[PATCH 00/15] bootconfig: fixes, cleanups, and modernization

[PATCH 00/15] bootconfig: fixes, cleanups, and modernization

[Josh Law]

This series addresses a collection of issues found during a review of
lib/bootconfig.c and include/linux/bootconfig.h, ranging from a
potential crash to coding style and API modernization.

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).
  - Fix xbc_node_get_data() returning NULL on WARN_ON, which causes
    NULL dereferences in callers that pass the result to strlen() or
    strcmp() without checking. Return an empty string instead so the
    WARN_ON remains non-fatal as intended (patch 15).
  - 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 (15):
  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
  lib/bootconfig: return empty string instead of NULL from
    xbc_node_get_data()

 include/linux/bootconfig.h                  |  6 +--
 lib/bootconfig.c                            | 51 +++++++++++----------
 tools/bootconfig/include/linux/bootconfig.h |  1 +
 3 files changed, 32 insertions(+), 26 deletions(-)

--
2.34.1

[PATCH 01/15] lib/bootconfig: add missing __init annotations to static helpers

[Josh Law]

skip_comment() and skip_spaces_until_newline() are static functions
called exclusively from __init code paths but lack the __init
annotation themselves. Add it so their memory can be reclaimed after
init.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index b0ef1e74e98a..51fd2299ec0f 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -509,7 +509,7 @@ static inline __init bool xbc_valid_keyword(char *key)
 	return *key == '\0';
 }
 
-static char *skip_comment(char *p)
+static char __init *skip_comment(char *p)
 {
 	char *ret;
 
@@ -522,7 +522,7 @@ static char *skip_comment(char *p)
 	return ret;
 }
 
-static char *skip_spaces_until_newline(char *p)
+static char __init *skip_spaces_until_newline(char *p)
 {
 	while (isspace(*p) && *p != '\n')
 		p++;
-- 
2.34.1

[PATCH 02/15] lib/bootconfig: fix typo "initiized" in xbc_root_node() kerneldoc

[Josh Law]

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 51fd2299ec0f..53aedc042f6e 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -112,7 +112,7 @@ static int __init xbc_parse_error(const char *msg, const char *p)
  * xbc_root_node() - Get the root node of extended boot config
  *
  * Return the address of root node of extended boot config. If the
- * extended boot config is not initiized, return NULL.
+ * extended boot config is not initialized, return NULL.
  */
 struct xbc_node * __init xbc_root_node(void)
 {
-- 
2.34.1

[PATCH 03/15] lib/bootconfig: fix typo "uder" in xbc_node_find_next_leaf()

[Josh Law]

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 53aedc042f6e..35091617bca5 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -364,7 +364,7 @@ struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root,
 			node = xbc_node_get_parent(node);
 			if (node == root)
 				return NULL;
-			/* User passed a node which is not uder parent */
+			/* User passed a node which is not under parent */
 			if (WARN_ON(!node))
 				return NULL;
 		}
-- 
2.34.1

[PATCH 04/15] lib/bootconfig: add blank line before xbc_get_info() kerneldoc

[Josh Law]

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 35091617bca5..e955d2f7e7ca 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -79,6 +79,7 @@ static inline void xbc_free_mem(void *addr, size_t size, bool early)
 	free(addr);
 }
 #endif
+
 /**
  * xbc_get_info() - Get the information of loaded boot config
  * @node_size: A pointer to store the number of nodes.
-- 
2.34.1

[PATCH 05/15] lib/bootconfig: fix inconsistent if/else bracing

[Josh Law]

When one branch of a conditional uses braces, both branches should
use them per kernel coding style.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index e955d2f7e7ca..45db51bc9cc7 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -473,8 +473,9 @@ static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, boo
 				sib->next = xbc_node_index(node);
 			}
 		}
-	} else
+	} else {
 		xbc_parse_error("Too many nodes", data);
+	}
 
 	return node;
 }
@@ -992,8 +993,9 @@ int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
 		if (emsg)
 			*emsg = xbc_err_msg;
 		_xbc_exit(true);
-	} else
+	} else {
 		ret = xbc_node_num;
+	}
 
 	return ret;
 }
-- 
2.34.1

[PATCH 06/15] lib/bootconfig: narrow flag parameter type from uint32_t to uint16_t

[Josh Law]

The flag parameter in the node creation helpers only ever carries
XBC_KEY (0) or XBC_VALUE (0x8000), both of which fit in uint16_t.
Using uint16_t matches the width of xbc_node.data where the flag is
ultimately stored.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 45db51bc9cc7..34bdc2d13881 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -408,7 +408,7 @@ const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
 
 /* XBC parse and tree build */
 
-static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)
+static int __init xbc_init_node(struct xbc_node *node, char *data, uint16_t flag)
 {
 	unsigned long offset = data - xbc_data;
 
