13ad20fe3SChristian Brauner /* SPDX-License-Identifier: GPL-2.0 */ 23ad20fe3SChristian Brauner 33ad20fe3SChristian Brauner #include <linux/compiler_types.h> 43ad20fe3SChristian Brauner #include <linux/errno.h> 53ad20fe3SChristian Brauner #include <linux/fs.h> 63ad20fe3SChristian Brauner #include <linux/fsnotify.h> 73ad20fe3SChristian Brauner #include <linux/gfp.h> 83ad20fe3SChristian Brauner #include <linux/idr.h> 93ad20fe3SChristian Brauner #include <linux/init.h> 103ad20fe3SChristian Brauner #include <linux/ipc_namespace.h> 113ad20fe3SChristian Brauner #include <linux/kdev_t.h> 123ad20fe3SChristian Brauner #include <linux/kernel.h> 133ad20fe3SChristian Brauner #include <linux/list.h> 1401b3f1fcSChristian Brauner #include <linux/namei.h> 153ad20fe3SChristian Brauner #include <linux/magic.h> 163ad20fe3SChristian Brauner #include <linux/major.h> 173ad20fe3SChristian Brauner #include <linux/miscdevice.h> 183ad20fe3SChristian Brauner #include <linux/module.h> 193ad20fe3SChristian Brauner #include <linux/mutex.h> 203ad20fe3SChristian Brauner #include <linux/mount.h> 213ad20fe3SChristian Brauner #include <linux/parser.h> 223ad20fe3SChristian Brauner #include <linux/radix-tree.h> 233ad20fe3SChristian Brauner #include <linux/sched.h> 24849d540dSChristian Brauner #include <linux/seq_file.h> 253ad20fe3SChristian Brauner #include <linux/slab.h> 263ad20fe3SChristian Brauner #include <linux/spinlock_types.h> 273ad20fe3SChristian Brauner #include <linux/stddef.h> 283ad20fe3SChristian Brauner #include <linux/string.h> 293ad20fe3SChristian Brauner #include <linux/types.h> 303ad20fe3SChristian Brauner #include <linux/uaccess.h> 313ad20fe3SChristian Brauner #include <linux/user_namespace.h> 323ad20fe3SChristian Brauner #include <linux/xarray.h> 333ad20fe3SChristian Brauner #include <uapi/asm-generic/errno-base.h> 343ad20fe3SChristian Brauner #include <uapi/linux/android/binder.h> 35c13295adSChristian Brauner #include <uapi/linux/android/binderfs.h> 363ad20fe3SChristian Brauner 373ad20fe3SChristian Brauner #include "binder_internal.h" 383ad20fe3SChristian Brauner 393ad20fe3SChristian Brauner #define FIRST_INODE 1 403ad20fe3SChristian Brauner #define SECOND_INODE 2 413ad20fe3SChristian Brauner #define INODE_OFFSET 3 423ad20fe3SChristian Brauner #define INTSTRLEN 21 433ad20fe3SChristian Brauner #define BINDERFS_MAX_MINOR (1U << MINORBITS) 4436bdf3caSChristian Brauner /* Ensure that the initial ipc namespace always has devices available. */ 4536bdf3caSChristian Brauner #define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4) 463ad20fe3SChristian Brauner 473ad20fe3SChristian Brauner static dev_t binderfs_dev; 483ad20fe3SChristian Brauner static DEFINE_MUTEX(binderfs_minors_mutex); 493ad20fe3SChristian Brauner static DEFINE_IDA(binderfs_minors); 503ad20fe3SChristian Brauner 51849d540dSChristian Brauner enum { 52849d540dSChristian Brauner Opt_max, 53f0083451SHridya Valsaraju Opt_stats_mode, 54849d540dSChristian Brauner Opt_err 55849d540dSChristian Brauner }; 56849d540dSChristian Brauner 57f0083451SHridya Valsaraju enum binderfs_stats_mode { 58f0083451SHridya Valsaraju STATS_NONE, 59f0083451SHridya Valsaraju STATS_GLOBAL, 60f0083451SHridya Valsaraju }; 61f0083451SHridya Valsaraju 62849d540dSChristian Brauner static const match_table_t tokens = { 63849d540dSChristian Brauner { Opt_max, "max=%d" }, 64f0083451SHridya Valsaraju { Opt_stats_mode, "stats=%s" }, 65849d540dSChristian Brauner { Opt_err, NULL } 66849d540dSChristian Brauner }; 67849d540dSChristian Brauner 683ad20fe3SChristian Brauner static inline struct binderfs_info *BINDERFS_I(const struct inode *inode) 693ad20fe3SChristian Brauner { 703ad20fe3SChristian Brauner return inode->i_sb->s_fs_info; 713ad20fe3SChristian Brauner } 723ad20fe3SChristian Brauner 733ad20fe3SChristian Brauner bool is_binderfs_device(const struct inode *inode) 743ad20fe3SChristian Brauner { 753ad20fe3SChristian Brauner if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) 763ad20fe3SChristian Brauner return true; 773ad20fe3SChristian Brauner 783ad20fe3SChristian Brauner return false; 793ad20fe3SChristian Brauner } 803ad20fe3SChristian Brauner 813ad20fe3SChristian Brauner /** 823ad20fe3SChristian Brauner * binderfs_binder_device_create - allocate inode from super block of a 833ad20fe3SChristian Brauner * binderfs mount 843ad20fe3SChristian Brauner * @ref_inode: inode from wich the super block will be taken 853ad20fe3SChristian Brauner * @userp: buffer to copy information about new device for userspace to 863ad20fe3SChristian Brauner * @req: struct binderfs_device as copied from userspace 873ad20fe3SChristian Brauner * 8801b3f1fcSChristian Brauner * This function allocates a new binder_device and reserves a new minor 893ad20fe3SChristian Brauner * number for it. 903ad20fe3SChristian Brauner * Minor numbers are limited and tracked globally in binderfs_minors. The 913ad20fe3SChristian Brauner * function will stash a struct binder_device for the specific binder 923ad20fe3SChristian Brauner * device in i_private of the inode. 