Skip to contentSkip to conversation

Dynamic Debug providing early boot debug messages via boot parameter

PATCH New [email protected] 1 participant 2 messages Jul 20, 2010

Subsystems (2)
Library code Dynamic debug
lore
Share & tools
lore

[email protected]

author
#0 lore raw

cover Dynamic Debug providing early boot debug messages via boot parameter

this patch is against 2.6.35-rc5. Not sure whether Jason's latest fix is in there already and whether it conflicts with this series, but it should patch.

Please tell me if I should (have to) re-diff and against which branch I should do that.

The patches got boot tested via ddebug_query="file ec.c +p" which worked out fine.

Would be great to see these in the next kernel cycle (2.6.36).

Thanks,

Thomas

Signature · 1 line
������$ز|��I�\��bI'z�楖��'���'%&gsu�3��%`*���&(����}i�.���I�*i>?��,���0�m����׵6�77�0
author
#1 lore raw

PATCH 1/1 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 <[email protected]>
CC [email protected]
CC [email protected]
CC [email protected]
---
 lib/dynamic_debug.c |   40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)
lib/dynamic_debug.c +25 -15
Index: linux-2.6.34-master/lib/dynamic_debug.c
===================================================================
@@ -429,6 +429,27 @@ static int ddebug_parse_flags(const char
 	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
 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
 		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;