[PATCH v2 1/4] bootconfig: Change array value to use child node

Masami Hiramatsu
2021-05-21T06:34:43Z

It is not possible to put an array value with subkeys under
a key node, because both of subkeys and the array elements
are using "next" field of the xbc_node.

Thus this changes the array values to use "child" field in
the array case. The reason why split this change is to
test it easily.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
Changes in v2:
- Fix /proc/bootconfig accroding to Devin's report (Thanks!)
- Update patch description to explain why, not what.
- Use xbc_node_is_array() instead of checking field directly.
---
fs/proc/bootconfig.c | 2 +-
include/linux/bootconfig.h | 6 +++---
lib/bootconfig.c | 23 +++++++++++++++++++----
tools/bootconfig/main.c | 2 +-
4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/fs/proc/bootconfig.c b/fs/proc/bootconfig.c
index ad31ec4ad627..6d8d4bf20837 100644
--- a/fs/proc/bootconfig.c
+++ b/fs/proc/bootconfig.c
@@ -49,7 +49,7 @@ static int __init copy_xbc_key_value_list(char *dst, size_t size)
else
q = '"';
ret = snprintf(dst, rest(dst, end), "%c%s%c%s",
- q, val, q, vnode->next ? ", " : "\n");
+ q, val, q, xbc_node_is_array(vnode) ? ", " : "\n");
if (ret < 0)
goto out;
dst += ret;
diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index 2696eb0fc149..3178a31fdabc 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -71,7 +71,7 @@ static inline __init bool xbc_node_is_key(struct xbc_node *node)
*/
static inline __init bool xbc_node_is_array(struct xbc_node *node)
{
- return xbc_node_is_value(node) && node->next != 0;
+ return xbc_node_is_value(node) && node->child != 0;
}

/**
@@ -140,7 +140,7 @@ static inline struct xbc_node * __init xbc_find_node(const char *key)
*/
#define xbc_array_for_each_value(anode, value) \
for (value = xbc_node_get_data(anode); anode != NULL ; \
- anode = xbc_node_get_next(anode), \
+ anode = xbc_node_get_child(anode), \
value = anode ? xbc_node_get_data(anode) : NULL)

/**
@@ -171,7 +171,7 @@ static inline struct xbc_node * __init xbc_find_node(const char *key)
*/
#define xbc_node_for_each_array_value(node, key, anode, value) \
for (value = xbc_node_find_value(node, key, &anode); value != NULL; \
- anode = xbc_node_get_next(anode), \
+ anode = xbc_node_get_child(anode), \
value = anode ? xbc_node_get_data(anode) : NULL)

/**
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 9f8c70a98fcf..44dcdcbd746a 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -367,6 +367,14 @@ static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)
return node;
}

+static inline __init struct xbc_node *xbc_last_child(struct xbc_node *node)
+{
+ while (node->child)
+ node = xbc_node_get_child(node);
+
+ return node;
+}
+
static struct xbc_node * __init xbc_add_sibling(char *data, u32 flag)
{
struct xbc_node *sib, *node = xbc_add_node(data, flag);
@@ -517,17 +525,20 @@ static int __init xbc_parse_array(char **__v)
char *next;
int c = 0;

+ if (last_parent->child)
+ last_parent = xbc_node_get_child(last_parent);
+
do {
c = __xbc_parse_value(__v, &next);
if (c < 0)
return c;

- node = xbc_add_sibling(*__v, XBC_VALUE);
+ node = xbc_add_child(*__v, XBC_VALUE);
if (!node)
return -ENOMEM;
*__v = next;
} while (c == ',');
- node->next = 0;
+ node->child = 0;

return c;
}
@@ -615,8 +626,12 @@ static int __init xbc_parse_kv(char **k, char *v, int op)

if (op == ':' && child) {
xbc_init_node(child, v, XBC_VALUE);
- } else if (!xbc_add_sibling(v, XBC_VALUE))
- return -ENOMEM;
+ } else {
+ if (op == '+' && child)
+ last_parent = xbc_last_child(child);
+ if (!xbc_add_sibling(v, XBC_VALUE))
+ return -ENOMEM;
+ }

if (c == ',') { /* Array */
c = xbc_parse_array(&next);
diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
index 7362bef1a368..7a98756e594a 100644
--- a/tools/bootconfig/main.c
+++ b/tools/bootconfig/main.c
@@ -27,7 +27,7 @@ static int xbc_show_value(struct xbc_node *node, bool semicolon)
q = '\'';
else
q = '"';
- printf("%c%s%c%s", q, val, q, node->next ? ", " : eol);
+ printf("%c%s%c%s", q, val, q, xbc_node_is_array(node) ? ", " : eol);
i++;
}
return i;