Re: [PATCH -tip 18/32] kernel/entry: Add support for core-wide protection of kernel-mode

2020-12-01 Thread Joel Fernandes
On Wed, Nov 25, 2020 at 10:37:00AM +0100, Peter Zijlstra wrote: > On Tue, Nov 17, 2020 at 06:19:48PM -0500, Joel Fernandes (Google) wrote: > > Core-scheduling prevents hyperthreads in usermode from attacking each > > other, but it does not do anything about one of the hyperthreads > > entering the

Re: [PATCH -tip 18/32] kernel/entry: Add support for core-wide protection of kernel-mode

2020-11-25 Thread Balbir Singh
On Tue, Nov 17, 2020 at 06:19:48PM -0500, Joel Fernandes (Google) wrote: > Core-scheduling prevents hyperthreads in usermode from attacking each > other, but it does not do anything about one of the hyperthreads > entering the kernel for any reason. This leaves the door open for MDS > and L1TF

Re: [PATCH -tip 18/32] kernel/entry: Add support for core-wide protection of kernel-mode

2020-11-25 Thread Peter Zijlstra
On Tue, Nov 17, 2020 at 06:19:48PM -0500, Joel Fernandes (Google) wrote: > Core-scheduling prevents hyperthreads in usermode from attacking each > other, but it does not do anything about one of the hyperthreads > entering the kernel for any reason. This leaves the door open for MDS > and L1TF

Re: [PATCH -tip 18/32] kernel/entry: Add support for core-wide protection of kernel-mode

2020-11-24 Thread Joel Fernandes
Hi Peter, On Tue, Nov 24, 2020 at 05:09:06PM +0100, Peter Zijlstra wrote: > On Tue, Nov 17, 2020 at 06:19:48PM -0500, Joel Fernandes (Google) wrote: > > Core-scheduling prevents hyperthreads in usermode from attacking each > > other, but it does not do anything about one of the hyperthreads > >

Re: [PATCH -tip 18/32] kernel/entry: Add support for core-wide protection of kernel-mode

2020-11-24 Thread Peter Zijlstra
On Tue, Nov 17, 2020 at 06:19:48PM -0500, Joel Fernandes (Google) wrote: > Core-scheduling prevents hyperthreads in usermode from attacking each > other, but it does not do anything about one of the hyperthreads > entering the kernel for any reason. This leaves the door open for MDS > and L1TF

[PATCH -tip 18/32] kernel/entry: Add support for core-wide protection of kernel-mode

2020-11-17 Thread Joel Fernandes (Google)
Core-scheduling prevents hyperthreads in usermode from attacking each other, but it does not do anything about one of the hyperthreads entering the kernel for any reason. This leaves the door open for MDS and L1TF attacks with concurrent execution sequences between hyperthreads. This patch