[PATCH AUTOSEL 5.2 36/42] kbuild: clean compressed initramfs image

[Sasha Levin]

From: Greg Thelen <gthelen@xxxxxxxxxx>

[ Upstream commit 6279eb3dd7946c69346a3b98473ed13d3a44adb5 ]

Since 9e3596b0c653 ("kbuild: initramfs cleanup, set target from Kconfig")
"make clean" leaves behind compressed initramfs images.  Example:

  $ make defconfig
  $ sed -i 's|CONFIG_INITRAMFS_SOURCE=""|CONFIG_INITRAMFS_SOURCE="/tmp/ir.cpio"|' .config
  $ make olddefconfig
  $ make -s
  $ make -s clean
  $ git clean -ndxf | grep initramfs
  Would remove usr/initramfs_data.cpio.gz

clean rules do not have CONFIG_* context so they do not know which
compression format was used.  Thus they don't know which files to delete.

Tell clean to delete all possible compression formats.

Once patched usr/initramfs_data.cpio.gz and friends are deleted by
"make clean".

Link: http://lkml.kernel.org/r/20190722063251.55541-1-gthelen@xxxxxxxxxx
Fixes: 9e3596b0c653 ("kbuild: initramfs cleanup, set target from Kconfig")
Signed-off-by: Greg Thelen <gthelen@xxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 usr/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/usr/Makefile b/usr/Makefile
index 4a70ae43c9cb5..bdb3f52fadc44 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -11,6 +11,9 @@ datafile_y = initramfs_data.cpio$(suffix_y)
 datafile_d_y = .$(datafile_y).d
 AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/$(datafile_y)"
 
+# clean rules do not have CONFIG_INITRAMFS_COMPRESSION.  So clean up after all
+# possible compression formats.
+clean-files += initramfs_data.cpio*
 
 # Generate builtin.o based on initramfs_data.o
 obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
-- 
2.20.1