Re: [patch -mm] update mq_notify to use a struct pid

[Cedric Le Goater <clg@fr.ibm.com>]

Eric W. Biederman wrote:

[ ... ]

> There is also the case that should not come up with signals where
> we have a pid from a child namespace, that we should also be able to
> compute the pid for.

I don't understand how a signal can come from a child pid namespace ?

> In essence I intend to have a list of pid_namespace, pid_t pairs connected
> to a struct pid that we can look through to find the appropriate pid.

yes, that's the purpose of pid_nr() I guess.

This list would contain in nearly all cases a single pair (current pid
namespace, pid value). It will contain 2 pairs for a task that has unshared
its pid namespace : a pair for the current pid namespace, that needs to
allocated when unshare() is called, and one pair for the ancestor pid
namespace which is already allocated.

Do you see more ?

C.