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From:   Marco Elver <elver@google.com>
Date:   Tue, 20 Sep 2022 21:09:42 +0200
Message-ID: <CANpmjNN0jyK0svOOHSFPAfFV9CAEUVUb+y_748Fww-sgf=3pdg@mail.gmail.com>
Subject: Re: [PATCH mm] kasan: initialize read-write lock in stack ring
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,
        Yu Zhao <yuzhao@google.com>, linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
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On Tue, 20 Sept 2022 at 20:58, <andrey.konovalov@linux.dev> wrote:
>
> From: Andrey Konovalov <andreyknvl@google.com>
>
> Use __RW_LOCK_UNLOCKED to initialize stack_ring.lock.
>
> Reported-by: Yu Zhao <yuzhao@google.com>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
>
> ---
>
> Andrew, could you please fold this patch into:
> "kasan: implement stack ring for tag-based modes".
> ---
>  mm/kasan/tags.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
> index 9d867cae1b7b..67a222586846 100644
> --- a/mm/kasan/tags.c
> +++ b/mm/kasan/tags.c
> @@ -36,7 +36,9 @@ DEFINE_STATIC_KEY_TRUE(kasan_flag_stacktrace);
>  /* Non-zero, as initial pointer values are 0. */
>  #define STACK_RING_BUSY_PTR ((void *)1)
>
> -struct kasan_stack_ring stack_ring;
> +struct kasan_stack_ring stack_ring = {
> +       .lock = __RW_LOCK_UNLOCKED(stack_ring.lock)
> +};

Reviewed-by: Marco Elver <elver@google.com>

>  /* kasan.stacktrace=off/on */
>  static int __init early_kasan_flag_stacktrace(char *arg)
> --
> 2.25.1
>