Re: [PATCH v3 2/3] x86/speculation: apply IBPB more strictly to avoid cross-process data leak

Jiri Kosina
2018-09-05T07:55:41Z

On Wed, 5 Sep 2018, Peter Zijlstra wrote:

> > if (tsk && tsk->mm &&
> > tsk->mm->context.ctx_id != last_ctx_id &&
> > - get_dumpable(tsk->mm) != SUID_DUMP_USER)
> > + ___ptrace_may_access(current, tsk, PTRACE_MODE_IBPB))
> > indirect_branch_prediction_barrier();
>
> See how the new (first) argument is 'current' and you could've just used
> the old __ptrace_may_access().

Yeah, 1/3 is dropped in my current series already; this was cherry-picked
from original Tim's series, but it is indeed superfluous.

Thanks,

--
Jiri Kosina
SUSE Labs