// SPDX-License-Identifier: GPL-2.0 #include <linux/compiler_types.h>#include <linux/errno.h>#include <linux/fs.h>#include <linux/fsnotify.h>#include <linux/gfp.h>#include <linux/idr.h>#include <linux/init.h>#include <linux/ipc_namespace.h>#include <linux/kdev_t.h>#include <linux/kernel.h>#include <linux/list.h>#include <linux/namei.h>#include <linux/magic.h>#include <linux/major.h>#include <linux/miscdevice.h>#include <linux/module.h>#include <linux/mutex.h>#include <linux/mount.h>#include <linux/fs_parser.h>#include <linux/sched.h>#include <linux/seq_file.h>#include <linux/slab.h>#include <linux/spinlock_types.h>#include <linux/stddef.h>#include <linux/string.h>#include <linux/types.h>#include <linux/uaccess.h>#include <linux/user_namespace.h>#include <linux/xarray.h>#include <uapi/linux/android/binder.h>#include <uapi/linux/android/binderfs.h> #include "binder_internal.h" #define FIRST_INODE 1#define SECOND_INODE 2#define INODE_OFFSET 3#define BINDERFS_MAX_MINOR (1U << MINORBITS)/* Ensure that the initial ipc namespace always has devices available. */#define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4) static dev_t binderfs_dev;static DEFINE_MUTEX(binderfs_minors_mutex);static DEFINE_IDA(binderfs_minors); enum binderfs_param { Opt_max, Opt_stats_mode,}; enum binderfs_stats_mode { binderfs_stats_mode_unset, binderfs_stats_mode_global,}; struct binder_features { bool oneway_spam_detection; bool extended_error; bool freeze_notification; bool transaction_report;}; static const struct constant_table binderfs_param_stats[] = { { "global", binderfs_stats_mode_global }, {}}; static const struct fs_parameter_spec binderfs_fs_parameters[] = { fsparam_u32("max", Opt_max), fsparam_enum("stats", Opt_stats_mode, binderfs_param_stats), {}}; static struct binder_features binder_features = { .oneway_spam_detection = true, .extended_error = true, .freeze_notification = true, .transaction_report = true,}; static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb){ return sb->s_fs_info;} bool is_binderfs_device(const struct inode *inode){ if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) return true; return false;} /** * binderfs_binder_device_create - allocate inode from super block of a * binderfs mount * @ref_inode: inode from which the super block will be taken * @userp: buffer to copy information about new device for userspace to * @req: struct binderfs_device as copied from userspace * * This function allocates a new binder_device and reserves a new minor * number for it. * Minor numbers are limited and tracked globally in binderfs_minors. The * function will stash a struct binder_device for the specific binder * device in i_private of the inode. * It will go on to allocate a new inode from the super block of the * filesystem mount, stash a struct binder_device in its i_private field * and attach a dentry to that inode. * * Return: 0 on success, negative errno on failure */static int binderfs_binder_device_create(struct inode *ref_inode, struct binderfs_device __user *userp, struct binderfs_device *req){ int minor, ret; struct dentry *dentry, *root; struct binder_device *device; char *name = NULL; struct inode *inode = NULL; struct super_block *sb = ref_inode->i_sb; struct binderfs_info *info = sb->s_fs_info;#if defined(CONFIG_IPC_NS) bool use_reserve = (info->ipc_ns == &init_ipc_ns);#else bool use_reserve = true;#endif /* Reserve new minor number for the new device. */ mutex_lock(&binderfs_minors_mutex); if (++info->device_count <= info->mount_opts.max) minor = ida_alloc_max(&binderfs_minors, use_reserve ? BINDERFS_MAX_MINOR - 1 : BINDERFS_MAX_MINOR_CAPPED - 1, GFP_KERNEL); else minor = -ENOSPC; if (minor < 0) { --info->device_count; mutex_unlock(&binderfs_minors_mutex); return minor; } mutex_unlock(&binderfs_minors_mutex); ret = -ENOMEM; device = kzalloc_obj(*device); if (!device) goto err; inode = new_inode(sb); if (!inode) goto err; inode->i_ino = minor + INODE_OFFSET; simple_inode_init_ts(inode); init_special_inode(inode, S_IFCHR | 0600, MKDEV(MAJOR(binderfs_dev), minor)); inode->i_fop = &binder_fops; inode->i_uid = info->root_uid; inode->i_gid = info->root_gid; req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ name = kstrdup(req->name, GFP_KERNEL); if (!name) goto err; refcount_set(&device->ref, 1); device->binderfs_inode = inode; device->context.binder_context_mgr_uid = INVALID_UID; device->context.name = name; device->miscdev.name = name; device->miscdev.minor = minor; mutex_init(&device->context.context_mgr_node_lock); req->major = MAJOR(binderfs_dev); req->minor = minor; if (userp && copy_to_user(userp, req, sizeof(*req))) { ret = -EFAULT; goto err; } root = sb->s_root; dentry = simple_start_creating(root, name); if (IS_ERR(dentry)) { ret = PTR_ERR(dentry); goto err; } inode->i_private = device; d_make_persistent(dentry, inode); fsnotify_create(root->d_inode, dentry); simple_done_creating(dentry); binder_add_device(device); return 0; err: kfree(name); kfree(device); mutex_lock(&binderfs_minors_mutex); --info->device_count; ida_free(&binderfs_minors, minor); mutex_unlock(&binderfs_minors_mutex); iput(inode); return ret;} /** * binder_ctl_ioctl - handle binder device node allocation requests * @file: The file pointer for the binder-control device node. * @cmd: The ioctl command. * @arg: The ioctl argument. * * The request handler for the binder-control device. All requests operate on * the binderfs mount the binder-control device resides in: * - BINDER_CTL_ADD * Allocate a new binder device. * * Return: %0 on success, negative errno on failure. */static long binder_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ int ret = -EINVAL; struct inode *inode = file_inode(file); struct binderfs_device __user *device = (struct binderfs_device __user *)arg; struct binderfs_device device_req; switch (cmd) { case BINDER_CTL_ADD: ret = copy_from_user(&device_req, device, sizeof(device_req)); if (ret) { ret = -EFAULT; break; } ret = binderfs_binder_device_create(inode, device, &device_req); break; default: break; } return ret;} static void binderfs_evict_inode(struct inode *inode){ struct binder_device *device = inode->i_private; struct binderfs_info *info = BINDERFS_SB(inode->i_sb); clear_inode(inode); if (!S_ISCHR(inode->i_mode) || !device) return; mutex_lock(&binderfs_minors_mutex); --info->device_count; ida_free(&binderfs_minors, device->miscdev.minor); mutex_unlock(&binderfs_minors_mutex); if (refcount_dec_and_test(&device->ref)) { binder_remove_device(device); kfree(device->context.name); kfree(device); }} static int binderfs_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param){ int opt; struct binderfs_mount_opts *ctx = fc->fs_private; struct fs_parse_result result; opt = fs_parse(fc, binderfs_fs_parameters, param, &result); if (opt < 0) return opt; switch (opt) { case Opt_max: if (result.uint_32 > BINDERFS_MAX_MINOR) return invalfc(fc, "Bad value for '%s'", param->key); ctx->max = result.uint_32; break; case Opt_stats_mode: if (!capable(CAP_SYS_ADMIN)) return -EPERM; ctx->stats_mode = result.uint_32; break; default: return invalfc(fc, "Unsupported parameter '%s'", param->key); } return 0;} static int binderfs_fs_context_reconfigure(struct fs_context *fc){ struct binderfs_mount_opts *ctx = fc->fs_private; struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb); if (info->mount_opts.stats_mode != ctx->stats_mode) return invalfc(fc, "Binderfs stats mode cannot be changed during a remount"); info->mount_opts.stats_mode = ctx->stats_mode; info->mount_opts.max = ctx->max; return 0;} static int binderfs_show_options(struct seq_file *seq, struct dentry *root){ struct binderfs_info *info = BINDERFS_SB(root->d_sb); if (info->mount_opts.max <= BINDERFS_MAX_MINOR) seq_printf(seq, ",max=%d", info->mount_opts.max); switch (info->mount_opts.stats_mode) { case binderfs_stats_mode_unset: break; case binderfs_stats_mode_global: seq_printf(seq, ",stats=global"); break; } return 0;} static const struct super_operations binderfs_super_ops = { .evict_inode = binderfs_evict_inode, .show_options = binderfs_show_options, .statfs = simple_statfs,}; static inline bool is_binderfs_control_device(const struct dentry *dentry){ struct binderfs_info *info = dentry->d_sb->s_fs_info; return info->control_dentry == dentry;} static int binderfs_rename(struct mnt_idmap *idmap, struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags){ if (is_binderfs_control_device(old_dentry) || is_binderfs_control_device(new_dentry)) return -EPERM; return simple_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags);} static int binderfs_unlink(struct inode *dir, struct dentry *dentry){ if (is_binderfs_control_device(dentry)) return -EPERM; return simple_unlink(dir, dentry);} static const struct file_operations binder_ctl_fops = { .owner = THIS_MODULE, .open = nonseekable_open, .unlocked_ioctl = binder_ctl_ioctl, .compat_ioctl = binder_ctl_ioctl, .llseek = noop_llseek,}; /** * binderfs_binder_ctl_create - create a new binder-control device * @sb: super block of the binderfs mount * * This function creates a new binder-control device node in the binderfs mount * referred to by @sb. * * Return: 0 on success, negative errno on failure */static int binderfs_binder_ctl_create(struct super_block *sb){ int minor, ret; struct dentry *dentry; struct binder_device *device; struct inode *inode = NULL; struct dentry *root = sb->s_root; struct binderfs_info *info = sb->s_fs_info;#if defined(CONFIG_IPC_NS) bool use_reserve = (info->ipc_ns == &init_ipc_ns);#else bool use_reserve = true;#endif device = kzalloc_obj(*device); if (!device) return -ENOMEM; ret = -ENOMEM; inode = new_inode(sb); if (!inode) goto out; /* Reserve a new minor number for the new device. */ mutex_lock(&binderfs_minors_mutex); minor = ida_alloc_max(&binderfs_minors, use_reserve ? BINDERFS_MAX_MINOR - 1 : BINDERFS_MAX_MINOR_CAPPED - 1, GFP_KERNEL); mutex_unlock(&binderfs_minors_mutex); if (minor < 0) { ret = minor; goto out; } inode->i_ino = SECOND_INODE; simple_inode_init_ts(inode); init_special_inode(inode, S_IFCHR | 0600, MKDEV(MAJOR(binderfs_dev), minor)); inode->i_fop = &binder_ctl_fops; inode->i_uid = info->root_uid; inode->i_gid = info->root_gid; refcount_set(&device->ref, 1); device->binderfs_inode = inode; device->miscdev.minor = minor; dentry = d_alloc_name(root, "binder-control"); if (!dentry) goto out; inode->i_private = device; info->control_dentry = dentry; d_make_persistent(dentry, inode); dput(dentry); return 0; out: kfree(device); iput(inode); return ret;} static const struct inode_operations binderfs_dir_inode_operations = { .lookup = simple_lookup, .rename = binderfs_rename, .unlink = binderfs_unlink,}; static struct inode *binderfs_make_inode(struct super_block *sb, int mode){ struct inode *ret; ret = new_inode(sb); if (ret) { ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET); ret->i_mode = mode; simple_inode_init_ts(ret); } return ret;} struct dentry *binderfs_create_file(struct dentry *parent, const char *name, const struct file_operations *fops, void *data){ struct dentry *dentry; struct inode *new_inode, *parent_inode; struct super_block *sb; parent_inode = d_inode(parent); dentry = simple_start_creating(parent, name); if (IS_ERR(dentry)) return dentry; sb = parent_inode->i_sb; new_inode = binderfs_make_inode(sb, S_IFREG | 0444); if (!new_inode) { simple_done_creating(dentry); return ERR_PTR(-ENOMEM); } new_inode->i_fop = fops; new_inode->i_private = data; d_make_persistent(dentry, new_inode); fsnotify_create(parent_inode, dentry); simple_done_creating(dentry); return dentry; // borrowed} static struct dentry *binderfs_create_dir(struct dentry *parent, const char *name){Lines 1–500 of 786. 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// SPDX-License-Identifier: GPL-2.0 #include <linux/compiler_types.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/fsnotify.h> #include <linux/gfp.h> #include <linux/idr.h> #include <linux/init.h> #include <linux/ipc_namespace.h> #include <linux/kdev_t.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/namei.h> #include <linux/magic.h> #include <linux/major.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/mount.h> #include <linux/fs_parser.h> #include <linux/sched.h> #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/spinlock_types.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/types.h> #include <linux/uaccess.h> #include <linux/user_namespace.h> #include <linux/xarray.h> #include <uapi/linux/android/binder.h> #include <uapi/linux/android/binderfs.h> #include "binder_internal.h" #define FIRST_INODE 1 #define SECOND_INODE 2 #define INODE_OFFSET 3 #define BINDERFS_MAX_MINOR (1U << MINORBITS) /* Ensure that the initial ipc namespace always has devices available. */ #define BINDERFS_MAX_MINOR_CAPPED (BINDERFS_MAX_MINOR - 4) static dev_t binderfs_dev; static DEFINE_MUTEX(binderfs_minors_mutex); static DEFINE_IDA(binderfs_minors); enum binderfs_param { Opt_max, Opt_stats_mode, }; enum binderfs_stats_mode { binderfs_stats_mode_unset, binderfs_stats_mode_global, }; struct binder_features { bool oneway_spam_detection; bool extended_error; bool freeze_notification; bool transaction_report; }; static const struct constant_table binderfs_param_stats[] = { { "global", binderfs_stats_mode_global }, {} }; static const struct fs_parameter_spec binderfs_fs_parameters[] = { fsparam_u32("max", Opt_max), fsparam_enum("stats", Opt_stats_mode, binderfs_param_stats), {} }; static