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 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 61fc470abfSCarlos Llamas struct binder_features { 62fc470abfSCarlos Llamas bool oneway_spam_detection; 63d23386edSCarlos Llamas bool extended_error; 64fc470abfSCarlos Llamas }; 65fc470abfSCarlos Llamas 66095cf502SChristian Brauner static const struct constant_table binderfs_param_stats[] = { 67095cf502SChristian Brauner { "global", binderfs_stats_mode_global }, 68095cf502SChristian Brauner {} 69849d540dSChristian Brauner }; 70849d540dSChristian Brauner 7189320020SWei Yongjun static const struct fs_parameter_spec binderfs_fs_parameters[] = { 72095cf502SChristian Brauner fsparam_u32("max", Opt_max), 73095cf502SChristian Brauner fsparam_enum("stats", Opt_stats_mode, binderfs_param_stats), 74095cf502SChristian Brauner {} 75095cf502SChristian Brauner }; 76095cf502SChristian Brauner 77fc470abfSCarlos Llamas static struct binder_features binder_features = { 78fc470abfSCarlos Llamas .oneway_spam_detection = true, 79d23386edSCarlos Llamas .extended_error = true, 80fc470abfSCarlos Llamas }; 81fc470abfSCarlos Llamas 82095cf502SChristian Brauner static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb) 833ad20fe3SChristian Brauner { 84095cf502SChristian Brauner return sb->s_fs_info; 853ad20fe3SChristian Brauner } 863ad20fe3SChristian Brauner 873ad20fe3SChristian Brauner bool is_binderfs_device(const struct inode *inode) 883ad20fe3SChristian Brauner { 893ad20fe3SChristian Brauner if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) 903ad20fe3SChristian Brauner return true; 913ad20fe3SChristian Brauner 923ad20fe3SChristian Brauner return false; 933ad20fe3SChristian Brauner } 943ad20fe3SChristian Brauner 953ad20fe3SChristian Brauner /** 963ad20fe3SChristian Brauner * binderfs_binder_device_create - allocate inode from super block of a 973ad20fe3SChristian Brauner * binderfs mount 983ad20fe3SChristian Brauner * @ref_inode: inode from wich the super block will be taken 993ad20fe3SChristian Brauner * @userp: buffer to copy information about new device for userspace to 1003ad20fe3SChristian Brauner * @req: struct binderfs_device as copied from userspace 1013ad20fe3SChristian Brauner * 10201b3f1fcSChristian Brauner * This function allocates a new binder_device and reserves a new minor 1033ad20fe3SChristian Brauner * number for it. 1043ad20fe3SChristian Brauner * Minor numbers are limited and tracked globally in binderfs_minors. The 1053ad20fe3SChristian Brauner * function will stash a struct binder_device for the specific binder 1063ad20fe3SChristian Brauner * device in i_private of the inode. 1073ad20fe3SChristian Brauner * It will go on to allocate a new inode from the super block of the 1083ad20fe3SChristian Brauner * filesystem mount, stash a struct binder_device in its i_private field 1093ad20fe3SChristian Brauner * and attach a dentry to that inode. 1103ad20fe3SChristian Brauner * 1113ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 1123ad20fe3SChristian Brauner */ 1133ad20fe3SChristian Brauner static int binderfs_binder_device_create(struct inode *ref_inode, 1143ad20fe3SChristian Brauner struct binderfs_device __user *userp, 1153ad20fe3SChristian Brauner struct binderfs_device *req) 1163ad20fe3SChristian Brauner { 1173ad20fe3SChristian Brauner int minor, ret; 11801b3f1fcSChristian Brauner struct dentry *dentry, *root; 1193ad20fe3SChristian Brauner struct binder_device *device; 1203ad20fe3SChristian Brauner char *name = NULL; 12101b3f1fcSChristian Brauner size_t name_len; 1223ad20fe3SChristian Brauner struct inode *inode = NULL; 1233ad20fe3SChristian Brauner struct super_block *sb = ref_inode->i_sb; 1243ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 1257fefaaddSChristian Brauner #if defined(CONFIG_IPC_NS) 12636bdf3caSChristian Brauner bool use_reserve = (info->ipc_ns == &init_ipc_ns); 1277fefaaddSChristian Brauner #else 1287fefaaddSChristian Brauner bool use_reserve = true; 1297fefaaddSChristian Brauner #endif 1303ad20fe3SChristian Brauner 1313ad20fe3SChristian Brauner /* Reserve new minor number for the new device. */ 1323ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 133849d540dSChristian Brauner if (++info->device_count <= info->mount_opts.max) 13436bdf3caSChristian Brauner minor = ida_alloc_max(&binderfs_minors, 13536bdf3caSChristian Brauner use_reserve ? BINDERFS_MAX_MINOR : 13636bdf3caSChristian Brauner BINDERFS_MAX_MINOR_CAPPED, 137849d540dSChristian Brauner GFP_KERNEL); 138849d540dSChristian Brauner else 139849d540dSChristian Brauner minor = -ENOSPC; 140849d540dSChristian Brauner if (minor < 0) { 141849d540dSChristian Brauner --info->device_count; 1423ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1433ad20fe3SChristian Brauner return minor; 144849d540dSChristian Brauner } 145849d540dSChristian Brauner mutex_unlock(&binderfs_minors_mutex); 1463ad20fe3SChristian Brauner 1473ad20fe3SChristian Brauner ret = -ENOMEM; 1483ad20fe3SChristian Brauner device = kzalloc(sizeof(*device), GFP_KERNEL); 1493ad20fe3SChristian Brauner if (!device) 1503ad20fe3SChristian Brauner goto err; 1513ad20fe3SChristian Brauner 1523ad20fe3SChristian Brauner inode = new_inode(sb); 1533ad20fe3SChristian Brauner if (!inode) 1543ad20fe3SChristian Brauner goto err; 1553ad20fe3SChristian Brauner 1563ad20fe3SChristian Brauner inode->i_ino = minor + INODE_OFFSET; 1573ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 1583ad20fe3SChristian Brauner init_special_inode(inode, S_IFCHR | 0600, 1593ad20fe3SChristian Brauner MKDEV(MAJOR(binderfs_dev), minor)); 1603ad20fe3SChristian Brauner inode->i_fop = &binder_fops; 1613ad20fe3SChristian Brauner inode->i_uid = info->root_uid; 1623ad20fe3SChristian Brauner inode->i_gid = info->root_gid; 1633ad20fe3SChristian Brauner 16401b3f1fcSChristian Brauner req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ 16501b3f1fcSChristian Brauner name_len = strlen(req->name); 16601b3f1fcSChristian Brauner /* Make sure to include terminating NUL byte */ 16701b3f1fcSChristian Brauner name = kmemdup(req->name, name_len + 1, GFP_KERNEL); 1683ad20fe3SChristian Brauner if (!name) 1693ad20fe3SChristian Brauner goto err; 1703ad20fe3SChristian Brauner 171f0fe2c0fSChristian Brauner refcount_set(&device->ref, 1); 1723ad20fe3SChristian Brauner device->binderfs_inode = inode; 1733ad20fe3SChristian Brauner device->context.binder_context_mgr_uid = INVALID_UID; 1743ad20fe3SChristian Brauner device->context.name = name; 1753ad20fe3SChristian Brauner device->miscdev.name = name; 1763ad20fe3SChristian Brauner device->miscdev.minor = minor; 1773ad20fe3SChristian Brauner mutex_init(&device->context.context_mgr_node_lock); 1783ad20fe3SChristian Brauner 1793ad20fe3SChristian Brauner req->major = MAJOR(binderfs_dev); 1803ad20fe3SChristian Brauner req->minor = minor; 1813ad20fe3SChristian Brauner 182ca2864c6SHridya Valsaraju if (userp && copy_to_user(userp, req, sizeof(*req))) { 1833ad20fe3SChristian Brauner ret = -EFAULT; 1843ad20fe3SChristian Brauner goto err; 1853ad20fe3SChristian Brauner } 1863ad20fe3SChristian Brauner 1873ad20fe3SChristian Brauner root = sb->s_root; 1883ad20fe3SChristian Brauner inode_lock(d_inode(root)); 18901b3f1fcSChristian Brauner 19001b3f1fcSChristian Brauner /* look it up */ 19101b3f1fcSChristian Brauner dentry = lookup_one_len(name, root, name_len); 19201b3f1fcSChristian Brauner if (IS_ERR(dentry)) { 1933ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 19401b3f1fcSChristian Brauner ret = PTR_ERR(dentry); 1953ad20fe3SChristian Brauner goto err; 1963ad20fe3SChristian Brauner } 1973ad20fe3SChristian Brauner 19801b3f1fcSChristian Brauner if (d_really_is_positive(dentry)) { 19901b3f1fcSChristian Brauner /* already exists */ 2003ad20fe3SChristian Brauner dput(dentry); 2013ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 2023ad20fe3SChristian Brauner ret = -EEXIST; 2033ad20fe3SChristian Brauner goto err; 2043ad20fe3SChristian Brauner } 2053ad20fe3SChristian Brauner 2063ad20fe3SChristian Brauner inode->i_private = device; 20701684db9SChristian Brauner d_instantiate(dentry, inode); 2083ad20fe3SChristian Brauner fsnotify_create(root->d_inode, dentry); 2093ad20fe3SChristian Brauner inode_unlock(d_inode(root)); 2103ad20fe3SChristian Brauner 2113ad20fe3SChristian Brauner return 0; 2123ad20fe3SChristian Brauner 2133ad20fe3SChristian Brauner err: 2143ad20fe3SChristian Brauner kfree(name); 2153ad20fe3SChristian Brauner kfree(device); 2163ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 217849d540dSChristian Brauner --info->device_count; 2183ad20fe3SChristian Brauner ida_free(&binderfs_minors, minor); 2193ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2203ad20fe3SChristian Brauner iput(inode); 2213ad20fe3SChristian Brauner 2223ad20fe3SChristian Brauner return ret; 2233ad20fe3SChristian Brauner } 2243ad20fe3SChristian Brauner 2253ad20fe3SChristian Brauner /** 2263ad20fe3SChristian Brauner * binderfs_ctl_ioctl - handle binder device node allocation requests 2273ad20fe3SChristian Brauner * 2283ad20fe3SChristian Brauner * The request handler for the binder-control device. All requests operate on 2293ad20fe3SChristian Brauner * the binderfs mount the binder-control device resides in: 2303ad20fe3SChristian Brauner * - BINDER_CTL_ADD 2313ad20fe3SChristian Brauner * Allocate a new binder device. 