Re: [RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

2020-11-19 Thread Thomas Gleixner
On Tue, Nov 17 2020 at 09:42, Alexandre Chartre wrote: > On 11/17/20 12:06 AM, Andy Lutomirski wrote: > The PTI stack does have guard pages because it maps only a part of the task > stack into the user page-table, so pages around the PTI stack are not mapped > into the user-pagetable (the page

Re: [RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

2020-11-17 Thread Andy Lutomirski
On Tue, Nov 17, 2020 at 12:42 AM Alexandre Chartre wrote: > > > On 11/17/20 12:06 AM, Andy Lutomirski wrote: > > On Mon, Nov 16, 2020 at 12:18 PM Alexandre Chartre > > wrote: > >> > >> > >> On 11/16/20 8:48 PM, Andy Lutomirski wrote: > >>> On Mon, Nov 16, 2020 at 6:49 AM Alexandre Chartre > >>>

Re: [RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

2020-11-17 Thread Alexandre Chartre
On 11/17/20 12:06 AM, Andy Lutomirski wrote: On Mon, Nov 16, 2020 at 12:18 PM Alexandre Chartre wrote: On 11/16/20 8:48 PM, Andy Lutomirski wrote: On Mon, Nov 16, 2020 at 6:49 AM Alexandre Chartre wrote: Extend PTI user mappings so that more kernel entry code can be executed with the

Re: [RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

2020-11-16 Thread Andy Lutomirski
On Mon, Nov 16, 2020 at 12:18 PM Alexandre Chartre wrote: > > > On 11/16/20 8:48 PM, Andy Lutomirski wrote: > > On Mon, Nov 16, 2020 at 6:49 AM Alexandre Chartre > > wrote: > >> > >> Extend PTI user mappings so that more kernel entry code can be executed > >> with the user page-table. To do so,

Re: [RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

2020-11-16 Thread Alexandre Chartre
On 11/16/20 8:48 PM, Andy Lutomirski wrote: On Mon, Nov 16, 2020 at 6:49 AM Alexandre Chartre wrote: Extend PTI user mappings so that more kernel entry code can be executed with the user page-table. To do so, we need to map syscall and interrupt entry code, per cpu offsets

Re: [RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

2020-11-16 Thread Andy Lutomirski
On Mon, Nov 16, 2020 at 6:49 AM Alexandre Chartre wrote: > > Extend PTI user mappings so that more kernel entry code can be executed > with the user page-table. To do so, we need to map syscall and interrupt > entry code, per cpu offsets (__per_cpu_offset, which is used some in > entry code), the

[RFC][PATCH v2 11/21] x86/pti: Extend PTI user mappings

2020-11-16 Thread Alexandre Chartre
Extend PTI user mappings so that more kernel entry code can be executed with the user page-table. To do so, we need to map syscall and interrupt entry code, per cpu offsets (__per_cpu_offset, which is used some in entry code), the stack canary, and the PTI stack (which is defined per task).