This is a note to let you know that I've just added the patch titled

android: binder: use VM_ALLOC to get vm area

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: android-binder-use-vm_alloc-to-get-vm-area.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From aac6830ec1cb681544212838911cdc57f2638216 Mon Sep 17 00:00:00 2001

From: Ganesh Mahendran opensource.ganesh@gmail.com Date: Wed, 10 Jan 2018 10:49:05 +0800 Subject: android: binder: use VM_ALLOC to get vm area

From: Ganesh Mahendran opensource.ganesh@gmail.com

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

--- drivers/android/binder_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -668,7 +668,7 @@ int binder_alloc_mmap_handler(struct bin 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";

Patches currently in stable-queue which might be from opensource.ganesh@gmail.com are

queue-4.14/android-binder-use-vm_alloc-to-get-vm-area.patch