OSCL-LXR linux-6.0.1/​lib/​bootconfig.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Extra Boot Config
  * Masami Hiramatsu <mhiramat@kernel.org>
  */
 
 #ifdef __KERNEL__
 #include <linux/bootconfig.h>
 #include <linux/bug.h>
 #include <linux/ctype.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/memblock.h>
 #include <linux/string.h>
 
 #ifdef CONFIG_BOOT_CONFIG_EMBED
 /* embedded_bootconfig_data is defined in bootconfig-data.S */
 extern __visible const char embedded_bootconfig_data[];
 extern __visible const char embedded_bootconfig_data_end[];
 
 const char * __init xbc_get_embedded_bootconfig(size_t *size)
 {
     *size = embedded_bootconfig_data_end - embedded_bootconfig_data;
     return (*size) ? embedded_bootconfig_data : NULL;
 }
 #endif
 
 #else /* !__KERNEL__ */
 /*
  * NOTE: This is only for tools/bootconfig, because tools/bootconfig will
  * run the parser sanity test.
  * This does NOT mean lib/bootconfig.c is available in the user space.
  * However, if you change this file, please make sure the tools/bootconfig
  * has no issue on building and running.
  */
 #include <linux/bootconfig.h>
 #endif
 
 /*
  * Extra Boot Config (XBC) is given as tree-structured ascii text of
  * key-value pairs on memory.
  * xbc_parse() parses the text to build a simple tree. Each tree node is
  * simply a key word or a value. A key node may have a next key node or/and
  * a child node (both key and value). A value node may have a next value
  * node (for array).
  */
 
 static struct xbc_node *xbc_nodes __initdata;
 static int xbc_node_num __initdata;
 static char *xbc_data __initdata;
 static size_t xbc_data_size __initdata;
 static struct xbc_node *last_parent __initdata;
 static const char *xbc_err_msg __initdata;
 static int xbc_err_pos __initdata;
 static int open_brace[XBC_DEPTH_MAX] __initdata;
 static int brace_index __initdata;
 
 #ifdef __KERNEL__
 static inline void * __init xbc_alloc_mem(size_t size)
 {
     return memblock_alloc(size, SMP_CACHE_BYTES);
 }
 
 static inline void __init xbc_free_mem(void *addr, size_t size)
 {
     memblock_free(addr, size);
 }
 
 #else /* !__KERNEL__ */
 
 static inline void *xbc_alloc_mem(size_t size)
 {
     return malloc(size);
 }
 
 static inline void xbc_free_mem(void *addr, size_t size)
 {
     free(addr);
 }
 #endif
 /**
  * xbc_get_info() - Get the information of loaded boot config
  * @node_size: A pointer to store the number of nodes.
  * @data_size: A pointer to store the size of bootconfig data.
  *
  * Get the number of used nodes in @node_size if it is not NULL,
  * and the size of bootconfig data in @data_size if it is not NULL.
  * Return 0 if the boot config is initialized, or return -ENODEV.
  */
 int __init xbc_get_info(int *node_size, size_t *data_size)
 {
     if (!xbc_data)
         return -ENODEV;
 
     if (node_size)
         *node_size = xbc_node_num;
     if (data_size)
         *data_size = xbc_data_size;
     return 0;
 }
 
 static int __init xbc_parse_error(const char *msg, const char *p)
 {
     xbc_err_msg = msg;
     xbc_err_pos = (int)(p - xbc_data);
 
     return -EINVAL;
 }
 
 /**
  * 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.
  */
 struct xbc_node * __init xbc_root_node(void)
 {
     if (unlikely(!xbc_data))
         return NULL;
 
     return xbc_nodes;
 }
 
 /**
  * xbc_node_index() - Get the index of XBC node
  * @node: A target node of getting index.
  *
  * Return the index number of @node in XBC node list.
  */
 int __init xbc_node_index(struct xbc_node *node)
 {
     return node - &xbc_nodes[0];
 }
 
 /**
  * xbc_node_get_parent() - Get the parent XBC node
  * @node: An XBC node.
  *
  * Return the parent node of @node. If the node is top node of the tree,
  * return NULL.
  */
 struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node)
 {
     return node->parent == XBC_NODE_MAX ? NULL : &xbc_nodes[node->parent];
 }
 