933ad20fe3SChristian Brauner * It will go on to allocate a new inode from the super block of the 943ad20fe3SChristian Brauner * filesystem mount, stash a struct binder_device in its i_private field 953ad20fe3SChristian Brauner * and attach a dentry to that inode. 963ad20fe3SChristian Brauner * 973ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 983ad20fe3SChristian Brauner */ 993ad20fe3SChristian Brauner static int binderfs_binder_device_create(struct inode *ref_inode, 1003ad20fe3SChristian Brauner struct binderfs_device __user *userp, 1013ad20fe3SChristian Brauner struct binderfs_device *req) 1023ad20fe3SChristian Brauner { 1033ad20fe3SChristian Brauner int minor, ret; 10401b3f1fcSChristian Brauner struct dentry *dentry, *root; 1053ad20fe3SChristian Brauner struct binder_device *device; 1063ad20fe3SChristian Brauner char *name = NULL; 10701b3f1fcSChristian Brauner size_t name_len; 1083ad20fe3SChristian Brauner struct inode *inode = NULL; 1093ad20fe3SChristian Brauner struct super_block *sb = ref_inode->i_sb; 1103ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 1117fefaaddSChristian Brauner #if defined(CONFIG_IPC_NS) 11236bdf3caSChristian Brauner bool use_reserve = (info->ipc_ns == &init_ipc_ns); 1137fefaaddSChristian Brauner #else 1147fefaaddSChristian Brauner bool use_reserve = true; 1157fefaaddSChristian Brauner #endif 1163ad20fe3SChristian Brauner 1173ad20fe3SChristian Brauner /* Reserve new minor number for the new device. */ 1183ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 119849d540dSChristian Brauner if (++info->device_count <= info->mount_opts.max) 12036bdf3caSChristian Brauner minor = ida_alloc_max(&binderfs_minors, 12136bdf3caSChristian Brauner use_reserve ? BINDERFS_MAX_MINOR : 12236bdf3caSChristian Brauner BINDERFS_MAX_MINOR_CAPPED, 123849d540dSChristian Brauner GFP_KERNEL); 124849d540dSChristian Brauner else 125849d540dSChristian Brauner minor = -ENOSPC; 126849d540dSChristian Brauner if (minor < 0) { 127849d540dSChristian Brauner --info->device_count; 1283ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1293ad20fe3SChristian Brauner return minor; 130849d540dSChristian Brauner } 131849d540dSChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1323ad20fe3SChristian Brauner 1333ad20fe3SChristian Brauner ret = -ENOMEM; 1343ad20fe3SChristian Brauner device = kzalloc(sizeof(*device), GFP_KERNEL); 1353ad20fe3SChristian Brauner if (!device) 1363ad20fe3SChristian Brauner goto err; 1373ad20fe3SChristian Brauner 1383ad20fe3SChristian Brauner inode = new_inode(sb); 1393ad20fe3SChristian Brauner if (!inode) 1403ad20fe3SChristian Brauner goto err; 1413ad20fe3SChristian Brauner 1423ad20fe3SChristian Brauner inode->i_ino = minor + INODE_OFFSET; 1433ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1443ad20fe3SChristian Brauner init_special_inode(inode, S_IFCHR | 0600, 1453ad20fe3SChristian Brauner MKDEV(MAJOR(binderfs_dev), minor)); 1463ad20fe3SChristian Brauner inode->i_fop = &binder_fops; 1473ad20fe3SChristian Brauner inode->i_uid = info->root_uid; 1483ad20fe3SChristian Brauner inode->i_gid = info->root_gid; 1493ad20fe3SChristian Brauner 15001b3f1fcSChristian Brauner req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ 15101b3f1fcSChristian Brauner name_len = strlen(req->name); 15201b3f1fcSChristian Brauner /* Make sure to include terminating NUL byte */ 15301b3f1fcSChristian Brauner name = kmemdup(req->name, name_len + 1, GFP_KERNEL); 1543ad20fe3SChristian Brauner if (!name) 1553ad20fe3SChristian Brauner goto err; 1563ad20fe3SChristian Brauner 157f0fe2c0fSChristian Brauner refcount_set(&device->ref, 1); 1583ad20fe3SChristian Brauner device->binderfs_inode = inode; 1593ad20fe3SChristian Brauner device->context.binder_context_mgr_uid = INVALID_UID; 1603ad20fe3SChristian Brauner device->context.name = name; 1613ad20fe3SChristian Brauner device->miscdev.name = name; 1623ad20fe3SChristian Brauner device->miscdev.minor = minor; 1633ad20fe3SChristian Brauner mutex_init(&device->context.context_mgr_node_lock); 1643ad20fe3SChristian Brauner 1653ad20fe3SChristian Brauner req->major = MAJOR(binderfs_dev); 1663ad20fe3SChristian Brauner req->minor = minor; 1673ad20fe3SChristian Brauner 168ca2864c6SHridya Valsaraju if (userp && copy_to_user(userp, req, sizeof(*req))) { 1693ad20fe3SChristian Brauner ret = -EFAULT; 1703ad20fe3SChristian Brauner goto err; 1713ad20fe3SChristian Brauner } 1723ad20fe3SChristian Brauner 1733ad20fe3SChristian Brauner root = sb->s_root; 1743ad20fe3SChristian Brauner inode_lock(d_inode(root)); 17501b3f1fcSChristian Brauner 17601b3f1fcSChristian Brauner /* look it up */ 17701b3f1fcSChristian Brauner dentry = lookup_one_len(name, root, name_len); 17801b3f1fcSChristian Brauner if (IS_ERR(dentry)) { 1793ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 18001b3f1fcSChristian Brauner ret = PTR_ERR(dentry); 1813ad20fe3SChristian Brauner goto err; 1823ad20fe3SChristian Brauner } 1833ad20fe3SChristian Brauner 18401b3f1fcSChristian Brauner if (d_really_is_positive(dentry)) { 18501b3f1fcSChristian Brauner /* already exists */ 1863ad20fe3SChristian Brauner dput(dentry); 1873ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 1883ad20fe3SChristian Brauner ret = -EEXIST; 1893ad20fe3SChristian Brauner