Re: [PATCH] Kernel panic on IA-64 Linux with SELinux

David Mosberger
2004-06-09T21:55:07Z

>>>>> On Wed, 09 Jun 2004 23:40:41 +0900, Kazuto MIYOSHI <miyoshi@linux.bs1.fc.nec.co.jp> said:

>> 2) We tried to set the current (r13) of cpu_idle to region 5
>> address. But it paniced and I could not grab the cause of the
>> panic. Is there any reason we must put init_task in region 5?

Kazuto> Please find the attached patch to make swapper to run on
Kazuto> region 5. It needs extra 2 instructions in ia64_switch_to()
Kazuto> to stop mapping of task stack if we are switching to idle,
Kazuto> to avoid TLB entry duplication caused by kernel text/data
Kazuto> mapping and CURRENT_STACK mapping.

Kazuto> I believe swapper (init_task) should be consistent for its
Kazuto> all members, not only for wait_chldexit, and the patch will
Kazuto> solve other potential list_head/current in-consistency
Kazuto> raised by swapper initialization, though I am not so sure if
Kazuto> it justifies extra instructions and complication in context
Kazuto> switch.

That is in my opinion a worse patch compared to the reinitialization
that you proposed esterday. Tony, what's your take on this problem?

--david