Commit ca2864c6 authored by Hridya Valsaraju's avatar Hridya Valsaraju Committed by Greg Kroah-Hartman
Browse files

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: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: default avatarHridya Valsaraju <hridya@google.com>
Reviewed-by: default avatarJoel 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: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 028fb582

drivers/android/binder.c

+3 −2
Original line number Diff line number Diff line
@@ -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.

drivers/android/binder_internal.h

+2 −0
Original line number Diff line number Diff line
@@ -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

drivers/android/binderfs.c

+20 −3
Original line number Diff line number Diff line
@@ -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,

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