Re: [RFC PATCH v3 02/12] powerpc/book3s: Introduce exclusive emergency stack for machine check exception.
From: Paul Mackerras <hidden>
Date: 2013-09-09 04:30:16
On Tue, Aug 27, 2013 at 01:01:32AM +0530, Mahesh J Salgaonkar wrote:
From: Mahesh Salgaonkar <redacted> This patch introduces exclusive emergency stack for machine check exception. We use emergency stack to handle machine check exception so that we can save MCE information (srr1, srr0, dar and dsisr) before turning on ME bit and be ready for re-entrancy. This helps us to prevent clobbering of MCE information in case of nested machine checks. The reason for using emergency stack over normal kernel stack is that the machine check might occur in the middle of setting up a stack frame which may result into improper use of kernel stack. Signed-off-by: Mahesh Salgaonkar <redacted>
Acked-by: Paul Mackerras <redacted>