goto err; 1903ad20fe3SChristian Brauner } 1913ad20fe3SChristian Brauner 1923ad20fe3SChristian Brauner inode->i_private = device; 19301684db9SChristian Brauner d_instantiate(dentry, inode); 1943ad20fe3SChristian Brauner fsnotify_create(root->d_inode, dentry); 1953ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 1963ad20fe3SChristian Brauner 1973ad20fe3SChristian Brauner return 0; 1983ad20fe3SChristian Brauner 1993ad20fe3SChristian Brauner err: 2003ad20fe3SChristian Brauner kfree(name); 2013ad20fe3SChristian Brauner kfree(device); 2023ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 203849d540dSChristian Brauner --info->device_count; 2043ad20fe3SChristian Brauner ida_free(&binderfs_minors, minor); 2053ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2063ad20fe3SChristian Brauner iput(inode); 2073ad20fe3SChristian Brauner 2083ad20fe3SChristian Brauner return ret; 2093ad20fe3SChristian Brauner } 2103ad20fe3SChristian Brauner 2113ad20fe3SChristian Brauner /** 2123ad20fe3SChristian Brauner * binderfs_ctl_ioctl - handle binder device node allocation requests 2133ad20fe3SChristian Brauner * 2143ad20fe3SChristian Brauner * The request handler for the binder-control device. All requests operate on 2153ad20fe3SChristian Brauner * the binderfs mount the binder-control device resides in: 2163ad20fe3SChristian Brauner * - BINDER_CTL_ADD 2173ad20fe3SChristian Brauner * Allocate a new binder device. 2183ad20fe3SChristian Brauner * 2193ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 2203ad20fe3SChristian Brauner */ 2213ad20fe3SChristian Brauner static long binder_ctl_ioctl(struct file *file, unsigned int cmd, 2223ad20fe3SChristian Brauner unsigned long arg) 2233ad20fe3SChristian Brauner { 2243ad20fe3SChristian Brauner int ret = -EINVAL; 2253ad20fe3SChristian Brauner struct inode *inode = file_inode(file); 2263ad20fe3SChristian Brauner struct binderfs_device __user *device = (struct binderfs_device __user *)arg; 2273ad20fe3SChristian Brauner struct binderfs_device device_req; 2283ad20fe3SChristian Brauner 2293ad20fe3SChristian Brauner switch (cmd) { 2303ad20fe3SChristian Brauner case BINDER_CTL_ADD: 2313ad20fe3SChristian Brauner ret = copy_from_user(&device_req, device, sizeof(device_req)); 2323ad20fe3SChristian Brauner if (ret) { 2333ad20fe3SChristian Brauner ret = -EFAULT; 2343ad20fe3SChristian Brauner break; 2353ad20fe3SChristian Brauner } 2363ad20fe3SChristian Brauner 2373ad20fe3SChristian Brauner ret = binderfs_binder_device_create(inode, device, &device_req); 2383ad20fe3SChristian Brauner break; 2393ad20fe3SChristian Brauner default: 2403ad20fe3SChristian Brauner break; 2413ad20fe3SChristian Brauner } 2423ad20fe3SChristian Brauner 2433ad20fe3SChristian Brauner return ret; 2443ad20fe3SChristian Brauner } 2453ad20fe3SChristian Brauner 2463ad20fe3SChristian Brauner static void binderfs_evict_inode(struct inode *inode) 2473ad20fe3SChristian Brauner { 2483ad20fe3SChristian Brauner struct binder_device *device = inode->i_private; 249849d540dSChristian Brauner struct binderfs_info *info = BINDERFS_I(inode); 2503ad20fe3SChristian Brauner 2513ad20fe3SChristian Brauner clear_inode(inode); 2523ad20fe3SChristian Brauner 2530e13e452SHridya Valsaraju if (!S_ISCHR(inode->i_mode) || !device) 2543ad20fe3SChristian Brauner return; 2553ad20fe3SChristian Brauner 2563ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 257849d540dSChristian Brauner --info->device_count; 2583ad20fe3SChristian Brauner ida_free(&binderfs_minors, device->miscdev.minor); 2593ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2603ad20fe3SChristian Brauner 261f0fe2c0fSChristian Brauner if (refcount_dec_and_test(&device->ref)) { 2623ad20fe3SChristian Brauner kfree(device->context.name); 2633ad20fe3SChristian Brauner kfree(device); 2643ad20fe3SChristian Brauner } 265f0fe2c0fSChristian Brauner } 2663ad20fe3SChristian Brauner 267849d540dSChristian Brauner /** 268849d540dSChristian Brauner * binderfs_parse_mount_opts - parse binderfs mount options 269849d540dSChristian Brauner * @data: options to set (can be NULL in which case defaults are used) 270849d540dSChristian Brauner */ 271849d540dSChristian Brauner static int binderfs_parse_mount_opts(char *data, 272849d540dSChristian Brauner struct binderfs_mount_opts *opts) 273849d540dSChristian Brauner { 274f0083451SHridya Valsaraju char *p, *stats; 275849d540dSChristian Brauner opts->max = BINDERFS_MAX_MINOR; 276f0083451SHridya Valsaraju opts->stats_mode = STATS_NONE; 277849d540dSChristian Brauner 278849d540dSChristian Brauner while ((p = strsep(&data, ",")) != NULL) { 279849d540dSChristian Brauner substring_t args[MAX_OPT_ARGS]; 280849d540dSChristian Brauner int token; 281849d540dSChristian Brauner int max_devices; 282849d540dSChristian Brauner 283849d540dSChristian Brauner if (!