17e84522cSMrinal Pandey // 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 BINDERFS_MAX_MINOR (1U << MINORBITS) 4336bdf3caSChristian Brauner /* Ensure that the initial ipc namespace always has devices available. */ 4436bdf3caSChristian Brauner #define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4) 453ad20fe3SChristian Brauner 463ad20fe3SChristian Brauner static dev_t binderfs_dev; 473ad20fe3SChristian Brauner static DEFINE_MUTEX(binderfs_minors_mutex); 483ad20fe3SChristian Brauner static DEFINE_IDA(binderfs_minors); 493ad20fe3SChristian Brauner 50095cf502SChristian Brauner enum binderfs_param { 51849d540dSChristian Brauner Opt_max, 52f0083451SHridya Valsaraju Opt_stats_mode, 53849d540dSChristian Brauner }; 54849d540dSChristian Brauner 55f0083451SHridya Valsaraju enum binderfs_stats_mode { 56095cf502SChristian Brauner binderfs_stats_mode_unset, 57095cf502SChristian Brauner binderfs_stats_mode_global, 58f0083451SHridya Valsaraju }; 59f0083451SHridya Valsaraju 60fc470abfSCarlos Llamas struct binder_features { 61fc470abfSCarlos Llamas bool oneway_spam_detection; 62d23386edSCarlos Llamas bool extended_error; 63fc470abfSCarlos Llamas }; 64fc470abfSCarlos Llamas 65095cf502SChristian Brauner static const struct constant_table binderfs_param_stats[] = { 66095cf502SChristian Brauner { "global", binderfs_stats_mode_global }, 67095cf502SChristian Brauner {} 68849d540dSChristian Brauner }; 69849d540dSChristian Brauner 7089320020SWei Yongjun static const struct fs_parameter_spec binderfs_fs_parameters[] = { 71095cf502SChristian Brauner fsparam_u32("max", Opt_max), 72095cf502SChristian Brauner fsparam_enum("stats", Opt_stats_mode, binderfs_param_stats), 73095cf502SChristian Brauner {} 74095cf502SChristian Brauner }; 75095cf502SChristian Brauner 76fc470abfSCarlos Llamas static struct binder_features binder_features = { 77fc470abfSCarlos Llamas .oneway_spam_detection = true, 78d23386edSCarlos Llamas .extended_error = true, 79fc470abfSCarlos Llamas }; 80fc470abfSCarlos Llamas 81095cf502SChristian Brauner static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb) 823ad20fe3SChristian Brauner { 83095cf502SChristian Brauner return sb->s_fs_info; 843ad20fe3SChristian Brauner } 853ad20fe3SChristian Brauner 863ad20fe3SChristian Brauner bool is_binderfs_device(const struct inode *inode) 873ad20fe3SChristian Brauner { 883ad20fe3SChristian Brauner if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) 893ad20fe3SChristian Brauner return true; 903ad20fe3SChristian Brauner 913ad20fe3SChristian Brauner return false; 923ad20fe3SChristian Brauner } 933ad20fe3SChristian Brauner 943ad20fe3SChristian Brauner /** 953ad20fe3SChristian Brauner * binderfs_binder_device_create - allocate inode from super block of a 963ad20fe3SChristian Brauner * binderfs mount 973ad20fe3SChristian Brauner * @ref_inode: inode from wich the super block will be taken 983ad20fe3SChristian Brauner * @userp: buffer to copy information about new device for userspace to 993ad20fe3SChristian Brauner * @req: struct binderfs_device as copied from userspace 1003ad20fe3SChristian Brauner * 10101b3f1fcSChristian Brauner * This function allocates a new binder_device and reserves a new minor 1023ad20fe3SChristian Brauner * number for it. 1033ad20fe3SChristian Brauner * Minor numbers are limited and tracked globally in binderfs_minors. The 1043ad20fe3SChristian Brauner * function will stash a struct binder_device for the specific binder 1053ad20fe3SChristian Brauner * device in i_private of the inode. 1063ad20fe3SChristian Brauner * It will go on to allocate a new inode from the super block of the 1073ad20fe3SChristian Brauner * filesystem mount, stash a struct binder_device in its i_private field 1083ad20fe3SChristian Brauner * and attach a dentry to that inode. 1093ad20fe3SChristian Brauner * 1103ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 1113ad20fe3SChristian Brauner */ 1123ad20fe3SChristian Brauner static int binderfs_binder_device_create(struct inode *ref_inode, 1133ad20fe3SChristian Brauner struct binderfs_device __user *userp, 1143ad20fe3SChristian Brauner struct binderfs_device *req) 1153ad20fe3SChristian Brauner { 1163ad20fe3SChristian Brauner int minor, ret; 11701b3f1fcSChristian Brauner struct dentry *dentry, *root; 1183ad20fe3SChristian Brauner struct binder_device *device; 1193ad20fe3SChristian Brauner char *name = NULL; 12001b3f1fcSChristian Brauner size_t name_len; 1213ad20fe3SChristian Brauner struct inode *inode = NULL; 1223ad20fe3SChristian Brauner struct super_block *sb = ref_inode->i_sb; 1233ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 