2323ad20fe3SChristian Brauner * 2333ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 2343ad20fe3SChristian Brauner */ 2353ad20fe3SChristian Brauner static long binder_ctl_ioctl(struct file *file, unsigned int cmd, 2363ad20fe3SChristian Brauner unsigned long arg) 2373ad20fe3SChristian Brauner { 2383ad20fe3SChristian Brauner int ret = -EINVAL; 2393ad20fe3SChristian Brauner struct inode *inode = file_inode(file); 2403ad20fe3SChristian Brauner struct binderfs_device __user *device = (struct binderfs_device __user *)arg; 2413ad20fe3SChristian Brauner struct binderfs_device device_req; 2423ad20fe3SChristian Brauner 2433ad20fe3SChristian Brauner switch (cmd) { 2443ad20fe3SChristian Brauner case BINDER_CTL_ADD: 2453ad20fe3SChristian Brauner ret = copy_from_user(&device_req, device, sizeof(device_req)); 2463ad20fe3SChristian Brauner if (ret) { 2473ad20fe3SChristian Brauner ret = -EFAULT; 2483ad20fe3SChristian Brauner break; 2493ad20fe3SChristian Brauner } 2503ad20fe3SChristian Brauner 2513ad20fe3SChristian Brauner ret = binderfs_binder_device_create(inode, device, &device_req); 2523ad20fe3SChristian Brauner break; 2533ad20fe3SChristian Brauner default: 2543ad20fe3SChristian Brauner break; 2553ad20fe3SChristian Brauner } 2563ad20fe3SChristian Brauner 2573ad20fe3SChristian Brauner return ret; 2583ad20fe3SChristian Brauner } 2593ad20fe3SChristian Brauner 2603ad20fe3SChristian Brauner static void binderfs_evict_inode(struct inode *inode) 2613ad20fe3SChristian Brauner { 2623ad20fe3SChristian Brauner struct binder_device *device = inode->i_private; 263095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(inode->i_sb); 2643ad20fe3SChristian Brauner 2653ad20fe3SChristian Brauner clear_inode(inode); 2663ad20fe3SChristian Brauner 2670e13e452SHridya Valsaraju if (!S_ISCHR(inode->i_mode) || !device) 2683ad20fe3SChristian Brauner return; 2693ad20fe3SChristian Brauner 2703ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 271849d540dSChristian Brauner --info->device_count; 2723ad20fe3SChristian Brauner ida_free(&binderfs_minors, device->miscdev.minor); 2733ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 2743ad20fe3SChristian Brauner 275f0fe2c0fSChristian Brauner if (refcount_dec_and_test(&device->ref)) { 2763ad20fe3SChristian Brauner kfree(device->context.name); 2773ad20fe3SChristian Brauner kfree(device); 2783ad20fe3SChristian Brauner } 279f0fe2c0fSChristian Brauner } 2803ad20fe3SChristian Brauner 281095cf502SChristian Brauner static int binderfs_fs_context_parse_param(struct fs_context *fc, 282095cf502SChristian Brauner struct fs_parameter *param) 283849d540dSChristian Brauner { 284095cf502SChristian Brauner int opt; 285095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 286095cf502SChristian Brauner struct fs_parse_result result; 287849d540dSChristian Brauner 288095cf502SChristian Brauner opt = fs_parse(fc, binderfs_fs_parameters, param, &result); 289095cf502SChristian Brauner if (opt < 0) 290095cf502SChristian Brauner return opt; 291849d540dSChristian Brauner 292095cf502SChristian Brauner switch (opt) { 293849d540dSChristian Brauner case Opt_max: 294095cf502SChristian Brauner if (result.uint_32 > BINDERFS_MAX_MINOR) 295095cf502SChristian Brauner return invalfc(fc, "Bad value for '%s'", param->key); 296849d540dSChristian Brauner 297095cf502SChristian Brauner ctx->max = result.uint_32; 298849d540dSChristian Brauner break; 299f0083451SHridya Valsaraju case Opt_stats_mode: 300f0083451SHridya Valsaraju if (!capable(CAP_SYS_ADMIN)) 301095cf502SChristian Brauner return -EPERM; 302f0083451SHridya Valsaraju 303095cf502SChristian Brauner ctx->stats_mode = result.uint_32; 304f0083451SHridya Valsaraju break; 305849d540dSChristian Brauner default: 306095cf502SChristian Brauner return invalfc(fc, "Unsupported parameter '%s'", param->key); 307849d540dSChristian Brauner } 308849d540dSChristian Brauner 309849d540dSChristian Brauner return 0; 310849d540dSChristian Brauner } 311849d540dSChristian Brauner 312095cf502SChristian Brauner static int binderfs_fs_context_reconfigure(struct fs_context *fc) 313849d540dSChristian Brauner { 314095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 315095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb); 316f0083451SHridya Valsaraju 317095cf502SChristian Brauner if (info->mount_opts.stats_mode != ctx->stats_mode) 318095cf502SChristian Brauner return invalfc(fc, "Binderfs stats mode cannot be changed during a remount"); 319f0083451SHridya Valsaraju 320095cf502SChristian Brauner info->mount_opts.stats_mode = ctx->stats_mode; 321095cf502SChristian Brauner info->mount_opts.max = ctx->max; 322f0083451SHridya Valsaraju return 0; 323849d540dSChristian Brauner } 324849d540dSChristian Brauner 325095cf502SChristian Brauner static int binderfs_show_options(struct seq_file *seq, struct dentry *root) 326849d540dSChristian Brauner { 327095cf502SChristian Brauner struct binderfs_info *info = BINDERFS_SB(root->d_sb); 328849d540dSChristian Brauner 329849d540dSChristian Brauner if (info->mount_opts.max <= BINDERFS_MAX_MINOR) 330849d540dSChristian Brauner seq_printf(seq, ",max=%d", info->mount_opts.max); 331095cf502SChristian Brauner 332095cf502SChristian Brauner switch (info->mount_opts.stats_mode) { 333095cf502SChristian Brauner case binderfs_stats_mode_unset: 334095cf502SChristian Brauner break; 335095cf502SChristian Brauner case binderfs_stats_mode_global: 336f0083451SHridya Valsaraju seq_printf(seq, ",stats=global"); 337095cf502SChristian Brauner break; 338095cf502SChristian Brauner } 339849d540dSChristian Brauner 340849d540dSChristian Brauner return 0; 341849d540dSChristian Brauner } 342849d540dSChristian Brauner 343095cf502SChristian