*p) 284849d540dSChristian Brauner continue; 285849d540dSChristian Brauner 286849d540dSChristian Brauner token = match_token(p, tokens, args); 287849d540dSChristian Brauner switch (token) { 288849d540dSChristian Brauner case Opt_max: 289849d540dSChristian Brauner if (match_int(&args[0], &max_devices) || 290849d540dSChristian Brauner (max_devices < 0 || 291849d540dSChristian Brauner (max_devices > BINDERFS_MAX_MINOR))) 292849d540dSChristian Brauner return -EINVAL; 293849d540dSChristian Brauner 294849d540dSChristian Brauner opts->max = max_devices; 295849d540dSChristian Brauner break; 296f0083451SHridya Valsaraju case Opt_stats_mode: 297f0083451SHridya Valsaraju if (!capable(CAP_SYS_ADMIN)) 298f0083451SHridya Valsaraju return -EINVAL; 299f0083451SHridya Valsaraju 300f0083451SHridya Valsaraju stats = match_strdup(&args[0]); 301f0083451SHridya Valsaraju if (!stats) 302f0083451SHridya Valsaraju return -ENOMEM; 303f0083451SHridya Valsaraju 304f0083451SHridya Valsaraju if (strcmp(stats, "global") != 0) { 305f0083451SHridya Valsaraju kfree(stats); 306f0083451SHridya Valsaraju return -EINVAL; 307f0083451SHridya Valsaraju } 308f0083451SHridya Valsaraju 309f0083451SHridya Valsaraju opts->stats_mode = STATS_GLOBAL; 310f0083451SHridya Valsaraju kfree(stats); 311f0083451SHridya Valsaraju break; 312849d540dSChristian Brauner default: 313849d540dSChristian Brauner pr_err("Invalid mount options\n"); 314849d540dSChristian Brauner return -EINVAL; 315849d540dSChristian Brauner } 316849d540dSChristian Brauner } 317849d540dSChristian Brauner 318849d540dSChristian Brauner return 0; 319849d540dSChristian Brauner } 320849d540dSChristian Brauner 321849d540dSChristian Brauner static int binderfs_remount(struct super_block *sb, int *flags, char *data) 322849d540dSChristian Brauner { 323f0083451SHridya Valsaraju int prev_stats_mode, ret; 324849d540dSChristian Brauner struct binderfs_info *info = sb->s_fs_info; 325f0083451SHridya Valsaraju 326f0083451SHridya Valsaraju prev_stats_mode = info->mount_opts.stats_mode; 327f0083451SHridya Valsaraju ret = binderfs_parse_mount_opts(data, &info->mount_opts); 328f0083451SHridya Valsaraju if (ret) 329f0083451SHridya Valsaraju return ret; 330f0083451SHridya Valsaraju 331f0083451SHridya Valsaraju if (prev_stats_mode != info->mount_opts.stats_mode) { 332f0083451SHridya Valsaraju pr_err("Binderfs stats mode cannot be changed during a remount\n"); 333f0083451SHridya Valsaraju info->mount_opts.stats_mode = prev_stats_mode; 334f0083451SHridya Valsaraju return -EINVAL; 335f0083451SHridya Valsaraju } 336f0083451SHridya Valsaraju 337f0083451SHridya Valsaraju return 0; 338849d540dSChristian Brauner } 339849d540dSChristian Brauner 340849d540dSChristian Brauner static int binderfs_show_mount_opts(struct seq_file *seq, struct dentry *root) 341849d540dSChristian Brauner { 342849d540dSChristian Brauner struct binderfs_info *info; 343849d540dSChristian Brauner 344849d540dSChristian Brauner info = root->d_sb->s_fs_info; 345849d540dSChristian Brauner if (info->mount_opts.max <= BINDERFS_MAX_MINOR) 346849d540dSChristian Brauner seq_printf(seq, ",max=%d", info->mount_opts.max); 347f0083451SHridya Valsaraju if (info->mount_opts.stats_mode == STATS_GLOBAL) 348f0083451SHridya Valsaraju seq_printf(seq, ",stats=global"); 349849d540dSChristian Brauner 350849d540dSChristian Brauner return 0; 351849d540dSChristian Brauner } 352849d540dSChristian Brauner 3533ad20fe3SChristian Brauner static const struct super_operations binderfs_super_ops = { 3543ad20fe3SChristian Brauner .evict_inode = binderfs_evict_inode, 355849d540dSChristian Brauner .remount_fs = binderfs_remount, 356849d540dSChristian Brauner .show_options = binderfs_show_mount_opts, 357849d540dSChristian Brauner .statfs = simple_statfs, 3583ad20fe3SChristian Brauner }; 3593ad20fe3SChristian Brauner 360e98e6fa1SChristian Brauner static inline bool is_binderfs_control_device(const struct dentry *dentry) 361e98e6fa1SChristian Brauner { 362e98e6fa1SChristian Brauner struct binderfs_info *info = dentry->d_sb->s_fs_info; 363e98e6fa1SChristian Brauner return info->control_dentry == dentry; 364e98e6fa1SChristian Brauner } 365e98e6fa1SChristian Brauner 3663ad20fe3SChristian Brauner static int binderfs_rename(struct inode *old_dir, struct dentry *old_dentry, 3673ad20fe3SChristian Brauner struct inode *new_dir, struct dentry *new_dentry, 3683ad20fe3SChristian Brauner unsigned int flags) 3693ad20fe3SChristian Brauner { 370e98e6fa1SChristian Brauner if (is_binderfs_control_device(old_dentry) || 371e98e6fa1SChristian Brauner is_binderfs_control_device(new_dentry)) 3723ad20fe3SChristian Brauner return -EPERM; 3733ad20fe3SChristian Brauner 374e98e6fa1SChristian Brauner return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 3753ad20fe3SChristian Brauner } 3763ad20fe3SChristian Brauner 3773ad20fe3SChristian Brauner static int binderfs_unlink(struct inode *dir, struct dentry *dentry) 3783ad20fe3SChristian Brauner { 379e98e6fa1SChristian Brauner if (is_binderfs_control_device(dentry)) 3803ad20fe3SChristian Brauner return -EPERM; 3813ad20fe3SChristian Brauner 3823ad20fe3SChristian Brauner return simple_unlink(dir, dentry); 3833ad20fe3SChristian Brauner } 3843ad20fe3SChristian Brauner 3853ad20fe3SChristian Brauner static const struct file_operations binder_ctl_fops = { 3863ad20fe3SChristian Brauner .owner = THIS_MODULE, 3873ad20fe3SChristian Brauner .open = nonseekable_open, 3883ad20fe3SChristian Brauner .unlocked_ioctl = binder_ctl_ioctl, 3893ad20fe3SChristian