Re: [RFC][PATCH 00/10] Use global pages with PTI - Truth about the white man.

2018-02-23 Thread thetruthbeforeus
Linus, this talk about the memory map bullshit is interesting and all, with that binary encoding and shit. But I want you to take a moment and reflect. I want you to reflect on truth. Ask yourself. "Am I a white man" and then listen to those who... who see you ALL for what you are and couldn't

Re: [RFC][PATCH 00/10] Use global pages with PTI - Truth about the white man.

2018-02-23 Thread thetruthbeforeus
Linus, this talk about the memory map bullshit is interesting and all, with that binary encoding and shit. But I want you to take a moment and reflect. I want you to reflect on truth. Ask yourself. "Am I a white man" and then listen to those who... who see you ALL for what you are and couldn't

Re: [RFC][PATCH 00/10] Use global pages with PTI

2018-02-23 Thread Linus Torvalds
On Fri, Feb 23, 2018 at 5:49 PM, Dave Hansen wrote: > On 02/22/2018 01:52 PM, Linus Torvalds wrote: >> Side note - and this may be crazy talk - I wonder if it might make >> sense to have a mode where we allow executable read-only kernel pages >> to be marked global

Re: [RFC][PATCH 00/10] Use global pages with PTI

2018-02-23 Thread Linus Torvalds
On Fri, Feb 23, 2018 at 5:49 PM, Dave Hansen wrote: > On 02/22/2018 01:52 PM, Linus Torvalds wrote: >> Side note - and this may be crazy talk - I wonder if it might make >> sense to have a mode where we allow executable read-only kernel pages >> to be marked global too (but only in the kernel

Re: [RFC][PATCH 00/10] Use global pages with PTI

2018-02-23 Thread Dave Hansen
On 02/22/2018 01:52 PM, Linus Torvalds wrote: > Side note - and this may be crazy talk - I wonder if it might make > sense to have a mode where we allow executable read-only kernel pages > to be marked global too (but only in the kernel mapping). We did that accidentally, somewhere. It causes

Re: [RFC][PATCH 00/10] Use global pages with PTI

2018-02-23 Thread Dave Hansen
On 02/22/2018 01:52 PM, Linus Torvalds wrote: > Side note - and this may be crazy talk - I wonder if it might make > sense to have a mode where we allow executable read-only kernel pages > to be marked global too (but only in the kernel mapping). We did that accidentally, somewhere. It causes

Re: [RFC][PATCH 00/10] Use global pages with PTI

2018-02-22 Thread Linus Torvalds
Side note - and this may be crazy talk - I wonder if it might make sense to have a mode where we allow executable read-only kernel pages to be marked global too (but only in the kernel mapping). Yes, yes, that potentially means that you can run meltdown on recently run kernel code that is still

Re: [RFC][PATCH 00/10] Use global pages with PTI

2018-02-22 Thread Linus Torvalds
Side note - and this may be crazy talk - I wonder if it might make sense to have a mode where we allow executable read-only kernel pages to be marked global too (but only in the kernel mapping). Yes, yes, that potentially means that you can run meltdown on recently run kernel code that is still

[RFC][PATCH 00/10] Use global pages with PTI

2018-02-22 Thread Dave Hansen
The later verions of the KAISER pathces (pre-PTI) allowed the user/kernel shared areas to be GLOBAL. The thought was that this would reduce the TLB overhead of keeping two copies of these mappings. During the switch over to PTI, we seem to have lost our ability to have GLOBAL mappings. This

[RFC][PATCH 00/10] Use global pages with PTI

2018-02-22 Thread Dave Hansen
The later verions of the KAISER pathces (pre-PTI) allowed the user/kernel shared areas to be GLOBAL. The thought was that this would reduce the TLB overhead of keeping two copies of these mappings. During the switch over to PTI, we seem to have lost our ability to have GLOBAL mappings. This