1247fefaaddSChristian Brauner #if defined(CONFIG_IPC_NS) 12536bdf3caSChristian Brauner bool use_reserve = (info->ipc_ns == &init_ipc_ns); 1267fefaaddSChristian Brauner #else 1277fefaaddSChristian Brauner bool use_reserve = true; 1287fefaaddSChristian Brauner #endif 1293ad20fe3SChristian Brauner 1303ad20fe3SChristian Brauner /* Reserve new minor number for the new device. */ 1313ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 132849d540dSChristian Brauner if (++info->device_count <= info->mount_opts.max) 13336bdf3caSChristian Brauner minor = ida_alloc_max(&binderfs_minors, 13436bdf3caSChristian Brauner use_reserve ? BINDERFS_MAX_MINOR : 13536bdf3caSChristian Brauner BINDERFS_MAX_MINOR_CAPPED, 136849d540dSChristian Brauner GFP_KERNEL); 137849d540dSChristian Brauner else 138849d540dSChristian Brauner minor = -ENOSPC; 139849d540dSChristian Brauner if (minor < 0) { 140849d540dSChristian Brauner --info->device_count; 1413ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1423ad20fe3SChristian Brauner return minor; 143849d540dSChristian Brauner } 144849d540dSChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1453ad20fe3SChristian Brauner 1463ad20fe3SChristian Brauner ret = -ENOMEM; 1473ad20fe3SChristian Brauner device = kzalloc(sizeof(*device), GFP_KERNEL); 1483ad20fe3SChristian Brauner if (!device) 1493ad20fe3SChristian Brauner goto err; 1503ad20fe3SChristian Brauner 1513ad20fe3SChristian Brauner inode = new_inode(sb); 1523ad20fe3SChristian Brauner if (!inode) 1533ad20fe3SChristian Brauner goto err; 1543ad20fe3SChristian Brauner 1553ad20fe3SChristian Brauner inode->i_ino = minor + INODE_OFFSET; 1563ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1573ad20fe3SChristian Brauner init_special_inode(inode, S_IFCHR | 0600, 1583ad20fe3SChristian Brauner MKDEV(MAJOR(binderfs_dev), minor)); 1593ad20fe3SChristian Brauner inode->i_fop = &binder_fops; 1603ad20fe3SChristian Brauner inode->i_uid = info->root_uid; 1613ad20fe3SChristian Brauner inode->i_gid = info->root_gid; 1623ad20fe3SChristian Brauner 16301b3f1fcSChristian Brauner req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ 16401b3f1fcSChristian Brauner name_len = strlen(req->name); 16501b3f1fcSChristian Brauner /* Make sure to include terminating NUL byte */ 16601b3f1fcSChristian Brauner name = kmemdup(req->name, name_len + 1, GFP_KERNEL); 1673ad20fe3SChristian Brauner if (!name) 1683ad20fe3SChristian Brauner goto err; 1693ad20fe3SChristian Brauner 170f0fe2c0fSChristian Brauner refcount_set(&device->ref, 1); 1713ad20fe3SChristian Brauner device->binderfs_inode = inode; 1723ad20fe3SChristian Brauner device->context.binder_context_mgr_uid = INVALID_UID; 1733ad20fe3SChristian Brauner device->context.name = name; 1743ad20fe3SChristian Brauner device->miscdev.name = name; 1753ad20fe3SChristian Brauner device->miscdev.minor = minor; 1763ad20fe3SChristian Brauner mutex_init(&device->context.context_mgr_node_lock); 1773ad20fe3SChristian Brauner 1783ad20fe3SChristian Brauner req->major = MAJOR(binderfs_dev); 1793ad20fe3SChristian Brauner req->minor = minor; 1803ad20fe3SChristian Brauner 181ca2864c6SHridya Valsaraju if (userp && copy_to_user(userp, req, sizeof(*req))) { 1823ad20fe3SChristian Brauner ret = -EFAULT; 1833ad20fe3SChristian Brauner goto err; 1843ad20fe3SChristian Brauner } 1853ad20fe3SChristian Brauner 1863ad20fe3SChristian Brauner root = sb->s_root; 1873ad20fe3SChristian Brauner inode_lock(d_inode(root)); 18801b3f1fcSChristian Brauner 18901b3f1fcSChristian Brauner /* look it up */ 19001b3f1fcSChristian Brauner dentry = lookup_one_len(name, root, name_len); 19101b3f1fcSChristian Brauner if (IS_ERR(dentry)) { 1923ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 19301b3f1fcSChristian Brauner ret = PTR_ERR(dentry); 1943ad20fe3SChristian Brauner goto err; 1953ad20fe3SChristian Brauner } 1963ad20fe3SChristian Brauner 19701b3f1fcSChristian Brauner if (d_really_is_positive(dentry)) { 19801b3f1fcSChristian Brauner /* already exists */ 1993ad20fe3SChristian Brauner dput(dentry); 2003ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 2013ad20fe3SChristian Brauner ret = -EEXIST; 2023ad20fe3SChristian Brauner goto err; 2033ad20fe3SChristian Brauner } 2043ad20fe3SChristian Brauner 2053ad20fe3SChristian Brauner inode->i_private = device; 20601684db9SChristian Brauner d_instantiate(dentry, inode); 2073ad20fe3SChristian Brauner fsnotify_create(root->d_inode, dentry); 2083ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 2093ad20fe3SChristian Brauner 2103ad20fe3SChristian Brauner return 0; 2113ad20fe3SChristian