[PATCH mm 11/11] kasan: speed up match_all_mem_tag test for SW_TAGS

[andrey . konovalov]

From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

Checking all 256 possible tag values in the match_all_mem_tag KASAN test
is slow and produces 256 reports. Instead, just check the first 8 and the
last 8.

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
 mm/kasan/kasan_test.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index 798df4983858..9c3a1aaab21b 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -1785,6 +1785,14 @@ static void match_all_mem_tag(struct kunit *test)
 
 	/* For each possible tag value not matching the pointer tag. */
 	for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) {
+		/*
+		 * For Software Tag-Based KASAN, skip the majority of tag
+		 * values to avoid the test printing too many reports.
+		 */
+		if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) &&
+		    tag >= KASAN_TAG_MIN + 8 && tag <= KASAN_TAG_KERNEL - 8)
+			continue;
+
 		if (tag == get_tag(ptr))
 			continue;
 
-- 
2.25.1