tree cb6a39846c57a68202e23d3f350b192f355e60d3
parent bce65f18316cc6dbf858b1577a36956d30caa315
author Peter Hurley <peter@hurleysoftware.com> 1413485984 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1415233573 -0800

uml: Fix unsafe pid reference to foreground process group

Although the tty core maintains a pid reference for the foreground
process group, if the foreground process group is changed that
pid reference is dropped. Thus, the pid reference used for signalling
could become stale.

Safely obtain a pid reference to the foreground process group and
release the reference after signalling is complete.

cc: Jeff Dike <jdike@addtoit.com>
Acked-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>