Brauner 2123ad20fe3SChristian Brauner err: 2133ad20fe3SChristian Brauner kfree(name); 2143ad20fe3SChristian Brauner kfree(device); 2153ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 216849d540dSChristian Brauner --info->device_count; 2173ad20fe3SChristian Brauner ida_free(&binderfs_minors, minor); 2183ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2193ad20fe3SChristian Brauner iput(inode); 2203ad20fe3SChristian Brauner 2213ad20fe3SChristian Brauner return ret; 2223ad20fe3SChristian Brauner } 2233ad20fe3SChristian Brauner 2243ad20fe3SChristian Brauner /** 2253ad20fe3SChristian Brauner * binderfs_ctl_ioctl - handle binder device node allocation requests 2263ad20fe3SChristian Brauner * 2273ad20fe3SChristian Brauner * The request handler for the binder-control device. All requests operate on 2283ad20fe3SChristian Brauner * the binderfs mount the binder-control device resides in: 2293ad20fe3SChristian Brauner * - BINDER_CTL_ADD 2303ad20fe3SChristian Brauner * Allocate a new binder device. 2313ad20fe3SChristian Brauner * 2323ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 2333ad20fe3SChristian Brauner */ 2343ad20fe3SChristian Brauner static long binder_ctl_ioctl(struct file *file, unsigned int cmd, 2353ad20fe3SChristian Brauner unsigned long arg) 2363ad20fe3SChristian Brauner { 2373ad20fe3SChristian Brauner int ret = -EINVAL; 2383ad20fe3SChristian Brauner struct inode *inode = file_inode(file); 2393ad20fe3SChristian Brauner struct binderfs_device __user *device = (struct binderfs_device __user *)arg; 2403ad20fe3SChristian Brauner struct binderfs_device device_req; 2413ad20fe3SChristian Brauner 2423ad20fe3SChristian Brauner switch (cmd) { 2433ad20fe3SChristian Brauner case BINDER_CTL_ADD: 2443ad20fe3SChristian Brauner ret = copy_from_user(&device_req, device, sizeof(device_req)); 2453ad20fe3SChristian Brauner if (ret) { 2463ad20fe3SChristian Brauner ret = -EFAULT; 2473ad20fe3SChristian Brauner break; 2483ad20fe3SChristian Brauner } 2493ad20fe3SChristian Brauner 2503ad20fe3SChristian Brauner ret = binderfs_binder_device_create(inode, device, &device_req); 2513ad20fe3SChristian Brauner break; 2523ad20fe3SChristian Brauner default: 2533ad20fe3SChristian Brauner break; 2543ad20fe3SChristian Brauner } 2553ad20fe3SChristian Brauner 2563ad20fe3SChristian Brauner return ret; 2573ad20fe3SChristian Brauner } 2583ad20fe3SChristian Brauner 2593ad20fe3SChristian Brauner static void binderfs_evict_inode(struct inode *inode) 2603ad20fe3SChristian Brauner { 2613ad20fe3SChristian Brauner struct binder_device *device = inode->i_private; 262095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(inode->i_sb); 2633ad20fe3SChristian Brauner 2643ad20fe3SChristian Brauner clear_inode(inode); 2653ad20fe3SChristian Brauner 2660e13e452SHridya Valsaraju if (!S_ISCHR(inode->i_mode) || !device) 2673ad20fe3SChristian Brauner return; 2683ad20fe3SChristian Brauner 2693ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 270849d540dSChristian Brauner --info->device_count; 2713ad20fe3SChristian Brauner ida_free(&binderfs_minors, device->miscdev.minor); 2723ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2733ad20fe3SChristian Brauner 274f0fe2c0fSChristian Brauner if (refcount_dec_and_test(&device->ref)) { 2753ad20fe3SChristian Brauner kfree(device->context.name); 2763ad20fe3SChristian Brauner kfree(device); 2773ad20fe3SChristian Brauner } 278f0fe2c0fSChristian Brauner } 2793ad20fe3SChristian Brauner 280095cf502SChristian Brauner static int binderfs_fs_context_parse_param(struct fs_context *fc, 281095cf502SChristian Brauner struct fs_parameter *param) 282849d540dSChristian Brauner { 283095cf502SChristian Brauner int opt; 284095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 285095cf502SChristian Brauner struct fs_parse_result result; 286849d540dSChristian Brauner 287095cf502SChristian Brauner opt = fs_parse(fc, binderfs_fs_parameters, param, &result); 288095cf502SChristian Brauner if (opt < 0) 289095cf502SChristian Brauner return opt; 290849d540dSChristian Brauner 291095cf502SChristian Brauner switch (opt) { 292849d540dSChristian Brauner case Opt_max: 293095cf502SChristian Brauner if (result.uint_32 > BINDERFS_MAX_MINOR) 294095cf502SChristian Brauner return invalfc(fc, "Bad value for '%s'", param->key); 295849d540dSChristian Brauner 296095cf502SChristian Brauner ctx->max = result.uint_32; 297849d540dSChristian Brauner break; 298f0083451SHridya Valsaraju case Opt_stats_mode: 299f0083451SHridya Valsaraju if (!capable(CAP_SYS_ADMIN)) 300095cf502SChristian Brauner return -EPERM; 301f0083451SHridya Valsaraju 