linux-kernel - Re: [PATCH] sysrq, kdump: fix regression, revert "simplify sysrq-c handler"

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 for Android: free password hash cracker in your pocket

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

Date:	Thu, 23 Jul 2009 10:09:20 +0900
From:	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
To:	Neil Horman <nhorman@...driver.com>
CC:	Lai Jiangshan <laijs@...fujitsu.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Vivek Goyal <vgoyal@...hat.com>,
	Brayan Arraes <brayan@...k.com.br>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	LKML <linux-kernel@...r.kernel.org>,
	"Ken'ichi Ohmichi" <oomichi@....nes.nec.co.jp>
Subject: Re: [PATCH] sysrq, kdump: fix regression, revert "simplify sysrq-c
 handler"

Neil Horman wrote:
> On Wed, Jul 22, 2009 at 11:01:29AM +0900, Hidetoshi Seto wrote:
>> Neil Horman wrote:
>>  static void sysrq_handle_crash(int key, struct tty_struct *tty)
>>  {
>> -	char *killer = NULL;
>> -	*killer = 1;
>> +	panic("SysRq-triggered panic!\n");
>>  }
>>
> Well, this removes the ability from sysrq-c to test the oops handling path, but
> I suppose it does buy us consistent behavior between the keyboard and proc
> interfaces, which is likely more important.  I can agree to that.  Perhaps we
> can create another sysctl to test the oops path later.
> 
>> I agree that causing a real crash(panic) is better way to test crashdump than
>> calling the entry function of the crashdump directly, and also that opening
>> the path for other dump mechanisms is welcomed.
>>  
> Ok, so we're in line there :)
> 
>>> It seems to
>>> me that right now your major complaint is that the documentation is out of date,
>>> and you're having to do things slightly differently to get the same behavioral
>>> results.  Would it solve your issue, if we simply updated the documentation to
>>> illustrate how it works now?
>> Of course the documentation should be updated asap.
>> But I think the major complaint is about a difference in the behaviors of SysRq-c
>> and "echo c > /proc/sysrq-trigger".
>>
> Ok, I can agree with that.  I'd support a change like what you have above to
> bring the keyboard and proc interface behavior in line.

Thank you for your understanding!

I'll write & post a patch soon.  Please review it.


Thanks,
H.Seto

--
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/