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From: Guenter Roeck <linux@roeck-us.net>
To: Convert@minyard.net, the@minyard.net, IPMI@minyard.net,
	watchdog@minyard.net, to@minyard.net, standard@minyard.net,
	interface@minyard.net
Cc: linux-watchdog@vger.kernel.org,
	Wim Van Sebroeck <wim@linux-watchdog.org>,
	Corey Minyard <cminyard@mvista.com>,
	Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Subject: Re: [PATCH 01/12] watchdog: NULL the default governor if it is unregistered
Date: Mon, 19 Aug 2019 15:35:04 -0700
Message-ID: <20190819223504.GA8869@roeck-us.net> (raw)
In-Reply-To: <20190819203711.32599-2-minyard@acm.org>

On Mon, Aug 19, 2019 at 03:37:00PM -0500, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
> 
> Otherwise it could be used after being freed.
> 
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> ---
>  drivers/watchdog/watchdog_pretimeout.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/watchdog/watchdog_pretimeout.c b/drivers/watchdog/watchdog_pretimeout.c
> index 01ca84be240f..b45041b0ef39 100644
> --- a/drivers/watchdog/watchdog_pretimeout.c
> +++ b/drivers/watchdog/watchdog_pretimeout.c
> @@ -162,6 +162,8 @@ void watchdog_unregister_governor(struct watchdog_governor *gov)
>  			break;
>  		}
>  	}
> +	if (gov == default_gov)
> +		default_gov = NULL;
>  

Good catch.

I think this should be inside the spinlock. I do wonder though why it
was removed with commit da0d12ff2b82 ("watchdog: pretimeout: add panic
pretimeout governor"). I think it was wrong to remove it, but I may be
missing something. Vladimir, do you recall ?

Guenter

>  	spin_lock_irq(&pretimeout_lock);
>  	list_for_each_entry(p, &pretimeout_list, entry)
> -- 
> 2.17.1
> 

  reply index

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190819203711.32599-1-minyard@acm.org>
2019-08-19 20:37 ` minyard
2019-08-19 22:35   ` Guenter Roeck [this message]
2019-08-19 20:37 ` [PATCH 02/12] watchdog: Add the ability to provide data to read minyard
2019-08-19 21:50   ` Guenter Roeck
2019-08-19 22:43   ` Guenter Roeck
2019-08-20  0:23     ` Corey Minyard
2019-08-20  1:09       ` Jerry Hoemann
2019-08-20 12:12         ` Corey Minyard
2019-08-20 13:53           ` Guenter Roeck
2019-08-20 15:58             ` Corey Minyard
2019-08-20 17:14               ` Guenter Roeck
2019-08-20 18:16                 ` Corey Minyard
2019-08-19 20:37 ` [PATCH 03/12] watchdog: Add a pretimeout governor to provide read data minyard
2019-08-19 20:37 ` [PATCH 04/12] watchdog: Allow pretimeout governor setting to be accessed from modules minyard
2019-08-19 21:49   ` Guenter Roeck
2019-08-20  0:24     ` Corey Minyard
2019-08-19 20:37 ` [PATCH 05/12] watchdog:ipmi: Move the IPMI watchdog to drivers/watchdog minyard
2019-08-19 20:37 ` [PATCH 06/12] watchdog:ipmi: Convert over to the standard watchdog infrastructure minyard
2019-08-19 20:37 ` [PATCH 07/12] watchdog:ipmi: Add the ability to fetch the current time left minyard
2019-08-19 20:37 ` [PATCH 08/12] watchdog: Add the ability to set the action of a timeout minyard
2019-08-19 21:58   ` Guenter Roeck
2019-08-20  0:39     ` Corey Minyard
2019-08-20 14:17       ` Guenter Roeck
2019-08-20 19:39         ` Corey Minyard
2019-08-19 20:37 ` [PATCH 09/12] watchdog:ipmi: Implement action and preaction functions minyard
2019-08-19 20:37 ` [PATCH 10/12] watchdog: Add a way to set the governor through the ioctl minyard
2019-08-19 20:37 ` [PATCH 11/12] watchdog: Add a sample program that can fully use the watchdog interface minyard
2019-08-19 20:37 ` [PATCH 12/12] watchdog: Set the preaction fields for drivers supporting pretimeout minyard

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