ANDROID: binder: remove 32-bit binder interface.
PATCH v2 1/1 ANDROID: binder: remove 32-bit binder interface.
From: Martijn Coenen <[email protected]>
New devices launching with Android P need to use the 64-bit binder interface, even on 32-bit SoCs [0].
This change removes the Kconfig option to select the 32-bit binder interface. We don't think this will affect existing userspace for the following reasons:
1) The latest Android common tree is 4.14, so we don't believe any Android devices are on kernels >4.14.
2) Android devices launch on an LTS release and stick with it, so we wouldn't expect devices running on <= 4.14 now to upgrade to 4.17 or later. But even if they did, they'd rebuild the world (kernel + userspace) anyway.
3) Other userspaces like 'anbox' are already using the 64-bit interface.
Note that this change doesn't remove the 32-bit UAPI itself; the reason for that is that Android userspace always uses the latest UAPI headers from upstream, and userspace retains 32-bit support for devices that are upgrading. This will be removed as well in 2-3 years, at which point we can remove the code from the UAPI as well.
Finally, this change introduces build errors on archs where 64-bit get_user/put_user is not supported, so make binder unavailable on m68k (which wouldn't want it anyway).
[0]: https://android-review.googlesource.com/c/platform/build/+/595193
---
Changes in v2:
- Dropped support for m68k to avoid build errors.
drivers/android/Kconfig | 15 +-------------- drivers/android/binder.c | 4 ---- 2 files changed, 1 insertion(+), 18 deletions(-)
drivers/android/Kconfig +1 -14
@@ -10,7 +10,7 @@ if ANDROID config ANDROID_BINDER_IPC bool "Android Binder IPC Driver" - depends on MMU + depends on MMU && !M68K default n ---help--- Binder is used in Android for both communication between processes,
@@ -32,19 +32,6 @@ config ANDROID_BINDER_DEVICES created. Each binder device has its own context manager, and is therefore logically separated from the other devices. -config ANDROID_BINDER_IPC_32BIT - bool "Use old (Android 4.4 and earlier) 32-bit binder API" - depends on !64BIT && ANDROID_BINDER_IPC - default y - ---help--- - The Binder API has been changed to support both 32 and 64bit - applications in a mixed environment. - - Enable this to support an old 32-bit Android user-space (v4.4 and - earlier). - - Note that enabling this will break newer Android user-space. - config ANDROID_BINDER_IPC_SELFTEST bool "Android Binder IPC Driver Selftest" depends on ANDROID_BINDER_IPC
drivers/android/binder.c +0 -4
@@ -72,10 +72,6 @@#include <linux/security.h> #include <linux/spinlock.h> -#ifdef CONFIG_ANDROID_BINDER_IPC_32BIT -#define BINDER_IPC_32BIT 1 -#endif -#include <uapi/linux/android/binder.h> #include "binder_alloc.h" #include "binder_trace.h"
Signature · 1 line
2.17.0.441.gb46fe60e1d-goog