Brauner static void binderfs_put_super(struct super_block *sb) 344095cf502SChristian Brauner { 345095cf502SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 346095cf502SChristian Brauner 347095cf502SChristian Brauner if (info && info->ipc_ns) 348095cf502SChristian Brauner put_ipc_ns(info->ipc_ns); 349095cf502SChristian Brauner 350095cf502SChristian Brauner kfree(info); 351095cf502SChristian Brauner sb->s_fs_info = NULL; 352095cf502SChristian Brauner } 353095cf502SChristian Brauner 3543ad20fe3SChristian Brauner static const struct super_operations binderfs_super_ops = { 3553ad20fe3SChristian Brauner .evict_inode = binderfs_evict_inode, 356095cf502SChristian Brauner .show_options = binderfs_show_options, 357849d540dSChristian Brauner .statfs = simple_statfs, 358095cf502SChristian Brauner .put_super = binderfs_put_super, 3593ad20fe3SChristian Brauner }; 3603ad20fe3SChristian Brauner 361e98e6fa1SChristian Brauner static inline bool is_binderfs_control_device(const struct dentry *dentry) 362e98e6fa1SChristian Brauner { 363e98e6fa1SChristian Brauner struct binderfs_info *info = dentry->d_sb->s_fs_info; 36481195f96SMrinal Pandey 365e98e6fa1SChristian Brauner return info->control_dentry == dentry; 366e98e6fa1SChristian Brauner } 367e98e6fa1SChristian Brauner 368549c7297SChristian Brauner static int binderfs_rename(struct user_namespace *mnt_userns, 369549c7297SChristian Brauner struct inode *old_dir, struct dentry *old_dentry, 3703ad20fe3SChristian Brauner struct inode *new_dir, struct dentry *new_dentry, 3713ad20fe3SChristian Brauner unsigned int flags) 3723ad20fe3SChristian Brauner { 373e98e6fa1SChristian Brauner if (is_binderfs_control_device(old_dentry) || 374e98e6fa1SChristian Brauner is_binderfs_control_device(new_dentry)) 3753ad20fe3SChristian Brauner return -EPERM; 3763ad20fe3SChristian Brauner 377549c7297SChristian Brauner return simple_rename(&init_user_ns, old_dir, old_dentry, new_dir, 378549c7297SChristian Brauner new_dentry, flags); 3793ad20fe3SChristian Brauner } 3803ad20fe3SChristian Brauner 3813ad20fe3SChristian Brauner static int binderfs_unlink(struct inode *dir, struct dentry *dentry) 3823ad20fe3SChristian Brauner { 383e98e6fa1SChristian Brauner if (is_binderfs_control_device(dentry)) 3843ad20fe3SChristian Brauner return -EPERM; 3853ad20fe3SChristian Brauner 3863ad20fe3SChristian Brauner return simple_unlink(dir, dentry); 3873ad20fe3SChristian Brauner } 3883ad20fe3SChristian Brauner 3893ad20fe3SChristian Brauner static const struct file_operations binder_ctl_fops = { 3903ad20fe3SChristian Brauner .owner = THIS_MODULE, 3913ad20fe3SChristian Brauner .open = nonseekable_open, 3923ad20fe3SChristian Brauner .unlocked_ioctl = binder_ctl_ioctl, 3933ad20fe3SChristian Brauner .compat_ioctl = binder_ctl_ioctl, 3943ad20fe3SChristian Brauner .llseek = noop_llseek, 3953ad20fe3SChristian Brauner }; 3963ad20fe3SChristian Brauner 3973ad20fe3SChristian Brauner /** 3983ad20fe3SChristian Brauner * binderfs_binder_ctl_create - create a new binder-control device 3993ad20fe3SChristian Brauner * @sb: super block of the binderfs mount 4003ad20fe3SChristian Brauner * 4013ad20fe3SChristian Brauner * This function creates a new binder-control device node in the binderfs mount 4023ad20fe3SChristian Brauner * referred to by @sb. 4033ad20fe3SChristian Brauner * 4043ad20fe3SChristian Brauner * Return: 0 on success, negative errno on failure 4053ad20fe3SChristian Brauner */ 4063ad20fe3SChristian Brauner static int binderfs_binder_ctl_create(struct super_block *sb) 4073ad20fe3SChristian Brauner { 4083ad20fe3SChristian Brauner int minor, ret; 4093ad20fe3SChristian Brauner struct dentry *dentry; 4103ad20fe3SChristian Brauner struct binder_device *device; 4113ad20fe3SChristian Brauner struct inode *inode = NULL; 4123ad20fe3SChristian Brauner struct dentry *root = sb->s_root; 4133ad20fe3SChristian Brauner struct binderfs_info *info = sb->s_fs_info; 414da8ddba5SChristian Brauner #if defined(CONFIG_IPC_NS) 415da8ddba5SChristian Brauner bool use_reserve = (info->ipc_ns == &init_ipc_ns); 416da8ddba5SChristian Brauner #else 417da8ddba5SChristian Brauner bool use_reserve = true; 418da8ddba5SChristian Brauner #endif 4193ad20fe3SChristian Brauner 4203ad20fe3SChristian Brauner device = kzalloc(sizeof(*device), GFP_KERNEL); 4213ad20fe3SChristian Brauner if (!device) 4223ad20fe3SChristian Brauner return -ENOMEM; 4233ad20fe3SChristian Brauner 4243ad20fe3SChristian Brauner /* If we have already created a binder-control node, return. */ 4253ad20fe3SChristian Brauner if (info->control_dentry) { 4263ad20fe3SChristian Brauner ret = 0; 4273ad20fe3SChristian Brauner goto out; 4283ad20fe3SChristian Brauner } 4293ad20fe3SChristian Brauner 4303ad20fe3SChristian Brauner ret = -ENOMEM; 4313ad20fe3SChristian Brauner inode = new_inode(sb); 4323ad20fe3SChristian Brauner if (!inode) 4333ad20fe3SChristian Brauner goto out; 4343ad20fe3SChristian Brauner 4353ad20fe3SChristian Brauner /* Reserve a new minor number for the new device. */ 