linux-kernel - [PATCH v6 01/31] dyndbg: factor ddebug_match_desc out from ddebug

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251118201842.1447666-2-jim.cromie@gmail.com>
Date: Tue, 18 Nov 2025 13:18:11 -0700
From: Jim Cromie <jim.cromie@...il.com>
To: linux-kernel@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	gregkh@...uxfoundation.org,
	jbaron@...mai.com
Cc: ukaszb@...omium.org,
	louis.chauvet@...tlin.com,
	Jim Cromie <jim.cromie@...il.com>
Subject: [PATCH v6 01/31] dyndbg: factor ddebug_match_desc out from ddebug_change

ddebug_change() is a big (~100 lines) function with a nested for loop.

The outer loop walks the per-module ddebug_tables list, and does
module stuff: it filters on a query's "module FOO*" and "class BAR",
failures here skip the entire inner loop.

The inner loop (60 lines) scans a module's descriptors.  It starts
with a long block of filters on function, line, format, and the
validated "BAR" class (or the legacy/_DPRINTK_CLASS_DFLT).

These filters "continue" past pr_debugs that don't match the query
criteria, before it falls through the code below that counts matches,
then adjusts the flags and static-keys.  This is unnecessarily hard to
think about.

So move the per-descriptor filter-block into a boolean function:
ddebug_match_desc(desc), and change each "continue" to "return false".
This puts a clear interface in place, so any future changes are either
inside, outside, or across this interface.

also fix checkpatch complaints about spaces and braces.

Signed-off-by: Jim Cromie <jim.cromie@...il.com>
---
 lib/dynamic_debug.c | 83 +++++++++++++++++++++++++--------------------
 1 file changed, 47 insertions(+), 36 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 5a007952f7f2..eb5146bcfaca 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -171,6 +171,52 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
  * callsites, normally the same as number of changes.  If verbose,
  * logs the changes.  Takes ddebug_lock.
  */
+static bool ddebug_match_desc(const struct ddebug_query *query,
+			      struct _ddebug *dp,
+			      int valid_class)
+{
+	/* match site against query-class */
+	if (dp->class_id != valid_class)
+		return false;
+
+	/* match against the source filename */
+	if (query->filename &&
+	    !match_wildcard(query->filename, dp->filename) &&
+	    !match_wildcard(query->filename,
+			    kbasename(dp->filename)) &&
+	    !match_wildcard(query->filename,
+			    trim_prefix(dp->filename)))
+		return false;
+
+	/* match against the function */
+	if (query->function &&
+	    !match_wildcard(query->function, dp->function))
+		return false;
+
+	/* match against the format */
+	if (query->format) {
+		if (*query->format == '^') {
+			char *p;
+			/* anchored search. match must be at beginning */
+			p = strstr(dp->format, query->format + 1);
+			if (p != dp->format)
+				return false;
+		} else if (!strstr(dp->format, query->format)) {
+			return false;
+		}
+	}
+
+	/* match against the line number range */
+	if (query->first_lineno &&
+	    dp->lineno < query->first_lineno)
+		return false;
+	if (query->last_lineno &&
+	    dp->lineno > query->last_lineno)
+		return false;
+
+	return true;
+}
+
 static int ddebug_change(const struct ddebug_query *query,
 			 struct flag_settings *modifiers)
 {
@@ -203,42 +249,7 @@ static int ddebug_change(const struct ddebug_query *query,
 		for (i = 0; i < dt->num_ddebugs; i++) {
 			struct _ddebug *dp = &dt->ddebugs[i];
 
-			/* match site against query-class */
-			if (dp->class_id != valid_class)
-				continue;
-
-			/* match against the source filename */
-			if (query->filename &&
-			    !match_wildcard(query->filename, dp->filename) &&
-			    !match_wildcard(query->filename,
-					   kbasename(dp->filename)) &&
-			    !match_wildcard(query->filename,
-					   trim_prefix(dp->filename)))
-				continue;
-
-			/* match against the function */
-			if (query->function &&
-			    !match_wildcard(query->function, dp->function))
-				continue;
-
-			/* match against the format */
-			if (query->format) {
-				if (*query->format == '^') {
-					char *p;
-					/* anchored search. match must be at beginning */
-					p = strstr(dp->format, query->format+1);
-					if (p != dp->format)
-						continue;
-				} else if (!strstr(dp->format, query->format))
-					continue;
-			}
-
-			/* match against the line number range */
-			if (query->first_lineno &&
-			    dp->lineno < query->first_lineno)
-				continue;
-			if (query->last_lineno &&
-			    dp->lineno > query->last_lineno)
+			if (!ddebug_match_desc(query, dp, valid_class))
 				continue;
 
 			nfound++;
-- 
2.51.1