 /**
  * xbc_node_get_child() - Get the child XBC node
  * @node: An XBC node.
  *
  * Return the first child node of @node. If the node has no child, return
  * NULL.
  */
 struct xbc_node * __init xbc_node_get_child(struct xbc_node *node)
 {
     return node->child ? &xbc_nodes[node->child] : NULL;
 }
 
 /**
  * xbc_node_get_next() - Get the next sibling XBC node
  * @node: An XBC node.
  *
  * Return the NEXT sibling node of @node. If the node has no next sibling,
  * return NULL. Note that even if this returns NULL, it doesn't mean @node
  * has no siblings. (You also has to check whether the parent's child node
  * is @node or not.)
  */
 struct xbc_node * __init xbc_node_get_next(struct xbc_node *node)
 {
     return node->next ? &xbc_nodes[node->next] : NULL;
 }
 
 /**
  * xbc_node_get_data() - Get the data of XBC 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.
  */
 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 xbc_data + offset;
 }
 
 static bool __init
 xbc_node_match_prefix(struct xbc_node *node, const char **prefix)
 {
     const char *p = xbc_node_get_data(node);
     int len = strlen(p);
 
     if (strncmp(*prefix, p, len))
         return false;
 
     p = *prefix + len;
     if (*p == '.')
         p++;
     else if (*p != '\0')
         return false;
     *prefix = p;
 
     return true;
 }
 
 /**
  * xbc_node_find_subkey() - Find a subkey node which matches given key
  * @parent: An XBC node.
  * @key: A key string.
  *
  * Search a key node under @parent which matches @key. The @key can contain
  * several words jointed with '.'. If @parent is NULL, this searches the
  * node from whole tree. Return NULL if no node is matched.
  */
 struct xbc_node * __init
 xbc_node_find_subkey(struct xbc_node *parent, const char *key)
 {
     struct xbc_node *node;
 
     if (parent)
         node = xbc_node_get_subkey(parent);
     else
         node = xbc_root_node();
 
     while (node && xbc_node_is_key(node)) {
         if (!xbc_node_match_prefix(node, &key))
             node = xbc_node_get_next(node);
         else if (*key != '\0')
             node = xbc_node_get_subkey(node);
         else
             break;
     }
 
     return node;
 }
 
 /**
  * xbc_node_find_value() - Find a value node which matches given key
  * @parent: An XBC node.
  * @key: A key string.
  * @vnode: A container pointer of found XBC node.
  *
  * Search a value node under @parent whose (parent) key node matches @key,
  * store it in *@vnode, and returns the value string.
  * The @key can contain several words jointed with '.'. If @parent is NULL,
  * this searches the node from whole tree. Return the value string if a
  * matched key found, return NULL if no node is matched.
  * Note that this returns 0-length string and stores NULL in *@vnode if the
  * key has no value. And also it will return the value of the first entry if
  * the value is an array.
  */
 const char * __init
 xbc_node_find_value(struct xbc_node *parent, const char *key,
             struct xbc_node **vnode)
 {
     struct xbc_node *node = xbc_node_find_subkey(parent, key);
 
     if (!node || !xbc_node_is_key(node))
         return NULL;
 
     node = xbc_node_get_child(node);
     if (node && !xbc_node_is_value(node))
         return NULL;
 
     if (vnode)
         *vnode = node;
 
     return node ? xbc_node_get_data(node) : "";
 }
 
 /**
  * xbc_node_compose_key_after() - Compose partial key string of the XBC node
  * @root: Root XBC node
  * @node: Target XBC node.
  * @buf: A buffer to store the key.
  * @size: The size of the @buf.
  *
  * Compose the partial key of the @node into @buf, which is starting right
  * after @root (@root is not included.) If @root is NULL, this returns full
  * key words of @node.
  * Returns the total length of the key stored in @buf. Returns -EINVAL
  * if @node is NULL or @root is not the ancestor of @node or @root is @node,
  * or returns -ERANGE if the key depth is deeper than max depth.
  * This is expected to be used with xbc_find_node() to list up all (child)
  * keys under given key.
  */
 int __init xbc_node_compose_key_after(struct xbc_node *root,
                       struct xbc_node *node,
                       char *buf, size_t size)
 {
     uint16_t keys[XBC_DEPTH_MAX];
     int depth = 0, ret = 0, total = 0;
 
     if (!node || node == root)
         return -EINVAL;
 
     if (xbc_node_is_value(node))
         node = xbc_node_get_parent(node);
 
     while (node && node != root) {
         keys[depth++] = xbc_node_index(node);
         if (depth == XBC_DEPTH_MAX)
             return -ERANGE;
         node = xbc_node_get_parent(node);
     }
     if (!node && root)
         return -EINVAL;
 
     while (--depth >= 0) {
         node = xbc_nodes + keys[depth];
         ret = snprintf(buf, size, "%s%s", xbc_node_get_data(node),
                    depth ? "." : "");
         if (ret < 0)
             return ret;
         if (ret > size) {
             size = 0;
         } else {
             size -= ret;
             buf += ret;
         }
         total += ret;
     }
 
     return total;
 }
 
 /**
  * xbc_node_find_next_leaf() - Find the next leaf node under given node
  * @root: An XBC root node
  * @node: An XBC node which starts from.
  *
  * Search the next leaf node (which means the terminal key node) of @node
  * under @root node (including @root node itself).
  * Return the next node or NULL if next leaf node is not found.
  */
 struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root,
                          struct xbc_node *node)
 {
     struct xbc_node *next;
 
     if (unlikely(!xbc_data))
         return NULL;
 
     if (!node) {    /* First try */
         node = root;
         if (!node)
             node = xbc_nodes;
     } else {
         /* Leaf node may have a subkey */
         next = xbc_node_get_subkey(node);
         if (next) {
             node = next;
             goto found;
         }
 
         if (node == root)   /* @root was a leaf, no child node. */
             return NULL;
 
         while (!node->next) {
             node = xbc_node_get_parent(node);
             if (node == root)
                 return NULL;
             /* User passed a node which is not uder parent */
             if (WARN_ON(!node))
                 return NULL;
         }
         node = xbc_node_get_next(node);
     }
 
 found:
     while (node && !xbc_node_is_leaf(node))
         node = xbc_node_get_child(node);
 
     return node;
 }
 
 /**
  * xbc_node_find_next_key_value() - Find the next key-value pair nodes
  * @root: An XBC root node
  * @leaf: A container pointer of XBC node which starts from.
  *
  * Search the next leaf node (which means the terminal key node) of *@leaf
  * under @root node. Returns the value and update *@leaf if next leaf node
  * is found, or NULL if no next leaf node is found.
  * Note that this returns 0-length string if the key has no value, or
  * the value of the first entry if the value is an array.
  */
 const char * __init xbc_node_find_next_key_value(struct xbc_node *root,
                          struct xbc_node **leaf)
 {
     /* tip must be passed */
     if (WARN_ON(!leaf))
         return NULL;
 
     *leaf = xbc_node_find_next_leaf(root, *leaf);
     if (!*leaf)
         return NULL;
     if ((*leaf)->child)
         return xbc_node_get_data(xbc_node_get_child(*leaf));
     else
         return "";  /* No value key */
 }
 
 /* XBC parse and tree build */
 
 static int __init xbc_init_node(struct xbc_node *node, char *data, uint32_t flag)
 {
     unsigned long offset = data - xbc_data;
 
     if (WARN_ON(offset >= XBC_DATA_MAX))
         return -EINVAL;
 
     node->data = (uint16_t)offset | flag;
     node->child = 0;
     node->next = 0;
 
     return 0;
 }
 
 static struct xbc_node * __init xbc_add_node(char *data, uint32_t flag)
 {
     struct xbc_node *node;
 
     if (xbc_node_num == XBC_NODE_MAX)
         return NULL;
 
     node = &xbc_nodes[xbc_node_num++];
     if (xbc_init_node(node, data, flag) < 0)
         return NULL;
 
     return node;
 }
 
 static inline __init struct xbc_node *xbc_last_sibling(struct xbc_node *node)
 {
     while (node->next)
         node = xbc_node_get_next(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, uint32_t flag, bool head)
 {
     struct xbc_node *sib, *node = xbc_add_node(data, flag);
 
