mm: introduce follow_pte()
mm: introduce follow_pte()

A generic readonly page table lookup helper to map an address space and an
address from it to a pte.

Signed-off-by: Johannes Weiner <331be22c6b63ca3e0a03d408c2d906b1b02cd5f2@cmpxchg.org>
Cc: Christoph Hellwig <923f7720577207a44b32e59bbfbea59d27f1ae8e@infradead.org>
Acked-by: Magnus Damm <1f369b7bccd13b930ed9aa83ec10be6225fd866f@gmail.com>
Cc: Hans Verkuil <f625be9dbdcbbd12a043857af148e8fb895d9a1d@xs4all.nl>
Cc: Paul Mundt <38b52dbb5f0b63d149982b6c5de788ec93a89032@linux-sh.org>
Cc: Hugh Dickins <a96f0e3e09e76642c8a5dcf04c8f12accf315063@tiscali.co.uk>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas