[PATCH] arc: Re-enable MMU upon die()

2017-09-01 Thread Jose Abreu
I recently came upon a scenario where I would get a double fault after a machine check error. It turns out that for Ksymbol lookup to work with modules we need to have MMU enabled because module address is mapped in the cached space. This patch re-enables the MMU before start printing the stacktra

Re: [PATCH] arc: Re-enable MMU upon die()

2017-09-01 Thread Alexey Brodkin
Hi Jose, On Fri, 2017-09-01 at 12:39 +0100, Jose Abreu wrote: > I recently came upon a scenario where I would get a double fault > after a machine check error. It turns out that for Ksymbol lookup > to work with modules we need to have MMU enabled because module > address is mapped in the cached s

Re: [PATCH] arc: Re-enable MMU upon die()

2017-09-01 Thread Jose Abreu
Hi Alexey, On 01-09-2017 12:48, Alexey Brodkin wrote: > Hi Jose, > > On Fri, 2017-09-01 at 12:39 +0100, Jose Abreu wrote: >> I recently came upon a scenario where I would get a double fault >> after a machine check error. It turns out that for Ksymbol lookup >> to work with modules we need to have

Re: [PATCH] arc: Re-enable MMU upon die()

2017-09-01 Thread Alexey Brodkin
Hi Jose, On Fri, 2017-09-01 at 13:33 +0100, Jose Abreu wrote: > Hi Alexey, > > On 01-09-2017 12:48, Alexey Brodkin wrote: > > > > Hi Jose, > > > > On Fri, 2017-09-01 at 12:39 +0100, Jose Abreu wrote: > > > > > > I recently came upon a scenario where I would get a double fault > > > after a mac

Re: [PATCH] arc: Re-enable MMU upon die()

2017-09-01 Thread Vineet Gupta
On 09/01/2017 04:40 AM, Jose Abreu wrote: I recently came upon a scenario where I would get a double fault after a machine check error. It turns out that for Ksymbol lookup to work with modules we need to have MMU enabled because module address is mapped in the cached space. This patch re-enable

[PATCH v2] arc: Re-enable MMU upon die()

2017-09-01 Thread Jose Abreu
I recently came upon a scenario where I would get a double fault after a machine check error. It turns out that for Ksymbol lookup to work with modules we need to have MMU enabled because module address is mapped in the cached space. This patch re-enables the MMU before start printing the stacktra

Re: [PATCH v2] arc: Re-enable MMU upon die()

2017-09-01 Thread Jose Abreu
Oops, the commit title is now a little bit odd. Let me rephrase and send a new version. On 01-09-2017 17:00, Jose Abreu wrote: > I recently came upon a scenario where I would get a double fault > after a machine check error. It turns out that for Ksymbol lookup > to work with modules we need to ha

[PATCH v3] arc: Re-enable MMU upon a Machine Check exception

2017-09-01 Thread Jose Abreu
I recently came upon a scenario where I would get a double fault after a machine check error. It turns out that for Ksymbol lookup to work with modules we need to have MMU enabled because module address is mapped in the cached space. This patch re-enables the MMU before calling die() so that stack

Re: [PATCH v2] arc: Re-enable MMU upon die()

2017-09-01 Thread Vineet Gupta
On 09/01/2017 09:01 AM, Jose Abreu wrote: Oops, the commit title is now a little bit odd. Let me rephrase and send a new version. Don't worry - I'll fix it up here ! Thx, -Vineet On 01-09-2017 17:00, Jose Abreu wrote: I recently came upon a scenario where I would get a double fault after a

Re: [PATCH v3] arc: Re-enable MMU upon a Machine Check exception

2017-09-01 Thread Vineet Gupta
Hi Jose, Some very minor nit picks to keep in mind for future patches. 1. all arc patches start with uppercase ARC: On 09/01/2017 09:05 AM, Jose Abreu wrote: I recently came upon a scenario where I would get a double fault after a machine check error. It turns out that for Ksymbol lookup to wo

[PATCH] ARC: Machine Check Exception: enable MMU in single place

2017-09-01 Thread Vineet Gupta
Machine check Exception is handled in distinc ways depending on cause - Duplicate TLB Entry (relevent mostly for ARC700) - everything else Currently we re-enable MMU seperately for each of these cases, which can be consolidated by dign this before we fork off the handling in low level handler.