     if (node) {
         if (!last_parent) {
             /* Ignore @head in this case */
             node->parent = XBC_NODE_MAX;
             sib = xbc_last_sibling(xbc_nodes);
             sib->next = xbc_node_index(node);
         } else {
             node->parent = xbc_node_index(last_parent);
             if (!last_parent->child || head) {
                 node->next = last_parent->child;
                 last_parent->child = xbc_node_index(node);
             } else {
                 sib = xbc_node_get_child(last_parent);
                 sib = xbc_last_sibling(sib);
                 sib->next = xbc_node_index(node);
             }
         }
     } else
         xbc_parse_error("Too many nodes", data);
 
     return node;
 }
 
 static inline struct xbc_node * __init xbc_add_sibling(char *data, uint32_t flag)
 {
     return __xbc_add_sibling(data, flag, false);
 }
 
 static inline struct xbc_node * __init xbc_add_head_sibling(char *data, uint32_t flag)
 {
     return __xbc_add_sibling(data, flag, true);
 }
 
 static inline __init struct xbc_node *xbc_add_child(char *data, uint32_t flag)
 {
     struct xbc_node *node = xbc_add_sibling(data, flag);
 
     if (node)
         last_parent = node;
 
     return node;
 }
 
 static inline __init bool xbc_valid_keyword(char *key)
 {
     if (key[0] == '\0')
         return false;
 
     while (isalnum(*key) || *key == '-' || *key == '_')
         key++;
 
     return *key == '\0';
 }
 
 static char *skip_comment(char *p)
 {
     char *ret;
 
     ret = strchr(p, '\n');
     if (!ret)
         ret = p + strlen(p);
     else
         ret++;
 
     return ret;
 }
 
 static char *skip_spaces_until_newline(char *p)
 {
     while (isspace(*p) && *p != '\n')
         p++;
     return p;
 }
 
 static int __init __xbc_open_brace(char *p)
 {
     /* Push the last key as open brace */
     open_brace[brace_index++] = xbc_node_index(last_parent);
     if (brace_index >= XBC_DEPTH_MAX)
         return xbc_parse_error("Exceed max depth of braces", p);
 
     return 0;
 }
 
 static int __init __xbc_close_brace(char *p)
 {
     brace_index--;
     if (!last_parent || brace_index < 0 ||
         (open_brace[brace_index] != xbc_node_index(last_parent)))
         return xbc_parse_error("Unexpected closing brace", p);
 
     if (brace_index == 0)
         last_parent = NULL;
     else
         last_parent = &xbc_nodes[open_brace[brace_index - 1]];
 
     return 0;
 }
 
 /*
  * Return delimiter or error, no node added. As same as lib/cmdline.c,
  * you can use " around spaces, but can't escape " for value.
  */
 static int __init __xbc_parse_value(char **__v, char **__n)
 {
     char *p, *v = *__v;
     int c, quotes = 0;
 
     v = skip_spaces(v);
     while (*v == '#') {
         v = skip_comment(v);
         v = skip_spaces(v);
     }
     if (*v == '"' || *v == '\'') {
         quotes = *v;
         v++;
     }
     p = v - 1;
     while ((c = *++p)) {
         if (!isprint(c) && !isspace(c))
             return xbc_parse_error("Non printable value", p);
         if (quotes) {
             if (c != quotes)
                 continue;
             quotes = 0;
             *p++ = '\0';
             p = skip_spaces_until_newline(p);
             c = *p;
             if (c && !strchr(",;\n#}", c))
                 return xbc_parse_error("No value delimiter", p);
             if (*p)
                 p++;
             break;
         }
         if (strchr(",;\n#}", c)) {
             *p++ = '\0';
             v = strim(v);
             break;
         }
     }
     if (quotes)
         return xbc_parse_error("No closing quotes", p);
     if (c == '#') {
         p = skip_comment(p);
         c = '\n';   /* A comment must be treated as a newline */
     }
     *__n = p;
     *__v = v;
 
     return c;
 }
 
 static int __init xbc_parse_array(char **__v)
 {
     struct xbc_node *node;
     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_child(*__v, XBC_VALUE);
         if (!node)
             return -ENOMEM;
         *__v = next;
     } while (c == ',');
     node->child = 0;
 