302095cf502SChristian Brauner ctx->stats_mode = result.uint_32; 303f0083451SHridya Valsaraju break; 304849d540dSChristian Brauner default: 305095cf502SChristian Brauner return invalfc(fc, "Unsupported parameter '%s'", param->key); 306849d540dSChristian Brauner } 307849d540dSChristian Brauner 308849d540dSChristian Brauner return 0; 309849d540dSChristian Brauner } 310849d540dSChristian Brauner 311095cf502SChristian Brauner static int binderfs_fs_context_reconfigure(struct fs_context *fc) 312849d540dSChristian Brauner { 313095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 314095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb); 315f0083451SHridya Valsaraju 316095cf502SChristian Brauner if (info->mount_opts.stats_mode != ctx->stats_mode) 317095cf502SChristian Brauner return invalfc(fc, "Binderfs stats mode cannot be changed during a remount"); 318f0083451SHridya Valsaraju 319095cf502SChristian Brauner info->mount_opts.stats_mode = ctx->stats_mode; 320095cf502SChristian Brauner info->mount_opts.max = ctx->max; 321f0083451SHridya Valsaraju return 0; 322849d540dSChristian Brauner } 323849d540dSChristian Brauner 324095cf502SChristian Brauner static int binderfs_show_options(struct seq_file *seq, struct dentry *root) 325849d540dSChristian Brauner { 326095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(root->d_sb); 327849d540dSChristian Brauner 328849d540dSChristian Brauner if (info->mount_opts.max <= BINDERFS_MAX_MINOR) 329849d540dSChristian Brauner seq_printf(seq, ",max=%d", info->mount_opts.max); 330095cf502SChristian Brauner 331095cf502SChristian Brauner switch (info->mount_opts.stats_mode) { 332095cf502SChristian Brauner case binderfs_stats_mode_unset: 333095cf502SChristian Brauner break; 334095cf502SChristian Brauner case binderfs_stats_mode_global: 335f0083451SHridya Valsaraju seq_printf(seq, ",stats=global"); 336095cf502SChristian Brauner break; 337095cf502SChristian Brauner } 338849d540dSChristian Brauner 339849d540dSChristian Brauner return 0; 340849d540dSChristian Brauner } 341849d540dSChristian Brauner 3423ad20fe3SChristian Brauner static const struct super_operations binderfs_super_ops = { 3433ad20fe3SChristian Brauner .evict_inode = binderfs_evict_inode, 344095cf502SChristian Brauner .show_options = binderfs_show_options, 345849d540dSChristian Brauner .statfs = simple_statfs, 3463ad20fe3SChristian Brauner }; 3473ad20fe3SChristian Brauner 348e98e6fa1SChristian Brauner static inline bool is_binderfs_control_device(const struct dentry *dentry) 349e98e6fa1SChristian Brauner { 350e98e6fa1SChristian Brauner struct binderfs_info *info = dentry->d_sb->s_fs_info; 35181195f96SMrinal Pandey 352e98e6fa1SChristian Brauner return info->control_dentry == dentry; 353e98e6fa1SChristian Brauner } 354e98e6fa1SChristian Brauner 355549c7297SChristian Brauner static int binderfs_rename(struct user_namespace *mnt_userns, 356549c7297SChristian Brauner struct inode *old_dir, struct dentry *old_dentry, 3573ad20fe3SChristian Brauner struct inode *new_dir, struct dentry *new_dentry, 3583ad20fe3SChristian Brauner unsigned int flags) 3593ad20fe3SChristian Brauner { 360e98e6fa1SChristian Brauner if (is_binderfs_control_device(old_dentry) || 361e98e6fa1SChristian Brauner is_binderfs_control_device(new_dentry)) 3623ad20fe3SChristian Brauner return -EPERM; 3633ad20fe3SChristian Brauner 364549c7297SChristian Brauner return simple_rename(&init_user_ns, old_dir, old_dentry, new_dir, 365549c7297SChristian Brauner 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 442211b64e4SChristian Brauner refcount_set(&device->ref, 1); 4433ad20fe3SChristian Brauner device->binderfs_inode = inode; 4443ad20fe3SChristian Brauner device->miscdev.minor = minor; 4453ad20fe3SChristian Brauner 4463ad20fe3SChristian Brauner dentry = d_alloc_name(root, "binder-control"); 4473ad20fe3SChristian Brauner if (!dentry) 4483ad20fe3SChristian Brauner goto out; 4493ad20fe3SChristian Brauner 4503ad20fe3SChristian Brauner inode->i_private = device; 4513ad20fe3SChristian Brauner info->control_dentry = dentry; 4523ad20fe3SChristian Brauner d_add(dentry, inode); 4533ad20fe3SChristian Brauner 4543ad20fe3SChristian Brauner return 0; 4553ad20fe3SChristian Brauner 4563ad20fe3SChristian Brauner out: 4573ad20fe3SChristian Brauner kfree(device); 4583ad20fe3SChristian Brauner iput(inode); 4593ad20fe3SChristian Brauner 4603ad20fe3SChristian Brauner return ret; 4613ad20fe3SChristian Brauner } 4623ad20fe3SChristian Brauner 4633ad20fe3SChristian Brauner static const struct inode_operations binderfs_dir_inode_operations = { 4643ad20fe3SChristian Brauner .lookup = simple_lookup, 4653ad20fe3SChristian Brauner .rename = binderfs_rename, 4663ad20fe3SChristian Brauner .unlink = binderfs_unlink, 4673ad20fe3SChristian Brauner }; 4683ad20fe3SChristian Brauner 4690e13e452SHridya Valsaraju static struct inode *binderfs_make_inode(struct super_block *sb, int mode) 4700e13e452SHridya Valsaraju { 4710e13e452SHridya Valsaraju struct inode *ret; 4720e13e452SHridya Valsaraju 4730e13e452SHridya Valsaraju ret = new_inode(sb); 4740e13e452SHridya Valsaraju if (ret) { 4750e13e452SHridya Valsaraju ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET); 4760e13e452SHridya Valsaraju ret->i_mode = mode; 4770e13e452SHridya Valsaraju ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret); 4780e13e452SHridya Valsaraju } 4790e13e452SHridya Valsaraju return ret; 4800e13e452SHridya Valsaraju } 4810e13e452SHridya Valsaraju 4820e13e452SHridya Valsaraju static struct dentry *binderfs_create_dentry(struct dentry *parent, 4830e13e452SHridya Valsaraju const char *name) 4840e13e452SHridya Valsaraju { 4850e13e452SHridya Valsaraju struct dentry *dentry; 4860e13e452SHridya Valsaraju 4870e13e452SHridya Valsaraju dentry = lookup_one_len(name, parent, strlen(name)); 4880e13e452SHridya Valsaraju if (IS_ERR(dentry)) 4890e13e452SHridya Valsaraju return dentry; 4900e13e452SHridya Valsaraju 4910e13e452SHridya Valsaraju /* Return error if the file/dir already exists. */ 4920e13e452SHridya Valsaraju if (d_really_is_positive(dentry)) { 4930e13e452SHridya Valsaraju dput(dentry); 4940e13e452SHridya Valsaraju return ERR_PTR(-EEXIST); 4950e13e452SHridya Valsaraju } 4960e13e452SHridya Valsaraju 4970e13e452SHridya Valsaraju return dentry; 4980e13e452SHridya Valsaraju } 4990e13e452SHridya Valsaraju 5004feb80faSHridya Valsaraju void binderfs_remove_file(struct dentry *dentry) 5014feb80faSHridya Valsaraju { 5024feb80faSHridya Valsaraju struct inode *parent_inode; 5034feb80faSHridya Valsaraju 5044feb80faSHridya Valsaraju parent_inode = d_inode(dentry->d_parent); 5054feb80faSHridya Valsaraju inode_lock(parent_inode); 5064feb80faSHridya Valsaraju if (simple_positive(dentry)) { 5074feb80faSHridya Valsaraju dget(dentry); 5084feb80faSHridya Valsaraju simple_unlink(parent_inode, dentry); 5094feb80faSHridya Valsaraju d_delete(dentry); 5104feb80faSHridya Valsaraju dput(dentry); 5114feb80faSHridya Valsaraju } 5124feb80faSHridya Valsaraju inode_unlock(parent_inode); 5134feb80faSHridya Valsaraju } 5144feb80faSHridya Valsaraju 5154feb80faSHridya Valsaraju struct dentry *binderfs_create_file(struct dentry *parent, const char *name, 5160e13e452SHridya Valsaraju const struct file_operations *fops, 5170e13e452SHridya Valsaraju void *data) 5180e13e452SHridya Valsaraju { 5190e13e452SHridya Valsaraju struct dentry *dentry; 5200e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5210e13e452SHridya Valsaraju struct super_block *sb; 5220e13e452SHridya Valsaraju 5230e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5240e13e452SHridya Valsaraju inode_lock(parent_inode); 5250e13e452SHridya Valsaraju 5260e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5270e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5280e13e452SHridya Valsaraju goto out; 5290e13e452SHridya Valsaraju 5300e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5310e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFREG | 0444); 5320e13e452SHridya Valsaraju if (!new_inode) { 5330e13e452SHridya Valsaraju dput(dentry); 5340e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5350e13e452SHridya Valsaraju goto out; 5360e13e452SHridya Valsaraju } 5370e13e452SHridya Valsaraju 5380e13e452SHridya Valsaraju new_inode->i_fop = fops; 5390e13e452SHridya Valsaraju new_inode->i_private = data; 5400e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5410e13e452SHridya Valsaraju fsnotify_create(parent_inode, dentry); 5420e13e452SHridya Valsaraju 5430e13e452SHridya Valsaraju out: 5440e13e452SHridya Valsaraju inode_unlock(parent_inode); 5450e13e452SHridya Valsaraju return dentry; 5460e13e452SHridya Valsaraju } 5470e13e452SHridya Valsaraju 5480e13e452SHridya Valsaraju static struct dentry *binderfs_create_dir(struct dentry *parent, 5490e13e452SHridya Valsaraju const char *name) 5500e13e452SHridya Valsaraju { 5510e13e452SHridya Valsaraju struct dentry *dentry; 5520e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5530e13e452SHridya Valsaraju struct super_block *sb; 5540e13e452SHridya Valsaraju 5550e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5560e13e452SHridya Valsaraju inode_lock(parent_inode); 5570e13e452SHridya Valsaraju 