msm: vidc: Initialize kernel space stack variables

This change initializes kernel space stack variables
that are passed between kernel space and user space
using ioctls.
Non initialization of these variables may lead to
leakage of memory values from the kernel stack to
user space.

Change-Id: Icb195470545ee48b55671ac09798610178e833e1
CRs-fixed: 556771,563420
Signed-off-by: Deepak Verma <dverma@codeaurora.org>
msm: vidc: free the recon buffers in cleanup function

- The recon buffers were not released when video recording
  was killed abruptly leading to memory leak.

- Fix provided to release the recon buffers when media
  server killed abruptly.

Change-Id: I48ac1a592719446b7e4bf87bbd707d09351d1e61
Signed-off-by: srikarri <sridur@codeaurora.org>
msm: vidc: return error in case of init failure

Return error if error comes in video driver
initialization.

Change-Id: I54c516808587fb7d94c3d517f8c72c6c9aa9d91d
CRs-fixed: 542535
Signed-off-by: Pushkaraj Patil <ppatil@codeaurora.org>
msm: vidc: Validate input data before processing

User controlled data needs to be validated before
processing, otherwise it may corrupt existing data
and other programming variables which may further
lead to crash in kernel space.
This change validates user specified buffer's data,
such as offset and data length, before performing
any operations in kernel.

Change-Id: Idb2a5c4c270cdbb55adfc0c22b9296b7dd359de9
CRs-fixed: 547695
Signed-off-by: Deepak Verma <dverma@codeaurora.org>
msm: vidc: Check validity of userspace address

Before writing to a userspace address, verification
of the validity of user space address is required.

Change-Id: I9141e44a6c11aaf3f4d57c08bb0dd26a7b214f34
CRs-fixed: 556356
Signed-off-by: Deepak Verma <dverma@codeaurora.org>
msm: vidc: Validate userspace buffer count before using it

Validate the number of buffers count variable before
using it to avoid structure overflow error.

Change-Id: I61582c93e0f26ec6842e437134fb8a42bdbc36ff
CRs-fixed: 563654
Signed-off-by: Pachika, Vikas Reddy <vpachi@codeaurora.org>
msm: vidc: Validate userspace buffer count

Makesure the number of buffers count is less than
the maximum limit to avoid structure overflow errors.

Change-Id: Icf3850de36325637ae43ac95f1c8f0f63e201d31
CRs-fixed: 563694
Signed-off-by: Pachika, Vikas Reddy <vpachi@codeaurora.org>