     return c;
 }
 
 static inline __init
 struct xbc_node *find_match_node(struct xbc_node *node, char *k)
 {
     while (node) {
         if (!strcmp(xbc_node_get_data(node), k))
             break;
         node = xbc_node_get_next(node);
     }
     return node;
 }
 
 static int __init __xbc_add_key(char *k)
 {
     struct xbc_node *node, *child;
 
     if (!xbc_valid_keyword(k))
         return xbc_parse_error("Invalid keyword", k);
 
     if (unlikely(xbc_node_num == 0))
         goto add_node;
 
     if (!last_parent)   /* the first level */
         node = find_match_node(xbc_nodes, k);
     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))
             child = xbc_node_get_next(child);
         node = find_match_node(child, k);
     }
 
     if (node)
         last_parent = node;
     else {
 add_node:
         node = xbc_add_child(k, XBC_KEY);
         if (!node)
             return -ENOMEM;
     }
     return 0;
 }
 
 static int __init __xbc_parse_keys(char *k)
 {
     char *p;
     int ret;
 
     k = strim(k);
     while ((p = strchr(k, '.'))) {
         *p++ = '\0';
         ret = __xbc_add_key(k);
         if (ret)
             return ret;
         k = p;
     }
 
     return __xbc_add_key(k);
 }
 
 static int __init xbc_parse_kv(char **k, char *v, int op)
 {
     struct xbc_node *prev_parent = last_parent;
     struct xbc_node *child;
     char *next;
     int c, ret;
 
     ret = __xbc_parse_keys(*k);
     if (ret)
         return ret;
 
     c = __xbc_parse_value(&v, &next);
     if (c < 0)
         return c;
 
     child = xbc_node_get_child(last_parent);
     if (child && xbc_node_is_value(child)) {
         if (op == '=')
             return xbc_parse_error("Value is redefined", v);
         if (op == ':') {
             unsigned short nidx = child->next;
 
             xbc_init_node(child, v, XBC_VALUE);
             child->next = nidx; /* keep subkeys */
             goto array;
         }
         /* op must be '+' */
         last_parent = xbc_last_child(child);
     }
     /* The value node should always be the first child */
     if (!xbc_add_head_sibling(v, XBC_VALUE))
         return -ENOMEM;
 
 array:
     if (c == ',') { /* Array */
         c = xbc_parse_array(&next);
         if (c < 0)
             return c;
     }
 
     last_parent = prev_parent;
 
     if (c == '}') {
         ret = __xbc_close_brace(next - 1);
         if (ret < 0)
             return ret;
     }
 
     *k = next;
 
     return 0;
 }
 
 static int __init xbc_parse_key(char **k, char *n)
 {
     struct xbc_node *prev_parent = last_parent;
     int ret;
 
     *k = strim(*k);
     if (**k != '\0') {
         ret = __xbc_parse_keys(*k);
         if (ret)
             return ret;
         last_parent = prev_parent;
     }
     *k = n;
 
     return 0;
 }
 
 static int __init xbc_open_brace(char **k, char *n)
 {
     int ret;
 
     ret = __xbc_parse_keys(*k);
     if (ret)
         return ret;
     *k = n;
 
     return __xbc_open_brace(n - 1);
 }
 
 static int __init xbc_close_brace(char **k, char *n)
 {
     int ret;
 
     ret = xbc_parse_key(k, n);
     if (ret)
         return ret;
     /* k is updated in xbc_parse_key() */
 
     return __xbc_close_brace(n - 1);
 }
 
 static int __init xbc_verify_tree(void)
 {
     int i, depth, len, wlen;
     struct xbc_node *n, *m;
 
     /* Brace closing */
     if (brace_index) {
         n = &xbc_nodes[open_brace[brace_index]];
         return xbc_parse_error("Brace is not closed",
                     xbc_node_get_data(n));
     }
 
     /* Empty tree */
     if (xbc_node_num == 0) {
         xbc_parse_error("Empty config", xbc_data);
         return -ENOENT;
     }
 
     for (i = 0; i < xbc_node_num; i++) {
         if (xbc_nodes[i].next > xbc_node_num) {
             return xbc_parse_error("No closing brace",
                 xbc_node_get_data(xbc_nodes + i));
         }
     }
 
