Re: [PATCH 07/16] x86/shstk: Re-layout the stack block for shadow stacks

2020-05-12 Thread Jan Beulich
On 11.05.2020 19:48, Andrew Cooper wrote: > On 04/05/2020 15:24, Jan Beulich wrote: >> On 02.05.2020 00:58, Andrew Cooper wrote: >>> --- a/xen/arch/x86/cpu/common.c >>> +++ b/xen/arch/x86/cpu/common.c >>> @@ -732,14 +732,14 @@ void load_system_tables(void) >>> .rsp2 = 0x8600

Re: [PATCH 07/16] x86/shstk: Re-layout the stack block for shadow stacks

2020-05-11 Thread Andrew Cooper
On 04/05/2020 15:24, Jan Beulich wrote: > On 02.05.2020 00:58, Andrew Cooper wrote: >> --- a/xen/arch/x86/cpu/common.c >> +++ b/xen/arch/x86/cpu/common.c >> @@ -732,14 +732,14 @@ void load_system_tables(void) >> .rsp2 = 0x8600ul, >> >> /* >> - * M

Re: [PATCH 07/16] x86/shstk: Re-layout the stack block for shadow stacks

2020-05-04 Thread Jan Beulich
On 02.05.2020 00:58, Andrew Cooper wrote: > --- a/xen/arch/x86/cpu/common.c > +++ b/xen/arch/x86/cpu/common.c > @@ -732,14 +732,14 @@ void load_system_tables(void) > .rsp2 = 0x8600ul, > > /* > - * MCE, NMI and Double Fault handlers get their ow

[PATCH 07/16] x86/shstk: Re-layout the stack block for shadow stacks

2020-05-01 Thread Andrew Cooper
We have two free pages in the current stack. A useful property of shadow stacks and regular stacks is that they act as each others guard pages as far as OoB writes go. Move the regular IST stacks up by one page, to allow their shadow stack page to be in slot 0. The primary shadow stack uses slot