Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/30/2015 04:05 PM, Andy Lutomirski wrote: On Thu, Jul 30, 2015 at 1:01 PM, Boris Ostrovsky wrote: On 07/30/2015 02:54 PM, Andrew Cooper wrote: On 30/07/15 19:30, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 5:29 PM, Andrew Cooper wrote: On 30/07/2015 00:13, Andy Lutomirski wrote: On

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Thu, Jul 30, 2015 at 1:01 PM, Boris Ostrovsky wrote: > On 07/30/2015 02:54 PM, Andrew Cooper wrote: >> >> On 30/07/15 19:30, Andy Lutomirski wrote: >>> >>> On Wed, Jul 29, 2015 at 5:29 PM, Andrew Cooper >>> wrote: On 30/07/2015 00:13, Andy Lutomirski wrote: > > On Wed, Jul 29

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/30/2015 02:54 PM, Andrew Cooper wrote: On 30/07/15 19:30, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 5:29 PM, Andrew Cooper wrote: On 30/07/2015 00:13, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 4:02 PM, Andrew Cooper wrote: On 29/07/2015 23:49, Boris Ostrovsky wrote: On 07/2

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 30/07/15 19:30, Andy Lutomirski wrote: > On Wed, Jul 29, 2015 at 5:29 PM, Andrew Cooper > wrote: >> On 30/07/2015 00:13, Andy Lutomirski wrote: >>> On Wed, Jul 29, 2015 at 4:02 PM, Andrew Cooper >>> wrote: On 29/07/2015 23:49, Boris Ostrovsky wrote: > On 07/29/2015 06:46 PM, David Vra

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Wed, Jul 29, 2015 at 5:29 PM, Andrew Cooper wrote: > On 30/07/2015 00:13, Andy Lutomirski wrote: >> On Wed, Jul 29, 2015 at 4:02 PM, Andrew Cooper >> wrote: >>> On 29/07/2015 23:49, Boris Ostrovsky wrote: On 07/29/2015 06:46 PM, David Vrabel wrote: > On 29/07/2015 23:11, Andrew Cooper

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 30/07/2015 00:13, Andy Lutomirski wrote: > On Wed, Jul 29, 2015 at 4:02 PM, Andrew Cooper > wrote: >> On 29/07/2015 23:49, Boris Ostrovsky wrote: >>> On 07/29/2015 06:46 PM, David Vrabel wrote: On 29/07/2015 23:11, Andrew Cooper wrote: > On 29/07/2015 23:05, Andy Lutomirski wrote:

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Wed, Jul 29, 2015 at 4:02 PM, Andrew Cooper wrote: > On 29/07/2015 23:49, Boris Ostrovsky wrote: >> On 07/29/2015 06:46 PM, David Vrabel wrote: >>> >>> On 29/07/2015 23:11, Andrew Cooper wrote: On 29/07/2015 23:05, Andy Lutomirski wrote: > On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/2015 23:49, Boris Ostrovsky wrote: > On 07/29/2015 06:46 PM, David Vrabel wrote: >> >> On 29/07/2015 23:11, Andrew Cooper wrote: >>> On 29/07/2015 23:05, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper wrote: > On 29/07/2015 22:26, Andy Lutomirski wrote

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/2015 23:49, Boris Ostrovsky wrote: > On 07/29/2015 06:46 PM, David Vrabel wrote: >> >> On 29/07/2015 23:11, Andrew Cooper wrote: >>> On 29/07/2015 23:05, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper wrote: > On 29/07/2015 22:26, Andy Lutomirski wro

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/29/2015 06:46 PM, David Vrabel wrote: On 29/07/2015 23:11, Andrew Cooper wrote: On 29/07/2015 23:05, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper wrote: On 29/07/2015 22:26, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky wrote: On 07

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/2015 23:11, Andrew Cooper wrote: > On 29/07/2015 23:05, Andy Lutomirski wrote: >> On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper >> wrote: >>> On 29/07/2015 22:26, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky wrote: > On 07/29/2015 03:03 PM, And

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/29/2015 06:11 PM, Andrew Cooper wrote: On 29/07/2015 23:05, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper wrote: On 29/07/2015 22:26, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky wrote: On 07/29/2015 03:03 PM, Andrew Cooper wrote: On

