Dynamic Debug: Split out query string parsing/setup from proc_write

The parsing and applying of dynamic debug strings is not only useful for
/sys/../dynamic_debug/control write access, but can also be used for
boot parameter parsing.
The boot parameter is introduced in a follow up patch.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: jbaron@redhat.com
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 25 insertions, 15 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 02afc2533728..84d103c474e4 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -429,6 +429,27 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
         return 0;
 }
 
+static int ddebug_exec_query(char *query_string)
+{
+        unsigned int flags = 0, mask = 0;
+        struct ddebug_query query;
+#define MAXWORDS 9
+        int nwords;
+        char *words[MAXWORDS];
+
+        nwords = ddebug_tokenize(query_string, words, MAXWORDS);
+        if (nwords <= 0)
+                return -EINVAL;
+        if (ddebug_parse_query(words, nwords-1, &query))
+                return -EINVAL;
+        if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
+                return -EINVAL;
+
+        /* actually go and implement the change */
+        ddebug_change(&query, flags, mask);
+        return 0;
+}
+
 /*
  * File_ops->write method for <debugfs>/dynamic_debug/conrol.  Gathers the
  * command text from userspace, parses and executes it.
@@ -436,12 +457,8 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
                                   size_t len, loff_t *offp)
 {
-        unsigned int flags = 0, mask = 0;
-        struct ddebug_query query;
-#define MAXWORDS 9
-        int nwords;
-        char *words[MAXWORDS];
         char tmpbuf[256];
+        int ret;
 
         if (len == 0)
                 return 0;
@@ -455,16 +472,9 @@ static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
                 printk(KERN_INFO "%s: read %d bytes from userspace\n",
                         __func__, (int)len);
 
-        nwords = ddebug_tokenize(tmpbuf, words, MAXWORDS);
-        if (nwords <= 0)
-                return -EINVAL;
-        if (ddebug_parse_query(words, nwords-1, &query))
-                return -EINVAL;
-        if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
-                return -EINVAL;
-
-        /* actually go and implement the change */
-        ddebug_change(&query, flags, mask);
+        ret = ddebug_exec_query(tmpbuf);
+        if (ret)
+                return ret;
 
         *offp += len;
         return len;