Brauner .compat_ioctl = binder_ctl_ioctl, 3903ad20fe3SChristian Brauner .llseek = noop_llseek, 3913ad20fe3SChristian Brauner }; 3923ad20fe3SChristian Brauner 3933ad20fe3SChristian Brauner /** 3943ad20fe3SChristian Brauner * binderfs_binder_ctl_create - create a new binder-control device 3953ad20fe3SChristian Brauner * @sb: super block of the binderfs mount 3963ad20fe3SChristian Brauner * 3973ad20fe3SChristian Brauner * This function creates a new binder-control device node in the binderfs mount 3983ad20fe3SChristian Brauner * referred to by @sb. 3993ad20fe3SChristian Brauner * 4003ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 4013ad20fe3SChristian Brauner */ 4023ad20fe3SChristian Brauner static int binderfs_binder_ctl_create(struct super_block *sb) 4033ad20fe3SChristian Brauner { 4043ad20fe3SChristian Brauner int minor, ret; 4053ad20fe3SChristian Brauner struct dentry *dentry; 4063ad20fe3SChristian Brauner struct binder_device *device; 4073ad20fe3SChristian Brauner struct inode *inode = NULL; 4083ad20fe3SChristian Brauner struct dentry *root = sb->s_root; 4093ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 410da8ddba5SChristian Brauner #if defined(CONFIG_IPC_NS) 411da8ddba5SChristian Brauner bool use_reserve = (info->ipc_ns == &init_ipc_ns); 412da8ddba5SChristian Brauner #else 413da8ddba5SChristian Brauner bool use_reserve = true; 414da8ddba5SChristian Brauner #endif 4153ad20fe3SChristian Brauner 4163ad20fe3SChristian Brauner device = kzalloc(sizeof(*device), GFP_KERNEL); 4173ad20fe3SChristian Brauner if (!device) 4183ad20fe3SChristian Brauner return -ENOMEM; 4193ad20fe3SChristian Brauner 4203ad20fe3SChristian Brauner /* If we have already created a binder-control node, return. */ 4213ad20fe3SChristian Brauner if (info->control_dentry) { 4223ad20fe3SChristian Brauner ret = 0; 4233ad20fe3SChristian Brauner goto out; 4243ad20fe3SChristian Brauner } 4253ad20fe3SChristian Brauner 4263ad20fe3SChristian Brauner ret = -ENOMEM; 4273ad20fe3SChristian Brauner inode = new_inode(sb); 4283ad20fe3SChristian Brauner if (!inode) 4293ad20fe3SChristian Brauner goto out; 4303ad20fe3SChristian Brauner 4313ad20fe3SChristian Brauner /* Reserve a new minor number for the new device. */ 4323ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 433da8ddba5SChristian Brauner minor = ida_alloc_max(&binderfs_minors, 434da8ddba5SChristian Brauner use_reserve ? BINDERFS_MAX_MINOR : 435da8ddba5SChristian Brauner BINDERFS_MAX_MINOR_CAPPED, 436da8ddba5SChristian Brauner GFP_KERNEL); 4373ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 4383ad20fe3SChristian Brauner if (minor < 0) { 4393ad20fe3SChristian Brauner ret = minor; 4403ad20fe3SChristian Brauner goto out; 4413ad20fe3SChristian Brauner } 4423ad20fe3SChristian Brauner 4433ad20fe3SChristian Brauner inode->i_ino = SECOND_INODE; 4443ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 4453ad20fe3SChristian Brauner init_special_inode(inode, S_IFCHR | 0600, 4463ad20fe3SChristian Brauner MKDEV(MAJOR(binderfs_dev), minor)); 4473ad20fe3SChristian Brauner inode->i_fop = &binder_ctl_fops; 4483ad20fe3SChristian Brauner inode->i_uid = info->root_uid; 4493ad20fe3SChristian Brauner inode->i_gid = info->root_gid; 4503ad20fe3SChristian Brauner 4513ad20fe3SChristian Brauner device->binderfs_inode = inode; 4523ad20fe3SChristian Brauner device->miscdev.minor = minor; 4533ad20fe3SChristian Brauner 4543ad20fe3SChristian Brauner dentry = d_alloc_name(root, "binder-control"); 4553ad20fe3SChristian Brauner if (!dentry) 4563ad20fe3SChristian Brauner goto out; 4573ad20fe3SChristian Brauner 4583ad20fe3SChristian Brauner inode->i_private = device; 4593ad20fe3SChristian Brauner info->control_dentry = dentry; 4603ad20fe3SChristian Brauner d_add(dentry, inode); 4613ad20fe3SChristian Brauner 4623ad20fe3SChristian Brauner return 0; 4633ad20fe3SChristian Brauner 4643ad20fe3SChristian Brauner out: 4653ad20fe3SChristian Brauner kfree(device); 4663ad20fe3SChristian Brauner iput(inode); 4673ad20fe3SChristian Brauner 4683ad20fe3SChristian Brauner return ret; 4693ad20fe3SChristian Brauner } 4703ad20fe3SChristian Brauner 4713ad20fe3SChristian Brauner static const struct inode_operations binderfs_dir_inode_operations = { 4723ad20fe3SChristian Brauner .lookup = simple_lookup, 4733ad20fe3SChristian Brauner .rename = binderfs_rename, 4743ad20fe3SChristian Brauner .unlink = binderfs_unlink, 4753ad20fe3SChristian Brauner }; 4763ad20fe3SChristian Brauner 4770e13e452SHridya Valsaraju static struct inode *binderfs_make_inode(struct super_block *sb, int mode) 4780e13e452SHridya Valsaraju { 4790e13e452SHridya Valsaraju struct inode *ret; 4800e13e452SHridya Valsaraju 4810e13e452SHridya Valsaraju ret = new_inode(sb); 4820e13e452SHridya Valsaraju if (ret) { 4830e13e452SHridya Valsaraju ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET); 4840e13e452SHridya Valsaraju ret->i_mode = mode; 4850e13e452SHridya Valsaraju ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret); 4860e13e452SHridya Valsaraju } 4870e13e452SHridya Valsaraju return ret; 4880e13e452SHridya Valsaraju } 4890e13e452SHridya Valsaraju 4900e13e452SHridya Valsaraju static