From: Tim Bird <tim.bird@am.sony.com>
To: Greg KH <gregkh@linuxfoundation.org>,
linux-embedded <linux-embedded@vger.kernel.org>,
linux kernel <linux-kernel@vger.kernel.org>,
Brian Swetland <swetland@google.com>,
Dima Zavin <dima@android.com>, Andrew Morton <akpm@osdl.org>
Subject: [PATCH 5/5] logger: clarify non-update of w_off in do_write_log_from_user
Date: Tue, 7 Feb 2012 18:34:28 -0800 [thread overview]
Message-ID: <4F31DF34.8000205@am.sony.com> (raw)
In-Reply-To: <4F31DC31.6040303@am.sony.com>
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>
---
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
next prev parent reply other threads:[~2012-02-08 2:34 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 ` Tim Bird [this message]
2012-02-09 6:10 ` [PATCH 5/5] logger: clarify non-update of w_off in do_write_log_from_user Dima Zavin
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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