mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm

We will soon modify the vanilla get_user_pages() so it can no
longer be used on mm/tasks other than 'current/current->mm',
which is by far the most common way it is called.  For now,
we allow the old-style calls, but warn when they are used.
(implemented in previous patch)

This patch switches all callers of:

	get_user_pages()
	get_user_pages_unlocked()
	get_user_pages_locked()

to stop passing tsk/mm so they will no longer see the warnings.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: jack@suse.cz
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210156.113E9407@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a11cfd2..0253ad9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1264,15 +1264,16 @@
 	return gfn_to_hva_memslot_prot(slot, gfn, writable);
 }
 
-static int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
-	unsigned long start, int write, struct page **page)
+static int get_user_page_nowait(unsigned long start, int write,
+		struct page **page)
 {
 	int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
 
 	if (write)
 		flags |= FOLL_WRITE;
 
-	return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
+	return __get_user_pages(current, current->mm, start, 1, flags, page,
+			NULL, NULL);
 }
 
 static inline int check_user_page_hwpoison(unsigned long addr)
@@ -1334,8 +1335,7 @@
 
 	if (async) {
 		down_read(&current->mm->mmap_sem);
-		npages = get_user_page_nowait(current, current->mm,
-					      addr, write_fault, page);
+		npages = get_user_page_nowait(addr, write_fault, page);
 		up_read(&current->mm->mmap_sem);
 	} else
 		npages = __get_user_pages_unlocked(current, current->mm, addr, 1,