Add binder and ashmem kernel drivers as out-of-tree modules

Based on code from https://github.com/hungys/binder-for-linux

kernel/ashmem/Makefile

+ccflags-y += -I$(src) -Wno-error=implicit-int
+
+ifneq ($(KERNELRELEASE),)
+obj-m := ashmem_linux.o
+ashmem_linux-y := deps.o ashmem.o
+
+$(obj)/deps.o: $(src)/deps.h
+
+$(obj)/deps.h: $(src)/gen_deps.sh
+	sudo $(src)/gen_deps.sh > $@
+else
+KERNEL_SRC ?= /lib/modules/$(shell uname -r)/build
+
+all:
+	$(MAKE) -C $(KERNEL_SRC) V=0 M=$$PWD
+
+clean:
+	rm -rf deps.h *.o *.ko *.mod.c *.symvers *.order .*.cmd .tmp_versions
+endif

kernel/ashmem/ashmem.h

+/*
+ * include/linux/ashmem.h
+ *
+ * Copyright 2008 Google Inc.
+ * Author: Robert Love
+ *
+ * This file is dual licensed.  It may be redistributed and/or modified
+ * under the terms of the Apache 2.0 License OR version 2 of the GNU
+ * General Public License.
+ */
+
+#ifndef _LINUX_ASHMEM_H
+#define _LINUX_ASHMEM_H
+
+#include <linux/limits.h>
+#include <linux/ioctl.h>
+#include <linux/compat.h>
+
+#include "uapi/ashmem.h"
+
+/* support of 32bit userspace on 64bit platforms */
+#ifdef CONFIG_COMPAT
+#define COMPAT_ASHMEM_SET_SIZE		_IOW(__ASHMEMIOC, 3, compat_size_t)
+#define COMPAT_ASHMEM_SET_PROT_MASK	_IOW(__ASHMEMIOC, 5, unsigned int)
+#endif
+
+#endif	/* _LINUX_ASHMEM_H */

kernel/ashmem/deps.c

+#include <linux/mm.h>
+
+#include "deps.h"
+
+static int (*shmem_zero_setup_ptr)(struct vm_area_struct *) = SHMEM_ZERO_SETUP;
+
+int shmem_zero_setup(struct vm_area_struct *vma)
+{
+    return shmem_zero_setup_ptr(vma);
+}

kernel/ashmem/gen_deps.sh

+#!/bin/sh
+
+SYMS="shmem_zero_setup"
+
+for sym in $SYMS; do 
+	addr=`cat /proc/kallsyms | grep -Ee '^[0-9a-f]+ T '$sym'$' | sed -e 's/\s.*$//g'`
+	if [ a$addr = 'a' ]; then
+		echo "Error: can't find symbol $sym"
+		exit 1
+	fi
+
+	name=`echo $sym | tr '[:lower:]' '[:upper:]'`
+	echo "#define $name\t(void *)0x$addr"
+done

kernel/ashmem/uapi/ashmem.h

+/*
+ * drivers/staging/android/uapi/ashmem.h
+ *
+ * Copyright 2008 Google Inc.
+ * Author: Robert Love
+ *
+ * This file is dual licensed.  It may be redistributed and/or modified
+ * under the terms of the Apache 2.0 License OR version 2 of the GNU
+ * General Public License.
+ */
+
+#ifndef _UAPI_LINUX_ASHMEM_H
+#define _UAPI_LINUX_ASHMEM_H
+
+#include <linux/ioctl.h>
+
+#define ASHMEM_NAME_LEN		256
+
+#define ASHMEM_NAME_DEF		"dev/ashmem"
+
+/* Return values from ASHMEM_PIN: Was the mapping purged while unpinned? */
+#define ASHMEM_NOT_PURGED	0
+#define ASHMEM_WAS_PURGED	1
+
+/* Return values from ASHMEM_GET_PIN_STATUS: Is the mapping pinned? */
+#define ASHMEM_IS_UNPINNED	0
+#define ASHMEM_IS_PINNED	1
+
+struct ashmem_pin {
+	__u32 offset;	/* offset into region, in bytes, page-aligned */
+	__u32 len;	/* length forward from offset, in bytes, page-aligned */
+};
+
+#define __ASHMEMIOC		0x77
+
+#define ASHMEM_SET_NAME		_IOW(__ASHMEMIOC, 1, char[ASHMEM_NAME_LEN])
+#define ASHMEM_GET_NAME		_IOR(__ASHMEMIOC, 2, char[ASHMEM_NAME_LEN])
+#define ASHMEM_SET_SIZE		_IOW(__ASHMEMIOC, 3, size_t)
+#define ASHMEM_GET_SIZE		_IO(__ASHMEMIOC, 4)
+#define ASHMEM_SET_PROT_MASK	_IOW(__ASHMEMIOC, 5, unsigned long)
+#define ASHMEM_GET_PROT_MASK	_IO(__ASHMEMIOC, 6)
+#define ASHMEM_PIN		_IOW(__ASHMEMIOC, 7, struct ashmem_pin)
+#define ASHMEM_UNPIN		_IOW(__ASHMEMIOC, 8, struct ashmem_pin)
+#define ASHMEM_GET_PIN_STATUS	_IO(__ASHMEMIOC, 9)
+#define ASHMEM_PURGE_ALL_CACHES	_IO(__ASHMEMIOC, 10)
+
+#endif	/* _UAPI_LINUX_ASHMEM_H */

