From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756378AbcJSBYE (ORCPT ); Tue, 18 Oct 2016 21:24:04 -0400 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:54904 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755414AbcJSBYB (ORCPT ); Tue, 18 Oct 2016 21:24:01 -0400 X-Original-SENDERIP: 156.147.1.127 X-Original-MAILFROM: namhyung@kernel.org X-Original-SENDERIP: 10.177.227.17 X-Original-MAILFROM: namhyung@kernel.org From: Namhyung Kim To: Kees Cook Cc: Anton Vorontsov , Colin Cross , Tony Luck , LKML , Stefan Hajnoczi Subject: [RFC/PATCH 2/2] pstore: Convert console write to use ->write_buf Date: Wed, 19 Oct 2016 10:23:41 +0900 Message-Id: <20161019012341.8032-2-namhyung@kernel.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20161019012341.8032-1-namhyung@kernel.org> References: <20161019012341.8032-1-namhyung@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Maybe I'm missing something, but I don't know why it needs to copy the input buffer to psinfo->buf and then write. Instead we can write the input buffer directly. The only implementation that supports console message (i.e. ramoops) already does it for ftrace messages. For the upcoming virtio backend driver, it needs to protect psinfo->buf overwritten from console messages. If it could use ->write_buf method instead of ->write, the problem will be solved easily. Cc: Stefan Hajnoczi Signed-off-by: Namhyung Kim --- fs/pstore/platform.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 14984d902a99..960d66251bab 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -584,8 +584,8 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c) } else { spin_lock_irqsave(&psinfo->buf_lock, flags); } - memcpy(psinfo->buf, s, c); - psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo); + psinfo->write_buf(PSTORE_TYPE_CONSOLE, 0, &id, 0, + s, 0, c, psinfo); spin_unlock_irqrestore(&psinfo->buf_lock, flags); s += c; c = e - s; -- 2.9.3