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/mm/mempolicy.c b/mm/mempolicy.c
index 4c4187c..dd0ce7f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -844,12 +844,12 @@
 	}
 }
 
-static int lookup_node(struct mm_struct *mm, unsigned long addr)
+static int lookup_node(unsigned long addr)
 {
 	struct page *p;
 	int err;
 
-	err = get_user_pages(current, mm, addr & PAGE_MASK, 1, 0, 0, &p, NULL);
+	err = get_user_pages(addr & PAGE_MASK, 1, 0, 0, &p, NULL);
 	if (err >= 0) {
 		err = page_to_nid(p);
 		put_page(p);
@@ -904,7 +904,7 @@
 
 	if (flags & MPOL_F_NODE) {
 		if (flags & MPOL_F_ADDR) {
-			err = lookup_node(mm, addr);
+			err = lookup_node(addr);
 			if (err < 0)
 				goto out;
 			*policy = err;