4363ad20fe3SChristian Brauner mutex_lock(&binderfs_minors_mutex); 437da8ddba5SChristian Brauner minor = ida_alloc_max(&binderfs_minors, 438da8ddba5SChristian Brauner use_reserve ? BINDERFS_MAX_MINOR : 439da8ddba5SChristian Brauner BINDERFS_MAX_MINOR_CAPPED, 440da8ddba5SChristian Brauner GFP_KERNEL); 4413ad20fe3SChristian Brauner mutex_unlock(&binderfs_minors_mutex); 4423ad20fe3SChristian Brauner if (minor < 0) { 4433ad20fe3SChristian Brauner ret = minor; 4443ad20fe3SChristian Brauner goto out; 4453ad20fe3SChristian Brauner } 4463ad20fe3SChristian Brauner 4473ad20fe3SChristian Brauner inode->i_ino = SECOND_INODE; 4483ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 4493ad20fe3SChristian Brauner init_special_inode(inode, S_IFCHR | 0600, 4503ad20fe3SChristian Brauner MKDEV(MAJOR(binderfs_dev), minor)); 4513ad20fe3SChristian Brauner inode->i_fop = &binder_ctl_fops; 4523ad20fe3SChristian Brauner inode->i_uid = info->root_uid; 4533ad20fe3SChristian Brauner inode->i_gid = info->root_gid; 4543ad20fe3SChristian Brauner 455211b64e4SChristian Brauner refcount_set(&device->ref, 1); 4563ad20fe3SChristian Brauner device->binderfs_inode = inode; 4573ad20fe3SChristian Brauner device->miscdev.minor = minor; 4583ad20fe3SChristian Brauner 4593ad20fe3SChristian Brauner dentry = d_alloc_name(root, "binder-control"); 4603ad20fe3SChristian Brauner if (!dentry) 4613ad20fe3SChristian Brauner goto out; 4623ad20fe3SChristian Brauner 4633ad20fe3SChristian Brauner inode->i_private = device; 4643ad20fe3SChristian Brauner info->control_dentry = dentry; 4653ad20fe3SChristian Brauner d_add(dentry, inode); 4663ad20fe3SChristian Brauner 4673ad20fe3SChristian Brauner return 0; 4683ad20fe3SChristian Brauner 4693ad20fe3SChristian Brauner out: 4703ad20fe3SChristian Brauner kfree(device); 4713ad20fe3SChristian Brauner iput(inode); 4723ad20fe3SChristian Brauner 4733ad20fe3SChristian Brauner return ret; 4743ad20fe3SChristian Brauner } 4753ad20fe3SChristian Brauner 4763ad20fe3SChristian Brauner static const struct inode_operations binderfs_dir_inode_operations = { 4773ad20fe3SChristian Brauner .lookup = simple_lookup, 4783ad20fe3SChristian Brauner .rename = binderfs_rename, 4793ad20fe3SChristian Brauner .unlink = binderfs_unlink, 4803ad20fe3SChristian Brauner }; 4813ad20fe3SChristian Brauner 4820e13e452SHridya Valsaraju static struct inode *binderfs_make_inode(struct super_block *sb, int mode) 4830e13e452SHridya Valsaraju { 4840e13e452SHridya Valsaraju struct inode *ret; 4850e13e452SHridya Valsaraju 4860e13e452SHridya Valsaraju ret = new_inode(sb); 4870e13e452SHridya Valsaraju if (ret) { 4880e13e452SHridya Valsaraju ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET); 4890e13e452SHridya Valsaraju ret->i_mode = mode; 4900e13e452SHridya Valsaraju ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret); 4910e13e452SHridya Valsaraju } 4920e13e452SHridya Valsaraju return ret; 4930e13e452SHridya Valsaraju } 4940e13e452SHridya Valsaraju 4950e13e452SHridya Valsaraju static struct dentry *binderfs_create_dentry(struct dentry *parent, 4960e13e452SHridya Valsaraju const char *name) 4970e13e452SHridya Valsaraju { 4980e13e452SHridya Valsaraju struct dentry *dentry; 4990e13e452SHridya Valsaraju 5000e13e452SHridya Valsaraju dentry = lookup_one_len(name, parent, strlen(name)); 5010e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5020e13e452SHridya Valsaraju return dentry; 5030e13e452SHridya Valsaraju 5040e13e452SHridya Valsaraju /* Return error if the file/dir already exists. */ 5050e13e452SHridya Valsaraju if (d_really_is_positive(dentry)) { 5060e13e452SHridya Valsaraju dput(dentry); 5070e13e452SHridya Valsaraju return ERR_PTR(-EEXIST); 5080e13e452SHridya Valsaraju } 5090e13e452SHridya Valsaraju 5100e13e452SHridya Valsaraju return dentry; 5110e13e452SHridya Valsaraju } 5120e13e452SHridya Valsaraju 5134feb80faSHridya Valsaraju void binderfs_remove_file(struct dentry *dentry) 5144feb80faSHridya Valsaraju { 5154feb80faSHridya Valsaraju struct inode *parent_inode; 5164feb80faSHridya Valsaraju 5174feb80faSHridya Valsaraju parent_inode = d_inode(dentry->d_parent); 5184feb80faSHridya Valsaraju inode_lock(parent_inode); 5194feb80faSHridya Valsaraju if (simple_positive(dentry)) { 5204feb80faSHridya Valsaraju dget(dentry); 5214feb80faSHridya Valsaraju simple_unlink(parent_inode, dentry); 5224feb80faSHridya Valsaraju d_delete(dentry); 5234feb80faSHridya Valsaraju dput(dentry); 5244feb80faSHridya Valsaraju } 5254feb80faSHridya Valsaraju inode_unlock(parent_inode); 5264feb80faSHridya Valsaraju } 5274feb80faSHridya Valsaraju 5284feb80faSHridya Valsaraju struct dentry *binderfs_create_file(struct dentry *parent, const char *name, 5290e13e452SHridya Valsaraju const struct file_operations *fops, 5300e13e452SHridya Valsaraju void *data) 5310e13e452SHridya Valsaraju { 5320e13e452SHridya Valsaraju struct dentry *dentry; 5330e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5340e13e452SHridya Valsaraju struct super_block *sb; 5350e13e452SHridya Valsaraju 