binder: Add default binder devices through binderfs when configured

Currently, since each binderfs instance needs its own
private binder devices, every time a binderfs instance is
mounted, all the default binder devices need to be created
via the BINDER_CTL_ADD IOCTL. This patch aims to
add a solution to automatically create the default binder
devices for each binderfs instance that gets mounted.
To achieve this goal, when CONFIG_ANDROID_BINDERFS is set,
the default binder devices specified by CONFIG_ANDROID_BINDER_DEVICES
are created in each binderfs instance instead of global devices
being created by the binder driver.

Co-developed-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190808222727.132744-2-hridya@google.com
Link: https://lore.kernel.org/r/20190904110704.8606-2-christian.brauner@ubuntu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hridya Valsaraju 2019-09-04 13:07:03 +02:00 committed by Greg Kroah-Hartman
parent 028fb5822b
commit ca2864c6e8
3 changed files with 25 additions and 5 deletions

View File

@ -122,7 +122,7 @@ static uint32_t binder_debug_mask = BINDER_DEBUG_USER_ERROR |
BINDER_DEBUG_FAILED_TRANSACTION | BINDER_DEBUG_DEAD_TRANSACTION;
module_param_named(debug_mask, binder_debug_mask, uint, 0644);
static char *binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES;
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);
@ -6131,7 +6131,8 @@ static int __init binder_init(void)
&transaction_log_fops);
}
if (strcmp(binder_devices_param, "") != 0) {
if (!IS_ENABLED(CONFIG_ANDROID_BINDERFS) &&
strcmp(binder_devices_param, "") != 0) {
/*
* Copy the module_parameter string, because we don't want to
* tokenize it in-place.

View File

@ -37,6 +37,8 @@ struct binder_device {
extern const struct file_operations binder_fops;
extern char *binder_devices_param;
#ifdef CONFIG_ANDROID_BINDERFS
extern bool is_binderfs_device(const struct inode *inode);
#else

View File

@ -186,8 +186,7 @@ static int binderfs_binder_device_create(struct inode *ref_inode,
req->major = MAJOR(binderfs_dev);
req->minor = minor;
ret = copy_to_user(userp, req, sizeof(*req));
if (ret) {
if (userp && copy_to_user(userp, req, sizeof(*req))) {
ret = -EFAULT;
goto err;
}
@ -467,6 +466,9 @@ static int binderfs_fill_super(struct super_block *sb, void *data, int silent)
int ret;
struct binderfs_info *info;
struct inode *inode = NULL;
struct binderfs_device device_info = { 0 };
const char *name;
size_t len;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
@ -521,7 +523,22 @@ static int binderfs_fill_super(struct super_block *sb, void *data, int silent)
if (!sb->s_root)
return -ENOMEM;
return binderfs_binder_ctl_create(sb);
ret = binderfs_binder_ctl_create(sb);
if (ret)
return ret;
name = binder_devices_param;
for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) {
strscpy(device_info.name, name, len + 1);
ret = binderfs_binder_device_create(inode, NULL, &device_info);
if (ret)
return ret;
name += len;
if (*name == ',')
name++;
}
return 0;
}
static struct dentry *binderfs_mount(struct file_system_type *fs_type,