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
	drivers/gpu/msm/kgsl_device.h

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.

Conflicts:
	drivers/gpu/msm/kgsl.c
	drivers/gpu/msm/kgsl_debugfs.c

Change-Id: Ic0dedbad3a3b54dc96251663fdf89c466fef3ca5
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Gaurav Gagrani <ggagrani@codeaurora.org>
msm: kgsl: prevent kgsl_get_pagetable from returning a destroyed pt

A race condition exists between kref_get_pagetable and
kref_put_pagetable such that is is possible to put the last
reference to a pagetable slightly before it has been removed
from the list. By checking kref_get_unless_zero we can determine
if the last reference has already been released. This is safe
because the list is protected by a ptlock.

Change-Id: If6a75e9ca0dec6a12bda5739f835c936a4c3a3b4
Signed-off-by: Jeff Boody <jboody@codeaurora.org>
msm: kgsl: Fix spinlock recursion in destroy pagetable

pagetable list is protected by ptlock. Few functions
while iterating over a pagetable list takes same ptlock,
kgsl_destroy_pagetable() also need same lock. This will
cause spinlock recursion if kgsl_destroy_pagetable()
called while iterating over a list. Created two versions
of same function one is with lock and other is without
lock.

CRs-Fixed: 621172
Change-Id: I61440f99022fce8629a57bb5661e2eef9613187b
Signed-off-by: Prakash Kamliya <pkamliya@codeaurora.org>
Signed-off-by: Gaurav Gagrani <ggagrani@codeaurora.org>