There are a number of stack, heap and data-segment buffers which are
unnecessary for initramfs unpacking. This patchset attempts to remove
them by:
- parsing cpio hex strings in place, instead of copying them for
nul-termination. (Patches 1 & 2).
- reusing a single heap buffer for cpio header, file and symlink paths,
instead of three separate buffers. (Patches 3 & 4).
- reusing the heap-allocated cpio buffer across both builtin and
bootloader-provided unpack attempts. (Patch 5).
- reusing the heap-allocated cpio buffer for error messages on
FSM-exit, instead of a data-segment buffer. (Patch 6).
I've flagged this as an RFC as I'd like to improve the commit messages
and also provide more thorough testing, likely via kunit / kselftest
integration.
Feedback appreciated.
David Disseldorp (6):
vsprintf: add simple_strntoul
initramfs: avoid memcpy for hex header fields
initramfs: remove extra symlink path buffer
initramfs: merge header_buf and name_buf
initramfs: reuse buf for built-in and bootloader initramfs
initramfs: avoid static buffer for error message
include/linux/kstrtox.h | 1 +
init/initramfs.c | 50 +++++++++++++++++++++--------------------
lib/vsprintf.c | 7 ++++++
3 files changed, 34 insertions(+), 24 deletions(-)