5360e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5370e13e452SHridya Valsaraju inode_lock(parent_inode); 5380e13e452SHridya Valsaraju 5390e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5400e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5410e13e452SHridya Valsaraju goto out; 5420e13e452SHridya Valsaraju 5430e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5440e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFREG | 0444); 5450e13e452SHridya Valsaraju if (!new_inode) { 5460e13e452SHridya Valsaraju dput(dentry); 5470e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5480e13e452SHridya Valsaraju goto out; 5490e13e452SHridya Valsaraju } 5500e13e452SHridya Valsaraju 5510e13e452SHridya Valsaraju new_inode->i_fop = fops; 5520e13e452SHridya Valsaraju new_inode->i_private = data; 5530e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5540e13e452SHridya Valsaraju fsnotify_create(parent_inode, dentry); 5550e13e452SHridya Valsaraju 5560e13e452SHridya Valsaraju out: 5570e13e452SHridya Valsaraju inode_unlock(parent_inode); 5580e13e452SHridya Valsaraju return dentry; 5590e13e452SHridya Valsaraju } 5600e13e452SHridya Valsaraju 5610e13e452SHridya Valsaraju static struct dentry *binderfs_create_dir(struct dentry *parent, 5620e13e452SHridya Valsaraju const char *name) 5630e13e452SHridya Valsaraju { 5640e13e452SHridya Valsaraju struct dentry *dentry; 5650e13e452SHridya Valsaraju struct inode *new_inode, *parent_inode; 5660e13e452SHridya Valsaraju struct super_block *sb; 5670e13e452SHridya Valsaraju 5680e13e452SHridya Valsaraju parent_inode = d_inode(parent); 5690e13e452SHridya Valsaraju inode_lock(parent_inode); 5700e13e452SHridya Valsaraju 5710e13e452SHridya Valsaraju dentry = binderfs_create_dentry(parent, name); 5720e13e452SHridya Valsaraju if (IS_ERR(dentry)) 5730e13e452SHridya Valsaraju goto out; 5740e13e452SHridya Valsaraju 5750e13e452SHridya Valsaraju sb = parent_inode->i_sb; 5760e13e452SHridya Valsaraju new_inode = binderfs_make_inode(sb, S_IFDIR | 0755); 5770e13e452SHridya Valsaraju if (!new_inode) { 5780e13e452SHridya Valsaraju dput(dentry); 5790e13e452SHridya Valsaraju dentry = ERR_PTR(-ENOMEM); 5800e13e452SHridya Valsaraju goto out; 5810e13e452SHridya Valsaraju } 5820e13e452SHridya Valsaraju 5830e13e452SHridya Valsaraju new_inode->i_fop = &simple_dir_operations; 5840e13e452SHridya Valsaraju new_inode->i_op = &simple_dir_inode_operations; 5850e13e452SHridya Valsaraju 5860e13e452SHridya Valsaraju set_nlink(new_inode, 2); 5870e13e452SHridya Valsaraju d_instantiate(dentry, new_inode); 5880e13e452SHridya Valsaraju inc_nlink(parent_inode); 5890e13e452SHridya Valsaraju fsnotify_mkdir(parent_inode, dentry); 5900e13e452SHridya Valsaraju 5910e13e452SHridya Valsaraju out: 5920e13e452SHridya Valsaraju inode_unlock(parent_inode); 5930e13e452SHridya Valsaraju return dentry; 5940e13e452SHridya Valsaraju } 5950e13e452SHridya Valsaraju 596fc470abfSCarlos Llamas static int binder_features_show(struct seq_file *m, void *unused) 597fc470abfSCarlos Llamas { 598fc470abfSCarlos Llamas bool *feature = m->private; 599fc470abfSCarlos Llamas 600fc470abfSCarlos Llamas seq_printf(m, "%d\n", *feature); 601fc470abfSCarlos Llamas 602fc470abfSCarlos Llamas return 0; 603fc470abfSCarlos Llamas } 604fc470abfSCarlos Llamas DEFINE_SHOW_ATTRIBUTE(binder_features); 605fc470abfSCarlos Llamas 606fc470abfSCarlos Llamas static int init_binder_features(struct super_block *sb) 607fc470abfSCarlos Llamas { 608fc470abfSCarlos Llamas struct dentry *dentry, *dir; 609fc470abfSCarlos Llamas 610fc470abfSCarlos Llamas dir = binderfs_create_dir(sb->s_root, "features"); 611fc470abfSCarlos Llamas if (IS_ERR(dir)) 612fc470abfSCarlos Llamas return PTR_ERR(dir); 613fc470abfSCarlos Llamas 614fc470abfSCarlos Llamas dentry = binderfs_create_file(dir, "oneway_spam_detection", 615fc470abfSCarlos Llamas &binder_features_fops, 616fc470abfSCarlos Llamas &binder_features.oneway_spam_detection); 617fc470abfSCarlos Llamas if (IS_ERR(dentry)) 618fc470abfSCarlos Llamas return PTR_ERR(dentry); 619fc470abfSCarlos Llamas 620d23386edSCarlos Llamas dentry = binderfs_create_file(dir, "extended_error", 621d23386edSCarlos Llamas &binder_features_fops, 622d23386edSCarlos Llamas &binder_features.extended_error); 623d23386edSCarlos Llamas if (IS_ERR(dentry)) 624d23386edSCarlos Llamas return PTR_ERR(dentry); 625d23386edSCarlos Llamas 626fc470abfSCarlos Llamas return 0; 627fc470abfSCarlos Llamas } 628fc470abfSCarlos Llamas 6290e13e452SHridya Valsaraju static int init_binder_logs(struct super_block *sb) 6300e13e452SHridya Valsaraju { 6314feb80faSHridya Valsaraju struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir; 632*b7e241bbSCarlos Llamas const struct binder_debugfs_entry *db_entry; 6334feb80faSHridya Valsaraju struct binderfs_info *info; 6340e13e452SHridya Valsaraju int ret = 0; 6350e13e452SHridya Valsaraju 6360e13e452SHridya Valsaraju binder_logs_root_dir = binderfs_create_dir(sb->s_root, 6370e13e452SHridya Valsaraju "binder_logs"); 