5580e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5590e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5600e13e452SHridya Valsaraju goto out; 5610e13e452SHridya Valsaraju 5620e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5630e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFDIR | 0755); 5640e13e452SHridya Valsaraju if (!new_inode) { 5650e13e452SHridya Valsaraju dput(dentry); 5660e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5670e13e452SHridya Valsaraju goto out; 5680e13e452SHridya Valsaraju } 5690e13e452SHridya Valsaraju 5700e13e452SHridya Valsaraju new_inode->i_fop = &simple_dir_operations; 5710e13e452SHridya Valsaraju new_inode->i_op = &simple_dir_inode_operations; 5720e13e452SHridya Valsaraju 5730e13e452SHridya Valsaraju set_nlink(new_inode, 2); 5740e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5750e13e452SHridya Valsaraju inc_nlink(parent_inode); 5760e13e452SHridya Valsaraju fsnotify_mkdir(parent_inode, dentry); 5770e13e452SHridya Valsaraju 5780e13e452SHridya Valsaraju out: 5790e13e452SHridya Valsaraju inode_unlock(parent_inode); 5800e13e452SHridya Valsaraju return dentry; 5810e13e452SHridya Valsaraju } 5820e13e452SHridya Valsaraju 583fc470abfSCarlos Llamas static int binder_features_show(struct seq_file *m, void *unused) 584fc470abfSCarlos Llamas { 585fc470abfSCarlos Llamas bool *feature = m->private; 586fc470abfSCarlos Llamas 587fc470abfSCarlos Llamas seq_printf(m, "%d\n", *feature); 588fc470abfSCarlos Llamas 589fc470abfSCarlos Llamas return 0; 590fc470abfSCarlos Llamas } 591fc470abfSCarlos Llamas DEFINE_SHOW_ATTRIBUTE(binder_features); 592fc470abfSCarlos Llamas 593fc470abfSCarlos Llamas static int init_binder_features(struct super_block *sb) 594fc470abfSCarlos Llamas { 595fc470abfSCarlos Llamas struct dentry *dentry, *dir; 596fc470abfSCarlos Llamas 597fc470abfSCarlos Llamas dir = binderfs_create_dir(sb->s_root, "features"); 598fc470abfSCarlos Llamas if (IS_ERR(dir)) 599fc470abfSCarlos Llamas return PTR_ERR(dir); 600fc470abfSCarlos Llamas 601fc470abfSCarlos Llamas dentry = binderfs_create_file(dir, "oneway_spam_detection", 602fc470abfSCarlos Llamas &binder_features_fops, 603fc470abfSCarlos Llamas &binder_features.oneway_spam_detection); 604fc470abfSCarlos Llamas if (IS_ERR(dentry)) 605fc470abfSCarlos Llamas return PTR_ERR(dentry); 606fc470abfSCarlos Llamas 607d23386edSCarlos Llamas dentry = binderfs_create_file(dir, "extended_error", 608d23386edSCarlos Llamas &binder_features_fops, 609d23386edSCarlos Llamas &binder_features.extended_error); 610d23386edSCarlos Llamas if (IS_ERR(dentry)) 611d23386edSCarlos Llamas return PTR_ERR(dentry); 612d23386edSCarlos Llamas 613fc470abfSCarlos Llamas return 0; 614fc470abfSCarlos Llamas } 615fc470abfSCarlos Llamas 6160e13e452SHridya Valsaraju static int init_binder_logs(struct super_block *sb) 6170e13e452SHridya Valsaraju { 6184feb80faSHridya Valsaraju struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir; 619b7e241bbSCarlos Llamas const struct binder_debugfs_entry *db_entry; 6204feb80faSHridya Valsaraju struct binderfs_info *info; 6210e13e452SHridya Valsaraju int ret = 0; 6220e13e452SHridya Valsaraju 6230e13e452SHridya Valsaraju binder_logs_root_dir = binderfs_create_dir(sb->s_root, 6240e13e452SHridya Valsaraju "binder_logs"); 6250e13e452SHridya Valsaraju if (IS_ERR(binder_logs_root_dir)) { 6260e13e452SHridya Valsaraju ret = PTR_ERR(binder_logs_root_dir); 6270e13e452SHridya Valsaraju goto out; 6280e13e452SHridya Valsaraju } 6290e13e452SHridya Valsaraju 630b7e241bbSCarlos Llamas binder_for_each_debugfs_entry(db_entry) { 63103e2e07eSHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, 632b7e241bbSCarlos Llamas db_entry->name, 633b7e241bbSCarlos Llamas db_entry->fops, 634b7e241bbSCarlos Llamas db_entry->data); 63503e2e07eSHridya Valsaraju if (IS_ERR(dentry)) { 63603e2e07eSHridya Valsaraju ret = PTR_ERR(dentry); 63703e2e07eSHridya Valsaraju goto out; 63803e2e07eSHridya Valsaraju } 6394feb80faSHridya Valsaraju } 6404feb80faSHridya Valsaraju 6414feb80faSHridya Valsaraju proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc"); 6424feb80faSHridya Valsaraju if (IS_ERR(proc_log_dir)) { 6434feb80faSHridya Valsaraju ret = PTR_ERR(proc_log_dir); 6444feb80faSHridya Valsaraju goto out; 6454feb80faSHridya Valsaraju } 6464feb80faSHridya Valsaraju info = sb->s_fs_info; 6474feb80faSHridya Valsaraju info->proc_log_dir = proc_log_dir; 6480e13e452SHridya Valsaraju 6490e13e452SHridya Valsaraju out: 6500e13e452SHridya Valsaraju return ret; 6510e13e452SHridya Valsaraju } 6520e13e452SHridya Valsaraju 653095cf502SChristian Brauner