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From: Daniel Thompson <daniel.thompson@linaro.org>
To: Douglas Anderson <dianders@chromium.org>
Cc: jason.wessel@windriver.com, gregkh@linuxfoundation.org,
	kgdb-bugreport@lists.sourceforge.net, mingo@redhat.com,
	hpa@zytor.com, bp@alien8.de, linux-serial@vger.kernel.org,
	agross@kernel.org, tglx@linutronix.de, frowand.list@gmail.com,
	bjorn.andersson@linaro.org, jslaby@suse.com,
	catalin.marinas@arm.com, corbet@lwn.net, will@kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/9] kgdb: Disable WARN_CONSOLE_UNLOCKED for all kgdb
Date: Mon, 27 Apr 2020 14:40:39 +0100	[thread overview]
Message-ID: <20200427134039.vog2eloyad55cww5@holly.lan> (raw)
In-Reply-To: <20200421141234.v2.1.Ied2b058357152ebcc8bf68edd6f20a11d98d7d4e@changeid>

On Tue, Apr 21, 2020 at 02:14:39PM -0700, Douglas Anderson wrote:
> In commit 81eaadcae81b ("kgdboc: disable the console lock when in
> kgdb") we avoided the WARN_CONSOLE_UNLOCKED() yell when we were in
> kgdboc.  That still works fine, but it turns out that we get a similar
> yell when using other I/O drivers.  One example is the "I/O driver"
> for the kgdb test suite (kgdbts).  When I enabled that I again got the
> same yells.
> 
> Even though "kgdbts" doesn't actually interact with the user over the
> console, using it still causes kgdb to print to the consoles.  That
> trips the same warning:
>   con_is_visible+0x60/0x68
>   con_scroll+0x110/0x1b8
>   lf+0x4c/0xc8
>   vt_console_print+0x1b8/0x348
>   vkdb_printf+0x320/0x89c
>   kdb_printf+0x68/0x90
>   kdb_main_loop+0x190/0x860
>   kdb_stub+0x2cc/0x3ec
>   kgdb_cpu_enter+0x268/0x744
>   kgdb_handle_exception+0x1a4/0x200
>   kgdb_compiled_brk_fn+0x34/0x44
>   brk_handler+0x7c/0xb8
>   do_debug_exception+0x1b4/0x228
> 
> Let's increment/decrement the "ignore_console_lock_warning" variable
> all the time when we enter the debugger.
> 
> This will allow us to later revert commit 81eaadcae81b ("kgdboc:
> disable the console lock when in kgdb").
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>

  reply	other threads:[~2020-04-27 13:40 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-21 21:14 [PATCH v2 0/9] kgdb: Support late serial drivers; enable early debug w/ boot consoles Douglas Anderson
2020-04-21 21:14 ` [PATCH v2 1/9] kgdb: Disable WARN_CONSOLE_UNLOCKED for all kgdb Douglas Anderson
2020-04-27 13:40   ` Daniel Thompson [this message]
2020-04-21 21:14 ` [PATCH v2 2/9] Revert "kgdboc: disable the console lock when in kgdb" Douglas Anderson
2020-04-27 13:41   ` Daniel Thompson
2020-04-21 21:14 ` [PATCH v2 3/9] kgdboc: Use a platform device to handle tty drivers showing up late Douglas Anderson
2020-04-27 14:19   ` Daniel Thompson
2020-04-21 21:14 ` [PATCH v2 4/9] kgdb: Delay "kgdbwait" to dbg_late_init() by default Douglas Anderson
2020-04-27 15:42   ` Daniel Thompson
2020-04-21 21:14 ` [PATCH v2 5/9] arm64: Add call_break_hook() to early_brk64() for early kgdb Douglas Anderson
2020-04-27 16:52   ` Daniel Thompson
2020-04-21 21:14 ` [PATCH v2 6/9] kgdboc: Add earlycon_kgdboc to support early kgdb using boot consoles Douglas Anderson
2020-04-27 16:36   ` Daniel Thompson
2020-04-28 21:32     ` Doug Anderson
2020-04-21 21:14 ` [PATCH v2 7/9] Documentation: kgdboc: Document new earlycon_kgdboc parameter Douglas Anderson
2020-04-27 16:46   ` Daniel Thompson
2020-04-28 21:32     ` Doug Anderson
2020-04-21 21:14 ` [PATCH v2 8/9] serial: qcom_geni_serial: Support earlycon_kgdboc Douglas Anderson
2020-04-27 16:48   ` Daniel Thompson
2020-04-21 21:14 ` [PATCH v2 9/9] serial: 8250_early: " Douglas Anderson
2020-04-27 16:50   ` Daniel Thompson
2020-04-23 13:50 ` [PATCH v2 0/9] kgdb: Support late serial drivers; enable early debug w/ boot consoles Greg KH
2020-04-24  8:32 ` Sumit Garg
2020-04-24 10:13   ` Daniel Thompson

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