From: ebiederm@xmission.com (Eric W. Biederman)
To: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Neil Horman <nhorman@tuxdriver.com>,
Vivek Goyal <vgoyal@redhat.com>,
Brayan Arraes <brayan@yack.com.br>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sysrq, kdump: fix regression, revert "simplify sysrq-c handler"
Date: Mon, 20 Jul 2009 12:22:57 -0700 [thread overview]
Message-ID: <m1d47vnoq6.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <4A64672E.8020005@cn.fujitsu.com> (Lai Jiangshan's message of "Mon\, 20 Jul 2009 20\:46\:38 +0800")
Lai Jiangshan <laijs@cn.fujitsu.com> writes:
> 1) This fix breaks our tools.
> This fix changes the ABI. panic_on_oops is default 0,
> and a lots system do not specify the boot option "panic",
> thus, Sysrq-c will not cause CrashDump(Kdump) as expected.
How does it break your tools?
> 2) When CONFIG_KEXEC=n, Sysrq-c should become an invalid
> command like Sysrq-D(CONFIG_LOCKDEP, show-all-locks).
> But this fix makes it a valid command and let it do a
> hazard thing: cause a page fault(NULL dereference) in kernel.
>
> So, we revert this fix.
The idea was to extend sysrq-d to also be a way of testing NULL
pointer dereferences. How is that a bad idea?
Eric
next prev parent reply other threads:[~2009-07-20 19:23 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-20 12:46 Lai Jiangshan
2009-07-20 19:22 ` Eric W. Biederman [this message]
2009-07-20 21:16 ` Neil Horman
2009-07-21 6:46 ` Lai Jiangshan
2009-07-21 22:18 ` Eric W. Biederman
2009-07-21 6:00 ` Lai Jiangshan
2009-07-21 6:56 ` Eric W. Biederman
2009-07-21 6:49 ` Hidetoshi Seto
2009-07-21 11:08 ` Neil Horman
2009-07-21 12:16 ` Lai Jiangshan
2009-07-22 2:01 ` Hidetoshi Seto
2009-07-22 11:10 ` Neil Horman
2009-07-22 13:42 ` Vivek Goyal
2009-07-22 19:38 ` Neil Horman
2009-07-23 1:10 ` Hidetoshi Seto
2009-07-23 1:09 ` Hidetoshi Seto
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