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> 21095cf502SChristian Brauner #include <linux/fs_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 51095cf502SChristian Brauner enum binderfs_param { 52849d540dSChristian Brauner Opt_max, 53f0083451SHridya Valsaraju Opt_stats_mode, 54849d540dSChristian Brauner }; 55849d540dSChristian Brauner 56f0083451SHridya Valsaraju enum binderfs_stats_mode { 57095cf502SChristian Brauner binderfs_stats_mode_unset, 58095cf502SChristian Brauner binderfs_stats_mode_global, 59f0083451SHridya Valsaraju }; 60f0083451SHridya Valsaraju 61095cf502SChristian Brauner static const struct constant_table binderfs_param_stats[] = { 62095cf502SChristian Brauner { "global", binderfs_stats_mode_global }, 63095cf502SChristian Brauner {} 64849d540dSChristian Brauner }; 65849d540dSChristian Brauner 66095cf502SChristian Brauner const struct fs_parameter_spec binderfs_fs_parameters[] = { 67095cf502SChristian Brauner fsparam_u32("max", Opt_max), 68095cf502SChristian Brauner fsparam_enum("stats", Opt_stats_mode, binderfs_param_stats), 69095cf502SChristian Brauner {} 70095cf502SChristian Brauner }; 71095cf502SChristian Brauner 72095cf502SChristian Brauner static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb) 733ad20fe3SChristian Brauner { 74095cf502SChristian Brauner return sb->s_fs_info; 753ad20fe3SChristian Brauner } 763ad20fe3SChristian Brauner 773ad20fe3SChristian Brauner bool is_binderfs_device(const struct inode *inode) 783ad20fe3SChristian Brauner { 793ad20fe3SChristian Brauner if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) 803ad20fe3SChristian Brauner return true; 813ad20fe3SChristian Brauner 823ad20fe3SChristian Brauner return false; 833ad20fe3SChristian Brauner } 843ad20fe3SChristian Brauner 853ad20fe3SChristian Brauner /** 863ad20fe3SChristian Brauner * binderfs_binder_device_create - allocate inode from super block of a 873ad20fe3SChristian Brauner * binderfs mount 883ad20fe3SChristian Brauner * @ref_inode: inode from wich the super block will be taken 893ad20fe3SChristian Brauner * @userp: buffer to copy information about new device for userspace to 903ad20fe3SChristian Brauner * @req: struct binderfs_device as copied from userspace 913ad20fe3SChristian Brauner * 9201b3f1fcSChristian Brauner * This function allocates a new binder_device and reserves a new minor 933ad20fe3SChristian Brauner * number for it. 943ad20fe3SChristian Brauner * Minor numbers are limited and tracked globally in binderfs_minors. The 953ad20fe3SChristian Brauner * function will stash a struct binder_device for the specific binder 963ad20fe3SChristian Brauner * device in i_private of the inode. 973ad20fe3SChristian Brauner * It will go on to allocate a new inode from the super block of the 983ad20fe3SChristian Brauner * filesystem mount, stash a struct binder_device in its i_private field 993ad20fe3SChristian Brauner * and attach a dentry to that inode. 1003ad20fe3SChristian Brauner * 1013ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 1023ad20fe3SChristian Brauner */ 1033ad20fe3SChristian Brauner static int binderfs_binder_device_create(struct inode *ref_inode, 1043ad20fe3SChristian Brauner struct binderfs_device __user *userp, 1053ad20fe3SChristian Brauner struct binderfs_device *req) 1063ad20fe3SChristian Brauner { 1073ad20fe3SChristian Brauner int minor, ret; 10801b3f1fcSChristian Brauner struct dentry *dentry, *root; 1093ad20fe3SChristian Brauner struct binder_device *device; 1103ad20fe3SChristian Brauner char *name = NULL; 11101b3f1fcSChristian Brauner size_t name_len; 1123ad20fe3SChristian Brauner struct inode *inode = NULL; 1133ad20fe3SChristian Brauner struct super_block *sb = ref_inode->i_sb; 1143ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 1157fefaaddSChristian Brauner #if defined(CONFIG_IPC_NS) 11636bdf3caSChristian Brauner bool use_reserve = (info->ipc_ns == &init_ipc_ns); 1177fefaaddSChristian Brauner #else 1187fefaaddSChristian Brauner bool use_reserve = true; 1197fefaaddSChristian Brauner #endif 1203ad20fe3SChristian Brauner 1213ad20fe3SChristian Brauner /* Reserve new minor number for the new device. */ 1223ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 123849d540dSChristian Brauner if (++info->device_count <= info->mount_opts.max) 12436bdf3caSChristian Brauner minor = ida_alloc_max(&binderfs_minors, 12536bdf3caSChristian Brauner use_reserve ? BINDERFS_MAX_MINOR : 12636bdf3caSChristian Brauner BINDERFS_MAX_MINOR_CAPPED, 127849d540dSChristian Brauner GFP_KERNEL); 128849d540dSChristian Brauner else 129849d540dSChristian Brauner minor = -ENOSPC; 130849d540dSChristian Brauner if (minor < 0) { 131849d540dSChristian Brauner --info->device_count; 1323ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1333ad20fe3SChristian Brauner return minor; 134849d540dSChristian Brauner } 