struct dentry *binderfs_create_dentry(struct dentry *parent, 4910e13e452SHridya Valsaraju const char *name) 4920e13e452SHridya Valsaraju { 4930e13e452SHridya Valsaraju struct dentry *dentry; 4940e13e452SHridya Valsaraju 4950e13e452SHridya Valsaraju dentry = lookup_one_len(name, parent, strlen(name)); 4960e13e452SHridya Valsaraju if (IS_ERR(dentry)) 4970e13e452SHridya Valsaraju return dentry; 4980e13e452SHridya Valsaraju 4990e13e452SHridya Valsaraju /* Return error if the file/dir already exists. */ 5000e13e452SHridya Valsaraju if (d_really_is_positive(dentry)) { 5010e13e452SHridya Valsaraju dput(dentry); 5020e13e452SHridya Valsaraju return ERR_PTR(-EEXIST); 5030e13e452SHridya Valsaraju } 5040e13e452SHridya Valsaraju 5050e13e452SHridya Valsaraju return dentry; 5060e13e452SHridya Valsaraju } 5070e13e452SHridya Valsaraju 5084feb80faSHridya Valsaraju void binderfs_remove_file(struct dentry *dentry) 5094feb80faSHridya Valsaraju { 5104feb80faSHridya Valsaraju struct inode *parent_inode; 5114feb80faSHridya Valsaraju 5124feb80faSHridya Valsaraju parent_inode = d_inode(dentry->d_parent); 5134feb80faSHridya Valsaraju inode_lock(parent_inode); 5144feb80faSHridya Valsaraju if (simple_positive(dentry)) { 5154feb80faSHridya Valsaraju dget(dentry); 5164feb80faSHridya Valsaraju simple_unlink(parent_inode, dentry); 5174feb80faSHridya Valsaraju d_delete(dentry); 5184feb80faSHridya Valsaraju dput(dentry); 5194feb80faSHridya Valsaraju } 5204feb80faSHridya Valsaraju inode_unlock(parent_inode); 5214feb80faSHridya Valsaraju } 5224feb80faSHridya Valsaraju 5234feb80faSHridya Valsaraju struct dentry *binderfs_create_file(struct dentry *parent, const char *name, 5240e13e452SHridya Valsaraju const struct file_operations *fops, 5250e13e452SHridya Valsaraju void *data) 5260e13e452SHridya Valsaraju { 5270e13e452SHridya Valsaraju struct dentry *dentry; 5280e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5290e13e452SHridya Valsaraju struct super_block *sb; 5300e13e452SHridya Valsaraju 5310e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5320e13e452SHridya Valsaraju inode_lock(parent_inode); 5330e13e452SHridya Valsaraju 5340e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5350e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5360e13e452SHridya Valsaraju goto out; 5370e13e452SHridya Valsaraju 5380e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5390e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFREG | 0444); 5400e13e452SHridya Valsaraju if (!new_inode) { 5410e13e452SHridya Valsaraju dput(dentry); 5420e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5430e13e452SHridya Valsaraju goto out; 5440e13e452SHridya Valsaraju } 5450e13e452SHridya Valsaraju 5460e13e452SHridya Valsaraju new_inode->i_fop = fops; 5470e13e452SHridya Valsaraju new_inode->i_private = data; 5480e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5490e13e452SHridya Valsaraju fsnotify_create(parent_inode, dentry); 5500e13e452SHridya Valsaraju 5510e13e452SHridya Valsaraju out: 5520e13e452SHridya Valsaraju inode_unlock(parent_inode); 5530e13e452SHridya Valsaraju return dentry; 5540e13e452SHridya Valsaraju } 5550e13e452SHridya Valsaraju 5560e13e452SHridya Valsaraju static struct dentry *binderfs_create_dir(struct dentry *parent, 5570e13e452SHridya Valsaraju const char *name) 5580e13e452SHridya Valsaraju { 5590e13e452SHridya Valsaraju struct dentry *dentry; 5600e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5610e13e452SHridya Valsaraju struct super_block *sb; 5620e13e452SHridya Valsaraju 5630e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5640e13e452SHridya Valsaraju inode_lock(parent_inode); 5650e13e452SHridya Valsaraju 5660e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5670e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5680e13e452SHridya Valsaraju goto out; 5690e13e452SHridya Valsaraju 5700e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5710e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFDIR | 0755); 5720e13e452SHridya Valsaraju if (!new_inode) { 5730e13e452SHridya Valsaraju dput(dentry); 5740e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5750e13e452SHridya Valsaraju goto out; 5760e13e452SHridya Valsaraju } 5770e13e452SHridya Valsaraju 5780e13e452SHridya Valsaraju new_inode->i_fop = &simple_dir_operations; 5790e13e452SHridya Valsaraju new_inode->i_op = &simple_dir_inode_operations; 5800e13e452SHridya Valsaraju 5810e13e452SHridya Valsaraju set_nlink(new_inode, 2); 5820e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5830e13e452SHridya Valsaraju inc_nlink(parent_inode); 5840e13e452SHridya Valsaraju fsnotify_mkdir(parent_inode, dentry); 5850e13e452SHridya Valsaraju 5860e13e452SHridya Valsaraju out: 5870e13e452SHridya Valsaraju inode_unlock(parent_inode); 5880e13e452SHridya Valsaraju return dentry; 5890e13e452SHridya Valsaraju } 5900e13e452SHridya Valsaraju 5910e13e452SHridya Valsaraju static int init_binder_logs(struct super_block *sb) 5920e13e452SHridya Valsaraju { 5934feb80faSHridya Valsaraju struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir; 5944feb80faSHridya Valsaraju struct binderfs_info *info; 5950e13e452SHridya