6380e13e452SHridya Valsaraju if (IS_ERR(binder_logs_root_dir)) { 6390e13e452SHridya Valsaraju ret = PTR_ERR(binder_logs_root_dir); 6400e13e452SHridya Valsaraju goto out; 6410e13e452SHridya Valsaraju } 6420e13e452SHridya Valsaraju 643*b7e241bbSCarlos Llamas binder_for_each_debugfs_entry(db_entry) { 64403e2e07eSHridya Valsaraju dentry = binderfs_create_file(binder_logs_root_dir, 645*b7e241bbSCarlos Llamas db_entry->name, 646*b7e241bbSCarlos Llamas db_entry->fops, 647*b7e241bbSCarlos Llamas db_entry->data); 64803e2e07eSHridya Valsaraju if (IS_ERR(dentry)) { 64903e2e07eSHridya Valsaraju ret = PTR_ERR(dentry); 65003e2e07eSHridya Valsaraju goto out; 65103e2e07eSHridya Valsaraju } 6524feb80faSHridya Valsaraju } 6534feb80faSHridya Valsaraju 6544feb80faSHridya Valsaraju proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc"); 6554feb80faSHridya Valsaraju if (IS_ERR(proc_log_dir)) { 6564feb80faSHridya Valsaraju ret = PTR_ERR(proc_log_dir); 6574feb80faSHridya Valsaraju goto out; 6584feb80faSHridya Valsaraju } 6594feb80faSHridya Valsaraju info = sb->s_fs_info; 6604feb80faSHridya Valsaraju info->proc_log_dir = proc_log_dir; 6610e13e452SHridya Valsaraju 6620e13e452SHridya Valsaraju out: 6630e13e452SHridya Valsaraju return ret; 6640e13e452SHridya Valsaraju } 6650e13e452SHridya Valsaraju 666095cf502SChristian Brauner static int binderfs_fill_super(struct super_block *sb, struct fs_context *fc) 6673ad20fe3SChristian Brauner { 66836975fc3SChristian Brauner int ret; 6693ad20fe3SChristian Brauner struct binderfs_info *info; 670095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 6713ad20fe3SChristian Brauner struct inode *inode = NULL; 6727a1c4f28STang Bin struct binderfs_device device_info = {}; 673ca2864c6SHridya Valsaraju const char *name; 674ca2864c6SHridya Valsaraju size_t len; 6753ad20fe3SChristian Brauner 6763ad20fe3SChristian Brauner sb->s_blocksize = PAGE_SIZE; 6773ad20fe3SChristian Brauner sb->s_blocksize_bits = PAGE_SHIFT; 6783ad20fe3SChristian Brauner 6793ad20fe3SChristian Brauner /* 6803ad20fe3SChristian Brauner * The binderfs filesystem can be mounted by userns root in a 6813ad20fe3SChristian Brauner * non-initial userns. By default such mounts have the SB_I_NODEV flag 6823ad20fe3SChristian Brauner * set in s_iflags to prevent security issues where userns root can 6833ad20fe3SChristian Brauner * just create random device nodes via mknod() since it owns the 6843ad20fe3SChristian Brauner * filesystem mount. But binderfs does not allow to create any files 6853ad20fe3SChristian Brauner * including devices nodes. The only way to create binder devices nodes 6863ad20fe3SChristian Brauner * is through the binder-control device which userns root is explicitly 6873ad20fe3SChristian Brauner * allowed to do. So removing the SB_I_NODEV flag from s_iflags is both 6883ad20fe3SChristian Brauner * necessary and safe. 6893ad20fe3SChristian Brauner */ 6903ad20fe3SChristian Brauner sb->s_iflags &= ~SB_I_NODEV; 6913ad20fe3SChristian Brauner sb->s_iflags |= SB_I_NOEXEC; 6923ad20fe3SChristian Brauner sb->s_magic = BINDERFS_SUPER_MAGIC; 6933ad20fe3SChristian Brauner sb->s_op = &binderfs_super_ops; 6943ad20fe3SChristian Brauner sb->s_time_gran = 1; 6953ad20fe3SChristian Brauner 69636975fc3SChristian Brauner sb->s_fs_info = kzalloc(sizeof(struct binderfs_info), GFP_KERNEL); 69736975fc3SChristian Brauner if (!sb->s_fs_info) 69836975fc3SChristian Brauner return -ENOMEM; 69936975fc3SChristian Brauner info = sb->s_fs_info; 70036975fc3SChristian Brauner 70136975fc3SChristian Brauner info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); 7023ad20fe3SChristian Brauner 7033ad20fe3SChristian Brauner info->root_gid = make_kgid(sb->s_user_ns, 0); 7043ad20fe3SChristian Brauner if (!gid_valid(info->root_gid)) 7053ad20fe3SChristian Brauner info->root_gid = GLOBAL_ROOT_GID; 7063ad20fe3SChristian Brauner info->root_uid = make_kuid(sb->s_user_ns, 0); 7073ad20fe3SChristian Brauner if (!uid_valid(info->root_uid)) 7083ad20fe3SChristian Brauner info->root_uid = GLOBAL_ROOT_UID; 709095cf502SChristian Brauner info->mount_opts.max = ctx->max; 710095cf502SChristian Brauner info->mount_opts.stats_mode = ctx->stats_mode; 7113ad20fe3SChristian Brauner 7123ad20fe3SChristian Brauner inode = new_inode(sb); 7133ad20fe3SChristian Brauner if (!inode) 71436975fc3SChristian Brauner return -ENOMEM; 7153ad20fe3SChristian Brauner 7163ad20fe3SChristian Brauner inode->i_ino = FIRST_INODE; 7173ad20fe3SChristian Brauner inode->i_fop = &simple_dir_operations; 7183ad20fe3SChristian Brauner inode->i_mode = S_IFDIR | 0755; 7193ad20fe3SChristian Brauner inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); 7203ad20fe3SChristian Brauner inode->i_op = &binderfs_dir_inode_operations; 7213ad20fe3SChristian Brauner set_nlink(inode, 2); 7223ad20fe3SChristian Brauner 7233ad20fe3SChristian Brauner sb->s_root = d_make_root(inode); 7243ad20fe3SChristian Brauner if (!sb->s_root) 72536975fc3SChristian Brauner return -ENOMEM; 7263ad20fe3SChristian Brauner 727ca2864c6SHridya