135849d540dSChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1363ad20fe3SChristian Brauner 1373ad20fe3SChristian Brauner ret = -ENOMEM; 1383ad20fe3SChristian Brauner device = kzalloc(sizeof(*device), GFP_KERNEL); 1393ad20fe3SChristian Brauner if (!device) 1403ad20fe3SChristian Brauner goto err; 1413ad20fe3SChristian Brauner 1423ad20fe3SChristian Brauner inode = new_inode(sb); 1433ad20fe3SChristian Brauner if (!inode) 1443ad20fe3SChristian Brauner goto err; 1453ad20fe3SChristian Brauner 1463ad20fe3SChristian Brauner inode->i_ino = minor + INODE_OFFSET; 1473ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1483ad20fe3SChristian Brauner init_special_inode(inode, S_IFCHR | 0600, 1493ad20fe3SChristian Brauner MKDEV(MAJOR(binderfs_dev), minor)); 1503ad20fe3SChristian Brauner inode->i_fop = &binder_fops; 1513ad20fe3SChristian Brauner inode->i_uid = info->root_uid; 1523ad20fe3SChristian Brauner inode->i_gid = info->root_gid; 1533ad20fe3SChristian Brauner 15401b3f1fcSChristian Brauner req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ 15501b3f1fcSChristian Brauner name_len = strlen(req->name); 15601b3f1fcSChristian Brauner /* Make sure to include terminating NUL byte */ 15701b3f1fcSChristian Brauner name = kmemdup(req->name, name_len + 1, GFP_KERNEL); 1583ad20fe3SChristian Brauner if (!name) 1593ad20fe3SChristian Brauner goto err; 1603ad20fe3SChristian Brauner 161f0fe2c0fSChristian Brauner refcount_set(&device->ref, 1); 1623ad20fe3SChristian Brauner device->binderfs_inode = inode; 1633ad20fe3SChristian Brauner device->context.binder_context_mgr_uid = INVALID_UID; 1643ad20fe3SChristian Brauner device->context.name = name; 1653ad20fe3SChristian Brauner device->miscdev.name = name; 1663ad20fe3SChristian Brauner device->miscdev.minor = minor; 1673ad20fe3SChristian Brauner mutex_init(&device->context.context_mgr_node_lock); 1683ad20fe3SChristian Brauner 1693ad20fe3SChristian Brauner req->major = MAJOR(binderfs_dev); 1703ad20fe3SChristian Brauner req->minor = minor; 1713ad20fe3SChristian Brauner 172ca2864c6SHridya Valsaraju if (userp && copy_to_user(userp, req, sizeof(*req))) { 1733ad20fe3SChristian Brauner ret = -EFAULT; 1743ad20fe3SChristian Brauner goto err; 1753ad20fe3SChristian Brauner } 1763ad20fe3SChristian Brauner 1773ad20fe3SChristian Brauner root = sb->s_root; 1783ad20fe3SChristian Brauner inode_lock(d_inode(root)); 17901b3f1fcSChristian Brauner 18001b3f1fcSChristian Brauner /* look it up */ 18101b3f1fcSChristian Brauner dentry = lookup_one_len(name, root, name_len); 18201b3f1fcSChristian Brauner if (IS_ERR(dentry)) { 1833ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 18401b3f1fcSChristian Brauner ret = PTR_ERR(dentry); 1853ad20fe3SChristian Brauner goto err; 1863ad20fe3SChristian Brauner } 1873ad20fe3SChristian Brauner 18801b3f1fcSChristian Brauner if (d_really_is_positive(dentry)) { 18901b3f1fcSChristian Brauner /* already exists */ 1903ad20fe3SChristian Brauner dput(dentry); 1913ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 1923ad20fe3SChristian Brauner ret = -EEXIST; 1933ad20fe3SChristian Brauner goto err; 1943ad20fe3SChristian Brauner } 1953ad20fe3SChristian Brauner 1963ad20fe3SChristian Brauner inode->i_private = device; 19701684db9SChristian Brauner d_instantiate(dentry, inode); 1983ad20fe3SChristian Brauner fsnotify_create(root->d_inode, dentry); 1993ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 2003ad20fe3SChristian Brauner 2013ad20fe3SChristian Brauner return 0; 2023ad20fe3SChristian Brauner 2033ad20fe3SChristian Brauner err: 2043ad20fe3SChristian Brauner kfree(name); 2053ad20fe3SChristian Brauner kfree(device); 2063ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 207849d540dSChristian Brauner --info->device_count; 2083ad20fe3SChristian Brauner ida_free(&binderfs_minors, minor); 2093ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2103ad20fe3SChristian Brauner iput(inode); 2113ad20fe3SChristian Brauner 2123ad20fe3SChristian Brauner return ret; 2133ad20fe3SChristian Brauner } 2143ad20fe3SChristian Brauner 2153ad20fe3SChristian Brauner /** 2163ad20fe3SChristian Brauner * binderfs_ctl_ioctl - handle binder device node allocation requests 2173ad20fe3SChristian Brauner * 2183ad20fe3SChristian Brauner * The request handler for the binder-control device. All requests operate on 2193ad20fe3SChristian Brauner * the binderfs mount the binder-control device resides in: 2203ad20fe3SChristian Brauner * - BINDER_CTL_ADD 2213ad20fe3SChristian Brauner * Allocate a new binder device. 