Re: [PATCH v3 4/6] powerpc/64s: Un-blacklist system_call() from kprobes

2017-06-22 Thread Naveen N. Rao
On 2017/06/22 11:14PM, Nicholas Piggin wrote: > On Thu, 22 Jun 2017 21:14:21 +1000 > Michael Ellerman wrote: > > > Nicholas Piggin writes: > > > > > On Thu, 22 Jun 2017 00:08:40 +0530 > > > "Naveen N. Rao" wrote: > > >

Re: [PATCH v3 4/6] powerpc/64s: Un-blacklist system_call() from kprobes

2017-06-22 Thread Nicholas Piggin
On Thu, 22 Jun 2017 21:14:21 +1000 Michael Ellerman wrote: > Nicholas Piggin writes: > > > On Thu, 22 Jun 2017 00:08:40 +0530 > > "Naveen N. Rao" wrote: > > > >> It is actually safe to probe system_call() in

Re: [PATCH v3 4/6] powerpc/64s: Un-blacklist system_call() from kprobes

2017-06-22 Thread Michael Ellerman
Nicholas Piggin writes: > On Thu, 22 Jun 2017 00:08:40 +0530 > "Naveen N. Rao" wrote: > >> It is actually safe to probe system_call() in entry_64.S, but only till >> we unset MSR_RI. To allow this, add a new symbol system_call_exit() >> after

Re: [PATCH v3 4/6] powerpc/64s: Un-blacklist system_call() from kprobes

2017-06-21 Thread Nicholas Piggin
On Thu, 22 Jun 2017 00:08:40 +0530 "Naveen N. Rao" wrote: > It is actually safe to probe system_call() in entry_64.S, but only till > we unset MSR_RI. To allow this, add a new symbol system_call_exit() > after the mtmsrd and blacklist that. Though the mtmsrd

[PATCH v3 4/6] powerpc/64s: Un-blacklist system_call() from kprobes

2017-06-21 Thread Naveen N. Rao
It is actually safe to probe system_call() in entry_64.S, but only till we unset MSR_RI. To allow this, add a new symbol system_call_exit() after the mtmsrd and blacklist that. Though the mtmsrd instruction itself is now whitelisted, we won't be allowed to probe on it as we don't allow probing on