[PATCH v2 3/6] x86: clean up _TIF_SYSCALL_EMU handling using ptrace_syscall_enter hook

[Andy Lutomirski]

On Mon, Mar 18, 2019 at 3:49 AM Sudeep Holla <sudeep.holla at arm.com> wrote:
>
> Now that we have a new hook ptrace_syscall_enter that can be called from
> syscall entry code and it handles PTRACE_SYSEMU in generic code, we
> can do some cleanup using the same in syscall_trace_enter.
>
> Further the extra logic to find single stepping PTRACE_SYSEMU_SINGLESTEP
> in syscall_slow_exit_work seems unnecessary. Let's remove the same.
>

Unless the patch set contains a selftest that exercises all the
interesting cases here, NAK.  To be clear, there needs to be a test
that passes on an unmodified kernel and still passes on a patched
kernel.  And that test case needs to *fail* if, for example, you force
"emulated" to either true or false rather than reading out the actual
value.

--Andy