2223ad20fe3SChristian Brauner * 2233ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 2243ad20fe3SChristian Brauner */ 2253ad20fe3SChristian Brauner static long binder_ctl_ioctl(struct file *file, unsigned int cmd, 2263ad20fe3SChristian Brauner unsigned long arg) 2273ad20fe3SChristian Brauner { 2283ad20fe3SChristian Brauner int ret = -EINVAL; 2293ad20fe3SChristian Brauner struct inode *inode = file_inode(file); 2303ad20fe3SChristian Brauner struct binderfs_device __user *device = (struct binderfs_device __user *)arg; 2313ad20fe3SChristian Brauner struct binderfs_device device_req; 2323ad20fe3SChristian Brauner 2333ad20fe3SChristian Brauner switch (cmd) { 2343ad20fe3SChristian Brauner case BINDER_CTL_ADD: 2353ad20fe3SChristian Brauner ret = copy_from_user(&device_req, device, sizeof(device_req)); 2363ad20fe3SChristian Brauner if (ret) { 2373ad20fe3SChristian Brauner ret = -EFAULT; 2383ad20fe3SChristian Brauner break; 2393ad20fe3SChristian Brauner } 2403ad20fe3SChristian Brauner 2413ad20fe3SChristian Brauner ret = binderfs_binder_device_create(inode, device, &device_req); 2423ad20fe3SChristian Brauner break; 2433ad20fe3SChristian Brauner default: 2443ad20fe3SChristian Brauner break; 2453ad20fe3SChristian Brauner } 2463ad20fe3SChristian Brauner 2473ad20fe3SChristian Brauner return ret; 2483ad20fe3SChristian Brauner } 2493ad20fe3SChristian Brauner 2503ad20fe3SChristian Brauner static void binderfs_evict_inode(struct inode *inode) 2513ad20fe3SChristian Brauner { 2523ad20fe3SChristian Brauner struct binder_device *device = inode->i_private; 253095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(inode->i_sb); 2543ad20fe3SChristian Brauner 2553ad20fe3SChristian Brauner clear_inode(inode); 2563ad20fe3SChristian Brauner 2570e13e452SHridya Valsaraju if (!S_ISCHR(inode->i_mode) || !device) 2583ad20fe3SChristian Brauner return; 2593ad20fe3SChristian Brauner 2603ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 261849d540dSChristian Brauner --info->device_count; 2623ad20fe3SChristian Brauner ida_free(&binderfs_minors, device->miscdev.minor); 2633ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2643ad20fe3SChristian Brauner 265f0fe2c0fSChristian Brauner if (refcount_dec_and_test(&device->ref)) { 2663ad20fe3SChristian Brauner kfree(device->context.name); 2673ad20fe3SChristian Brauner kfree(device); 2683ad20fe3SChristian Brauner } 269f0fe2c0fSChristian Brauner } 2703ad20fe3SChristian Brauner 271095cf502SChristian Brauner static int binderfs_fs_context_parse_param(struct fs_context *fc, 272095cf502SChristian Brauner struct fs_parameter *param) 273849d540dSChristian Brauner { 274095cf502SChristian Brauner int opt; 275095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 276095cf502SChristian Brauner struct fs_parse_result result; 277849d540dSChristian Brauner 278095cf502SChristian Brauner opt = fs_parse(fc, binderfs_fs_parameters, param, &result); 279095cf502SChristian Brauner if (opt < 0) 280095cf502SChristian Brauner return opt; 281849d540dSChristian Brauner 282095cf502SChristian Brauner switch (opt) { 283849d540dSChristian Brauner case Opt_max: 284095cf502SChristian Brauner if (result.uint_32 > BINDERFS_MAX_MINOR) 285095cf502SChristian Brauner return invalfc(fc, "Bad value for '%s'", param->key); 286849d540dSChristian Brauner 287095cf502SChristian Brauner ctx->max = result.uint_32; 288849d540dSChristian Brauner break; 289f0083451SHridya Valsaraju case Opt_stats_mode: 290f0083451SHridya Valsaraju if (!capable(CAP_SYS_ADMIN)) 291095cf502SChristian Brauner return -EPERM; 292f0083451SHridya Valsaraju 293095cf502SChristian Brauner ctx->stats_mode = result.uint_32; 294f0083451SHridya Valsaraju break; 295849d540dSChristian Brauner default: 296095cf502SChristian Brauner return invalfc(fc, "Unsupported parameter '%s'", param->key); 297849d540dSChristian Brauner } 298849d540dSChristian Brauner 299849d540dSChristian Brauner return 0; 300849d540dSChristian Brauner } 301849d540dSChristian Brauner 302095cf502SChristian Brauner static int binderfs_fs_context_reconfigure(struct fs_context *fc) 303849d540dSChristian Brauner { 304095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 305095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb); 306f0083451SHridya Valsaraju 307095cf502SChristian Brauner if (info->mount_opts.stats_mode != ctx->stats_mode) 308095cf502SChristian Brauner return invalfc(fc, "Binderfs stats mode cannot be changed during a remount"); 309f0083451SHridya Valsaraju 310095cf502SChristian Brauner info->mount_opts.stats_mode = ctx->stats_mode; 311095cf502SChristian Brauner info->mount_opts.max = ctx->max; 312f0083451SHridya Valsaraju return 0; 313849d540dSChristian Brauner } 314849d540dSChristian Brauner 315095cf502SChristian Brauner static int binderfs_show_options(struct seq_file *seq, struct dentry *root) 316849d540dSChristian Brauner { 317095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(root->d_sb); 318849d540dSChristian Brauner 319849d540dSChristian Brauner if (info->mount_opts.max <= BINDERFS_MAX_MINOR) 320849d540dSChristian Brauner seq_printf(seq, ",max=%d", info->mount_opts.max); 321095cf502SChristian Brauner 322095cf502SChristian Brauner switch (info->mount_opts.stats_mode) { 323095cf502SChristian Brauner case binderfs_stats_mode_unset: 