm -f "${pdir}/lib/modules/${KERNELRELEASE}/build"



	# Install the kernel
@@ -110,25 +110,21 @@ install_linux_image () { 


install_linux_image_dbg () {

	pdir=$1

	image_pdir=$2



	rm -rf ${pdir}



	for module in $(find ${image_pdir}/lib/modules/ -name *.ko -printf '%P\n'); do

		module=lib/modules/${module}

		mkdir -p $(dirname ${pdir}/usr/lib/debug/${module})

		# only keep debug symbols in the debug file

		${OBJCOPY} --only-keep-debug ${image_pdir}/${module} ${pdir}/usr/lib/debug/${module}

		# strip original module from debug symbols

		${OBJCOPY} --strip-debug ${image_pdir}/${module}

		# then add a link to those

		${OBJCOPY} --add-gnu-debuglink=${pdir}/usr/lib/debug/${module} ${image_pdir}/${module}

	done

	# Parse modules.order directly because 'make modules_install' may sign,

	# compress modules, and then run unneeded depmod.

	while read -r mod; do

		mod="${mod%.o}.ko"

		dbg="${pdir}/usr/lib/debug/lib/modules/${KERNELRELEASE}/kernel/${mod}"

		buildid=$("${READELF}" -n "${mod}" | sed -n 's@^.*Build ID: \(..\)\(.*\)@\1/\2@p')

		link="${pdir}/usr/lib/debug/.build-id/${buildid}.debug"



	# re-sign stripped modules

	if is_enabled CONFIG_MODULE_SIG_ALL; then

		${MAKE} -f ${srctree}/Makefile INSTALL_MOD_PATH="${image_pdir}" modules_sign

	fi

		mkdir -p "${dbg%/*}" "${link%/*}"

		"${OBJCOPY}" --only-keep-debug "${mod}" "${dbg}"

		ln -sf --relative "${dbg}" "${link}"

	done < modules.order



	# Build debug package

	# Different tools want the image in different locations
@@ -176,9 +172,7 @@ for package in ${packages_enabled} 
do

	case ${package} in

	*-dbg)

		# This must be done after linux-image, that is, we expect the

		# debug package appears after linux-image in debian/control.

		install_linux_image_dbg debian/linux-image-dbg debian/linux-image;;

		install_linux_image_dbg debian/linux-image-dbg;;

	linux-image-*|user-mode-linux-*)

		install_linux_image debian/linux-image ${package};;

	linux-libc-dev)