linux/drivers/android/Kconfig
Todd Kjos 44d8047f1d binder: use standard functions to allocate fds
Binder uses internal fs interfaces to allocate and install fds:

__alloc_fd
__fd_install
__close_fd
get_files_struct
put_files_struct

These were used to support the passing of fds between processes
as part of a transaction. The actual allocation and installation
of the fds in the target process was handled by the sending
process so the standard functions, alloc_fd() and fd_install()
which assume task==current couldn't be used.

This patch refactors this mechanism so that the fds are
allocated and installed by the target process allowing the
standard functions to be used.

The sender now creates a list of fd fixups that contains the
struct *file and the address to fixup with the new fd once
it is allocated. This list is processed by the target process
when the transaction is dequeued.

A new error case is introduced by this change. If an async
transaction with file descriptors cannot allocate new
fds in the target (probably due to out of file descriptors),
the transaction is discarded with a log message. In the old
implementation this would have been detected in the sender
context and failed prior to sending.

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-14 15:22:36 +02:00

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# SPDX-License-Identifier: GPL-2.0
menu "Android"
config ANDROID
bool "Android Drivers"
---help---
Enable support for various drivers needed on the Android platform
if ANDROID
config ANDROID_BINDER_IPC
bool "Android Binder IPC Driver"
depends on MMU && !CPU_CACHE_VIVT
default n
---help---
Binder is used in Android for both communication between processes,
and remote method invocation.
This means one Android process can call a method/routine in another
Android process, using Binder to identify, invoke and pass arguments
between said processes.
config ANDROID_BINDER_DEVICES
string "Android Binder devices"
depends on ANDROID_BINDER_IPC
default "binder,hwbinder,vndbinder"
---help---
Default value for the binder.devices parameter.
The binder.devices parameter is a comma-separated list of strings
that specifies the names of the binder device nodes that will be
created. Each binder device has its own context manager, and is
therefore logically separated from the other devices.
config ANDROID_BINDER_IPC_SELFTEST
bool "Android Binder IPC Driver Selftest"
depends on ANDROID_BINDER_IPC
---help---
This feature allows binder selftest to run.
Binder selftest checks the allocation and free of binder buffers
exhaustively with combinations of various buffer sizes and
alignments.
endif # if ANDROID
endmenu