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From:   andrey.konovalov@linux.dev
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Marco Elver <elver@google.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH mm] fix for "kasan: improve vmalloc tests"
Date:   Tue, 15 Feb 2022 19:39:38 +0100
Message-Id: <865c91ba49b90623ab50c7526b79ccb955f544f0.1644950160.git.andreyknvl@google.com>
MIME-Version: 1.0
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From: Andrey Konovalov <andreyknvl@google.com>

vmap_tags() and vm_map_ram_tags() pass invalid page array size to
vm_map_ram() and vm_unmap_ram(). It's supposed to be 1, but it's
1 << order == 2 currently.

Remove order variable (it can only be 0 with the current code)
and hardcode the number of pages in these tests.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 lib/test_kasan.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 491a82006f06..8416161d5177 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -1149,7 +1149,6 @@ static void vmap_tags(struct kunit *test)
 {
 	char *p_ptr, *v_ptr;
 	struct page *p_page, *v_page;
-	size_t order = 1;
 
 	/*
 	 * This test is specifically crafted for the software tag-based mode,
@@ -1159,12 +1158,12 @@ static void vmap_tags(struct kunit *test)
 
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
 
-	p_page = alloc_pages(GFP_KERNEL, order);
+	p_page = alloc_pages(GFP_KERNEL, 1);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_page);
 	p_ptr = page_address(p_page);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
 
-	v_ptr = vmap(&p_page, 1 << order, VM_MAP, PAGE_KERNEL);
+	v_ptr = vmap(&p_page, 1, VM_MAP, PAGE_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
 
 	/*
@@ -1186,14 +1185,13 @@ static void vmap_tags(struct kunit *test)
 	KUNIT_EXPECT_PTR_EQ(test, p_page, v_page);
 
 	vunmap(v_ptr);
-	free_pages((unsigned long)p_ptr, order);
+	free_pages((unsigned long)p_ptr, 1);
 }
 
 static void vm_map_ram_tags(struct kunit *test)
 {
 	char *p_ptr, *v_ptr;
 	struct page *page;
-	size_t order = 1;
 
 	/*
 	 * This test is specifically crafted for the software tag-based mode,
@@ -1201,12 +1199,12 @@ static void vm_map_ram_tags(struct kunit *test)
 	 */
 	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
 
-	page = alloc_pages(GFP_KERNEL, order);
+	page = alloc_pages(GFP_KERNEL, 1);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
 	p_ptr = page_address(page);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
 
-	v_ptr = vm_map_ram(&page, 1 << order, -1);
+	v_ptr = vm_map_ram(&page, 1, -1);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
 
 	KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
@@ -1216,8 +1214,8 @@ static void vm_map_ram_tags(struct kunit *test)
 	*p_ptr = 0;
 	*v_ptr = 0;
 
-	vm_unmap_ram(v_ptr, 1 << order);
-	free_pages((unsigned long)p_ptr, order);
+	vm_unmap_ram(v_ptr, 1);
+	free_pages((unsigned long)p_ptr, 1);
 }
 
 static void vmalloc_percpu(struct kunit *test)
-- 
2.25.1