mm/vmalloc.c: clean up map_vm_area third argument

Currently map_vm_area() takes (struct page *** pages) as third argument,
and after mapping, it moves (*pages) to point to (*pages +
nr_mappped_pages).

It looks like this kind of increment is useless to its caller these
days.  The callers don't care about the increments and actually they're
trying to avoid this by passing another copy to map_vm_area().

The caller can always guarantee all the pages can be mapped into vm_area
as specified in first argument and the caller only cares about whether
map_vm_area() fails or not.

This patch cleans up the pointer movement in map_vm_area() and updates
its callers accordingly.

Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 02b0379..4f34dc0 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -585,7 +585,6 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate,
 
 	for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
 		int ret;
-		struct page **page_array_ptr;
 
 		page = &proc->pages[(page_addr - proc->buffer) / PAGE_SIZE];
 
@@ -598,8 +597,7 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate,
 		}
 		tmp_area.addr = page_addr;
 		tmp_area.size = PAGE_SIZE + PAGE_SIZE /* guard page? */;
-		page_array_ptr = page;
-		ret = map_vm_area(&tmp_area, PAGE_KERNEL, &page_array_ptr);
+		ret = map_vm_area(&tmp_area, PAGE_KERNEL, page);
 		if (ret) {
 			pr_err("%d: binder_alloc_buf failed to map page at %p in kernel\n",
 			       proc->pid, page_addr);