Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1441863

Re: Minor PKRU bug?

Show all headers | View raw

On 07/12/16 08:32, Dave Hansen wrote:
> On 07/09/2016 02:27 PM, Andy Lutomirski wrote:
>> is_prefetch in arch/x86/mm/fault.c can be called on a user address
>> that's not readable due to PKRU.  This could break it.  You might need
>> to add a get_user_exec or similar.
> 
> Thanks for the heads-up.  I think I'll just need a version that does
> something along the lines of stac/clac, but with PKRU.
> 
> I think I can do it with an "_exec" variant of probe_kernel_address(),
> but it's a bit messy.
> 

Can this particular codepath even be executed on a PKRU-equipped
machine?  I thought it was a bug fix for a specific AMD CPU line.

	-hpa

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: Minor PKRU bug? Dave Hansen <dave.hansen@linux.intel.com> - 2016-07-12 17:40 +0200
  Re: Minor PKRU bug? "H. Peter Anvin" <hpa@zytor.com> - 2016-07-13 01:00 +0200
    Re: Minor PKRU bug? Dave Hansen <dave.hansen@linux.intel.com> - 2016-07-13 01:10 +0200
    Re: Minor PKRU bug? Andy Lutomirski <luto@amacapital.net> - 2016-07-13 01:10 +0200
      Re: Minor PKRU bug? Dave Hansen <dave.hansen@linux.intel.com> - 2016-07-21 23:40 +0200
        Re: Minor PKRU bug? Andy Lutomirski <luto@amacapital.net> - 2016-07-21 23:50 +0200
          Re: Minor PKRU bug? "H. Peter Anvin" <hpa@zytor.com> - 2016-07-22 00:00 +0200
            Re: Minor PKRU bug? Dave Hansen <dave.hansen@linux.intel.com> - 2016-07-22 00:30 +0200

csiph-web