Generate debuginfo for kernel packages

- Support uncompressed (std-def) and compressed (un-def) modules. Also,
  support xz(1) compression if we'd switch to it.
- If module is uncompressed it stays in the kernel-image rpm, if it's
  compressed then uncompressed module goes into /usr/lib/debug tree and
  will be in debuginfo rpm. Compressed modules will be re-compressed after
  stripping.
- vmlinuz binary triggers extraction of vmlinux from the kernel-source
  tree, and it's then placed into /usr/lib/debug tree, then processed and
  stripped as usual.
- Logic of processing of vmlinux binary for domU packages is not changed.
  Some flavours do not even pack it. Thus, do not remove your
  `%brp_strip_none'.
- Output of file(1) for vmlinuz is only parsed for filename, because, on
  different architectures it detects completely different things.
- Debug files are compressed with `eu-elfcompress'.
- You still need to enable `CONFIG_DEBUG_INFO=y' in for `.config'.
  No other changes to spec should be needed.

Thanks to Nikita Ermakov for starting this work.

scripts/brp-debuginfo.in

@@ -26,9 +26,36 @@ prune_tests="$(printf %s "$prune_paths" |
 find . '(' -path './.*' $prune_tests ')' -prune -o -type f -print |sort |
 file -NF$'\t' -f - |
 sed -n -e '/ ELF .* shared object, no machine, /d' \
-       -e 's/\t.* ELF .* \(executable\|shared object\), .*, not stripped.*//p' |
+       -e 's/\t.* ELF .* \(executable\|shared object\|relocatable\), .*, not stripped.*//p' \
+       -e 's/^\(\.\/lib\/modules\/.*\.ko\.[gx]z\)\t.* \(gzip\|xz\) compressed data.*/\1/p' \
+       -e 's/^\(\.\/boot\/vmlinuz-.*\)\t.*/\1/p' |
 xargs -r --delimiter='\n' stat -c '%h %i %n' >.tmp/flist
 while read -r nlink ino f; do
+	rezip=
+	elfcompress=
+	if [ -z "${f#./lib/modules/*.ko}" ]; then
+		elfcompress=yes
+	elif [ -z "${f#./lib/modules/*.ko.[gx]z}" ]; then
+		rezip=${f##*.}
+		rezip=${rezip/gz/gzip}
+		# Compressed module: uncompress it, and work with uncompressed one.
+		$rezip --decompress --force "$f"
+		f=${f%.[gx]z}
+		elfcompress=yes
+	elif [ -z "${f##./boot/vmlinuz-*}" ]; then
+		# Compressed kernel: trigger extraction of vmlinux from the source.
+		kver=${f#./boot/vmlinuz-}
+		vmlinuxs=$(set +f; ls "$RPM_BUILD_DIR"/kernel-image-*/kernel-source-*/vmlinux)
+		vmlinuxd=./usr/lib/debug/lib/modules/$kver/vmlinux
+		if [ -f "$vmlinuxs" ]; then
+			install -pD -m644 "$vmlinuxs" "$vmlinuxd"
+			f=$vmlinuxd
+			elfcompress=yes
+		else
+			echo "Warning: vmlinux not found for -debuginfo" >&2
+		fi
+	fi
+
 	debugf=./usr/lib/debug${f#.}.debug
 	if [ "$nlink" -gt 1 ]; then
 		eval f0="\${f0_$ino-}"
@@ -63,6 +90,9 @@ while read -r nlink ino f; do
 	if [ -n "$strip" ]; then
 		mkdir -p "${debugf%/*}"
 		LD_ORIGIN_PATH=/usr/bin eu-strip $strip --remove-comment -f "$debugf" "$f"
+		if [ -n "$elfcompress" ]; then
+			LD_ORIGIN_PATH=/usr/bin eu-elfcompress "$debugf"
+		fi
 		touch -r .tmp/stamp "$debugf" "$f"
 		chmod 644 "$debugf"
 	else
@@ -77,6 +107,11 @@ while read -r nlink ino f; do
 		printf '%s\n' /usr/src/debug/"$src"
 	done >.debuginfo/src/"$f"
 	rm .tmp/src
+	if [ -n "$rezip" ]; then
+		# Compress module, move uncompressed into debug tree.
+		$rezip --keep --force "$f"
+		mv "$f" ./usr/lib/debug"${f#.}"
+	fi
 done <.tmp/flist
 
 # Make symbolic links that mimic the original tree.

scripts/find-debuginfo-files.in

@@ -21,6 +21,24 @@ mkdir .tmp
 
 while read -r f; do
 	f=${f#$RPM_BUILD_ROOT}
+
+	if [ -z "${f##/boot/vmlinuz-*}" ]; then
+		# Redirect to vmlinux saved by debuginfo.brp into debug tree's
+		# %modules_dir.
+		kver=${f#/boot/vmlinuz-}
+		f=/usr/lib/debug/lib/modules/$kver/vmlinux
+		printf '%s\n' "$f" >> .tmp/files
+	fi
+	fbin=$f # Actual binary for linking
+
+	if [ -z "${f#/lib/modules/*.ko.[gx]z}" ]; then
+		# For gzipped modules actual binary is kept in debug tree
+		# (placed by debuginfo.brp) and goes into -debuginfo package.
+		f=${f%.[gx]z}
+		fbin=/usr/lib/debug$f
+		printf '%s\n' "$fbin" >> .tmp/files
+	fi
+
 	if [ -f .debuginfo/src/"$f" ]; then
 		LC_ALL=C sort -m -u -o .tmp/src .tmp/src .debuginfo/src/"$f"
 	fi
@@ -43,11 +61,11 @@ while read -r f; do
 	link=./usr/lib/debug/.build-id/${id:0:2}/${id:2}
 	if [ ! -L "$link" ]; then
 		mkdir -p "${link%/*}"
-		ln -snf "$(relative "$f" "${link#.}")" "$link"
+		ln -snf "$(relative "$fbin" "${link#.}")" "$link"
 		ln -snf "$(relative "${debugf#.}" "${link#.}".debug)" "$link".debug
 	fi
 	to=$(readlink -vm "$link")
-	if [ "$to" = "$RPM_BUILD_ROOT$f" ]; then
+	if [ "$to" = "$RPM_BUILD_ROOT$fbin" ]; then
 		printf '%s\n' "${link#.}" >> .tmp/links
 		printf '%s\n' "${link#.}".debug >> .tmp/links
 	fi