[PATCH 3/4] mm: kmemleak: factor leak confirmation into a helper

[Breno Leitao]

The reporting loop in kmemleak_scan() decided whether to tag an object as
a reported leak with a four-term compound condition whose last operand
also had a side effect (++object->unref_scans). Mixing the candidate
tests with the counter update made the check hard to read.

Move the state transition into confirm_leak(): it returns true when a
still-unreferenced suspect crosses min_unref_scans consecutive scans and
is newly flagged OBJECT_REPORTED, leaving only the reporting bookkeeping
in the caller. No functional change.

Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
 mm/kmemleak.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index 2fff11637e490..85f18b17e79c4 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -2014,6 +2014,26 @@ static int __kmemleak_scan(bool full)
 	return nr_suspects;
 }
 
+/*
+ * Promote a suspected object to a reported leak once it has stayed
+ * unreferenced for min_unref_scans consecutive scans. Called with
+ * object->lock held; returns true when the object is newly reported.
+ */
+static bool confirm_leak(struct kmemleak_object *object)
+{
+	if (!unreferenced_object(object) ||
+	    !(object->flags & OBJECT_SUSPECT) ||
+	    (object->flags & OBJECT_REPORTED))
+		return false;
+
+	object->unref_scans += 1;
+	if (object->unref_scans < min_unref_scans)
+		return false;
+
+	object->flags |= OBJECT_REPORTED;
+	return true;
+}
+
 /*
  * Scan the memory and report the unreferenced objects as leaks. Must be
  * called with the scan_mutex held.
@@ -2074,11 +2094,7 @@ static void kmemleak_scan(void)
 		trace_handle = 0;
 		dedup_print = false;
 
-		if (unreferenced_object(object) &&
-		    (object->flags & OBJECT_SUSPECT) &&
-		    !(object->flags & OBJECT_REPORTED) &&
-		    ++object->unref_scans >= min_unref_scans) {
-			object->flags |= OBJECT_REPORTED;
+		if (confirm_leak(object)) {
 			if (kmemleak_verbose) {
 				trace_handle = object->trace_handle;
 				dedup_print = true;

-- 
2.53.0-Meta