[PATCH v2 00/14] bootconfig: fixes, cleanups, and modernization

From: Josh Law

Date: Sat Mar 14 2026 - 17:56:07 EST


This series addresses a collection of issues found during a review of
lib/bootconfig.c and include/linux/bootconfig.h, ranging from an
off-by-one in a bounds check to coding style and API modernization.

Changes since v1:
- Dropped "return empty string instead of NULL from
xbc_node_get_data()" — returning "" causes false matches in
xbc_node_match_prefix() because strncmp(..., "", 0) always
returns 0.

Bug fixes:
- Fix off-by-one in xbc_verify_tree() where a next-node index equal
to xbc_node_num passes the bounds check despite being out of range
(patch 8).
- Move xbc_node_num increment to after xbc_init_node() validation
so a failed init does not leave a partially initialized node
counted in the array (patch 9).

Correctness:
- Add missing __init annotations to skip_comment() and
skip_spaces_until_newline() so their memory can be reclaimed
after init (patch 1).
- Narrow the flag parameter in node creation helpers from uint32_t
to uint16_t to match the xbc_node.data field width (patch 6).
- Constify the xbc_calc_checksum() data parameter since it only
reads the buffer (patch 12).

Cleanups:
- Fix comment typos (patches 2-3), missing blank line before
kerneldoc (patch 4), inconsistent if/else bracing (patches 5, 7).
- Drop redundant memset after memblock_alloc which already returns
zeroed memory; switch the userspace path from malloc to calloc
to match (patch 10).

Modernization:
- Replace open-coded __attribute__((__packed__)) with the __packed
macro, adding the definition to the tools/bootconfig shim header
(patches 11, 14).
- Replace the catch-all linux/kernel.h include with the specific
headers needed: linux/cache.h, linux/compiler.h, and
linux/sprintf.h (patch 13).

Build-tested with both the in-kernel build (lib/bootconfig.o,
init/main.o) and the userspace tools/bootconfig build. All 70
tools/bootconfig test cases pass.

Josh Law (14):
lib/bootconfig: add missing __init annotations to static helpers
lib/bootconfig: fix typo "initiized" in xbc_root_node() kerneldoc
lib/bootconfig: fix typo "uder" in xbc_node_find_next_leaf()
lib/bootconfig: add blank line before xbc_get_info() kerneldoc
lib/bootconfig: fix inconsistent if/else bracing
lib/bootconfig: narrow flag parameter type from uint32_t to uint16_t
lib/bootconfig: fix inconsistent if/else bracing in __xbc_add_key()
lib/bootconfig: fix off-by-one in xbc_verify_tree() next node check
lib/bootconfig: increment xbc_node_num after node init succeeds
lib/bootconfig: drop redundant memset of xbc_nodes
bootconfig: use __packed macro for struct xbc_node
bootconfig: constify xbc_calc_checksum() data parameter
lib/bootconfig: replace linux/kernel.h with specific includes
bootconfig: add __packed definition to tools/bootconfig shim header

include/linux/bootconfig.h | 6 +--
lib/bootconfig.c | 47 ++++++++++++---------
tools/bootconfig/include/linux/bootconfig.h | 1 +
3 files changed, 30 insertions(+), 24 deletions(-)

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2.34.1