proc/bootconfig: Fix to use correct quotes for value

Fix /proc/bootconfig to select double or single quotes
corrctly according to the value.

If a bootconfig value includes a double quote character,
we must use single-quotes to quote that value.

This modifies if() condition and blocks for avoiding
double-quote in value check in 2 places. Anyway, since
xbc_array_for_each_value() can handle the array which
has a single node correctly.
Thus,

if (vnode && xbc_node_is_array(vnode)) {
	xbc_array_for_each_value(vnode)	/* vnode->next != NULL */
		...
} else {
	snprintf(val); /* val is an empty string if !vnode */
}

is equivalent to

if (vnode) {
	xbc_array_for_each_value(vnode)	/* vnode->next can be NULL */
		...
} else {
	snprintf("");	/* value is always empty */
}

Link: http://lkml.kernel.org/r/159230244786.65555.3763894451251622488.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: c1a3c36017d4 ("proc: bootconfig: Add /proc/bootconfig to show boot config list")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/fs/proc/bootconfig.c b/fs/proc/bootconfig.c
index 9955d75..ad31ec4 100644 (file)
--- a/fs/proc/bootconfig.c
+++ b/fs/proc/bootconfig.c
@@ -26,8 +26,9 @@ static int boot_config_proc_show(struct seq_file *m, void *v)
 static int __init copy_xbc_key_value_list(char *dst, size_t size)
 {
        struct xbc_node *leaf, *vnode;
-       const char *val;
        char *key, *end = dst + size;
+       const char *val;
+       char q;
        int ret = 0;
 
        key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL);
@@ -41,16 +42,20 @@ static int __init copy_xbc_key_value_list(char *dst, size_t size)
                        break;
                dst += ret;
                vnode = xbc_node_get_child(leaf);
-               if (vnode && xbc_node_is_array(vnode)) {
+               if (vnode) {
                        xbc_array_for_each_value(vnode, val) {
-                               ret = snprintf(dst, rest(dst, end), "\"%s\"%s",
-                                       val, vnode->next ? ", " : "\n");
+                               if (strchr(val, '"'))
+                                       q = '\'';
+                               else
+                                       q = '"';
+                               ret = snprintf(dst, rest(dst, end), "%c%s%c%s",
+                                       q, val, q, vnode->next ? ", " : "\n");
                                if (ret < 0)
                                        goto out;
                                dst += ret;
                        }
                } else {
-                       ret = snprintf(dst, rest(dst, end), "\"%s\"\n", val);
+                       ret = snprintf(dst, rest(dst, end), "\"\"\n");
                        if (ret < 0)
                                break;
                        dst += ret;