From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Sumit Garg <sumit.garg@linaro.org>,
Jason Wessel <jason.wessel@windriver.com>,
Douglas Anderson <dianders@chromium.org>,
kgdb-bugreport@lists.sourceforge.net,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
John Ogness <john.ogness@linutronix.de>
Subject: Re: [PATCH v2] printk/kdb: Redirect printk messages into kdb in any context
Date: Wed, 20 May 2020 20:17:46 +0900 [thread overview]
Message-ID: <20200520111746.GB520@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <20200520102233.GC3464@linux-b0ei>
On (20/05/20 12:22), Petr Mladek wrote:
> kdb has to get messages on consoles even when the system is stopped.
> It uses kdb_printf() internally and calls console drivers on its own.
>
> It uses a hack to reuse an existing code. It sets "kdb_trap_printk"
> global variable to redirect even the normal printk() into the
> kdb_printf() variant.
>
> The variable "kdb_trap_printk" is checked in printk_default() and
> it is ignored when printk is redirected to printk_safe in NMI context.
> Solve this by moving the check into printk_func().
>
> It is obvious that it is not fully safe. But it does not make things
> worse. The console drivers are already called in this context by
> db_printf() direct calls.
>
> Reported-by: Sumit Garg <sumit.garg@linaro.org>
> Tested-by: Sumit Garg <sumit.garg@linaro.org>
> Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
-ss
next prev parent reply other threads:[~2020-05-20 11:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 8:48 [PATCH] kgdb: Fix broken handling of printk() in NMI context Sumit Garg
2020-05-12 14:25 ` Daniel Thompson
2020-05-13 13:34 ` Sumit Garg
2020-05-14 8:42 ` Petr Mladek
2020-05-15 5:46 ` Sumit Garg
2020-05-15 8:50 ` [PATCH] printk/kdb: Redirect printk messages into kdb in any context Petr Mladek
2020-05-15 10:33 ` Sergey Senozhatsky
2020-05-15 12:02 ` Sumit Garg
2020-05-15 16:36 ` Sergey Senozhatsky
2020-05-15 16:52 ` Doug Anderson
2020-05-18 6:19 ` Sumit Garg
2020-06-10 16:41 ` Daniel Thompson
2020-06-11 7:27 ` Sergey Senozhatsky
2020-06-11 7:58 ` Petr Mladek
2020-05-15 13:48 ` Daniel Thompson
2020-05-15 16:24 ` Sergey Senozhatsky
2020-05-18 9:21 ` Petr Mladek
2020-05-20 4:21 ` Sergey Senozhatsky
2020-05-20 9:35 ` Daniel Thompson
2020-05-20 10:22 ` [PATCH v2] " Petr Mladek
2020-05-20 11:17 ` Sergey Senozhatsky [this message]
2020-05-20 16:07 ` Daniel Thompson
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