Valsaraju ret = binderfs_binder_ctl_create(sb); 728ca2864c6SHridya Valsaraju if (ret) 729ca2864c6SHridya Valsaraju return ret; 730ca2864c6SHridya Valsaraju 731ca2864c6SHridya Valsaraju name = binder_devices_param; 732ca2864c6SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 733ca2864c6SHridya Valsaraju strscpy(device_info.name, name, len + 1); 734ca2864c6SHridya Valsaraju ret = binderfs_binder_device_create(inode, NULL, &device_info); 735ca2864c6SHridya Valsaraju if (ret) 736ca2864c6SHridya Valsaraju return ret; 737ca2864c6SHridya Valsaraju name += len; 738ca2864c6SHridya Valsaraju if (*name == ',') 739ca2864c6SHridya Valsaraju name++; 740ca2864c6SHridya Valsaraju } 741ca2864c6SHridya Valsaraju 742fc470abfSCarlos Llamas ret = init_binder_features(sb); 743fc470abfSCarlos Llamas if (ret) 744fc470abfSCarlos Llamas return ret; 745fc470abfSCarlos Llamas 746095cf502SChristian Brauner if (info->mount_opts.stats_mode == binderfs_stats_mode_global) 7470e13e452SHridya Valsaraju return init_binder_logs(sb); 7480e13e452SHridya Valsaraju 749ca2864c6SHridya Valsaraju return 0; 7503ad20fe3SChristian Brauner } 7513ad20fe3SChristian Brauner 752095cf502SChristian Brauner static int binderfs_fs_context_get_tree(struct fs_context *fc) 7533ad20fe3SChristian Brauner { 754095cf502SChristian Brauner return get_tree_nodev(fc, binderfs_fill_super); 7553ad20fe3SChristian Brauner } 7563ad20fe3SChristian Brauner 757095cf502SChristian Brauner static void binderfs_fs_context_free(struct fs_context *fc) 7583ad20fe3SChristian Brauner { 759095cf502SChristian Brauner struct binderfs_mount_opts *ctx = fc->fs_private; 7603ad20fe3SChristian Brauner 761095cf502SChristian Brauner kfree(ctx); 762095cf502SChristian Brauner } 76341984795SChristian Brauner 764095cf502SChristian Brauner static const struct fs_context_operations binderfs_fs_context_ops = { 765095cf502SChristian Brauner .free = binderfs_fs_context_free, 766095cf502SChristian Brauner .get_tree = binderfs_fs_context_get_tree, 767095cf502SChristian Brauner .parse_param = binderfs_fs_context_parse_param, 768095cf502SChristian Brauner .reconfigure = binderfs_fs_context_reconfigure, 769095cf502SChristian Brauner }; 7703ad20fe3SChristian Brauner 771095cf502SChristian Brauner static int binderfs_init_fs_context(struct fs_context *fc) 772095cf502SChristian Brauner { 7739e306ba3SColin Ian King struct binderfs_mount_opts *ctx; 774095cf502SChristian Brauner 775095cf502SChristian Brauner ctx = kzalloc(sizeof(struct binderfs_mount_opts), GFP_KERNEL); 776095cf502SChristian Brauner if (!ctx) 777095cf502SChristian Brauner return -ENOMEM; 778095cf502SChristian Brauner 779095cf502SChristian Brauner ctx->max = BINDERFS_MAX_MINOR; 780095cf502SChristian Brauner ctx->stats_mode = binderfs_stats_mode_unset; 781095cf502SChristian Brauner 782095cf502SChristian Brauner fc->fs_private = ctx; 783095cf502SChristian Brauner fc->ops = &binderfs_fs_context_ops; 784095cf502SChristian Brauner 785095cf502SChristian Brauner return 0; 7863ad20fe3SChristian Brauner } 7873ad20fe3SChristian Brauner 7883ad20fe3SChristian Brauner static struct file_system_type binder_fs_type = { 7893ad20fe3SChristian Brauner .name = "binder", 790095cf502SChristian Brauner .init_fs_context = binderfs_init_fs_context, 791095cf502SChristian Brauner .parameters = binderfs_fs_parameters, 792095cf502SChristian Brauner .kill_sb = kill_litter_super, 7933ad20fe3SChristian Brauner .fs_flags = FS_USERNS_MOUNT, 7943ad20fe3SChristian Brauner }; 7953ad20fe3SChristian Brauner 7965b9633afSChristian Brauner int __init init_binderfs(void) 7973ad20fe3SChristian Brauner { 7983ad20fe3SChristian Brauner int ret; 799028fb582SHridya Valsaraju const char *name; 800028fb582SHridya Valsaraju size_t len; 801028fb582SHridya Valsaraju 802028fb582SHridya Valsaraju /* Verify that the default binderfs device names are valid. */ 803028fb582SHridya Valsaraju name = binder_devices_param; 804028fb582SHridya Valsaraju for (len = strcspn(name, ","); len > 0; len = strcspn(name, ",")) { 805028fb582SHridya Valsaraju if (len > BINDERFS_MAX_NAME) 806028fb582SHridya Valsaraju return -E2BIG; 807028fb582SHridya Valsaraju name += len; 808028fb582SHridya Valsaraju if (*name == ',') 809028fb582SHridya Valsaraju name++; 810028fb582SHridya Valsaraju } 8113ad20fe3SChristian Brauner 8123ad20fe3SChristian Brauner /* Allocate new major number for binderfs. */ 8133ad20fe3SChristian Brauner ret = alloc_chrdev_region(&binderfs_dev, 0, BINDERFS_MAX_MINOR, 8143ad20fe3SChristian Brauner "binder"); 8153ad20fe3SChristian Brauner if (ret) 8163ad20fe3SChristian Brauner return ret; 8173ad20fe3SChristian Brauner 8183ad20fe3SChristian Brauner ret = register_filesystem(&binder_fs_type); 8193ad20fe3SChristian Brauner if (ret) { 8203ad20fe3SChristian Brauner unregister_chrdev_region(binderfs_dev, BINDERFS_MAX_MINOR); 8213ad20fe3SChristian Brauner return ret; 8223ad20fe3SChristian Brauner } 8233ad20fe3SChristian Brauner 8243ad20fe3SChristian Brauner return ret; 8253ad20fe3SChristian Brauner } 826