Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-08-02 Thread Mark Rutland
On Wed, Jul 11, 2018 at 06:59:28AM +0100, Mark Rutland wrote: > On Mon, Jul 09, 2018 at 06:42:29PM -0400, Boris Ostrovsky wrote: > > On 07/02/2018 12:02 PM, Mark Rutland wrote: > > > On Mon, Jul 02, 2018 at 05:46:55PM +0200, Peter Zijlstra wrote: > > >> On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mar

Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-12 Thread Boris Ostrovsky
On 07/12/2018 07:56 AM, Mark Rutland wrote: > On Mon, Jul 09, 2018 at 06:42:29PM -0400, Boris Ostrovsky wrote: >> On 07/02/2018 12:02 PM, Mark Rutland wrote: >>> On Mon, Jul 02, 2018 at 05:46:55PM +0200, Peter Zijlstra wrote: On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mark Rutland wrote: >

Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-12 Thread Mark Rutland
On Mon, Jul 09, 2018 at 06:42:29PM -0400, Boris Ostrovsky wrote: > On 07/02/2018 12:02 PM, Mark Rutland wrote: > > On Mon, Jul 02, 2018 at 05:46:55PM +0200, Peter Zijlstra wrote: > >> On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mark Rutland wrote: > >>> +static struct pt_regs *perf_get_sample_regs(st

Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-11 Thread Boris Ostrovsky
On 07/11/2018 01:59 AM, Mark Rutland wrote: > On Mon, Jul 09, 2018 at 06:42:29PM -0400, Boris Ostrovsky wrote: >> On 07/02/2018 12:02 PM, Mark Rutland wrote: >>> On Mon, Jul 02, 2018 at 05:46:55PM +0200, Peter Zijlstra wrote: On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mark Rutland wrote: >

Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-10 Thread Mark Rutland
On Mon, Jul 09, 2018 at 06:42:29PM -0400, Boris Ostrovsky wrote: > On 07/02/2018 12:02 PM, Mark Rutland wrote: > > On Mon, Jul 02, 2018 at 05:46:55PM +0200, Peter Zijlstra wrote: > >> On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mark Rutland wrote: > >>> +static struct pt_regs *perf_get_sample_regs(st

Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-09 Thread Boris Ostrovsky
On 07/02/2018 12:02 PM, Mark Rutland wrote: > On Mon, Jul 02, 2018 at 05:46:55PM +0200, Peter Zijlstra wrote: >> On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mark Rutland wrote: >>> Users can request that general purpose registers, instruction pointer, >>> etc, are sampled when a perf event counter ov

Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-02 Thread Mark Rutland
On Mon, Jul 02, 2018 at 05:46:55PM +0200, Peter Zijlstra wrote: > On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mark Rutland wrote: > > Users can request that general purpose registers, instruction pointer, > > etc, are sampled when a perf event counter overflows. To try to avoid > > this resulting in

Re: [RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-02 Thread Peter Zijlstra
On Mon, Jul 02, 2018 at 04:12:50PM +0100, Mark Rutland wrote: > Users can request that general purpose registers, instruction pointer, > etc, are sampled when a perf event counter overflows. To try to avoid > this resulting in kernel state being leaked, unprivileged users are > usually forbidden fr

[RFC PATCH] perf/core: don't sample kernel regs upon skid

2018-07-02 Thread Mark Rutland
Users can request that general purpose registers, instruction pointer, etc, are sampled when a perf event counter overflows. To try to avoid this resulting in kernel state being leaked, unprivileged users are usually forbidden from opening events which count while the kernel is running. Unfortunat