static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc) 6543ad20fe3SChristian Brauner { 65536975fc3SChristian Brauner int ret; 6563ad20fe3SChristian Brauner struct binderfs_info *info; 657095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 6583ad20fe3SChristian Brauner struct inode *inode = NULL; 6597a1c4f28STang Bin struct binderfs_device device_info = {}; 660ca2864c6SHridya Valsaraju const char *name; 661ca2864c6SHridya Valsaraju size_t len; 6623ad20fe3SChristian Brauner 6633ad20fe3SChristian Brauner sb->s_blocksize = PAGE_SIZE; 6643ad20fe3SChristian Brauner sb->s_blocksize_bits = PAGE_SHIFT; 6653ad20fe3SChristian Brauner 6663ad20fe3SChristian Brauner /* 6673ad20fe3SChristian Brauner * The binderfs filesystem can be mounted by userns root in a 6683ad20fe3SChristian Brauner * non-initial userns. By default such mounts have the SB_I_NODEV flag 6693ad20fe3SChristian Brauner * set in s_iflags to prevent security issues where userns root can 6703ad20fe3SChristian Brauner * just create random device nodes via mknod() since it owns the 6713ad20fe3SChristian Brauner * filesystem mount. But binderfs does not allow to create any files 6723ad20fe3SChristian Brauner * including devices nodes. The only way to create binder devices nodes 6733ad20fe3SChristian Brauner * is through the binder-control device which userns root is explicitly 6743ad20fe3SChristian Brauner * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both 6753ad20fe3SChristian Brauner * necessary and safe. 6763ad20fe3SChristian Brauner */ 6773ad20fe3SChristian Brauner sb->s_iflags &= ~SB_I_NODEV; 6783ad20fe3SChristian Brauner sb->s_iflags |= SB_I_NOEXEC; 6793ad20fe3SChristian Brauner sb->s_magic = BINDERFS_SUPER_MAGIC; 6803ad20fe3SChristian Brauner sb->s_op = &binderfs_super_ops; 6813ad20fe3SChristian Brauner sb->s_time_gran = 1; 6823ad20fe3SChristian Brauner 68336975fc3SChristian Brauner sb->s_fs_info = kzalloc(sizeof(struct binderfs_info), GFP_KERNEL); 68436975fc3SChristian Brauner if (!sb->s_fs_info) 68536975fc3SChristian Brauner return -ENOMEM; 68636975fc3SChristian Brauner info = sb->s_fs_info; 68736975fc3SChristian Brauner 68836975fc3SChristian Brauner info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); 6893ad20fe3SChristian Brauner 6903ad20fe3SChristian Brauner info->root_gid = make_kgid(sb->s_user_ns, 0); 6913ad20fe3SChristian Brauner if (!gid_valid(info->root_gid)) 6923ad20fe3SChristian Brauner info->root_gid = GLOBAL_ROOT_GID; 6933ad20fe3SChristian Brauner info->root_uid = make_kuid(sb->s_user_ns, 0); 6943ad20fe3SChristian Brauner if (!uid_valid(info->root_uid)) 6953ad20fe3SChristian Brauner info->root_uid = GLOBAL_ROOT_UID; 696095cf502SChristian Brauner info->mount_opts.max = ctx->max; 697095cf502SChristian Brauner info->mount_opts.stats_mode = ctx->stats_mode; 6983ad20fe3SChristian Brauner 6993ad20fe3SChristian Brauner inode = new_inode(sb); 7003ad20fe3SChristian Brauner if (!inode) 70136975fc3SChristian Brauner return -ENOMEM; 7023ad20fe3SChristian Brauner 7033ad20fe3SChristian Brauner inode->i_ino = FIRST_INODE; 7043ad20fe3SChristian Brauner inode->i_fop = &simple_dir_operations; 7053ad20fe3SChristian Brauner inode->i_mode = S_IFDIR | 0755; 7063ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 7073ad20fe3SChristian Brauner inode->i_op = &binderfs_dir_inode_operations; 7083ad20fe3SChristian Brauner set_nlink(inode, 2); 7093ad20fe3SChristian Brauner 7103ad20fe3SChristian Brauner sb->s_root = d_make_root(inode); 7113ad20fe3SChristian Brauner if (!sb->s_root) 71236975fc3SChristian Brauner return -ENOMEM; 7133ad20fe3SChristian Brauner 714ca2864c6SHridya Valsaraju ret = binderfs_binder_ctl_create(sb); 715ca2864c6SHridya Valsaraju if (ret) 716ca2864c6SHridya Valsaraju return ret; 717ca2864c6SHridya Valsaraju 718ca2864c6SHridya Valsaraju name = binder_devices_param; 719ca2864c6SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 720ca2864c6SHridya Valsaraju strscpy(device_info.name, name, len + 1); 721ca2864c6SHridya Valsaraju ret = binderfs_binder_device_create(inode, NULL, &device_info); 722ca2864c6SHridya Valsaraju if (ret) 723ca2864c6SHridya Valsaraju return ret; 724ca2864c6SHridya Valsaraju name += len; 725ca2864c6SHridya Valsaraju if (*name == ',') 726ca2864c6SHridya Valsaraju name++; 727ca2864c6SHridya Valsaraju } 728ca2864c6SHridya Valsaraju 729fc470abfSCarlos Llamas ret = init_binder_features(sb); 730fc470abfSCarlos Llamas if (ret) 731fc470abfSCarlos Llamas return ret; 732fc470abfSCarlos Llamas 733095cf502SChristian Brauner if (info->mount_opts.stats_mode == binderfs_stats_mode_global) 7340e13e452SHridya Valsaraju return