From ac4812c5ffbb88dd3280a6dacd39fcb73e077fe4 Mon Sep 17 00:00:00 2001 From: Martijn Coenen Date: Fri, 3 Feb 2017 14:40:48 -0800 Subject: [PATCH] binder: Support multiple /dev instances MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Cc: Martijn Coenen Cc: Arve Hjønnevåg Cc: Amit Pundir Cc: Serban Constantinescu Cc: Dmitry Shmidt Cc: Rom Lemarchand Cc: Android Kernel Team Signed-off-by: Martijn Coenen [jstultz: minor checkpatch warning fix] Signed-off-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- drivers/android/Kconfig | 12 ++++++ drivers/android/binder.c | 83 ++++++++++++++++++++++++++++++++++------ 2 files changed, 84 insertions(+), 11 deletions(-) diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig index bdfc6c6f4f5a..a82fc022d34b 100644 --- a/drivers/android/Kconfig +++ b/drivers/android/Kconfig @@ -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 diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 97e4ed424932..705caf55005e 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -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 @@ err_bad_arg: 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; }