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/2015 23:05, Andy Lutomirski wrote: > On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper > wrote: >> On 29/07/2015 22:26, Andy Lutomirski wrote: >>> On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky >>> wrote: On 07/29/2015 03:03 PM, Andrew Cooper wrote: > On 29/07/15 15:43, Boris Ost

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Wed, Jul 29, 2015 at 2:37 PM, Andrew Cooper wrote: > On 29/07/2015 22:26, Andy Lutomirski wrote: >> On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky >> wrote: >>> On 07/29/2015 03:03 PM, Andrew Cooper wrote: On 29/07/15 15:43, Boris Ostrovsky wrote: > FYI, I have got a repro now and a

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/2015 22:26, Andy Lutomirski wrote: > On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky > wrote: >> On 07/29/2015 03:03 PM, Andrew Cooper wrote: >>> On 29/07/15 15:43, Boris Ostrovsky wrote: FYI, I have got a repro now and am investigating. >>> Good and bad news. This bug has nothing

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/29/2015 05:26 PM, Andy Lutomirski wrote: On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky wrote: On 07/29/2015 03:03 PM, Andrew Cooper wrote: On 29/07/15 15:43, Boris Ostrovsky wrote: FYI, I have got a repro now and am investigating. Good and bad news. This bug has nothing to do with

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Wed, Jul 29, 2015 at 2:23 PM, Boris Ostrovsky wrote: > On 07/29/2015 03:03 PM, Andrew Cooper wrote: >> >> On 29/07/15 15:43, Boris Ostrovsky wrote: >>> >>> FYI, I have got a repro now and am investigating. >> >> Good and bad news. This bug has nothing to do with LDTs themselves. >> >> I have w

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/29/2015 03:03 PM, Andrew Cooper wrote: On 29/07/15 15:43, Boris Ostrovsky wrote: FYI, I have got a repro now and am investigating. Good and bad news. This bug has nothing to do with LDTs themselves. I have worked out what is going on, but this: diff --git a/arch/x86/xen/enlighten.c b/a

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/15 15:43, Boris Ostrovsky wrote: > FYI, I have got a repro now and am investigating. Good and bad news. This bug has nothing to do with LDTs themselves. I have worked out what is going on, but this: diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 5abeaac..7e1a82e

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/29/2015 10:21 AM, Andrew Cooper wrote: On 29/07/15 06:28, Andy Lutomirski wrote: On Tue, Jul 28, 2015 at 8:01 PM, Boris Ostrovsky wrote: On 07/28/2015 08:47 PM, Andrew Cooper wrote: On 29/07/2015 01:21, Andy Lutomirski wrote: On Tue, Jul 28, 2015 at 10:10 AM, Boris Ostrovsky wrote: O

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/15 06:28, Andy Lutomirski wrote: > On Tue, Jul 28, 2015 at 8:01 PM, Boris Ostrovsky > wrote: >> On 07/28/2015 08:47 PM, Andrew Cooper wrote: >>> On 29/07/2015 01:21, Andy Lutomirski wrote: On Tue, Jul 28, 2015 at 10:10 AM, Boris Ostrovsky wrote: > On 07/28/2015 01:07 PM, An

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Tue, Jul 28, 2015 at 8:01 PM, Boris Ostrovsky wrote: > On 07/28/2015 08:47 PM, Andrew Cooper wrote: >> >> On 29/07/2015 01:21, Andy Lutomirski wrote: >>> >>> On Tue, Jul 28, 2015 at 10:10 AM, Boris Ostrovsky >>> wrote: On 07/28/2015 01:07 PM, Andy Lutomirski wrote: > > On Tue

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Tue, Jul 28, 2015 at 8:01 PM, Boris Ostrovsky wrote: > On 07/28/2015 08:47 PM, Andrew Cooper wrote: >> >> On 29/07/2015 01:21, Andy Lutomirski wrote: >>> >>> On Tue, Jul 28, 2015 at 10:10 AM, Boris Ostrovsky >>> wrote: On 07/28/2015 01:07 PM, Andy Lutomirski wrote: > > On Tue

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/28/2015 08:47 PM, Andrew Cooper wrote: On 29/07/2015 01:21, Andy Lutomirski wrote: On Tue, Jul 28, 2015 at 10:10 AM, Boris Ostrovsky wrote: On 07/28/2015 01:07 PM, Andy Lutomirski wrote: On Tue, Jul 28, 2015 at 9:30 AM, Andrew Cooper wrote: I suspect that the set_ldt(NULL, 0) call has