init_binder_logs(sb); 7350e13e452SHridya Valsaraju 736ca2864c6SHridya Valsaraju return 0; 7373ad20fe3SChristian Brauner } 7383ad20fe3SChristian Brauner 739095cf502SChristian Brauner static int binderfs_fs_context_get_tree(struct fs_context *fc) 7403ad20fe3SChristian Brauner { 741095cf502SChristian Brauner return get_tree_nodev(fc, binderfs_fill_super); 7423ad20fe3SChristian Brauner } 7433ad20fe3SChristian Brauner 744095cf502SChristian Brauner static void binderfs_fs_context_free(struct fs_context *fc) 7453ad20fe3SChristian Brauner { 746095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 7473ad20fe3SChristian Brauner 748095cf502SChristian Brauner kfree(ctx); 749095cf502SChristian Brauner } 75041984795SChristian Brauner 751095cf502SChristian Brauner static const struct fs_context_operations binderfs_fs_context_ops = { 752095cf502SChristian Brauner .free = binderfs_fs_context_free, 753095cf502SChristian Brauner .get_tree = binderfs_fs_context_get_tree, 754095cf502SChristian Brauner .parse_param = binderfs_fs_context_parse_param, 755095cf502SChristian Brauner .reconfigure = binderfs_fs_context_reconfigure, 756095cf502SChristian Brauner }; 7573ad20fe3SChristian Brauner 758095cf502SChristian Brauner static int binderfs_init_fs_context(struct fs_context *fc) 759095cf502SChristian Brauner { 7609e306ba3SColin Ian King struct binderfs_mount_opts *ctx; 761095cf502SChristian Brauner 762095cf502SChristian Brauner ctx = kzalloc(sizeof(struct binderfs_mount_opts), GFP_KERNEL); 763095cf502SChristian Brauner if (!ctx) 764095cf502SChristian Brauner return -ENOMEM; 765095cf502SChristian Brauner 766095cf502SChristian Brauner ctx->max = BINDERFS_MAX_MINOR; 767095cf502SChristian Brauner ctx->stats_mode = binderfs_stats_mode_unset; 768095cf502SChristian Brauner 769095cf502SChristian Brauner fc->fs_private = ctx; 770095cf502SChristian Brauner fc->ops = &binderfs_fs_context_ops; 771095cf502SChristian Brauner 772095cf502SChristian Brauner return 0; 7733ad20fe3SChristian Brauner } 7743ad20fe3SChristian Brauner 775*9d64d240SAl Viro static void binderfs_kill_super(struct super_block *sb) 776*9d64d240SAl Viro { 777*9d64d240SAl Viro struct binderfs_info *info = sb->s_fs_info; 778*9d64d240SAl Viro 779*9d64d240SAl Viro /* 780*9d64d240SAl Viro * During inode eviction struct binderfs_info is needed. 781*9d64d240SAl Viro * So first wipe the super_block then free struct binderfs_info. 782*9d64d240SAl Viro */ 783*9d64d240SAl Viro kill_litter_super(sb); 784*9d64d240SAl Viro 785*9d64d240SAl Viro if (info && info->ipc_ns) 786*9d64d240SAl Viro put_ipc_ns(info->ipc_ns); 787*9d64d240SAl Viro 788*9d64d240SAl Viro kfree(info); 789*9d64d240SAl Viro } 790*9d64d240SAl Viro 7913ad20fe3SChristian Brauner static struct file_system_type binder_fs_type = { 7923ad20fe3SChristian Brauner .name = "binder", 793095cf502SChristian Brauner .init_fs_context = binderfs_init_fs_context, 794095cf502SChristian Brauner .parameters = binderfs_fs_parameters, 795*9d64d240SAl Viro .kill_sb = binderfs_kill_super, 7963ad20fe3SChristian Brauner .fs_flags = FS_USERNS_MOUNT, 7973ad20fe3SChristian Brauner }; 7983ad20fe3SChristian Brauner 7995b9633afSChristian Brauner int __init init_binderfs(void) 8003ad20fe3SChristian Brauner { 8013ad20fe3SChristian Brauner int ret; 802028fb582SHridya Valsaraju const char *name; 803028fb582SHridya Valsaraju size_t len; 804028fb582SHridya Valsaraju 805028fb582SHridya Valsaraju /* Verify that the default binderfs device names are valid. */ 806028fb582SHridya Valsaraju name = binder_devices_param; 807028fb582SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 808028fb582SHridya Valsaraju if (len > BINDERFS_MAX_NAME) 809028fb582SHridya Valsaraju return -E2BIG; 810028fb582SHridya Valsaraju name += len; 811028fb582SHridya Valsaraju if (*name == ',') 812028fb582SHridya Valsaraju name++; 813028fb582SHridya Valsaraju } 8143ad20fe3SChristian Brauner 8153ad20fe3SChristian Brauner /* Allocate new major number for binderfs. */ 8163ad20fe3SChristian Brauner ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR, 8173ad20fe3SChristian Brauner "binder"); 8183ad20fe3SChristian Brauner if (ret) 8193ad20fe3SChristian Brauner return ret; 8203ad20fe3SChristian Brauner 8213ad20fe3SChristian Brauner ret = register_filesystem(&binder_fs_type); 8223ad20fe3SChristian Brauner if (ret) { 8233ad20fe3SChristian Brauner unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR); 8243ad20fe3SChristian Brauner return ret; 8253ad20fe3SChristian Brauner } 8263ad20fe3SChristian Brauner 8273ad20fe3SChristian Brauner return ret; 8283ad20fe3SChristian Brauner } 829