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binder: Support multiple /dev instances

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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.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Martijn Coenen <maco@google.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Serban Constantinescu <serban.constantinescu@arm.com>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Rom Lemarchand <romlem@google.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Martijn Coenen <maco@google.com>
[jstultz: minor checkpatch warning fix]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Martijn Coenen 2017-02-03 14:40:48 -08:00 committed by Greg Kroah-Hartman
parent 14db31814a
commit ac4812c5ff
2 changed files with 84 additions and 11 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

12
drivers/android/Kconfig
View file

@ -19,6 +19,18 @@ config ANDROID_BINDER_IPC
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

83
drivers/android/binder.c
View file

@ -50,6 +50,7 @@ static DEFINE_MUTEX(binder_main_lock);
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 @@ module_param_named(debug_mask, binder_debug_mask, uint, S_IWUSR | S_IRUGO);
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, 0444);
static DECLARE_WAIT_QUEUE_HEAD(binder_user_error_wait);
static int binder_stop_on_user_error;
@ -220,9 +224,10 @@ struct binder_context {
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 {
@ -3047,6 +3052,7 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
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);
@ -3057,10 +3063,12 @@ static int binder_open(struct inode *nodp, struct file *filp)
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__);
@ -3767,26 +3775,50 @@ static const struct file_operations binder_fops = {
.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,
@ -3814,6 +3846,35 @@ static int __init binder_init(void)
&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;
}