msm: kgsl: hold a process_private refcount in process_mem_print

There is a possible race condition where the process can be going
away while its debugfs 'mem' file is being read, which could cause
memory corruption.

Conflicts:

	drivers/gpu/msm/kgsl.c

CRs-Fixed: 627780
Change-Id: I697486faeb3f186fd1220d0acc1e449a4f7b77b0
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
msm: kgsl: Look up the process struct in process_mem_open()

The pointer to an active process struct stands the risk of going stale
if process_mem_open() is called just before the debugfs dentry is
destroyed.  Instead of storing and using the pointer pass the process pid
to process_mem_open() and do a lookup to ensure that we always get active
processes.

Change-Id: Ic0dedbad3a3b54dc96251663fdf89c466fef3ca5
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: kgsl: Add a flag to mark user mapped GPU buffers

Add a flag in /sys/kernel/debug/kgsl/kgsl-3do/proc/<pid>/mem
file to indicate for each GPU buffer if it is mapped to userspace
in <pid> or not.

CRs-fixed: 634962

Conflicts:

	drivers/gpu/msm/kgsl_debugfs.c

Change-Id: I8abda74ef5656aca6b1c0315af8deb77460fa5a9
Signed-off-by: Harsh Vardhan Dwivedi <hdwivedi@codeaurora.org>
Signed-off-by: Prabhat Awasthi <pawasthi@codeaurora.org>