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 29/07/2015 01:21, Andy Lutomirski wrote: > On Tue, Jul 28, 2015 at 10:10 AM, Boris Ostrovsky > wrote: >> On 07/28/2015 01:07 PM, Andy Lutomirski wrote: >>> On Tue, Jul 28, 2015 at 9:30 AM, Andrew Cooper >>> wrote: I suspect that the set_ldt(NULL, 0) call hasn't reached Xen before xen

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Tue, Jul 28, 2015 at 10:10 AM, Boris Ostrovsky wrote: > On 07/28/2015 01:07 PM, Andy Lutomirski wrote: >> >> On Tue, Jul 28, 2015 at 9:30 AM, Andrew Cooper >> wrote: >>> >>> I suspect that the set_ldt(NULL, 0) call hasn't reached Xen before >>> xen_free_ldt() is attempting to nab back the page

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/28/2015 01:07 PM, Andy Lutomirski wrote: On Tue, Jul 28, 2015 at 9:30 AM, Andrew Cooper wrote: I suspect that the set_ldt(NULL, 0) call hasn't reached Xen before xen_free_ldt() is attempting to nab back the pages which Xen still has mapped as an LDT. I just instrumented it with yet more

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Tue, Jul 28, 2015 at 9:30 AM, Andrew Cooper wrote: > I suspect that the set_ldt(NULL, 0) call hasn't reached Xen before > xen_free_ldt() is attempting to nab back the pages which Xen still has > mapped as an LDT. > I just instrumented it with yet more LSL instructions. I'm pretty sure that se

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 28/07/15 16:43, Andy Lutomirski wrote: > After forward-porting my virtio patches, I got this thing to run on Xen. After several tries, I got: [ 53.985707] [ cut here ] [ 53.986314] kernel BUG at arch/x86/xen/enlighten.c:496! [ 53.98667

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/28/2015 11:23 AM, Andrew Cooper wrote: On 28/07/15 15:50, Boris Ostrovsky wrote: On 07/28/2015 10:35 AM, Andrew Cooper wrote: On 28/07/15 15:05, Boris Ostrovsky wrote: On 07/28/2015 06:29 AM, Andrew Cooper wrote: After forward-porting my virtio patches, I got this thing to run on Xen.

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Jul 28, 2015 3:30 AM, "Andrew Cooper" wrote: > > On 28/07/15 04:16, Andy Lutomirski wrote: > > On Mon, Jul 27, 2015 at 7:20 PM, Andy Lutomirski > > wrote: > >> On Mon, Jul 27, 2015 at 9:18 AM, Boris Ostrovsky > >> wrote: > >>> On 07/27/2015 11:53 AM, Andy Lutomirski wrote: > On Mon, Jul

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/28/2015 11:15 AM, Konrad Rzeszutek Wilk wrote: On Tue, Jul 28, 2015 at 10:50:39AM -0400, Boris Ostrovsky wrote: On 07/28/2015 10:35 AM, Andrew Cooper wrote: On 28/07/15 15:05, Boris Ostrovsky wrote: On 07/28/2015 06:29 AM, Andrew Cooper wrote: After forward-porting my virtio patches, I

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 28/07/15 15:50, Boris Ostrovsky wrote: > On 07/28/2015 10:35 AM, Andrew Cooper wrote: >> On 28/07/15 15:05, Boris Ostrovsky wrote: >>> On 07/28/2015 06:29 AM, Andrew Cooper wrote: >> After forward-porting my virtio patches, I got this thing to run on >> Xen. After several tries, I got:

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Tue, Jul 28, 2015 at 10:50:39AM -0400, Boris Ostrovsky wrote: > On 07/28/2015 10:35 AM, Andrew Cooper wrote: > >On 28/07/15 15:05, Boris Ostrovsky wrote: > >>On 07/28/2015 06:29 AM, Andrew Cooper wrote: > >After forward-porting my virtio patches, I got this thing to run on > >Xen. After

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/28/2015 10:35 AM, Andrew Cooper wrote: On 28/07/15 15:05, Boris Ostrovsky wrote: On 07/28/2015 06:29 AM, Andrew Cooper wrote: After forward-porting my virtio patches, I got this thing to run on Xen. After several tries, I got: [ 53.985707] [ cut here ] [ 53.9

