Re: [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-25 Thread Andrei Vagin
On Wed, Jun 24, 2020 at 05:18:01PM +0200, Christian Brauner wrote: > On Wed, Jun 24, 2020 at 01:33:17AM -0700, Andrei Vagin wrote: > > The order of vvar pages depends on whether a task belongs to the root > > time namespace or not. In the root time namespace, a task doesn't have a > > per-namespace

Re: [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-24 Thread Christian Brauner
On Wed, Jun 24, 2020 at 01:33:17AM -0700, Andrei Vagin wrote: > The order of vvar pages depends on whether a task belongs to the root > time namespace or not. In the root time namespace, a task doesn't have a > per-namespace page. In a non-root namespace, the VVAR page which contains > the system-w

[PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-24 Thread Andrei Vagin
The order of vvar pages depends on whether a task belongs to the root time namespace or not. In the root time namespace, a task doesn't have a per-namespace page. In a non-root namespace, the VVAR page which contains the system-wide VDSO data is replaced with a namespace specific page that contains

Re: [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-23 Thread Christian Brauner
On Tue, Jun 23, 2020 at 12:33:05AM -0700, Andrei Vagin wrote: > On Fri, Jun 19, 2020 at 05:38:12PM +0200, Christian Brauner wrote: > > On Tue, Jun 16, 2020 at 12:55:41AM -0700, Andrei Vagin wrote: > > > The VVAR page layout depends on whether a task belongs to the root or > > > non-root time namesp

Re: [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-23 Thread Andrei Vagin
On Fri, Jun 19, 2020 at 05:38:12PM +0200, Christian Brauner wrote: > On Tue, Jun 16, 2020 at 12:55:41AM -0700, Andrei Vagin wrote: > > The VVAR page layout depends on whether a task belongs to the root or > > non-root time namespace. Whenever a task changes its namespace, the VVAR > > page tables a

Re: [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-19 Thread Christian Brauner
On Tue, Jun 16, 2020 at 12:55:41AM -0700, Andrei Vagin wrote: > The VVAR page layout depends on whether a task belongs to the root or > non-root time namespace. Whenever a task changes its namespace, the VVAR > page tables are cleared and then they will be re-faulted with a > corresponding layout.

Re: [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-16 Thread Dmitry Safonov
Hi Mark, On 6/16/20 12:24 PM, Mark Rutland wrote: > On Tue, Jun 16, 2020 at 12:55:41AM -0700, Andrei Vagin wrote: [..] >> Whenever a task changes its namespace, the VVAR >> page tables are cleared and then they will be re-faulted with a >> corresponding layout. > > How does this work for multi-th

Re: [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-16 Thread Mark Rutland
On Tue, Jun 16, 2020 at 12:55:41AM -0700, Andrei Vagin wrote: > The VVAR page layout depends on whether a task belongs to the root or > non-root time namespace. Please be more explicit as to what you mean by `layout` here, as that seems to be an overloaded term. For example, the comment above time

[PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-16 Thread Andrei Vagin
The VVAR page layout depends on whether a task belongs to the root or non-root time namespace. Whenever a task changes its namespace, the VVAR page tables are cleared and then they will be re-faulted with a corresponding layout. Reviewed-by: Vincenzo Frascino Reviewed-by: Dmitry Safonov Signed-o

[PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace

2020-06-02 Thread Andrei Vagin
The VVAR page layout depends on whether a task belongs to the root or non-root time namespace. Whenever a task changes its namespace, the VVAR page tables are cleared and then they will be re-faulted with a corresponding layout. Reviewed-by: Vincenzo Frascino Signed-off-by: Andrei Vagin --- arc