From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760153AbcLUOlU (ORCPT ); Wed, 21 Dec 2016 09:41:20 -0500 Received: from mail-pg0-f65.google.com ([74.125.83.65]:33634 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935221AbcLUOhJ (ORCPT ); Wed, 21 Dec 2016 09:37:09 -0500 From: Sergey Senozhatsky To: Andrew Morton Cc: Petr Mladek , Jan Kara , Tejun Heo , Calvin Owens , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Andy Lutomirski , Linus Torvalds , Peter Hurley , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: [PATCHv6 4/7] printk: always use deferred printk when flush printk_safe lines Date: Wed, 21 Dec 2016 23:36:02 +0900 Message-Id: <20161221143605.2272-5-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20161221143605.2272-1-sergey.senozhatsky@gmail.com> References: <20161221143605.2272-1-sergey.senozhatsky@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Always use printk_deferred() in printk_safe_flush_line(). Flushing can be done from NMI or printk_safe contexts (when we are in panic), so we can't call console drivers, yet still want to store the messages in the logbuf buffer. Therefore we use a deferred printk version. Signed-off-by: Sergey Senozhatsky Suggested-by: Petr Mladek Reviewed-by: Petr Mladek --- kernel/printk/printk_safe.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c index a041927a127b..9e8ef6a2070c 100644 --- a/kernel/printk/printk_safe.c +++ b/kernel/printk/printk_safe.c @@ -113,14 +113,12 @@ static int printk_safe_log_store(struct printk_safe_seq_buf *s, static void printk_safe_flush_line(const char *text, int len) { /* - * The buffers are flushed in NMI only on panic. The messages must - * go only into the ring buffer at this stage. Consoles will get - * explicitly called later when a crashdump is not generated. + * Avoid any console drivers calls from here, because we may be + * in NMI or printk_safe context (when in panic). The messages + * must go only into the ring buffer at this stage. Consoles will + * get explicitly called later when a crashdump is not generated. */ - if (in_nmi()) - printk_deferred("%.*s", len, text); - else - printk("%.*s", len, text); + printk_deferred("%.*s", len, text); } /* printk part of the temporary buffer line by line */ -- 2.11.0