     /* Key tree limitation check */
     n = &xbc_nodes[0];
     depth = 1;
     len = 0;
 
     while (n) {
         wlen = strlen(xbc_node_get_data(n)) + 1;
         len += wlen;
         if (len > XBC_KEYLEN_MAX)
             return xbc_parse_error("Too long key length",
                 xbc_node_get_data(n));
 
         m = xbc_node_get_child(n);
         if (m && xbc_node_is_key(m)) {
             n = m;
             depth++;
             if (depth > XBC_DEPTH_MAX)
                 return xbc_parse_error("Too many key words",
                         xbc_node_get_data(n));
             continue;
         }
         len -= wlen;
         m = xbc_node_get_next(n);
         while (!m) {
             n = xbc_node_get_parent(n);
             if (!n)
                 break;
             len -= strlen(xbc_node_get_data(n)) + 1;
             depth--;
             m = xbc_node_get_next(n);
         }
         n = m;
     }
 
     return 0;
 }
 
 /* Need to setup xbc_data and xbc_nodes before call this. */
 static int __init xbc_parse_tree(void)
 {
     char *p, *q;
     int ret = 0, c;
 
     last_parent = NULL;
     p = xbc_data;
     do {
         q = strpbrk(p, "{}=+;:\n#");
         if (!q) {
             p = skip_spaces(p);
             if (*p != '\0')
                 ret = xbc_parse_error("No delimiter", p);
             break;
         }
 
         c = *q;
         *q++ = '\0';
         switch (c) {
         case ':':
         case '+':
             if (*q++ != '=') {
                 ret = xbc_parse_error(c == '+' ?
                         "Wrong '+' operator" :
                         "Wrong ':' operator",
                             q - 2);
                 break;
             }
             fallthrough;
         case '=':
             ret = xbc_parse_kv(&p, q, c);
             break;
         case '{':
             ret = xbc_open_brace(&p, q);
             break;
         case '#':
             q = skip_comment(q);
             fallthrough;
         case ';':
         case '\n':
             ret = xbc_parse_key(&p, q);
             break;
         case '}':
             ret = xbc_close_brace(&p, q);
             break;
         }
     } while (!ret);
 
     return ret;
 }
 
 /**
  * xbc_exit() - Clean up all parsed bootconfig
  *
  * This clears all data structures of parsed bootconfig on memory.
  * If you need to reuse xbc_init() with new boot config, you can
  * use this.
  */
 void __init xbc_exit(void)
 {
     xbc_free_mem(xbc_data, xbc_data_size);
     xbc_data = NULL;
     xbc_data_size = 0;
     xbc_node_num = 0;
     xbc_free_mem(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX);
     xbc_nodes = NULL;
     brace_index = 0;
 }
 
 /**
  * xbc_init() - Parse given XBC file and build XBC internal tree
  * @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 @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(const char *data, size_t size, const char **emsg, int *epos)
 {
     int ret;
 
     if (epos)
         *epos = -1;
 
     if (xbc_data) {
         if (emsg)
             *emsg = "Bootconfig is already initialized";
         return -EBUSY;
     }
     if (size > XBC_DATA_MAX || size == 0) {
         if (emsg)
             *emsg = size ? "Config data is too big" :
                 "Config data is empty";
         return -ERANGE;
     }
 
     xbc_data = xbc_alloc_mem(size + 1);
     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 = xbc_alloc_mem(sizeof(struct xbc_node) * XBC_NODE_MAX);
     if (!xbc_nodes) {
         if (emsg)
             *emsg = "Failed to allocate bootconfig nodes";
         xbc_exit();
         return -ENOMEM;
     }
     memset(xbc_nodes, 0, sizeof(struct xbc_node) * XBC_NODE_MAX);
 
     ret = xbc_parse_tree();
     if (!ret)
         ret = xbc_verify_tree();
 
     if (ret < 0) {
         if (epos)
             *epos = xbc_err_pos;
         if (emsg)
             *emsg = xbc_err_msg;
         xbc_exit();
     } else
         ret = xbc_node_num;
 
     return ret;
 }

This page was automatically generated by the 2.1.0 LXR engine. The LXR team