324095cf502SChristian Brauner break; 325095cf502SChristian Brauner case binderfs_stats_mode_global: 326f0083451SHridya Valsaraju seq_printf(seq, ",stats=global"); 327095cf502SChristian Brauner break; 328095cf502SChristian Brauner } 329849d540dSChristian Brauner 330849d540dSChristian Brauner return 0; 331849d540dSChristian Brauner } 332849d540dSChristian Brauner 333095cf502SChristian Brauner static void binderfs_put_super(struct super_block *sb) 334095cf502SChristian Brauner { 335095cf502SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 336095cf502SChristian Brauner 337095cf502SChristian Brauner if (info && info->ipc_ns) 338095cf502SChristian Brauner put_ipc_ns(info->ipc_ns); 339095cf502SChristian Brauner 340095cf502SChristian Brauner kfree(info); 341095cf502SChristian Brauner sb->s_fs_info = NULL; 342095cf502SChristian Brauner } 343095cf502SChristian Brauner 3443ad20fe3SChristian Brauner static const struct super_operations binderfs_super_ops = { 3453ad20fe3SChristian Brauner .evict_inode = binderfs_evict_inode, 346095cf502SChristian Brauner .show_options = binderfs_show_options, 347849d540dSChristian Brauner .statfs = simple_statfs, 348095cf502SChristian Brauner .put_super = binderfs_put_super, 3493ad20fe3SChristian Brauner }; 3503ad20fe3SChristian Brauner 351e98e6fa1SChristian Brauner static inline bool is_binderfs_control_device(const struct dentry *dentry) 352e98e6fa1SChristian Brauner { 353e98e6fa1SChristian Brauner struct binderfs_info *info = dentry->d_sb->s_fs_info; 354e98e6fa1SChristian Brauner return info->control_dentry == dentry; 355e98e6fa1SChristian Brauner } 356e98e6fa1SChristian Brauner 3573ad20fe3SChristian Brauner static int binderfs_rename(struct inode *old_dir, struct dentry *old_dentry, 3583ad20fe3SChristian Brauner struct inode *new_dir, struct dentry *new_dentry, 3593ad20fe3SChristian Brauner unsigned int flags) 3603ad20fe3SChristian Brauner { 361e98e6fa1SChristian Brauner if (is_binderfs_control_device(old_dentry) || 362e98e6fa1SChristian Brauner is_binderfs_control_device(new_dentry)) 3633ad20fe3SChristian Brauner return -EPERM; 3643ad20fe3SChristian Brauner 365e98e6fa1SChristian Brauner return simple_rename(old_dir, old_dentry, new_dir, new_dentry, flags); 3663ad20fe3SChristian Brauner } 3673ad20fe3SChristian Brauner 3683ad20fe3SChristian Brauner static int binderfs_unlink(struct inode *dir, struct dentry *dentry) 3693ad20fe3SChristian Brauner { 370e98e6fa1SChristian Brauner if (is_binderfs_control_device(dentry)) 3713ad20fe3SChristian Brauner return -EPERM; 3723ad20fe3SChristian Brauner 3733ad20fe3SChristian Brauner return simple_unlink(dir, dentry); 3743ad20fe3SChristian Brauner } 3753ad20fe3SChristian Brauner 3763ad20fe3SChristian Brauner static const struct file_operations binder_ctl_fops = { 3773ad20fe3SChristian Brauner .owner = THIS_MODULE, 3783ad20fe3SChristian Brauner .open = nonseekable_open, 3793ad20fe3SChristian Brauner .unlocked_ioctl = binder_ctl_ioctl, 3803ad20fe3SChristian Brauner .compat_ioctl = binder_ctl_ioctl, 3813ad20fe3SChristian Brauner .llseek = noop_llseek, 3823ad20fe3SChristian Brauner }; 3833ad20fe3SChristian Brauner 3843ad20fe3SChristian Brauner /** 3853ad20fe3SChristian Brauner * binderfs_binder_ctl_create - create a new binder-control device 3863ad20fe3SChristian Brauner * @sb: super block of the binderfs mount 3873ad20fe3SChristian Brauner * 3883ad20fe3SChristian Brauner * This function creates a new binder-control device node in the binderfs mount 3893ad20fe3SChristian Brauner * referred to by @sb. 3903ad20fe3SChristian Brauner * 3913ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 3923ad20fe3SChristian Brauner */ 3933ad20fe3SChristian Brauner static int binderfs_binder_ctl_create(struct super_block *sb) 3943ad20fe3SChristian Brauner { 3953ad20fe3SChristian Brauner int minor, ret; 3963ad20fe3SChristian Brauner struct dentry *dentry; 3973ad20fe3SChristian Brauner struct binder_device *device; 3983ad20fe3SChristian Brauner struct inode *inode = NULL; 3993ad20fe3SChristian Brauner struct dentry *root = sb->s_root; 4003ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 401da8ddba5SChristian Brauner #if defined(CONFIG_IPC_NS) 402da8ddba5SChristian Brauner bool use_reserve = (info->ipc_ns == &init_ipc_ns); 403da8ddba5SChristian Brauner #else 404da8ddba5SChristian Brauner bool use_reserve = true; 405da8ddba5SChristian Brauner #endif 4063ad20fe3SChristian Brauner 4073ad20fe3SChristian Brauner device = kzalloc(sizeof(*device), GFP_KERNEL); 4083ad20fe3SChristian Brauner if (!device) 4093ad20fe3SChristian Brauner return -ENOMEM; 4103ad20fe3SChristian Brauner 4113ad20fe3SChristian Brauner /* If we have already created a binder-control node, return. */ 4123ad20fe3SChristian Brauner if (info->control_dentry) { 4133ad20fe3SChristian Brauner ret = 0; 4143ad20fe3SChristian Brauner goto out; 