linux-kernel - Re: [PATCH 2/2] ramoops: use buffer_size() and buffer

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Date:   Thu, 8 Sep 2016 13:44:31 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Geliang Tang <geliangtang@...il.com>
Cc:     Anton Vorontsov <anton@...msg.org>,
        Colin Cross <ccross@...roid.com>,
        Tony Luck <tony.luck@...el.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] ramoops: use buffer_size() and buffer_start()

On Tue, Aug 30, 2016 at 5:24 AM, Geliang Tang <geliangtang@...il.com> wrote:
> Since buffer_size() and buffer_start() have been defined in ram_core.c,
> use them instead of open-coding.
>
> Signed-off-by: Geliang Tang <geliangtang@...il.com>

Hi!

Thanks for this clean-up. However, since the _atomic method has been
removed entirely now, I don't want to make this change, since it makes
reading the atomic_read/atomic_set in functions unmatched. I'd prefer
to leave this as-is.

-Kees

> ---
>  fs/pstore/ram_core.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
> index 76c3f80..a8500cd 100644
> --- a/fs/pstore/ram_core.c
> +++ b/fs/pstore/ram_core.c
> @@ -54,7 +54,7 @@ static size_t buffer_start_add_atomic(struct persistent_ram_zone *prz, size_t a)
>         int new;
>
>         do {
> -               old = atomic_read(&prz->buffer->start);
> +               old = buffer_start(prz);
>                 new = old + a;
>                 while (unlikely(new >= prz->buffer_size))
>                         new -= prz->buffer_size;
> @@ -69,11 +69,11 @@ static void buffer_size_add_atomic(struct persistent_ram_zone *prz, size_t a)
>         size_t old;
>         size_t new;
>
> -       if (atomic_read(&prz->buffer->size) == prz->buffer_size)
> +       if (buffer_size(prz) == prz->buffer_size)
>                 return;
>
>         do {
> -               old = atomic_read(&prz->buffer->size);
> +               old = buffer_size(prz);
>                 new = old + a;
>                 if (new > prz->buffer_size)
>                         new = prz->buffer_size;
> @@ -91,7 +91,7 @@ static size_t buffer_start_add_locked(struct persistent_ram_zone *prz, size_t a)
>
>         raw_spin_lock_irqsave(&buffer_lock, flags);
>
> -       old = atomic_read(&prz->buffer->start);
> +       old = buffer_start(prz);
>         new = old + a;
>         while (unlikely(new >= prz->buffer_size))
>                 new -= prz->buffer_size;
> @@ -111,7 +111,7 @@ static void buffer_size_add_locked(struct persistent_ram_zone *prz, size_t a)
>
>         raw_spin_lock_irqsave(&buffer_lock, flags);
>
> -       old = atomic_read(&prz->buffer->size);
> +       old = buffer_size(prz);
>         if (old == prz->buffer_size)
>                 goto exit;
>
> --
> 2.7.4
>



-- 
Kees Cook
Nexus Security