From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sachin Sant Subject: Re: 2.6.31-rc5-git2 crash on a idle system. Date: Thu, 06 Aug 2009 19:03:37 +0530 Message-ID: <4A7ADBB1.3050906@in.ibm.com> References: <4A78292A.5000607@in.ibm.com> <1249421223.18245.36.camel@pasglop> <4A794E26.8080207@in.ibm.com> <1249465934.18245.54.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1249465934.18245.54.camel@pasglop> Sender: linux-raid-owner@vger.kernel.org To: Benjamin Herrenschmidt Cc: linuxppc-dev@ozlabs.org, neilb@suse.de, linux-raid@vger.kernel.org List-Id: linux-raid.ids Benjamin Herrenschmidt wrote: > Thanks. Since it's a memory corruption (or seems to be) however, it's > possible that the bisection will mislead you. IE. The culprit could be > somewhere else, and the commit you'll find via bisection just happens to > move things around in the kernel in such a way that the corruption hits > that code path instead of another rarely used one. > > I would suggest using printk to print out the content of memory where > the code appears to have been smashed at different stages during boot > (maybe even in the initcalls loop in init/main.c) to try to point out > what appears to be causing the corruption. > By the time machine is up and running the particular memory location in question is already overwritten. So seems like the corruption occurs during the boot. I added few printks in the initcall debug code patch. The o/p suggests that by the time first initicall debug message is printed the code is already corrupted. Further debug suggests, when start_kernel() is called the code at address(0xc000000000600000) is already corrupted. About 28 bytes of code starting from the above address is overwritten. I will try to add few more debug statements to find the place where this corruption might me happening. Thanks -Sachin -- --------------------------------- Sachin Sant IBM Linux Technology Center India Systems and Technology Labs Bangalore, India ---------------------------------