Re: [PATCH v2 0/7] CLONE_FD: Task exit notification via file descriptor

From: David Drysdale
Date: Mon Mar 23 2015 - 10:13:43 EST


On Mon, Mar 16, 2015 at 11:29 PM, <josh@xxxxxxxxxxxxxxxx> wrote:
> On Mon, Mar 16, 2015 at 03:14:14PM -0700, Thiago Macieira wrote:
>> On Monday 16 March 2015 14:44:20 Kees Cook wrote:
>> > > O_CLOEXEC
>> > > Set the close-on-exec flag on the new file
>> > >descriptor. See the description of the O_CLOEXEC flag in open(2) for
>> > >reasons why this may be useful.
>> >
>> > This begs the question: what happens when all CLONE_FD fds for a
>> > process are closed? Will the parent get SIGCHLD instead, will it
>> > auto-reap, or will it be un-wait-able (I assume not this...)
>>
>> Depends on CLONE_AUTOREAP. If it's on, then no one gets SIGCHLD, no one can
>> wait() on it and the process autoreaps itself.
>
> Minor nit: CLONE_AUTOREAP makes the process autoreap and nobody can wait
> on it, but if you pass SIGCHLD or some other exit signal to clone then
> you'll still get that signal.

Quick query: does CLONE_AUTOREAP also affect waiting for non-exit
events (i.e. WUNTRACED / WCONTINUED), by original parent and/or ptracer?
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