kernel/binder/Makefile

+ccflags-y += -I$(src)
+
+ifneq ($(KERNELRELEASE),)
+obj-m := binder_linux.o
+binder_linux-y := deps.o binder.o
+
+$(obj)/deps.o: $(src)/deps.h
+
+$(obj)/deps.h: $(src)/gen_deps.sh
+	sudo $(src)/gen_deps.sh > $@
+else
+KERNEL_SRC ?= /lib/modules/$(shell uname -r)/build
+
+all:
+	$(MAKE) -C $(KERNEL_SRC) V=0 M=$$PWD
+
+clean:
+	rm -rf deps.h *.o *.ko *.mod.c *.symvers *.order .*.cmd .tmp_versions
+endif
\ No newline at end of file

kernel/binder/deps.c

+#include <linux/sched.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/atomic.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "deps.h"
+
+static struct vm_struct *(*get_vm_area_ptr)(unsigned long, unsigned long) = GET_VM_AREA;
+static void (*zap_page_range_ptr)(struct vm_area_struct *, unsigned long, unsigned long, struct zap_details *) = ZAP_PAGE_RANGE;
+static int (*map_kernel_range_noflush_ptr)(unsigned long start, unsigned long size, pgprot_t prot, struct page **pages) = MAP_KERNEL_RANGE_NOFLUSH;
+static void (*unmap_kernel_range_ptr)(unsigned long, unsigned long) = UNMAP_KERNEL_RANGE;
+static struct files_struct *(*get_files_struct_ptr)(struct task_struct *) = GET_FILES_STRUCT;
+static void (*put_files_struct_ptr)(struct files_struct *) = PUT_FILES_STRUCT;
+static struct sighand_struct *(*__lock_task_sighand_ptr)(struct task_struct *, unsigned long *) = __LOCK_TASK_SIGHAND;
+static int (*__alloc_fd_ptr)(struct files_struct *files, unsigned start, unsigned end, unsigned flags) = __ALLOC_FD;
+static void (*__fd_install_ptr)(struct files_struct *files, unsigned int fd, struct file *file) = __FD_INSTALL;
+static int (*__close_fd_ptr)(struct files_struct *files, unsigned int fd) = __CLOSE_FD;
+static int (*can_nice_ptr)(const struct task_struct *, const int) = CAN_NICE;
+static int (*security_binder_set_context_mgr_ptr)(struct task_struct *mgr) = SECURITY_BINDER_SET_CONTEXT_MGR;
+static int (*security_binder_transaction_ptr)(struct task_struct *from, struct task_struct *to) = SECURITY_BINDER_TRANSACTION;
+static int (*security_binder_transfer_binder_ptr)(struct task_struct *from, struct task_struct *to) = SECURITY_BINDER_TRANSFER_BINDER;
+static int (*security_binder_transfer_file_ptr)(struct task_struct *from, struct task_struct *to, struct file *file) = SECURITY_BINDER_TRANSFER_FILE;
+
+struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
+{
+	return get_vm_area_ptr(size, flags);
+}
+
+void zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *details)
+{
+	zap_page_range_ptr(vma, address, size, details);
+}
+
+int map_kernel_range_noflush(unsigned long start, unsigned long size, pgprot_t prot, struct page **pages)
+{
+	return map_kernel_range_noflush_ptr(start, size, prot, pages);
+}
+
+void unmap_kernel_range(unsigned long addr, unsigned long size)
+{
+	unmap_kernel_range_ptr(addr, size);
+}
+
+struct files_struct *get_files_struct(struct task_struct *task)
+{
+	return get_files_struct_ptr(task);
+}
+
+void put_files_struct(struct files_struct *files)
+{
+	put_files_struct_ptr(files);
+}
+
+struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, unsigned long *flags)
+{
+	return __lock_task_sighand_ptr(tsk, flags);
+}
+
+int __alloc_fd(struct files_struct *files, unsigned start, unsigned end, unsigned flags)
+{
+	return __alloc_fd_ptr(files, start, end, flags);
+}
+
+void __fd_install(struct files_struct *files, unsigned int fd, struct file *file)
+{
+	__fd_install_ptr(files, fd, file);
+}
+
+int __close_fd(struct files_struct *files, unsigned int fd)
+{
+	return __close_fd_ptr(files, fd);
+}
+
+int can_nice(const struct task_struct *p, const int nice)
+{
+	return can_nice_ptr(p, nice);
+}
+
+int security_binder_set_context_mgr(struct task_struct *mgr)
+{
+	return security_binder_set_context_mgr_ptr(mgr);
+}
+
+int security_binder_transaction(struct task_struct *from, struct task_struct *to)
+{
+	return security_binder_transaction_ptr(from, to);
+}
+
+int security_binder_transfer_binder(struct task_struct *from, struct task_struct *to)
+{
+	return security_binder_transfer_binder_ptr(from, to);
+}
+
+int security_binder_transfer_file(struct task_struct *from, struct task_struct *to, struct file *file)
+{
+	return security_binder_transfer_file_ptr(from, to, file);
+}

kernel/binder/gen_deps.sh

+#!/bin/sh
+
+SYMS="get_vm_area zap_page_range map_kernel_range_noflush unmap_kernel_range "\
+"get_files_struct put_files_struct __lock_task_sighand "\
+"__alloc_fd __fd_install __close_fd can_nice "\
+"security_binder_set_context_mgr security_binder_transaction "\
+"security_binder_transfer_binder security_binder_transfer_file"
+
+for sym in $SYMS; do 
+	addr=`cat /proc/kallsyms | grep -Ee '^[0-9a-f]+ T '$sym'$' | sed -e 's/\s.*$//g'`
+	if [ a$addr = 'a' ]; then
+		echo "Error: can't find symbol $sym"
+		exit 1
+	fi
+
+	name=`echo $sym | tr '[:lower:]' '[:upper:]'`
+	echo "#define $name\t(void *)0x$addr"
+done