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 28/07/15 15:05, Boris Ostrovsky wrote: > On 07/28/2015 06:29 AM, Andrew Cooper wrote: >> After forward-porting my virtio patches, I got this thing to run on Xen. After several tries, I got: [ 53.985707] [ cut here ] [ 53.986314] kernel BUG at

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/28/2015 06:29 AM, Andrew Cooper wrote: After forward-porting my virtio patches, I got this thing to run on Xen. After several tries, I got: [ 53.985707] [ cut here ] [ 53.986314] kernel BUG at arch/x86/xen/enlighten.c:496! [ 53.986677] invalid opcode:

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 28/07/15 04:16, Andy Lutomirski wrote: > On Mon, Jul 27, 2015 at 7:20 PM, Andy Lutomirski wrote: >> On Mon, Jul 27, 2015 at 9:18 AM, Boris Ostrovsky >> wrote: >>> On 07/27/2015 11:53 AM, Andy Lutomirski wrote: On Mon, Jul 27, 2015 at 8:36 AM, Boris Ostrovsky wrote: > On 07/25/20

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/27/2015 11:16 PM, Andy Lutomirski wrote: On Mon, Jul 27, 2015 at 7:20 PM, Andy Lutomirski wrote: On Mon, Jul 27, 2015 at 9:18 AM, Boris Ostrovsky wrote: On 07/27/2015 11:53 AM, Andy Lutomirski wrote: On Mon, Jul 27, 2015 at 8:36 AM, Boris Ostrovsky wrote: On 07/25/2015 01:36 AM, Andy

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Mon, Jul 27, 2015 at 8:16 PM, Andy Lutomirski wrote: > On Mon, Jul 27, 2015 at 7:20 PM, Andy Lutomirski wrote: >> On Mon, Jul 27, 2015 at 9:18 AM, Boris Ostrovsky >> wrote: >>> On 07/27/2015 11:53 AM, Andy Lutomirski wrote: On Mon, Jul 27, 2015 at 8:36 AM, Boris Ostrovsky wrot

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Mon, Jul 27, 2015 at 7:20 PM, Andy Lutomirski wrote: > On Mon, Jul 27, 2015 at 9:18 AM, Boris Ostrovsky > wrote: >> On 07/27/2015 11:53 AM, Andy Lutomirski wrote: >>> >>> On Mon, Jul 27, 2015 at 8:36 AM, Boris Ostrovsky >>> wrote: On 07/25/2015 01:36 AM, Andy Lutomirski wrote: >

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Mon, Jul 27, 2015 at 9:18 AM, Boris Ostrovsky wrote: > On 07/27/2015 11:53 AM, Andy Lutomirski wrote: >> >> On Mon, Jul 27, 2015 at 8:36 AM, Boris Ostrovsky >> wrote: >>> >>> On 07/25/2015 01:36 AM, Andy Lutomirski wrote: Here's v3. It fixes the "dazed and confused" issue, I hope.

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/27/2015 11:53 AM, Andy Lutomirski wrote: On Mon, Jul 27, 2015 at 8:36 AM, Boris Ostrovsky wrote: On 07/25/2015 01:36 AM, Andy Lutomirski wrote: Here's v3. It fixes the "dazed and confused" issue, I hope. It's also probably a good general attack surface reduction, and it replaces some s

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Mon, Jul 27, 2015 at 8:36 AM, Boris Ostrovsky wrote: > On 07/25/2015 01:36 AM, Andy Lutomirski wrote: >> >> Here's v3. It fixes the "dazed and confused" issue, I hope. It's also >> probably a good general attack surface reduction, and it replaces some >> scary code with IMO less scary code. >

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On 07/25/2015 01:36 AM, Andy Lutomirski wrote: Here's v3. It fixes the "dazed and confused" issue, I hope. It's also probably a good general attack surface reduction, and it replaces some scary code with IMO less scary code. Also, servers and embedded systems should probably turn off modify_ld

Re: [Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

On Fri, Jul 24, 2015 at 10:36:43PM -0700, Andy Lutomirski wrote: > Willy and Kees: I left the config option alone. The -tiny people will > like it, and we can always add a sysctl of some sort later. OK, please ignore my other e-mail I missed this part. I'll see if I can propose the sysctl complet

[Xen-devel] [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option

Here's v3. It fixes the "dazed and confused" issue, I hope. It's also probably a good general attack surface reduction, and it replaces some scary code with IMO less scary code. Also, servers and embedded systems should probably turn off modify_ldt. This makes that possible. Xen people, can you