4153ad20fe3SChristian Brauner } 4163ad20fe3SChristian Brauner 4173ad20fe3SChristian Brauner ret = -ENOMEM; 4183ad20fe3SChristian Brauner inode = new_inode(sb); 4193ad20fe3SChristian Brauner if (!inode) 4203ad20fe3SChristian Brauner goto out; 4213ad20fe3SChristian Brauner 4223ad20fe3SChristian Brauner /* Reserve a new minor number for the new device. */ 4233ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 424da8ddba5SChristian Brauner minor = ida_alloc_max(&binderfs_minors, 425da8ddba5SChristian Brauner use_reserve ? BINDERFS_MAX_MINOR : 426da8ddba5SChristian Brauner BINDERFS_MAX_MINOR_CAPPED, 427da8ddba5SChristian Brauner GFP_KERNEL); 4283ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 4293ad20fe3SChristian Brauner if (minor < 0) { 4303ad20fe3SChristian Brauner ret = minor; 4313ad20fe3SChristian Brauner goto out; 4323ad20fe3SChristian Brauner } 4333ad20fe3SChristian Brauner 4343ad20fe3SChristian Brauner inode->i_ino = SECOND_INODE; 4353ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 4363ad20fe3SChristian Brauner init_special_inode(inode, S_IFCHR | 0600, 4373ad20fe3SChristian Brauner MKDEV(MAJOR(binderfs_dev), minor)); 4383ad20fe3SChristian Brauner inode->i_fop = &binder_ctl_fops; 4393ad20fe3SChristian Brauner inode->i_uid = info->root_uid; 4403ad20fe3SChristian Brauner inode->i_gid = info->root_gid; 4413ad20fe3SChristian Brauner 4423ad20fe3SChristian Brauner device->binderfs_inode = inode; 4433ad20fe3SChristian Brauner device->miscdev.minor = minor; 4443ad20fe3SChristian Brauner 4453ad20fe3SChristian Brauner dentry = d_alloc_name(root, "binder-control"); 4463ad20fe3SChristian Brauner if (!dentry) 4473ad20fe3SChristian Brauner goto out; 4483ad20fe3SChristian Brauner 4493ad20fe3SChristian Brauner inode->i_private = device; 4503ad20fe3SChristian Brauner info->control_dentry = dentry; 4513ad20fe3SChristian Brauner d_add(dentry, inode); 4523ad20fe3SChristian Brauner 4533ad20fe3SChristian Brauner return 0; 4543ad20fe3SChristian Brauner 4553ad20fe3SChristian Brauner out: 4563ad20fe3SChristian Brauner kfree(device); 4573ad20fe3SChristian Brauner iput(inode); 4583ad20fe3SChristian Brauner 4593ad20fe3SChristian Brauner return ret; 4603ad20fe3SChristian Brauner } 4613ad20fe3SChristian Brauner 4623ad20fe3SChristian Brauner static const struct inode_operations binderfs_dir_inode_operations = { 4633ad20fe3SChristian Brauner .lookup = simple_lookup, 4643ad20fe3SChristian Brauner .rename = binderfs_rename, 4653ad20fe3SChristian Brauner .unlink = binderfs_unlink, 4663ad20fe3SChristian Brauner }; 4673ad20fe3SChristian Brauner 4680e13e452SHridya Valsaraju static struct inode *binderfs_make_inode(struct super_block *sb, int mode) 4690e13e452SHridya Valsaraju { 4700e13e452SHridya Valsaraju struct inode *ret; 4710e13e452SHridya Valsaraju 4720e13e452SHridya Valsaraju ret = new_inode(sb); 4730e13e452SHridya Valsaraju if (ret) { 4740e13e452SHridya Valsaraju ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET); 4750e13e452SHridya Valsaraju ret->i_mode = mode; 4760e13e452SHridya Valsaraju ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret); 4770e13e452SHridya Valsaraju } 4780e13e452SHridya Valsaraju return ret; 4790e13e452SHridya Valsaraju } 4800e13e452SHridya Valsaraju 4810e13e452SHridya Valsaraju static struct dentry *binderfs_create_dentry(struct dentry *parent, 4820e13e452SHridya Valsaraju const char *name) 4830e13e452SHridya Valsaraju { 4840e13e452SHridya Valsaraju struct dentry *dentry; 4850e13e452SHridya Valsaraju 4860e13e452SHridya Valsaraju dentry = lookup_one_len(name, parent, strlen(name)); 4870e13e452SHridya Valsaraju if (IS_ERR(dentry)) 4880e13e452SHridya Valsaraju return dentry; 4890e13e452SHridya Valsaraju 4900e13e452SHridya Valsaraju /* Return error if the file/dir already exists. */ 4910e13e452SHridya Valsaraju if (d_really_is_positive(dentry)) { 4920e13e452SHridya Valsaraju dput(dentry); 4930e13e452SHridya Valsaraju return ERR_PTR(-EEXIST); 4940e13e452SHridya Valsaraju } 4950e13e452SHridya Valsaraju 4960e13e452SHridya Valsaraju return dentry; 4970e13e452SHridya Valsaraju } 4980e13e452SHridya Valsaraju 4994feb80faSHridya Valsaraju void binderfs_remove_file(struct dentry *dentry) 5004feb80faSHridya Valsaraju { 5014feb80faSHridya Valsaraju struct inode *parent_inode; 5024feb80faSHridya Valsaraju 5034feb80faSHridya Valsaraju parent_inode = d_inode(dentry->d_parent); 5044feb80faSHridya Valsaraju inode_lock(parent_inode); 5054feb80faSHridya Valsaraju if (simple_positive(dentry)) { 5064feb80faSHridya Valsaraju dget(dentry); 5074feb80faSHridya Valsaraju simple_unlink(parent_inode, dentry); 5084feb80faSHridya Valsaraju d_delete(dentry); 5094feb80faSHridya Valsaraju dput(dentry); 5104feb80faSHridya Valsaraju } 5114feb80faSHridya Valsaraju inode_unlock(parent_inode); 5124feb80faSHridya Valsaraju } 5134feb80faSHridya Valsaraju 5144feb80faSHridya Valsaraju struct dentry *binderfs_create_file(struct dentry *parent, const char *name, 5150e13e452SHridya Valsaraju const struct file_operations *fops, 5160e13e452SHridya Valsaraju void *data) 5170e13e452SHridya Valsaraju { 5180e13e452SHridya Valsaraju struct dentry *dentry; 5190e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5200e13e452SHridya Valsaraju struct super_block *sb; 5210e13e452SHridya Valsaraju 5220e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5230e13e452SHridya Valsaraju inode_lock(parent_inode); 5240e13e452SHridya Valsaraju 5250e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5260e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5270e13e452SHridya Valsaraju goto out; 5280e13e452SHridya Valsaraju 5290e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5300e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFREG | 0444); 5310e13e452SHridya Valsaraju if (!new_inode) { 5320e13e452SHridya Valsaraju dput(dentry); 5330e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5340e13e452SHridya Valsaraju goto out; 5350e13e452SHridya Valsaraju } 5360e13e452SHridya Valsaraju 5370e13e452SHridya Valsaraju new_inode->i_fop = fops; 5380e13e452SHridya Valsaraju new_inode->i_private = data; 5390e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5400e13e452SHridya Valsaraju fsnotify_create(parent_inode, dentry); 5410e13e452SHridya Valsaraju 5420e13e452SHridya Valsaraju out: 5430e13e452SHridya Valsaraju inode_unlock(parent_inode); 5440e13e452SHridya Valsaraju return dentry; 5450e13e452SHridya Valsaraju } 5460e13e452SHridya Valsaraju 5470e13e452SHridya Valsaraju static struct dentry *binderfs_create_dir(struct dentry *parent, 5480e13e452SHridya Valsaraju const char *name) 5490e13e452SHridya Valsaraju { 5500e13e452SHridya Valsaraju struct dentry *dentry; 5510e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5520e13e452SHridya Valsaraju struct super_block *sb; 5530e13e452SHridya Valsaraju 5540e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5550e13e452SHridya Valsaraju inode_lock(parent_inode); 5560e13e452SHridya Valsaraju 5570e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5580e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5590e13e452SHridya Valsaraju goto out; 5600e13e452SHridya Valsaraju 5610e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5620e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFDIR | 0755); 5630e13e452SHridya Valsaraju if (!new_inode) { 5640e13e452SHridya Valsaraju dput(dentry); 5650e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5660e13e452SHridya Valsaraju goto out; 5670e13e452SHridya Valsaraju } 5680e13e452SHridya Valsaraju 5690e13e452SHridya Valsaraju new_inode->i_fop = &simple_dir_operations; 5700e13e452SHridya Valsaraju new_inode->i_op = &simple_dir_inode_operations; 5710e13e452SHridya Valsaraju 5720e13e452SHridya Valsaraju set_nlink(new_inode, 2); 5730e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5740e13e452SHridya Valsaraju inc_nlink(parent_inode); 5750e13e452SHridya Valsaraju fsnotify_mkdir(parent_inode, dentry); 5760e13e452SHridya Valsaraju 5770e13e452SHridya Valsaraju out: 5780e13e452SHridya Valsaraju inode_unlock(parent_inode); 5790e13e452SHridya Valsaraju return dentry; 5800e13e452SHridya Valsaraju } 5810e13e452SHridya Valsaraju 5820e13e452SHridya Valsaraju static int init_binder_logs(struct super_block *sb) 5830e13e452SHridya Valsaraju { 5844feb80faSHridya Valsaraju struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir; 5854feb80faSHridya Valsaraju struct binderfs_info *info; 5860e13e452SHridya Valsaraju int ret = 0; 5870e13e452SHridya Valsaraju 5880e13e452SHridya Valsaraju binder_logs_root_dir = binderfs_create_dir(sb->s_root, 5890e13e452SHridya Valsaraju "binder_logs"); 5900e13e452SHridya Valsaraju if (IS_ERR(binder_logs_root_dir)) { 5910e13e452SHridya Valsaraju ret = PTR_ERR(binder_logs_root_dir); 5920e13e452SHridya Valsaraju goto out; 5930e13e452SHridya Valsaraju } 5940e13e452SHridya Valsaraju 5950e13e452SHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, "stats", 5960e13e452SHridya Valsaraju &binder_stats_fops, NULL); 5970e13e452SHridya Valsaraju if (IS_ERR(dentry)) { 5980e13e452SHridya Valsaraju ret = PTR_ERR(dentry); 5990e13e452SHridya Valsaraju goto out; 6000e13e452SHridya Valsaraju } 6010e13e452SHridya Valsaraju 6020e13e452SHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, "state", 6030e13e452SHridya Valsaraju &binder_state_fops, NULL); 6040e13e452SHridya Valsaraju if (IS_ERR(dentry)) { 6050e13e452SHridya Valsaraju ret = PTR_ERR(dentry); 6060e13e452SHridya Valsaraju goto out; 6070e13e452SHridya Valsaraju } 6080e13e452SHridya Valsaraju 6090e13e452SHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, "transactions", 6100e13e452SHridya Valsaraju &binder_transactions_fops, NULL); 61103e2e07eSHridya Valsaraju if (IS_ERR(dentry)) { 61203e2e07eSHridya Valsaraju ret = PTR_ERR(dentry); 61303e2e07eSHridya Valsaraju goto out; 61403e2e07eSHridya Valsaraju } 61503e2e07eSHridya Valsaraju 61603e2e07eSHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, 61703e2e07eSHridya Valsaraju "transaction_log", 61803e2e07eSHridya Valsaraju &binder_transaction_log_fops, 61903e2e07eSHridya Valsaraju &binder_transaction_log); 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 "failed_transaction_log", 62703e2e07eSHridya Valsaraju &binder_transaction_log_fops, 62803e2e07eSHridya Valsaraju &binder_transaction_log_failed); 6294feb80faSHridya Valsaraju if (IS_ERR(dentry)) { 6300e13e452SHridya Valsaraju ret = PTR_ERR(dentry); 6314feb80faSHridya Valsaraju goto out; 6324feb80faSHridya Valsaraju } 6334feb80faSHridya Valsaraju 6344feb80faSHridya Valsaraju proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc"); 6354feb80faSHridya Valsaraju if (IS_ERR(proc_log_dir)) { 6364feb80faSHridya Valsaraju ret = PTR_ERR(proc_log_dir); 6374feb80faSHridya Valsaraju goto out; 6384feb80faSHridya Valsaraju } 6394feb80faSHridya Valsaraju info = sb->s_fs_info; 6404feb80faSHridya Valsaraju info->proc_log_dir = proc_log_dir; 6410e13e452SHridya Valsaraju 6420e13e452SHridya Valsaraju out: 6430e13e452SHridya Valsaraju return ret; 6440e13e452SHridya Valsaraju } 6450e13e452SHridya Valsaraju 646095cf502SChristian Brauner static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc) 6473ad20fe3SChristian Brauner { 64836975fc3SChristian Brauner int ret; 6493ad20fe3SChristian Brauner struct binderfs_info *info; 650095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 6513ad20fe3SChristian Brauner struct inode *inode = NULL; 652ca2864c6SHridya Valsaraju struct binderfs_device device_info = { 0 }; 653ca2864c6SHridya Valsaraju const char *name; 654ca2864c6SHridya Valsaraju size_t len; 6553ad20fe3SChristian Brauner 6563ad20fe3SChristian Brauner sb->s_blocksize = PAGE_SIZE; 6573ad20fe3SChristian Brauner sb->s_blocksize_bits = PAGE_SHIFT; 6583ad20fe3SChristian Brauner 6593ad20fe3SChristian Brauner /* 6603ad20fe3SChristian Brauner * The binderfs filesystem can be mounted by userns root in a 6613ad20fe3SChristian Brauner * non-initial userns. By default such mounts have the SB_I_NODEV flag 6623ad20fe3SChristian Brauner * set in s_iflags to prevent security issues where userns root can 6633ad20fe3SChristian Brauner * just create random device nodes via mknod() since it owns the 6643ad20fe3SChristian Brauner * filesystem mount. But binderfs does not allow to create any files 6653ad20fe3SChristian Brauner * including devices nodes. The only way to create binder devices nodes 6663ad20fe3SChristian Brauner * is through the binder-control device which userns root is explicitly 6673ad20fe3SChristian Brauner * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both 6683ad20fe3SChristian Brauner * necessary and safe. 6693ad20fe3SChristian Brauner */ 6703ad20fe3SChristian Brauner sb->s_iflags &= ~SB_I_NODEV; 6713ad20fe3SChristian Brauner sb->s_iflags |= SB_I_NOEXEC; 6723ad20fe3SChristian Brauner sb->s_magic = BINDERFS_SUPER_MAGIC; 6733ad20fe3SChristian Brauner sb->s_op = &binderfs_super_ops; 6743ad20fe3SChristian Brauner sb->s_time_gran = 1; 6753ad20fe3SChristian Brauner 67636975fc3SChristian Brauner sb->s_fs_info = kzalloc(sizeof(struct binderfs_info), GFP_KERNEL); 67736975fc3SChristian Brauner if (!sb->s_fs_info) 67836975fc3SChristian Brauner return -ENOMEM; 67936975fc3SChristian Brauner info = sb->s_fs_info; 68036975fc3SChristian Brauner 68136975fc3SChristian Brauner info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); 6823ad20fe3SChristian Brauner 6833ad20fe3SChristian Brauner info->root_gid = make_kgid(sb->s_user_ns, 0); 6843ad20fe3SChristian Brauner if (!gid_valid(info->root_gid)) 6853ad20fe3SChristian Brauner info->root_gid = GLOBAL_ROOT_GID; 6863ad20fe3SChristian Brauner info->root_uid = make_kuid(sb->s_user_ns, 0); 6873ad20fe3SChristian Brauner if (!uid_valid(info->root_uid)) 6883ad20fe3SChristian Brauner info->root_uid = GLOBAL_ROOT_UID; 689095cf502SChristian Brauner info->mount_opts.max = ctx->max; 690095cf502SChristian Brauner info->mount_opts.stats_mode = ctx->stats_mode; 6913ad20fe3SChristian Brauner 6923ad20fe3SChristian Brauner inode = new_inode(sb); 6933ad20fe3SChristian Brauner if (!inode) 69436975fc3SChristian Brauner return -ENOMEM; 6953ad20fe3SChristian Brauner 6963ad20fe3SChristian Brauner inode->i_ino = FIRST_INODE; 6973ad20fe3SChristian Brauner inode->i_fop = &simple_dir_operations; 6983ad20fe3SChristian Brauner inode->i_mode = S_IFDIR | 0755; 6993ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 7003ad20fe3SChristian Brauner inode->i_op = &binderfs_dir_inode_operations; 7013ad20fe3SChristian Brauner set_nlink(inode, 2); 7023ad20fe3SChristian Brauner 7033ad20fe3SChristian Brauner sb->s_root = d_make_root(inode); 7043ad20fe3SChristian Brauner if (!sb->s_root) 