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From: Will Deacon <will@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jason Baron <jbaron@akamai.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	linux-kernel@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v4] dynamic_debug: allow to work if debugfs is disabled
Date: Thu, 23 Jan 2020 09:36:28 +0000	[thread overview]
Message-ID: <20200123093628.GA18991@willie-the-truck> (raw)
In-Reply-To: <20200123085015.GA436361@kroah.com>

On Thu, Jan 23, 2020 at 09:50:15AM +0100, Greg Kroah-Hartman wrote:
> With the realization that having debugfs enabled on "production" systems is
> generally not a good idea, debugfs is being disabled from more and more
> platforms over time.  However, the functionality of dynamic debugging still is
> needed at times, and since it relies on debugfs for its user api, having
> debugfs disabled also forces dynamic debug to be disabled.
> 
> To get around this, move the "control" file for dynamic_debug to procfs IFF
> debugfs is disabled.  This lets people turn on debugging as needed at runtime
> for individual driverfs and subsystems.
> 
> Reported-by: many different companies
> Cc: Jason Baron <jbaron@akamai.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> v4: tweaks to the .rst text thanks to Randy's review
> v3: rename init function as it is now no longer just for debugfs, thanks
>     to Jason for the review.
>     Fix build warning for debugfs_initialized call.
> v2: Fix up octal permissions and add procfs reference to the Kconfig
>     entry, thanks to Will for the review.
> 
>  .../admin-guide/dynamic-debug-howto.rst       |  3 +++
>  lib/Kconfig.debug                             |  7 ++++---
>  lib/dynamic_debug.c                           | 21 ++++++++++++++-----
>  3 files changed, 23 insertions(+), 8 deletions(-)

I had a brief "oh crap" moment when I thought you were exposing both the
procfs and debugfs interfaces at the same time, but thankfully that's not
the case. Whilst it's a bit of a shame that it's come to this, the code
looks pretty decent to me, so:

Acked-by: Will Deacon <will@kernel.org>

Thanks,

Will

  reply	other threads:[~2020-01-23  9:36 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-22  7:43 [PATCH] dynamic_debug: allow to work if debugfs is disabled Greg Kroah-Hartman
2020-01-22  8:03 ` Will Deacon
2020-01-22  8:12   ` Greg Kroah-Hartman
2020-01-22 13:53     ` [PATCH v2] " Greg Kroah-Hartman
2020-01-22 18:56       ` Jason Baron
2020-01-22 19:29         ` Greg Kroah-Hartman
2020-01-22 19:31           ` [PATCH v3] " Greg Kroah-Hartman
2020-01-22 21:43             ` Randy Dunlap
2020-01-23  8:48               ` Greg Kroah-Hartman
2020-01-23  8:50                 ` [PATCH v4] " Greg Kroah-Hartman
2020-01-23  9:36                   ` Will Deacon [this message]
2020-01-23 15:53             ` [PATCH v3] " Theodore Y. Ts'o
2020-01-23 17:55               ` Greg Kroah-Hartman
2020-01-24  6:02                 ` Theodore Y. Ts'o
2020-01-24  7:29                   ` Greg Kroah-Hartman
2020-01-25  1:42                     ` Theodore Y. Ts'o
2020-01-25 17:11                       ` Jonathan Corbet
2020-01-27 22:19                         ` Saravana Kannan
2020-02-09 11:05               ` [PATCH v5] " Greg Kroah-Hartman
2020-02-09 15:53                 ` Joe Perches
2020-02-09 17:03                   ` Greg Kroah-Hartman
2020-02-10 21:11                 ` [PATCH v6] " Greg Kroah-Hartman
2020-02-10 21:15                   ` Randy Dunlap
2020-02-12 21:58                     ` Greg Kroah-Hartman
2020-02-11 11:01                   ` Will Deacon
2020-01-25  0:03 ` [PATCH] " kbuild test robot

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