Valsaraju int ret = 0; 5960e13e452SHridya Valsaraju 5970e13e452SHridya Valsaraju binder_logs_root_dir = binderfs_create_dir(sb->s_root, 5980e13e452SHridya Valsaraju "binder_logs"); 5990e13e452SHridya Valsaraju if (IS_ERR(binder_logs_root_dir)) { 6000e13e452SHridya Valsaraju ret = PTR_ERR(binder_logs_root_dir); 6010e13e452SHridya Valsaraju goto out; 6020e13e452SHridya Valsaraju } 6030e13e452SHridya Valsaraju 6040e13e452SHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, "stats", 6050e13e452SHridya Valsaraju &binder_stats_fops, NULL); 6060e13e452SHridya Valsaraju if (IS_ERR(dentry)) { 6070e13e452SHridya Valsaraju ret = PTR_ERR(dentry); 6080e13e452SHridya Valsaraju goto out; 6090e13e452SHridya Valsaraju } 6100e13e452SHridya Valsaraju 6110e13e452SHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, "state", 6120e13e452SHridya Valsaraju &binder_state_fops, NULL); 6130e13e452SHridya Valsaraju if (IS_ERR(dentry)) { 6140e13e452SHridya Valsaraju ret = PTR_ERR(dentry); 6150e13e452SHridya Valsaraju goto out; 6160e13e452SHridya Valsaraju } 6170e13e452SHridya Valsaraju 6180e13e452SHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, "transactions", 6190e13e452SHridya Valsaraju &binder_transactions_fops, NULL); 62003e2e07eSHridya Valsaraju if (IS_ERR(dentry)) { 62103e2e07eSHridya Valsaraju ret = PTR_ERR(dentry); 62203e2e07eSHridya Valsaraju goto out; 62303e2e07eSHridya Valsaraju } 62403e2e07eSHridya Valsaraju 62503e2e07eSHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, 62603e2e07eSHridya Valsaraju "transaction_log", 62703e2e07eSHridya Valsaraju &binder_transaction_log_fops, 62803e2e07eSHridya Valsaraju &binder_transaction_log); 62903e2e07eSHridya Valsaraju if (IS_ERR(dentry)) { 63003e2e07eSHridya Valsaraju ret = PTR_ERR(dentry); 63103e2e07eSHridya Valsaraju goto out; 63203e2e07eSHridya Valsaraju } 63303e2e07eSHridya Valsaraju 63403e2e07eSHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, 63503e2e07eSHridya Valsaraju "failed_transaction_log", 63603e2e07eSHridya Valsaraju &binder_transaction_log_fops, 63703e2e07eSHridya Valsaraju &binder_transaction_log_failed); 6384feb80faSHridya Valsaraju if (IS_ERR(dentry)) { 6390e13e452SHridya Valsaraju ret = PTR_ERR(dentry); 6404feb80faSHridya Valsaraju goto out; 6414feb80faSHridya Valsaraju } 6424feb80faSHridya Valsaraju 6434feb80faSHridya Valsaraju proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc"); 6444feb80faSHridya Valsaraju if (IS_ERR(proc_log_dir)) { 6454feb80faSHridya Valsaraju ret = PTR_ERR(proc_log_dir); 6464feb80faSHridya Valsaraju goto out; 6474feb80faSHridya Valsaraju } 6484feb80faSHridya Valsaraju info = sb->s_fs_info; 6494feb80faSHridya Valsaraju info->proc_log_dir = proc_log_dir; 6500e13e452SHridya Valsaraju 6510e13e452SHridya Valsaraju out: 6520e13e452SHridya Valsaraju return ret; 6530e13e452SHridya Valsaraju } 6540e13e452SHridya Valsaraju 6553ad20fe3SChristian Brauner static int binderfs_fill_super(struct super_block *sb, void *data, int silent) 6563ad20fe3SChristian Brauner { 65736975fc3SChristian Brauner int ret; 6583ad20fe3SChristian Brauner struct binderfs_info *info; 6593ad20fe3SChristian Brauner struct inode *inode = NULL; 660ca2864c6SHridya Valsaraju struct binderfs_device device_info = { 0 }; 661ca2864c6SHridya Valsaraju const char *name; 662ca2864c6SHridya Valsaraju size_t len; 6633ad20fe3SChristian Brauner 6643ad20fe3SChristian Brauner sb->s_blocksize = PAGE_SIZE; 6653ad20fe3SChristian Brauner sb->s_blocksize_bits = PAGE_SHIFT; 6663ad20fe3SChristian Brauner 6673ad20fe3SChristian Brauner /* 6683ad20fe3SChristian Brauner * The binderfs filesystem can be mounted by userns root in a 6693ad20fe3SChristian Brauner * non-initial userns. By default such mounts have the SB_I_NODEV flag 6703ad20fe3SChristian Brauner * set in s_iflags to prevent security issues where userns root can 6713ad20fe3SChristian Brauner * just create random device nodes via mknod() since it owns the 6723ad20fe3SChristian Brauner * filesystem mount. But binderfs does not allow to create any files 6733ad20fe3SChristian Brauner * including devices nodes. The only way to create binder devices nodes 6743ad20fe3SChristian Brauner * is through the binder-control device which userns root is explicitly 6753ad20fe3SChristian Brauner * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both 6763ad20fe3SChristian Brauner * necessary and safe. 6773ad20fe3SChristian Brauner */ 6783ad20fe3SChristian Brauner sb->s_iflags &= ~SB_I_NODEV; 6793ad20fe3SChristian Brauner sb->s_iflags |= SB_I_NOEXEC; 6803ad20fe3SChristian Brauner sb->s_magic = BINDERFS_SUPER_MAGIC; 6813ad20fe3SChristian Brauner sb->s_op = &binderfs_super_ops; 6823ad20fe3SChristian Brauner sb->s_time_gran = 1; 6833ad20fe3SChristian Brauner 68436975fc3SChristian Brauner sb->s_fs_info = kzalloc(sizeof(struct binderfs_info), GFP_KERNEL); 68536975fc3SChristian Brauner if (!sb->s_fs_info) 68636975fc3SChristian Brauner return -ENOMEM; 68736975fc3SChristian Brauner info = sb->s_fs_info; 68836975fc3SChristian Brauner 68936975fc3SChristian Brauner info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); 6903ad20fe3SChristian Brauner 