70536975fc3SChristian Brauner return -ENOMEM; 7063ad20fe3SChristian Brauner 707ca2864c6SHridya Valsaraju ret = binderfs_binder_ctl_create(sb); 708ca2864c6SHridya Valsaraju if (ret) 709ca2864c6SHridya Valsaraju return ret; 710ca2864c6SHridya Valsaraju 711ca2864c6SHridya Valsaraju name = binder_devices_param; 712ca2864c6SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 713ca2864c6SHridya Valsaraju strscpy(device_info.name, name, len + 1); 714ca2864c6SHridya Valsaraju ret = binderfs_binder_device_create(inode, NULL, &device_info); 715ca2864c6SHridya Valsaraju if (ret) 716ca2864c6SHridya Valsaraju return ret; 717ca2864c6SHridya Valsaraju name += len; 718ca2864c6SHridya Valsaraju if (*name == ',') 719ca2864c6SHridya Valsaraju name++; 720ca2864c6SHridya Valsaraju } 721ca2864c6SHridya Valsaraju 722095cf502SChristian Brauner if (info->mount_opts.stats_mode == binderfs_stats_mode_global) 7230e13e452SHridya Valsaraju return init_binder_logs(sb); 7240e13e452SHridya Valsaraju 725ca2864c6SHridya Valsaraju return 0; 7263ad20fe3SChristian Brauner } 7273ad20fe3SChristian Brauner 728095cf502SChristian Brauner static int binderfs_fs_context_get_tree(struct fs_context *fc) 7293ad20fe3SChristian Brauner { 730095cf502SChristian Brauner return get_tree_nodev(fc, binderfs_fill_super); 7313ad20fe3SChristian Brauner } 7323ad20fe3SChristian Brauner 733095cf502SChristian Brauner static void binderfs_fs_context_free(struct fs_context *fc) 7343ad20fe3SChristian Brauner { 735095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 7363ad20fe3SChristian Brauner 737095cf502SChristian Brauner kfree(ctx); 738095cf502SChristian Brauner } 73941984795SChristian Brauner 740095cf502SChristian Brauner static const struct fs_context_operations binderfs_fs_context_ops = { 741095cf502SChristian Brauner .free = binderfs_fs_context_free, 742095cf502SChristian Brauner .get_tree = binderfs_fs_context_get_tree, 743095cf502SChristian Brauner .parse_param = binderfs_fs_context_parse_param, 744095cf502SChristian Brauner .reconfigure = binderfs_fs_context_reconfigure, 745095cf502SChristian Brauner }; 7463ad20fe3SChristian Brauner 747095cf502SChristian Brauner static int binderfs_init_fs_context(struct fs_context *fc) 748095cf502SChristian Brauner { 749095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 750095cf502SChristian Brauner 751095cf502SChristian Brauner ctx = kzalloc(sizeof(struct binderfs_mount_opts), GFP_KERNEL); 752095cf502SChristian Brauner if (!ctx) 753095cf502SChristian Brauner return -ENOMEM; 754095cf502SChristian Brauner 755095cf502SChristian Brauner ctx->max = BINDERFS_MAX_MINOR; 756095cf502SChristian Brauner ctx->stats_mode = binderfs_stats_mode_unset; 757095cf502SChristian Brauner 758095cf502SChristian Brauner fc->fs_private = ctx; 759095cf502SChristian Brauner fc->ops = &binderfs_fs_context_ops; 760095cf502SChristian Brauner 761095cf502SChristian Brauner return 0; 7623ad20fe3SChristian Brauner } 7633ad20fe3SChristian Brauner 7643ad20fe3SChristian Brauner static struct file_system_type binder_fs_type = { 7653ad20fe3SChristian Brauner .name = "binder", 766095cf502SChristian Brauner .init_fs_context = binderfs_init_fs_context, 767095cf502SChristian Brauner .parameters = binderfs_fs_parameters, 768095cf502SChristian Brauner .kill_sb = kill_litter_super, 7693ad20fe3SChristian Brauner .fs_flags = FS_USERNS_MOUNT, 7703ad20fe3SChristian Brauner }; 7713ad20fe3SChristian Brauner 7725b9633afSChristian Brauner int __init init_binderfs(void) 7733ad20fe3SChristian Brauner { 7743ad20fe3SChristian Brauner int ret; 775028fb582SHridya Valsaraju const char *name; 776028fb582SHridya Valsaraju size_t len; 777028fb582SHridya Valsaraju 778028fb582SHridya Valsaraju /* Verify that the default binderfs device names are valid. */ 779028fb582SHridya Valsaraju name = binder_devices_param; 780028fb582SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 781028fb582SHridya Valsaraju if (len > BINDERFS_MAX_NAME) 782028fb582SHridya Valsaraju return -E2BIG; 783028fb582SHridya Valsaraju name += len; 784028fb582SHridya Valsaraju if (*name == ',') 785028fb582SHridya Valsaraju name++; 786028fb582SHridya Valsaraju } 7873ad20fe3SChristian Brauner 7883ad20fe3SChristian Brauner /* Allocate new major number for binderfs. */ 7893ad20fe3SChristian Brauner ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR, 7903ad20fe3SChristian Brauner "binder"); 7913ad20fe3SChristian Brauner if (ret) 7923ad20fe3SChristian Brauner return ret; 7933ad20fe3SChristian Brauner 7943ad20fe3SChristian Brauner ret = register_filesystem(&binder_fs_type); 7953ad20fe3SChristian Brauner if (ret) { 7963ad20fe3SChristian Brauner unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR); 7973ad20fe3SChristian Brauner return ret; 7983ad20fe3SChristian Brauner } 7993ad20fe3SChristian Brauner 8003ad20fe3SChristian Brauner return ret; 8013ad20fe3SChristian Brauner } 802