Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754693Ab2BIGK5 (ORCPT ); Thu, 9 Feb 2012 01:10:57 -0500 Received: from mail-vx0-f174.google.com ([209.85.220.174]:51320 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750819Ab2BIGKz convert rfc822-to-8bit (ORCPT ); Thu, 9 Feb 2012 01:10:55 -0500 MIME-Version: 1.0 In-Reply-To: <4F31DF34.8000205@am.sony.com> References: <4F31DC31.6040303@am.sony.com> <4F31DF34.8000205@am.sony.com> Date: Wed, 8 Feb 2012 22:10:54 -0800 X-Google-Sender-Auth: Kac0z6NvMuTpqam1Csr_sVw6SdY Message-ID: Subject: Re: [PATCH 5/5] logger: clarify non-update of w_off in do_write_log_from_user From: Dima Zavin To: Tim Bird Cc: Greg KH , linux-embedded , linux kernel , Brian Swetland , Andrew Morton Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1497 Lines: 37 On Tue, Feb 7, 2012 at 6:34 PM, Tim Bird 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 Acked-by: Dima Zavin > --- > ?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 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/