linux-kernel - Re: [BUGFIX 2/2] gdth: bugfix for the Timer at exit crash

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 13 Feb 2008 12:48:42 +0200
From:	Boaz Harrosh <bharrosh@...asas.com>
To:	Sven Köhler <skoehler@....de>,
	Christoph Hellwig <hch@...radead.org>,
	Jeff Garzik <jeff@...zik.org>
CC:	linux-scsi <linux-scsi@...r.kernel.org>,
	James Bottomley <James.Bottomley@...senPartnership.com>,
	linux-kernel@...r.kernel.org, Joerg Dorchain <joerg@...chain.net>,
	Jon Chelton <jchelton@...global.com>,
	Stefan Priebe - allied internet ag 
	<s.priebe@...ied-internet.ag>, Dave Milter <davemilter@...il.com>
Subject: Re: [BUGFIX 2/2] gdth: bugfix for the Timer at exit crash

On Tue, Feb 12 2008 at 19:40 +0200, Boaz Harrosh <bharrosh@...asas.com> wrote:
> gdth _exit would first remove all cards then stop the timer
> and would not sync with the timer function. This caused a crash
> in gdth_timer() when module was unloaded.
> 
> del_timer_sync the timer before we delete the cards.
> 
> NOT YET TESTED
> 
> Signed-off-by: Boaz Harrosh <bharrosh@...asas.com>

Tested-by: Stefan Priebe <s.priebe@...ied-internet.ag>

> ---
>  drivers/scsi/gdth.c |   15 ++++++++-------
>  1 files changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
> index 8eb78be..103280e 100644
> --- a/drivers/scsi/gdth.c
> +++ b/drivers/scsi/gdth.c
> @@ -3793,6 +3793,8 @@ static void gdth_timeout(ulong data)
>      gdth_ha_str *ha;
>      ulong flags;
>  
> +    BUG_ON(list_empty(&gdth_instances));
> +
>      ha = list_first_entry(&gdth_instances, gdth_ha_str, list);
>      spin_lock_irqsave(&ha->smp_lock, flags);
>  
> @@ -5146,8 +5148,6 @@ static void gdth_remove_one(gdth_ha_str *ha)
>  		ha->sdev = NULL;
>  	}
>  
> -	gdth_flush(ha);
> -
>  	if (shp->irq)
>  		free_irq(shp->irq,ha);
>  
> @@ -5245,14 +5245,15 @@ static void __exit gdth_exit(void)
>  {
>  	gdth_ha_str *ha;
>  
> -	list_for_each_entry(ha, &gdth_instances, list)
> -		gdth_remove_one(ha);
> +	unregister_chrdev(major,"gdth");
> +	unregister_reboot_notifier(&gdth_notifier);
>  
>  #ifdef GDTH_STATISTICS
> -	del_timer(&gdth_timer);
> +	del_timer_sync(&gdth_timer);
>  #endif
> -	unregister_chrdev(major,"gdth");
> -	unregister_reboot_notifier(&gdth_notifier);
> +
> +	list_for_each_entry(ha, &gdth_instances, list)
> +		gdth_remove_one(ha);
>  }
>  
>  module_init(gdth_init);

James please put this patch in rc-fixes also. It has now been tested
by few people, and it solves a reproducible problem in the unloading
of the driver.

It was not yet confirmed by Andrew's reporter with the:
	+    if (list_empty(&gdth_instances))
	+	return;

at gdth_timer() In -mm tree. In my patch I have converted the if() to a 
BUG_ON because now it should not happen. But I figure it is not worse then 
what there is now, which is nothing.

With your recommendation I will push both patches to the stable branches
People have emailed me requesting it.

Thanks
Boaz
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/