@@ -422,7 +422,7 @@ static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag
 	return 0;
 }
 
-static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)
+static struct xbc_node * __init xbc_add_node(char *data, uint16_t flag)
 {
 	struct xbc_node *node;
 
@@ -452,7 +452,7 @@ static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)
 	return node;
 }
 
-static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, bool head)
+static struct xbc_node * __init __xbc_add_sibling(char *data, uint16_t flag, bool head)
 {
 	struct xbc_node *sib, *node = xbc_add_node(data, flag);
 
@@ -480,17 +480,17 @@ static struct xbc_node * __init __xbc_add_sibling(char *data, uint32_t flag, boo
 	return node;
 }
 
-static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)
+static inline struct xbc_node * __init xbc_add_sibling(char *data, uint16_t flag)
 {
 	return __xbc_add_sibling(data, flag, false);
 }
 
-static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)
+static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint16_t flag)
 {
 	return __xbc_add_sibling(data, flag, true);
 }
 
-static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)
+static inline __init struct xbc_node *xbc_add_child(char *data, uint16_t flag)
 {
 	struct xbc_node *node = xbc_add_sibling(data, flag);
 
-- 
2.34.1

[PATCH 07/15] lib/bootconfig: fix inconsistent if/else bracing in __xbc_add_key()

[Josh Law]

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 34bdc2d13881..58d6ae297280 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -657,9 +657,9 @@ static int __init __xbc_add_key(char *k)
 	if (unlikely(xbc_node_num == 0))
 		goto add_node;
 
-	if (!last_parent)	/* the first level */
+	if (!last_parent) {	/* the first level */
 		node = find_match_node(xbc_nodes, k);
-	else {
+	} else {
 		child = xbc_node_get_child(last_parent);
 		/* Since the value node is the first child, skip it. */
 		if (child && xbc_node_is_value(child))
@@ -667,9 +667,9 @@ static int __init __xbc_add_key(char *k)
 		node = find_match_node(child, k);
 	}
 
-	if (node)
+	if (node) {
 		last_parent = node;
-	else {
+	} else {
 add_node:
 		node = xbc_add_child(k, XBC_KEY);
 		if (!node)
-- 
2.34.1

[PATCH 08/15] lib/bootconfig: fix off-by-one in xbc_verify_tree() next node check

[Josh Law]

Valid node indices are 0 to xbc_node_num-1, so a next value equal to
xbc_node_num is out of bounds. Use >= instead of > to catch this.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 58d6ae297280..56fbedc9e725 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -816,7 +816,7 @@ static int __init xbc_verify_tree(void)
 	}
 
 	for (i = 0; i < xbc_node_num; i++) {
-		if (xbc_nodes[i].next > xbc_node_num) {
+		if (xbc_nodes[i].next >= xbc_node_num) {
 			return xbc_parse_error("No closing brace",
 				xbc_node_get_data(xbc_nodes + i));
 		}
-- 
2.34.1

[PATCH 09/15] lib/bootconfig: increment xbc_node_num after node init succeeds

[Josh Law]

Move the xbc_node_num increment to after xbc_init_node() so a failed
init does not leave a partially initialized node counted in the array.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 56fbedc9e725..06e8a79ab472 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -429,9 +429,10 @@ static struct xbc_node * __init xbc_add_node(char *data, uint16_t flag)
 	if (xbc_node_num == XBC_NODE_MAX)
 		return NULL;
 
-	node = &xbc_nodes[xbc_node_num++];
+	node = &xbc_nodes[xbc_node_num];
 	if (xbc_init_node(node, data, flag) < 0)
 		return NULL;
+	xbc_node_num++;
 
 	return node;
 }
-- 
2.34.1

[PATCH 10/15] lib/bootconfig: drop redundant memset of xbc_nodes

[Josh Law]

memblock_alloc() already returns zeroed memory, so the explicit memset
in xbc_init() is redundant. Switch the userspace xbc_alloc_mem() from
malloc() to calloc() so both paths return zeroed memory, and remove
the separate memset call.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 06e8a79ab472..fe1053043752 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -71,7 +71,7 @@ static inline void __init xbc_free_mem(void *addr, size_t size, bool early)
 
 static inline void *xbc_alloc_mem(size_t size)
 {
-	return malloc(size);
+	return calloc(1, size);
 }
 
 static inline void xbc_free_mem(void *addr, size_t size, bool early)
@@ -982,7 +982,6 @@ int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
 		_xbc_exit(true);
 		return -ENOMEM;
 	}
-	memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
 
 	ret = xbc_parse_tree();
 	if (!ret)
-- 
2.34.1

[PATCH 11/15] bootconfig: use __packed macro for struct xbc_node

[Josh Law]

