android: binder: use VM_ALLOC to get vm area

BugLink: http://bugs.launchpad.net/bugs/1747169
commit aac6830ec1cb681544212838911cdc57f2638216 upstream.

VM_IOREMAP is used to access hardware through a mechanism called
I/O mapped memory. Android binder is a IPC machanism which will
not access I/O memory.

And VM_IOREMAP has alignment requiement which may not needed in
binder.
    __get_vm_area_node()
    {
    ...
        if (flags & VM_IOREMAP)
            align = 1ul << clamp_t(int, fls_long(size),
               PAGE_SHIFT, IOREMAP_MAX_ORDER);
    ...
    }

This patch will save some kernel vm area, especially for 32bit os.

In 32bit OS, kernel vm area is only 240MB. We may got below
error when launching a app:

<3>[ 4482.440053] binder_alloc: binder_alloc_mmap_handler: 15728 8ce67000-8cf65000 get_vm_area failed -12
<3>[ 4483.218817] binder_alloc: binder_alloc_mmap_handler: 15745 8ce67000-8cf65000 get_vm_area failed -12

Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Martijn Coenen <maco@android.com>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 6f6f745605afc44861c22c29b55f8a74f42f3dd6..bef8c65af8fc5624be31a78453f3b8101d67a021 100644 (file)
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -666,7 +666,7 @@ int binder_alloc_mmap_handler(struct binder_alloc *alloc,
                goto err_already_mapped;
        }
 
-       area = get_vm_area(vma->vm_end - vma->vm_start, VM_IOREMAP);
+       area = get_vm_area(vma->vm_end - vma->vm_start, VM_ALLOC);
        if (area == NULL) {
                ret = -ENOMEM;
                failure_string = "get_vm_area";