[PATCH v4 2/4] bootconfig: Allocate xbc_data inside xbc_init()

From: Masami Hiramatsu
Date: Thu Sep 16 2021 - 02:23:41 EST


Allocate 'xbc_data' in the xbc_init() so that it does
not need to care about the ownership of the copied
data.

Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
include/linux/bootconfig.h | 2 +-
init/main.c | 13 ++-----------
lib/bootconfig.c | 33 +++++++++++++++++++++------------
tools/bootconfig/main.c | 6 +++---
4 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index 537e1b991f11..62e09b788172 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -271,7 +271,7 @@ static inline int __init xbc_node_compose_key(struct xbc_node *node,
}

/* XBC node initializer */
-int __init xbc_init(char *buf, const char **emsg, int *epos);
+int __init xbc_init(const char *buf, size_t size, const char **emsg, int *epos);


/* XBC cleanup data structures */
diff --git a/init/main.c b/init/main.c
index 0b054fff8e92..77c309ed9f17 100644
--- a/init/main.c
+++ b/init/main.c
@@ -410,7 +410,7 @@ static void __init setup_boot_config(void)
const char *msg;
int pos;
u32 size, csum;
- char *data, *copy, *err;
+ char *data, *err;
int ret;

/* Cut out the bootconfig data even if we have no bootconfig option */
@@ -443,16 +443,7 @@ static void __init setup_boot_config(void)
return;
}

- copy = memblock_alloc(size + 1, SMP_CACHE_BYTES);
- if (!copy) {
- pr_err("Failed to allocate memory for bootconfig\n");
- return;
- }
-
- memcpy(copy, data, size);
- copy[size] = '\0';
-
- ret = xbc_init(copy, &msg, &pos);
+ ret = xbc_init(data, size, &msg, &pos);
if (ret < 0) {
if (pos < 0)
pr_err("Failed to init bootconfig: %s.\n", msg);
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index 5ae248b29373..66b02fddfea8 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -789,6 +789,7 @@ static int __init xbc_verify_tree(void)
*/
void __init xbc_destroy_all(void)
{
+ memblock_free_ptr(xbc_data, xbc_data_size);
xbc_data = NULL;
xbc_data_size = 0;
xbc_node_num = 0;
@@ -799,19 +800,20 @@ void __init xbc_destroy_all(void)

/**
* xbc_init() - Parse given XBC file and build XBC internal tree
- * @buf: boot config text
+ * @data: The boot config text original data
+ * @size: The size of @data
* @emsg: A pointer of const char * to store the error message
* @epos: A pointer of int to store the error position
*
- * This parses the boot config text in @buf. @buf must be a
- * null terminated string and smaller than XBC_DATA_MAX.
+ * This parses the boot config text in @data. @size must be smaller
+ * than XBC_DATA_MAX.
* Return the number of stored nodes (>0) if succeeded, or -errno
* if there is any error.
* In error cases, @emsg will be updated with an error message and
* @epos will be updated with the error position which is the byte offset
* of @buf. If the error is not a parser error, @epos will be -1.
*/
-int __init xbc_init(char *buf, const char **emsg, int *epos)
+int __init xbc_init(const char *data, size_t size, const char **emsg, int *epos)
{
char *p, *q;
int ret, c;
@@ -824,28 +826,35 @@ int __init xbc_init(char *buf, const char **emsg, int *epos)
*emsg = "Bootconfig is already initialized";
return -EBUSY;
}
-
- ret = strlen(buf);
- if (ret > XBC_DATA_MAX - 1 || ret == 0) {
+ if (size > XBC_DATA_MAX || size == 0) {
if (emsg)
- *emsg = ret ? "Config data is too big" :
+ *emsg = size ? "Config data is too big" :
"Config data is empty";
return -ERANGE;
}

+ xbc_data = memblock_alloc(size + 1, SMP_CACHE_BYTES);
+ if (!xbc_data) {
+ if (emsg)
+ *emsg = "Failed to allocate bootconfig data";
+ return -ENOMEM;
+ }
+ memcpy(xbc_data, data, size);
+ xbc_data[size] = '\0';
+ xbc_data_size = size + 1;
+
xbc_nodes = memblock_alloc(sizeof(struct xbc_node) * XBC_NODE_MAX,
SMP_CACHE_BYTES);
if (!xbc_nodes) {
if (emsg)
*emsg = "Failed to allocate bootconfig nodes";
+ xbc_destroy_all();
return -ENOMEM;
}
memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
- xbc_data = buf;
- xbc_data_size = ret + 1;
- last_parent = NULL;

- p = buf;
+ last_parent = NULL;
+ p = xbc_data;
do {
q = strpbrk(p, "{}=+;:\n#");
if (!q) {
diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
index fd67496a947f..7269c9e35335 100644
--- a/tools/bootconfig/main.c
+++ b/tools/bootconfig/main.c
@@ -229,7 +229,7 @@ static int load_xbc_from_initrd(int fd, char **buf)
return -EINVAL;
}

- ret = xbc_init(*buf, &msg, NULL);
+ ret = xbc_init(*buf, size, &msg, NULL);
/* Wrong data */
if (ret < 0) {
pr_err("parse error: %s.\n", msg);
@@ -269,7 +269,7 @@ static int init_xbc_with_error(char *buf, int len)
if (!copy)
return -ENOMEM;

- ret = xbc_init(buf, &msg, &pos);
+ ret = xbc_init(buf, len, &msg, &pos);
if (ret < 0)
show_xbc_error(copy, msg, pos);
free(copy);
@@ -382,7 +382,7 @@ static int apply_xbc(const char *path, const char *xbc_path)
memcpy(data, buf, size);

/* Check the data format */
- ret = xbc_init(buf, &msg, &pos);
+ ret = xbc_init(buf, size, &msg, &pos);
if (ret < 0) {
show_xbc_error(data, msg, pos);
free(data);