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References: <53be40fc-6ec4-c714-a64e-f69c96f7058f@redhat.com> <8166cf23-db52-7679-3378-8523889a9cd0@sandeen.net>
In-Reply-To: <8166cf23-db52-7679-3378-8523889a9cd0@sandeen.net>
From:   Kees Cook <keescook@chromium.org>
Date:   Thu, 21 Feb 2019 10:40:18 -0800
Message-ID: <CAGXu5j+m8TBnBZYUAAeS-e8d-ZtPWZ+KFw=ibGAekHs9JT57nA@mail.gmail.com>
Subject: Re: [PATCH] sysctl: add proc_do_large_bitmap test node
To:     Eric Sandeen <sandeen@sandeen.net>
Cc:     Eric Sandeen <sandeen@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        fsdevel <linux-fsdevel@vger.kernel.org>,
        Network Development <netdev@vger.kernel.org>,
        Luis Chamberlain <mcgrof@kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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On Thu, Feb 21, 2019 at 9:45 AM Eric Sandeen <sandeen@sandeen.net> wrote:
>
> Add a test node for proc_do_large_bitmap to the test_sysctl.c
> infrastructure.  It's sized the same as the one existing user.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>
> diff --git a/lib/test_sysctl.c b/lib/test_sysctl.c
> index 3dd801c1c85b..1263be4ebfaf 100644
> --- a/lib/test_sysctl.c
> +++ b/lib/test_sysctl.c
> @@ -47,6 +47,9 @@ struct test_sysctl_data {
>         unsigned int uint_0001;
>
>         char string_0001[65];
> +
> +#define SYSCTL_TEST_BITMAP_SIZE        65536
> +       unsigned long *bitmap_0001;
>  };
>
>  static struct test_sysctl_data test_data = {
> @@ -102,6 +106,13 @@ static struct ctl_table test_table[] = {
>                 .mode           = 0644,
>                 .proc_handler   = proc_dostring,
>         },
> +       {
> +               .procname       = "bitmap_0001",
> +               .data           = &test_data.bitmap_0001,
> +               .maxlen         = SYSCTL_TEST_BITMAP_SIZE,
> +               .mode           = 0644,
> +               .proc_handler   = proc_do_large_bitmap,
> +       },
>         { }
>  };
>
> @@ -129,15 +140,21 @@ static struct ctl_table_header *test_sysctl_header;
>
>  static int __init test_sysctl_init(void)
>  {
> +       test_data.bitmap_0001 = kzalloc(SYSCTL_TEST_BITMAP_SIZE/8, GFP_KERNEL);
> +       if (!test_data.bitmap_0001)
> +               return -ENOMEM;
>         test_sysctl_header = register_sysctl_table(test_sysctl_root_table);
> -       if (!test_sysctl_header)
> +       if (!test_sysctl_header) {
> +               kfree(test_data.bitmap_0001);
>                 return -ENOMEM;
> +       }
>         return 0;
>  }
>  late_initcall(test_sysctl_init);
>
>  static void __exit test_sysctl_exit(void)
>  {
> +       kfree(test_data.bitmap_0001);
>         if (test_sysctl_header)
>                 unregister_sysctl_table(test_sysctl_header);
>  }
>


-- 
Kees Cook