Re: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

2018-09-07 Thread Peter Zijlstra
On Thu, Sep 06, 2018 at 04:27:48PM -0700, Sai Praneeth Prakhya wrote: > From: Sai Praneeth > > There may exist some buggy UEFI firmware implementations that might > access efi regions other than EFI_RUNTIME_SERVICES_ even > after the kernel has assumed control of the platform. This violates UEFI

RE: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

2018-09-07 Thread Prakhya, Sai Praneeth
> > There may exist some buggy UEFI firmware implementations that might > > access efi regions other than EFI_RUNTIME_SERVICES_ even > > after the kernel has assumed control of the platform. This violates > > UEFI specification. > > > > If selected, this debug option will print a warning message if

Re: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

2018-09-07 Thread Bhupesh Sharma
On 09/07/2018 11:53 PM, Prakhya, Sai Praneeth wrote: >> There may exist some buggy UEFI firmware implementations that might >> access efi regions other than EFI_RUNTIME_SERVICES_ even >> after the kernel has assumed control of the platform. This violates >> UEFI specification. >> >> If selected,

RE: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

2018-09-07 Thread Prakhya, Sai Praneeth
> > > Why make this optional? > > > > I made it as a config option in RFC because the page fault handler was > > complicated and touching many parts (it had lots of code change and I > > didn't want to break any existing functionality). Now that it's > > simple, I don't think we need the config opt

RE: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

2018-09-07 Thread Thomas Gleixner
On Fri, 7 Sep 2018, Prakhya, Sai Praneeth wrote: > > > So, if Thomas, Ingo, Andy, Ard and Boris are ok.. I will make it as > > > default (i.e. without config). Yes, that's the right thing to do. > > Also, some distributions already have specific ways to handle buggy > > firmwares which can be at

Re: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

2018-09-07 Thread Bhupesh Sharma
On Sat, Sep 8, 2018 at 12:52 AM, Thomas Gleixner wrote: > On Fri, 7 Sep 2018, Prakhya, Sai Praneeth wrote: >> > > So, if Thomas, Ingo, Andy, Ard and Boris are ok.. I will make it as >> > > default (i.e. without config). > > Yes, that's the right thing to do. > >> > Also, some distributions already

Re: [PATCH V4 3/3] x86/efi: Introduce EFI_PAGE_FAULT_HANDLER

2018-09-07 Thread Thomas Gleixner
On Sat, 8 Sep 2018, Bhupesh Sharma wrote: > On Sat, Sep 8, 2018 at 12:52 AM, Thomas Gleixner wrote: > > If the distro patched their kernel to deal with buggy firmware, then: > > > > 1) why did they not upstream it ? > > Because some of the kernel fixes are (for such cases), well to be > honest,