Re: [PATCH] [v4] x86/doc: add PTI description

2018-01-05 Thread Randy Dunlap
On 01/05/2018 09:44 AM, Dave Hansen wrote:
> Changes from v3:
>  * Increasingly minor text fixes.

Yeah.  Just merge it and use patches for anything else.
Reviewed-by: Randy Dunlap 

Thanks.

> Changes from v2:
>  * Update some wording
>  * Minor typo and grammar fixes
>  * Further clarify what INVPCID is.
> 
> Changes from v1:
>  * update kernel-parameters.txt to clarify that the pti= option
>is not just for disabling.  Also describe what 'pti=auto' does
>and why
>  * Add a note about the presence of NX in the user portion of the
>kernel page tables
>  * Clarify _additional_ 4k of PGD space
>  * Add a note about the runtime overhead of PCID without INVPCID
> 
> ---
> 
> From: Dave Hansen 
> 
> Add some details about how PTI works, what some of the downsides
> are, and how to debug it when things go wrong.
> 
> Also document the kernel parameter: 'nopti'.
> 
> Signed-off-by: Dave Hansen 
> Reviewed-by: Kees Cook 
> Cc: Moritz Lipp 
> Cc: Daniel Gruss 
> Cc: Michael Schwarz 
> Cc: Richard Fellner 
> Cc: Andy Lutomirski 
> Cc: Linus Torvalds 
> Cc: Hugh Dickins 
> Cc: x...@kernel.org
> ---
> 
>  b/Documentation/admin-guide/kernel-parameters.txt |   21 +-
>  b/Documentation/x86/pti.txt   |  186 
> ++
>  2 files changed, 200 insertions(+), 7 deletions(-)


-- 
~Randy


Re: [PATCH] [v4] x86/doc: add PTI description

2018-01-05 Thread Randy Dunlap
On 01/05/2018 09:44 AM, Dave Hansen wrote:
> Changes from v3:
>  * Increasingly minor text fixes.

Yeah.  Just merge it and use patches for anything else.
Reviewed-by: Randy Dunlap 

Thanks.

> Changes from v2:
>  * Update some wording
>  * Minor typo and grammar fixes
>  * Further clarify what INVPCID is.
> 
> Changes from v1:
>  * update kernel-parameters.txt to clarify that the pti= option
>is not just for disabling.  Also describe what 'pti=auto' does
>and why
>  * Add a note about the presence of NX in the user portion of the
>kernel page tables
>  * Clarify _additional_ 4k of PGD space
>  * Add a note about the runtime overhead of PCID without INVPCID
> 
> ---
> 
> From: Dave Hansen 
> 
> Add some details about how PTI works, what some of the downsides
> are, and how to debug it when things go wrong.
> 
> Also document the kernel parameter: 'nopti'.
> 
> Signed-off-by: Dave Hansen 
> Reviewed-by: Kees Cook 
> Cc: Moritz Lipp 
> Cc: Daniel Gruss 
> Cc: Michael Schwarz 
> Cc: Richard Fellner 
> Cc: Andy Lutomirski 
> Cc: Linus Torvalds 
> Cc: Hugh Dickins 
> Cc: x...@kernel.org
> ---
> 
>  b/Documentation/admin-guide/kernel-parameters.txt |   21 +-
>  b/Documentation/x86/pti.txt   |  186 
> ++
>  2 files changed, 200 insertions(+), 7 deletions(-)


-- 
~Randy