691849d540dSChristian Brauner ret = binderfs_parse_mount_opts(data, &info->mount_opts); 692849d540dSChristian Brauner if (ret) 69336975fc3SChristian Brauner return ret; 694849d540dSChristian Brauner 6953ad20fe3SChristian Brauner info->root_gid = make_kgid(sb->s_user_ns, 0); 6963ad20fe3SChristian Brauner if (!gid_valid(info->root_gid)) 6973ad20fe3SChristian Brauner info->root_gid = GLOBAL_ROOT_GID; 6983ad20fe3SChristian Brauner info->root_uid = make_kuid(sb->s_user_ns, 0); 6993ad20fe3SChristian Brauner if (!uid_valid(info->root_uid)) 7003ad20fe3SChristian Brauner info->root_uid = GLOBAL_ROOT_UID; 7013ad20fe3SChristian Brauner 7023ad20fe3SChristian Brauner inode = new_inode(sb); 7033ad20fe3SChristian Brauner if (!inode) 70436975fc3SChristian Brauner return -ENOMEM; 7053ad20fe3SChristian Brauner 7063ad20fe3SChristian Brauner inode->i_ino = FIRST_INODE; 7073ad20fe3SChristian Brauner inode->i_fop = &simple_dir_operations; 7083ad20fe3SChristian Brauner inode->i_mode = S_IFDIR | 0755; 7093ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 7103ad20fe3SChristian Brauner inode->i_op = &binderfs_dir_inode_operations; 7113ad20fe3SChristian Brauner set_nlink(inode, 2); 7123ad20fe3SChristian Brauner 7133ad20fe3SChristian Brauner sb->s_root = d_make_root(inode); 7143ad20fe3SChristian Brauner if (!sb->s_root) 71536975fc3SChristian Brauner return -ENOMEM; 7163ad20fe3SChristian Brauner 717ca2864c6SHridya Valsaraju ret = binderfs_binder_ctl_create(sb); 718ca2864c6SHridya Valsaraju if (ret) 719ca2864c6SHridya Valsaraju return ret; 720ca2864c6SHridya Valsaraju 721ca2864c6SHridya Valsaraju name = binder_devices_param; 722ca2864c6SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 723ca2864c6SHridya Valsaraju strscpy(device_info.name, name, len + 1); 724ca2864c6SHridya Valsaraju ret = binderfs_binder_device_create(inode, NULL, &device_info); 725ca2864c6SHridya Valsaraju if (ret) 726ca2864c6SHridya Valsaraju return ret; 727ca2864c6SHridya Valsaraju name += len; 728ca2864c6SHridya Valsaraju if (*name == ',') 729ca2864c6SHridya Valsaraju name++; 730ca2864c6SHridya Valsaraju } 731ca2864c6SHridya Valsaraju 7320e13e452SHridya Valsaraju if (info->mount_opts.stats_mode == STATS_GLOBAL) 7330e13e452SHridya Valsaraju return init_binder_logs(sb); 7340e13e452SHridya Valsaraju 735ca2864c6SHridya Valsaraju return 0; 7363ad20fe3SChristian Brauner } 7373ad20fe3SChristian Brauner 7383ad20fe3SChristian Brauner static struct dentry *binderfs_mount(struct file_system_type *fs_type, 7393ad20fe3SChristian Brauner int flags, const char *dev_name, 7403ad20fe3SChristian Brauner void *data) 7413ad20fe3SChristian Brauner { 742b6c770d7SChristian Brauner return mount_nodev(fs_type, flags, data, binderfs_fill_super); 7433ad20fe3SChristian Brauner } 7443ad20fe3SChristian Brauner 7453ad20fe3SChristian Brauner static void binderfs_kill_super(struct super_block *sb) 7463ad20fe3SChristian Brauner { 7473ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 7483ad20fe3SChristian Brauner 74941984795SChristian Brauner kill_litter_super(sb); 75041984795SChristian Brauner 7513ad20fe3SChristian Brauner if (info && info->ipc_ns) 7523ad20fe3SChristian Brauner put_ipc_ns(info->ipc_ns); 7533ad20fe3SChristian Brauner 7543ad20fe3SChristian Brauner kfree(info); 7553ad20fe3SChristian Brauner } 7563ad20fe3SChristian Brauner 7573ad20fe3SChristian Brauner static struct file_system_type binder_fs_type = { 7583ad20fe3SChristian Brauner .name = "binder", 7593ad20fe3SChristian Brauner .mount = binderfs_mount, 7603ad20fe3SChristian Brauner .kill_sb = binderfs_kill_super, 7613ad20fe3SChristian Brauner .fs_flags = FS_USERNS_MOUNT, 7623ad20fe3SChristian Brauner }; 7633ad20fe3SChristian Brauner 7645b9633afSChristian Brauner int __init init_binderfs(void) 7653ad20fe3SChristian Brauner { 7663ad20fe3SChristian Brauner int ret; 767028fb582SHridya Valsaraju const char *name; 768028fb582SHridya Valsaraju size_t len; 769028fb582SHridya Valsaraju 770028fb582SHridya Valsaraju /* Verify that the default binderfs device names are valid. */ 771028fb582SHridya Valsaraju name = binder_devices_param; 772028fb582SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 773028fb582SHridya Valsaraju if (len > BINDERFS_MAX_NAME) 774028fb582SHridya Valsaraju return -E2BIG; 775028fb582SHridya Valsaraju name += len; 776028fb582SHridya Valsaraju if (*name == ',') 777028fb582SHridya Valsaraju name++; 778028fb582SHridya Valsaraju } 7793ad20fe3SChristian Brauner 7803ad20fe3SChristian Brauner /* Allocate new major number for binderfs. */ 7813ad20fe3SChristian Brauner ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR, 7823ad20fe3SChristian Brauner "binder"); 7833ad20fe3SChristian Brauner if (ret) 7843ad20fe3SChristian Brauner return ret; 7853ad20fe3SChristian Brauner 7863ad20fe3SChristian Brauner ret = register_filesystem(&binder_fs_type); 7873ad20fe3SChristian Brauner if (ret) { 7883ad20fe3SChristian Brauner unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR); 7893ad20fe3SChristian Brauner return ret; 7903ad20fe3SChristian Brauner } 7913ad20fe3SChristian Brauner 7923ad20fe3SChristian Brauner return ret; 7933ad20fe3SChristian Brauner } 794