From: Andrey Konovalov <andreyknvl@google.com>
Date: Thu, 21 Dec 2023 20:04:53 +0000 (+0100)
Subject: kasan: speed up match_all_mem_tag test for SW_TAGS
X-Git-Tag: v6.8-rc1~180^2~73
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4e397274e10beb385cee1a04c7850c1c46ae5d3e;p=thirdparty%2Flinux.git

kasan: speed up match_all_mem_tag test for SW_TAGS

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.

Link: https://lkml.kernel.org/r/6fe51262defd80cdc1150c42404977aafd1b6167.1703188911.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c
index 691c15fc7cdbd..971cfff4ca0b7 100644
--- a/mm/kasan/kasan_test.c
+++ b/mm/kasan/kasan_test.c
@@ -1797,6 +1797,14 @@ 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;