staging: binder: add vm_fault handler

An issue was observed when a userspace task exits.
The page which hits error here is the zero page.
In binder mmap, the whole of vma is not mapped.
On a task crash, when debuggerd reads the binder regions,
the unmapped areas fall to do_anonymous_page in handle_pte_fault,
due to the absence of a vm_fault handler. This results in
zero page being mapped. Later in zap_pte_range, vm_normal_page
returns zero page in the case of VM_MIXEDMAP and it results in the
error.

BUG: Bad page map in process mediaserver  pte:9dff379f pmd:9bfbd831
page:c0ed8e60 count:1 mapcount:-1 mapping:  (null) index:0x0
page flags: 0x404(referenced|reserved)
addr:40c3f000 vm_flags:10220051 anon_vma:  (null) mapping:d9fe0764 index:fd
vma->vm_ops->fault:   (null)
vma->vm_file->f_op->mmap: binder_mmap+0x0/0x274
CPU: 0 PID: 1463 Comm: mediaserver Tainted: G        W    3.10.17+ #1
[<c001549c>] (unwind_backtrace+0x0/0x11c) from [<c001200c>] (show_stack+0x10/0x14)
[<c001200c>] (show_stack+0x10/0x14) from [<c0103d78>] (print_bad_pte+0x158/0x190)
[<c0103d78>] (print_bad_pte+0x158/0x190) from [<c01055f0>] (unmap_single_vma+0x2e4/0x598)
[<c01055f0>] (unmap_single_vma+0x2e4/0x598) from [<c010618c>] (unmap_vmas+0x34/0x50)
[<c010618c>] (unmap_vmas+0x34/0x50) from [<c010a9e4>] (exit_mmap+0xc8/0x1e8)
[<c010a9e4>] (exit_mmap+0xc8/0x1e8) from [<c00520f0>] (mmput+0x54/0xd0)
[<c00520f0>] (mmput+0x54/0xd0) from [<c005972c>] (do_exit+0x360/0x990)
[<c005972c>] (do_exit+0x360/0x990) from [<c0059ef0>] (do_group_exit+0x84/0xc0)
[<c0059ef0>] (do_group_exit+0x84/0xc0) from [<c0066de0>] (get_signal_to_deliver+0x4d4/0x548)
[<c0066de0>] (get_signal_to_deliver+0x4d4/0x548) from [<c0011500>] (do_signal+0xa8/0x3b8)

Add a vm_fault handler which returns VM_FAULT_SIGBUS, and prevents the
wrong fallback to do_anonymous_page.

CRs-Fixed: 673147
Change-Id: I43730a51b6c819538b46c5e4dc5c96c8a384098d
Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Patch-mainline: linux-arm-kernel @ 06/02/14, 18:17
Signed-off-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org>
binder: NULL pointer reference

This fix handles a possible NULL pointer reference in
debug message.

CRs-fixed: 642883
Change-Id: Ide78f281ec0cff5cbd8231b85c305d13a892854e
Signed-off-by: Paresh Nakhe <pnakhe@codeaurora.org>
(cherry picked from commit 0457d25cb875de4bc39003ffe8b80b578fb45d9c)

Conflicts:
	drivers/staging/android/binder.c
Fix typo
staging: android: binder: modify struct binder_write_read to use size_t

This change mirrors the userspace operation where struct binder_write_read
members that specify the buffer size and consumed size are size_t elements.

The patch also fixes the binder_thread_write() and binder_thread_read()
functions prototypes to conform with the definition of binder_write_read.

The changes do not affect existing 32bit ABI.

Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>
Acked-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 397334fc2be6a7e2f77474bd2b24880efea007bf
Git-repo: https://android.googlesource.com/kernel/common/
Change-Id: If606f0fe135ffc4a630dbf34d755f559c36ee62a
Signed-off-by: Neeti Desai <neetid@codeaurora.org>
Signed-off-by: Ajay Dudani <adudani@codeaurora.org>
(cherry picked from commit ab036dbda5a2da2488b1a63ec4f98062b397ce71)

Conflicts:
	drivers/staging/android/binder.c
Binder: More offset validation