[PATCH v3] dynamic_debug: add wildcard support to filter files/functions/modules

From: Du, Changbin
Date: Tue Oct 29 2013 - 09:34:18 EST


From: "Du, Changbin" <changbin.du@xxxxxxxxx>

This patch add wildcard '*'(matches zero or more characters) and '?'
(matches one character) support when qurying debug flags.

Now we can open debug messages using keywords. eg:
1. open debug logs in all usb drivers
echo "file drivers/usb/* +p" > <debugfs>/dynamic_debug/control
2. open debug logs for usb xhci code
echo "file *xhci* +p" > <debugfs>/dynamic_debug/control

Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx>
---
changes since v2:
remove the goto statements.
code style issue.
---
lib/dynamic_debug.c | 49 ++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 44 insertions(+), 5 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c37aeac..b166d19 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -127,6 +127,43 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
query->first_lineno, query->last_lineno);
}

+/* check if the string matches given pattern which includes wildcards */
+static bool match_pattern(const char *pattern, const char *string)
+{
+ const char *s = string,
+ *p = pattern;
+ bool star = 0;
+
+ while (*s) {
+ switch (*p) {
+ case '?':
+ ++s, ++p;
+ break;
+ case '*':
+ star = true;
+ string = s;
+ if (!*++p)
+ return true;
+ pattern = p;;
+ break;
+ default:
+ if (*s != *p) {
+ if (!star)
+ return false;
+ string++;
+ s = string;
+ p = pattern;
+ break;
+ }
+ ++s, ++p;
+ }
+ }
+
+ if (*p == '*')
+ ++p;
+ return !*p;
+}
+
/*
* Search the tables for _ddebug's which match the given `query' and
* apply the `flags' and `mask' to them. Returns number of matching
@@ -147,7 +184,7 @@ static int ddebug_change(const struct ddebug_query *query,
list_for_each_entry(dt, &ddebug_tables, link) {

/* match against the module name */
- if (query->module && strcmp(query->module, dt->mod_name))
+ if (query->module && !match_pattern(query->module, dt->mod_name))
continue;

for (i = 0; i < dt->num_ddebugs; i++) {
@@ -155,14 +192,16 @@ static int ddebug_change(const struct ddebug_query *query,

/* match against the source filename */
if (query->filename &&
- strcmp(query->filename, dp->filename) &&
- strcmp(query->filename, kbasename(dp->filename)) &&
- strcmp(query->filename, trim_prefix(dp->filename)))
+ !match_pattern(query->filename, dp->filename) &&
+ !match_pattern(query->filename,
+ kbasename(dp->filename)) &&
+ !match_pattern(query->filename,
+ trim_prefix(dp->filename)))
continue;

/* match against the function */
if (query->function &&
- strcmp(query->function, dp->function))
+ !match_pattern(query->function, dp->function))
continue;

/* match against the format */
--
1.8.1.2

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