ANDROID: binder: support multiple /dev instances.
Add a new module parameter 'devices', that can be
used to specify the names of the binder device
nodes we want to populate in /dev.
Each device node has its own context manager, and
is therefore logically separated from all the other
device nodes.
The config option CONFIG_ANDROID_BINDER_DEVICES can
be used to set the default value of the parameter.
This approach was favored over using IPC namespaces,
mostly because we require a single process to be a
part of multiple binder contexts, which seemed harder
to achieve with namespaces.
Change-Id: I3df72b2a19b5ad5a0360e6322482db7b00a12b24
Signed-off-by: Martijn Coenen <maco@google.com>
diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig
index bdfc6c6..a82fc02 100644
--- a/drivers/android/Kconfig
+++ b/drivers/android/Kconfig
@@ -19,6 +19,18 @@
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"
+ ---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_32BIT
bool
depends on !64BIT && ANDROID_BINDER_IPC
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 0b57866d6..5e84ed0 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -50,6 +50,7 @@
static DEFINE_MUTEX(binder_deferred_lock);
static DEFINE_MUTEX(binder_mmap_lock);
+static HLIST_HEAD(binder_devices);
static HLIST_HEAD(binder_procs);
static HLIST_HEAD(binder_deferred_list);
static HLIST_HEAD(binder_dead_nodes);
@@ -113,6 +114,9 @@
static bool binder_debug_no_lock;
module_param_named(proc_no_lock, binder_debug_no_lock, bool, S_IWUSR | S_IRUGO);
+static char *binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES;
+module_param_named(devices, binder_devices_param, charp, S_IRUGO);
+
static DECLARE_WAIT_QUEUE_HEAD(binder_user_error_wait);
static int binder_stop_on_user_error;
@@ -220,9 +224,10 @@
const char *name;
};
-static struct binder_context global_context = {
- .binder_context_mgr_uid = INVALID_UID,
- .name = "binder",
+struct binder_device {
+ struct hlist_node hlist;
+ struct miscdevice miscdev;
+ struct binder_context context;
};
struct binder_work {
@@ -3048,6 +3053,7 @@
static int binder_open(struct inode *nodp, struct file *filp)
{
struct binder_proc *proc;
+ struct binder_device *binder_dev;
binder_debug(BINDER_DEBUG_OPEN_CLOSE, "binder_open: %d:%d\n",
current->group_leader->pid, current->pid);
@@ -3058,10 +3064,12 @@
get_task_struct(current);
proc->tsk = current;
proc->vma_vm_mm = current->mm;
- proc->context = &global_context;
INIT_LIST_HEAD(&proc->todo);
init_waitqueue_head(&proc->wait);
proc->default_priority = task_nice(current);
+ binder_dev = container_of(filp->private_data, struct binder_device,
+ miscdev);
+ proc->context = &binder_dev->context;
binder_lock(__func__);
@@ -3768,26 +3776,50 @@
.release = binder_release,
};
-static struct miscdevice binder_miscdev = {
- .minor = MISC_DYNAMIC_MINOR,
- .name = "binder",
- .fops = &binder_fops
-};
-
BINDER_DEBUG_ENTRY(state);
BINDER_DEBUG_ENTRY(stats);
BINDER_DEBUG_ENTRY(transactions);
BINDER_DEBUG_ENTRY(transaction_log);
+static int __init init_binder_device(const char *name)
+{
+ int ret;
+ struct binder_device *binder_device;
+
+ binder_device = kzalloc(sizeof(*binder_device), GFP_KERNEL);
+ if (!binder_device)
+ return -ENOMEM;
+
+ binder_device->miscdev.fops = &binder_fops;
+ binder_device->miscdev.minor = MISC_DYNAMIC_MINOR;
+ binder_device->miscdev.name = name;
+
+ binder_device->context.binder_context_mgr_uid = INVALID_UID;
+ binder_device->context.name = name;
+
+ ret = misc_register(&binder_device->miscdev);
+ if (ret < 0) {
+ kfree(binder_device);
+ return ret;
+ }
+
+ hlist_add_head(&binder_device->hlist, &binder_devices);
+
+ return ret;
+}
+
static int __init binder_init(void)
{
int ret;
+ char *device_name, *device_names;
+ struct binder_device *device;
+ struct hlist_node *tmp;
binder_debugfs_dir_entry_root = debugfs_create_dir("binder", NULL);
if (binder_debugfs_dir_entry_root)
binder_debugfs_dir_entry_proc = debugfs_create_dir("proc",
binder_debugfs_dir_entry_root);
- ret = misc_register(&binder_miscdev);
+
if (binder_debugfs_dir_entry_root) {
debugfs_create_file("state",
S_IRUGO,
@@ -3815,6 +3847,35 @@
&binder_transaction_log_failed,
&binder_transaction_log_fops);
}
+
+ /*
+ * Copy the module_parameter string, because we don't want to
+ * tokenize it in-place.
+ */
+ device_names = kzalloc(strlen(binder_devices_param) + 1, GFP_KERNEL);
+ if (!device_names) {
+ ret = -ENOMEM;
+ goto err_alloc_device_names_failed;
+ }
+ strcpy(device_names, binder_devices_param);
+
+ while ((device_name = strsep(&device_names, ","))) {
+ ret = init_binder_device(device_name);
+ if (ret)
+ goto err_init_binder_device_failed;
+ }
+
+ return ret;
+
+err_init_binder_device_failed:
+ hlist_for_each_entry_safe(device, tmp, &binder_devices, hlist) {
+ misc_deregister(&device->miscdev);
+ hlist_del(&device->hlist);
+ kfree(device);
+ }
+err_alloc_device_names_failed:
+ debugfs_remove_recursive(binder_debugfs_dir_entry_root);
+
return ret;
}