This patchset adds basic kunit test coverage for initramfs unpacking and cleans up some minor buffer handling issues / inefficiencies. Changes since v3: - Drop shared unpack buffer changes + rework into initramfs: allocate heap buffers together (patch 5/8) + extra review complexity wasn't worth the tiny boot-time heap saving - move hardlink hash leak repro into first initramfs_test patch - add note regarding kunit section=.data -> section=.init.text warning Changes since v2 (patch 2 only): - fix !CONFIG_INITRAMFS_PRESERVE_MTIME kunit test checks - add test MODULE_DESCRIPTION(), as suggested by Jeff Johnson - add some missing headers, reported by kernel test robot Changes since v1 (RFC): - rebase atop v6.12-rc6 and filename field overrun fix from https://lore.kernel.org/r/20241030035509.20194-2-ddiss@xxxxxxx - add unit test coverage (new patches 1 and 2) - add patch: fix hardlink hash leak without TRAILER - rework patch: avoid static buffer for error message + drop unnecessary message propagation - drop patch: cpio_buf reuse for built-in and bootloader initramfs + no good justification for the change Feedback appreciated. David Disseldorp (8): init: add initramfs_internal.h initramfs_test: kunit tests for initramfs unpacking vsprintf: add simple_strntoul initramfs: avoid memcpy for hex header fields initramfs: allocate heap buffers together initramfs: reuse name_len for dir mtime tracking initramfs: fix hardlink hash leak without TRAILER initramfs: avoid static buffer for error message include/linux/kstrtox.h | 1 + init/.kunitconfig | 3 + init/Kconfig | 7 + init/Makefile | 1 + init/initramfs.c | 66 ++++---- init/initramfs_internal.h | 8 + init/initramfs_test.c | 407 ++++++++++++++++++++++++++++++++++++++++++++++ lib/vsprintf.c | 7 + 8 files changed, 472 insertions(+), 28 deletions(-) create mode 100644 init/.kunitconfig create mode 100644 init/initramfs_internal.h create mode 100644 init/initramfs_test.c
