From: Ganesh Mahendran opensource.ganesh@gmail.com

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 Cc: stable stable@vger.kernel.org

---- V3: update comments V2: update comments Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/android/binder_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 8989e31..6da12c5 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -626,7 +626,7 @@ 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";