Re: [PATCH] ptrace: fix PTRACE_LISTEN race corrupting task->state

From: Oleg Nesterov
Date: Wed Feb 22 2017 - 12:15:38 EST

On 02/22, Oleg Nesterov wrote:
> note also that PTRACE_LISTEN itself can do ptrace_signal_wake_up(true),

please ignore, in this case the __TASK_TRACED at the start of _unfreeze()
saves us.

> > This causes it to instead clobber TASK_WAKING,
> even if it is already TASK_RUNNING it is simply wrong to set TASK_TRACED
> in both cases, right?
> Thanks. The patch looks good at first glance, but let me think a bit...
> perhaps we should change PTRACE_LISTEN instead, not sure.
> Oleg.