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From: Dima Zavin <dima@android.com>
To: Tim Bird <tim.bird@am.sony.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
	linux-embedded <linux-embedded@vger.kernel.org>,
	linux kernel <linux-kernel@vger.kernel.org>,
	Brian Swetland <swetland@google.com>,
	Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH 5/5] logger: clarify non-update of w_off in do_write_log_from_user
Date: Wed, 8 Feb 2012 22:10:54 -0800	[thread overview]
Message-ID: <CAPz4a6CrJ2VS8-igOz5aRFAL32-xUi5a6cHa6rEqtK3B5689Og@mail.gmail.com> (raw)
In-Reply-To: <4F31DF34.8000205@am.sony.com>

On Tue, Feb 7, 2012 at 6:34 PM, Tim Bird <tim.bird@am.sony.com> wrote:
> Add comment to explain when w_off is not updated in case of failed second
> fragment copy to buffer.
>
> Signed-off-by: Tim Bird <tim.bird@am.sony.com>

Acked-by: Dima Zavin <dima@android.com>

> ---
>  drivers/staging/android/logger.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/staging/android/logger.c b/drivers/staging/android/logger.c
> index 8d9d4f1..115d8ed 100644
> --- a/drivers/staging/android/logger.c
> +++ b/drivers/staging/android/logger.c
> @@ -330,6 +330,12 @@ static ssize_t do_write_log_from_user(struct logger_log *log,
>
>        if (count != len)
>                if (copy_from_user(log->buffer, buf + len, count - len))
> +                       /*
> +                        * Note that by not updating w_off, this abandons the
> +                        * portion of the new entry that *was* successfully
> +                        * copied, just above.  This is intentional to avoid
> +                        * message corruption from missing fragments.
> +                        */
>                        return -EFAULT;
>
>        log->w_off = logger_offset(log, log->w_off + count);
> --
> 1.7.2.3
>

  reply	other threads:[~2012-02-09  6:10 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-08  2:21 [PATCH 1/5] logger: Change logger_offset() from macro to function Tim Bird
2012-02-08  2:28 ` [PATCH 2/5] logger: simplify and optimize get_entry_len Tim Bird
2012-02-08 18:37   ` [PATCH 2/5 v2] " Tim Bird
2012-02-09  5:15     ` Dima Zavin
2012-02-09  5:58       ` Tim Bird
2012-02-08  2:30 ` [PATCH 3/5] logger: reorder prepare_to_wait and mutex_lock Tim Bird
2012-02-09  5:56   ` Dima Zavin
2012-02-08  2:32 ` [PATCH 4/5] logger: clarify code in clock_interval Tim Bird
2012-02-09  6:09   ` Dima Zavin
2012-02-08  2:34 ` [PATCH 5/5] logger: clarify non-update of w_off in do_write_log_from_user Tim Bird
2012-02-09  6:10   ` Dima Zavin [this message]
2012-02-08  3:22 ` [PATCH 1/5] logger: Change logger_offset() from macro to function Frank Rowand
2012-02-09  4:54 ` Dima Zavin

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