Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-15 Thread Andrew Cooper
On 15/07/2019 07:54, Jan Beulich wrote: > On 15.07.2019 07:05, Zhenzhong Duan wrote: >> On 2019/7/12 22:06, Andrew Cooper wrote: >>> On 11/07/2019 03:15, Zhenzhong Duan wrote: Commit 7457c0da024b ("x86/alternatives: Add int3_emulate_call() selftest") is used to ensure there is a gap

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-15 Thread Jan Beulich
On 15.07.2019 07:05, Zhenzhong Duan wrote: > > On 2019/7/12 22:06, Andrew Cooper wrote: >> On 11/07/2019 03:15, Zhenzhong Duan wrote: >>> Commit 7457c0da024b ("x86/alternatives: Add int3_emulate_call() >>> selftest") is used to ensure there is a gap setup in exception stack >>> which could be

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-14 Thread Zhenzhong Duan
On 2019/7/12 22:06, Andrew Cooper wrote: On 11/07/2019 03:15, Zhenzhong Duan wrote: Commit 7457c0da024b ("x86/alternatives: Add int3_emulate_call() selftest") is used to ensure there is a gap setup in exception stack which could be used for inserting call return address. This gap is missed in

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-12 Thread Andrew Cooper
On 11/07/2019 03:15, Zhenzhong Duan wrote: > Commit 7457c0da024b ("x86/alternatives: Add int3_emulate_call() > selftest") is used to ensure there is a gap setup in exception stack > which could be used for inserting call return address. > > This gap is missed in XEN PV int3 exception entry path,

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-12 Thread Zhenzhong Duan
On 2019/7/12 21:09, Peter Zijlstra wrote: On Fri, Jul 12, 2019 at 09:04:22PM +0800, Zhenzhong Duan wrote: On 2019/7/12 20:06, Peter Zijlstra wrote: On Thu, Jul 11, 2019 at 04:15:21PM +0800, Zhenzhong Duan wrote: diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-12 Thread Peter Zijlstra
On Fri, Jul 12, 2019 at 03:09:16PM +0200, Peter Zijlstra wrote: > On Fri, Jul 12, 2019 at 09:04:22PM +0800, Zhenzhong Duan wrote: > > > > On 2019/7/12 20:06, Peter Zijlstra wrote: > > > On Thu, Jul 11, 2019 at 04:15:21PM +0800, Zhenzhong Duan wrote: > > > > diff --git

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-12 Thread Peter Zijlstra
On Fri, Jul 12, 2019 at 09:04:22PM +0800, Zhenzhong Duan wrote: > > On 2019/7/12 20:06, Peter Zijlstra wrote: > > On Thu, Jul 11, 2019 at 04:15:21PM +0800, Zhenzhong Duan wrote: > > > diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c > > > index 4722ba2..2138d69 100644 > > >

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-12 Thread Zhenzhong Duan
On 2019/7/12 20:06, Peter Zijlstra wrote: On Thu, Jul 11, 2019 at 04:15:21PM +0800, Zhenzhong Duan wrote: diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 4722ba2..2138d69 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -596,7 +596,7 @@

Re: [Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-12 Thread Peter Zijlstra
On Thu, Jul 11, 2019 at 04:15:21PM +0800, Zhenzhong Duan wrote: > diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c > index 4722ba2..2138d69 100644 > --- a/arch/x86/xen/enlighten_pv.c > +++ b/arch/x86/xen/enlighten_pv.c > @@ -596,7 +596,7 @@ struct trap_array_entry { > >

[Xen-devel] [PATCH v2] xen/pv: Fix a boot up hang revealed by int3 self test

2019-07-12 Thread Zhenzhong Duan
Commit 7457c0da024b ("x86/alternatives: Add int3_emulate_call() selftest") is used to ensure there is a gap setup in exception stack which could be used for inserting call return address. This gap is missed in XEN PV int3 exception entry path, then below panic triggered: [0.772876] general