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

[Sudeep Holla]

On 30/04/2019 17:46, Andy Lutomirski wrote:
> On Mon, Mar 18, 2019 at 3:49 AM Sudeep Holla <sudeep.holla@xxxxxxx> 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.
> 

Tested using tools/testing/selftests/x86/ptrace_syscall.c

Also v3 doesn't change any logic or additional call to new function as
in v2. It's just simple cleanup as suggested by Oleg.

-- 
Regards,
Sudeep