Re: [PATCH mm] fix for "kasan: improve vmalloc tests"

From: Marco Elver <elver@google.com>
To: andrey.konovalov@linux.dev
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Andrey Konovalov <andreyknvl@gmail.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: Re: [PATCH mm] fix for "kasan: improve vmalloc tests"
Date: Wed, 16 Feb 2022 11:01:39 +0100	[thread overview]
Message-ID: <CANpmjNNtE9nYT-NKZpn3k2gwBUY_223mWOKZPgLyDQNzfygBTA@mail.gmail.com> (raw)
In-Reply-To: <865c91ba49b90623ab50c7526b79ccb955f544f0.1644950160.git.andreyknvl@google.com>

On Tue, 15 Feb 2022 at 19:39, <andrey.konovalov@linux.dev> wrote:
>
> 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>

Acked-by: Marco Elver <elver@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
>