[PATCH v8 13/13] lib/bootconfig: change xbc_node_index() return type to uint16_t

Josh Law
2026-03-18T15:59:36Z

lib/bootconfig.c:136:21: warning: conversion from 'long int' to
'int' may change value [-Wconversion]
lib/bootconfig.c:308:33: warning: conversion from 'int' to 'uint16_t'
may change value [-Wconversion]
lib/bootconfig.c:467:37: warning: conversion from 'int' to 'uint16_t'
may change value [-Wconversion]
lib/bootconfig.c:469:40: warning: conversion from 'int' to 'uint16_t'
may change value [-Wconversion]
lib/bootconfig.c:472:54: warning: conversion from 'int' to 'uint16_t'
may change value [-Wconversion]
lib/bootconfig.c:476:45: warning: conversion from 'int' to 'uint16_t'
may change value [-Wconversion]

xbc_node_index() returns the position of a node in the xbc_nodes array,
which has at most XBC_NODE_MAX (8192) entries, well within uint16_t
range. Every caller stores the result in a uint16_t field (node->parent,
node->child, node->next, or the keys[] array in compose_key_after), so
the int return type causes narrowing warnings at all six call sites.

Change the return type to uint16_t and add an explicit cast on the
pointer subtraction to match the storage width and eliminate the
warnings.

Signed-off-by: Josh Law <objecting@objecting.org>
---
include/linux/bootconfig.h | 2 +-
lib/bootconfig.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index 23a96c5edcf3..692a5acc2ffc 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -66,7 +66,7 @@ struct xbc_node {

/* Node tree access raw APIs */
struct xbc_node * __init xbc_root_node(void);
-int __init xbc_node_index(struct xbc_node *node);
+uint16_t __init xbc_node_index(struct xbc_node *node);
struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node);
struct xbc_node * __init xbc_node_get_child(struct xbc_node *node);
struct xbc_node * __init xbc_node_get_next(struct xbc_node *node);
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 272d9427e879..57f07e33868e 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -131,9 +131,9 @@ struct xbc_node * __init xbc_root_node(void)
*
* Return the index number of @node in XBC node list.
*/
-int __init xbc_node_index(struct xbc_node *node)
+uint16_t __init xbc_node_index(struct xbc_node *node)
{
- return node - &xbc_nodes[0];
+ return (uint16_t)(node - &xbc_nodes[0]);
}

/**
--
2.34.1