From: Petr Mladek <pmladek@suse.com>
To: Jason Wessel <jason.wessel@windriver.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        linux-kernel@vger.kernel.org, Petr Mladek <pmladek@suse.com>
Subject: [PATCH 0/2] kdb: Fix locking in vkdb_printf()
Date: Fri, 21 Oct 2016 14:50:33 +0200
Message-Id: <1477054235-1624-1-git-send-email-pmladek@suse.com>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 936
Lines: 25

I have been asked whether it is safe to call vkdb_printf() from
vprintk_nmi() in NMI context. It seems that it is not safe.
Well, is not a big deal.

But I have noticed suspicious patterns when looking at the
vkdb_printf() locking code and prepared two patches that
should avoid some possible races.

Please, note that I am not familiar with the kdb implementation.
I hope that I have got the requested behavior right. I did
some basic testing and did not found any problem. But I am sure
that I did not test all usecases.

Petr Mladek (2):
  kdb: Properly synchronize vkdb_printf() calls with other CPUs
  kdb: Call vkdb_printf() from vprintk_default() only when wanted

 include/linux/kdb.h            |  1 +
 kernel/debug/kdb/kdb_io.c      | 41 +++++++++++++++++------------------------
 kernel/debug/kdb/kdb_private.h |  1 -
 kernel/printk/printk.c         |  4 +++-
 4 files changed, 21 insertions(+), 26 deletions(-)

-- 
1.8.5.6