Replace the open-coded __attribute__((__packed__)) with the kernel
__packed macro for consistency with the rest of the kernel.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 include/linux/bootconfig.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index 25df9260d206..c37e0096c4f1 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -53,7 +53,7 @@ struct xbc_node {
 	uint16_t child;
 	uint16_t parent;
 	uint16_t data;
-} __attribute__ ((__packed__));
+} __packed;
 
 #define XBC_KEY		0
 #define XBC_VALUE	(1 << 15)
-- 
2.34.1

[PATCH 12/15] bootconfig: constify xbc_calc_checksum() data parameter

[Josh Law]

xbc_calc_checksum() only reads the data buffer, so mark the parameter
as const void * and the internal pointer as const unsigned char *.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 include/linux/bootconfig.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index c37e0096c4f1..d78c2b62debf 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -36,9 +36,9 @@ bool __init cmdline_has_extra_options(void);
  * The checksum will be used with the BOOTCONFIG_MAGIC and the size for
  * embedding the bootconfig in the initrd image.
  */
-static inline __init uint32_t xbc_calc_checksum(void *data, uint32_t size)
+static inline __init uint32_t xbc_calc_checksum(const void *data, uint32_t size)
 {
-	unsigned char *p = data;
+	const unsigned char *p = data;
 	uint32_t ret = 0;
 
 	while (size--)
-- 
2.34.1

[PATCH 13/15] lib/bootconfig: replace linux/kernel.h with specific includes

[Josh Law]

linux/kernel.h is a legacy catch-all header. Replace it with the
specific headers actually needed: linux/cache.h for SMP_CACHE_BYTES,
linux/compiler.h for unlikely(), and linux/sprintf.h for snprintf().

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index fe1053043752..0823491221f4 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -17,7 +17,9 @@
 #include <linux/bug.h>
 #include <linux/ctype.h>
 #include <linux/errno.h>
-#include <linux/kernel.h>
+#include <linux/cache.h>
+#include <linux/compiler.h>
+#include <linux/sprintf.h>
 #include <linux/memblock.h>
 #include <linux/string.h>
 
-- 
2.34.1

[PATCH 14/15] bootconfig: add __packed definition to tools/bootconfig shim header

[Josh Law]

The tools/bootconfig userspace build includes the main bootconfig.h
via a shim header that defines kernel macros for userspace. Add the
__packed macro so the struct xbc_node declaration works after the
conversion from open-coded __attribute__((__packed__)).

Signed-off-by: Josh Law <objecting@objecting.org>
---
 tools/bootconfig/include/linux/bootconfig.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/bootconfig/include/linux/bootconfig.h b/tools/bootconfig/include/linux/bootconfig.h
index 6784296a0692..41c50ab95ba5 100644
--- a/tools/bootconfig/include/linux/bootconfig.h
+++ b/tools/bootconfig/include/linux/bootconfig.h
@@ -48,6 +48,7 @@ static inline char *strim(char *s)
 
 #define __init
 #define __initdata
+#define __packed	__attribute__((__packed__))
 
 #include "../../../../include/linux/bootconfig.h"
 
-- 
2.34.1

[PATCH 15/15] lib/bootconfig: return empty string instead of NULL from xbc_node_get_data()

[Josh Law]

xbc_node_get_data() uses WARN_ON (non-fatal) when it detects an
invalid data offset, but returns NULL. Multiple callers pass the
result directly to strlen() or strcmp() without NULL checks, which
would cause a NULL pointer dereference after the non-fatal warning:

  - xbc_node_match_prefix(): strlen(p) on line 197
  - find_match_node(): strcmp(xbc_node_get_data(node), k) on line 644
  - xbc_verify_tree(): strlen(xbc_node_get_data(n)) on lines 832, 853
  - xbc_node_find_next_key_value(): returns NULL to caller on line 404

Return an empty string instead so the WARN_ON remains non-fatal as
intended. The warning backtrace still signals corruption, but the
kernel won't crash in the callers.

Signed-off-by: Josh Law <objecting@objecting.org>
---
 lib/bootconfig.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 0823491221f4..fae4e6790f34 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -179,14 +179,14 @@ struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)
  * @node: An XBC node.
  *
  * Return the data (which is always a null terminated string) of @node.
- * If the node has invalid data, warn and return NULL.
+ * If the node has invalid data, warn and return an empty string.
  */
 const char * __init xbc_node_get_data(struct xbc_node *node)
 {
 	int offset = node->data & ~XBC_VALUE;
 
 	if (WARN_ON(offset >= xbc_data_size))
-		return NULL;
+		return "";
 
 	return xbc_data + offset;
 }
-- 
2.34.1