[Buildroot] [git commit branch/2022.02.x] fs/common.mk: use find instead of shell glob patterns

[Buildroot] [git commit branch/2022.02.x] fs/common.mk: use find instead of shell glob patterns

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=063ee76d294cf1bdc79f9b90a75ab6f70ed32d9f
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/2022.02.x

Different shells can have different behaviours when it comes to globbing
patterns. The dash shell (/bin/sh) on Debian testing switched to a
different fnmatch/glob implementation that results in this new behaviour:

Using bash:
    $ mkdir /tmp/foo
    $ echo /tmp/foo/.[^.]*
    /tmp/foo/.[^.]*

Using dash:
    $ mkdir /tmp/foo
    $ echo /tmp/foo/.[^.]*
    /tmp/foo/..

The current FAKEROOT script uses this shell glob pattern which now fails
on recent Debian testing systems:

    rm: refusing to remove '.' or '..' directory: skipping '/build/buildroot-fs/cpio/target/run/..'
    rm: refusing to remove '.' or '..' directory: skipping '/build/buildroot-fs/cpio/target/tmp/..'

Additionally, the glob will miss files which have at least two leading
dots, like ..foo ...bar or ......buz  (highly improbable, but still).

It seems safer to use `find | xargs rm` here instead of relying on shell
globbing patterns.

Signed-off-by: Mathieu Mirmont <mat@parad0x.org>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 38c4f6b807e9b519922172089915559fb8642046)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
 fs/common.mk | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/common.mk b/fs/common.mk
index 45beb5ae7b..37eafac4f7 100644
--- a/fs/common.mk
+++ b/fs/common.mk
@@ -186,7 +186,8 @@ $$(BINARIES_DIR)/$$(ROOTFS_$(2)_FINAL_IMAGE_NAME): $$(ROOTFS_$(2)_DEPENDENCIES)
 
 	$$(foreach hook,$$(ROOTFS_$(2)_PRE_GEN_HOOKS),\
 		$$(call PRINTF,$$($$(hook))) >> $$(FAKEROOT_SCRIPT)$$(sep))
-	echo "rm -rf $$(TARGET_DIR)/run/* $$(TARGET_DIR)/run/.[^.]* $$(TARGET_DIR)/tmp/* $$(TARGET_DIR)/tmp/.[^.]*" >> $$(FAKEROOT_SCRIPT)
+	echo "find $$(TARGET_DIR)/run/ -mindepth 1 -prune -print0 | xargs -0r rm -rf --" >> $$(FAKEROOT_SCRIPT)
+	echo "find $$(TARGET_DIR)/tmp/ -mindepth 1 -prune -print0 | xargs -0r rm -rf --" >> $$(FAKEROOT_SCRIPT)
 	$$(call PRINTF,$$(ROOTFS_REPRODUCIBLE)) >> $$(FAKEROOT_SCRIPT)
 	$$(call PRINTF,$$(ROOTFS_SELINUX)) >> $$(FAKEROOT_SCRIPT)
 	$$(call PRINTF,$$(ROOTFS_$(2)_CMD)) >> $$(FAKEROOT_SCRIPT)
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