struct binder_features binder_features = { .oneway_spam_detection = true, .extended_error = true, .freeze_notification = true, .transaction_report = true, }; static inline struct binderfs_info *BINDERFS_SB(const struct super_block *sb) { return sb->s_fs_info; } bool is_binderfs_device(const struct inode *inode) { if (inode->i_sb->s_magic == BINDERFS_SUPER_MAGIC) return true; return false; } /** * binderfs_binder_device_create - allocate inode from super block of a * binderfs mount * @ref_inode: inode from which the super block will be taken * @userp: buffer to copy information about new device for userspace to * @req: struct binderfs_device as copied from userspace * * This function allocates a new binder_device and reserves a new minor * number for it. * Minor numbers are limited and tracked globally in binderfs_minors. The * function will stash a struct binder_device for the specific binder * device in i_private of the inode. * It will go on to allocate a new inode from the super block of the * filesystem mount, stash a struct binder_device in its i_private field * and attach a dentry to that inode. * * Return: 0 on success, negative errno on failure */ static int binderfs_binder_device_create(struct inode *ref_inode, struct binderfs_device __user *userp, struct binderfs_device *req) { int minor, ret; struct dentry *dentry, *root; struct binder_device *device; char *name = NULL; struct inode *inode = NULL; struct super_block *sb = ref_inode->i_sb; struct binderfs_info *info = sb->s_fs_info; #if defined(CONFIG_IPC_NS) bool use_reserve = (info->ipc_ns == &init_ipc_ns); #else bool use_reserve = true; #endif /* Reserve new minor number for the new device. */ mutex_lock(&binderfs_minors_mutex); if (++info->device_count <= info->mount_opts.max) minor = ida_alloc_max(&binderfs_minors, use_reserve ? BINDERFS_MAX_MINOR - 1 : BINDERFS_MAX_MINOR_CAPPED - 1, GFP_KERNEL); else minor = -ENOSPC; if (minor < 0) { --info->device_count; mutex_unlock(&binderfs_minors_mutex); return minor; } mutex_unlock(&binderfs_minors_mutex); ret = -ENOMEM; device = kzalloc_obj(*device); if (!device) goto err; inode = new_inode(sb); if (!inode) goto err; inode->i_ino = minor + INODE_OFFSET; simple_inode_init_ts(inode); init_special_inode(inode, S_IFCHR | 0600, MKDEV(MAJOR(binderfs_dev), minor)); inode->i_fop = &binder_fops; inode->i_uid = info->root_uid; inode->i_gid = info->root_gid; req->name[BINDERFS_MAX_NAME] = '\0'; /* NUL-terminate */ name = kstrdup(req->name, GFP_KERNEL); if (!name) goto err; refcount_set(&device->ref, 1); device->binderfs_inode = inode; device->context.binder_context_mgr_uid = INVALID_UID; device->context.name = name; device->miscdev.name = name; device->miscdev.minor = minor; mutex_init(&device->context.context_mgr_node_lock); req->major = MAJOR(binderfs_dev); req->minor = minor; if (userp && copy_to_user(userp, req, sizeof(*req))) { ret = -EFAULT; goto err; } root = sb->s_root; dentry = simple_start_creating(root, name); if (IS_ERR(dentry)) { ret = PTR_ERR(dentry); goto err; } inode->i_private = device; d_make_persistent(dentry, inode); fsnotify_create(root->d_inode, dentry); simple_done_creating(dentry); binder_add_device(device); return 0; err: kfree(name); kfree(device); mutex_lock(&binderfs_minors_mutex); --info->device_count; ida_free(&binderfs_minors, minor); mutex_unlock(&binderfs_minors_mutex); iput(inode); return ret; } /** * binder_ctl_ioctl - handle binder device node allocation requests * @file: The file pointer for the binder-control device node. * @cmd: The ioctl command. * @arg: The ioctl argument. * * The request handler for the binder-control device. All requests operate on * the binderfs mount the binder-control device resides in: * - BINDER_CTL_ADD * Allocate a new binder device. * * Return: %0 on success, negative errno on failure. */ static long binder_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int ret = -EINVAL; struct inode *inode = file_inode(file); struct binderfs_device __user *device = (struct binderfs_device __user *)arg; struct binderfs_device device_req; switch (cmd) { case BINDER_CTL_ADD: ret = copy_from_user(&device_req, device, sizeof(device_req)); if (ret) { ret = -EFAULT; break; } ret = binderfs_binder_device_create(inode, device, &device_req); break; default: break; } return ret; } static void binderfs_evict_inode(struct inode *inode) { struct binder_device *device = inode->i_private; struct binderfs_info *info = BINDERFS_SB(inode->i_sb); clear_inode(inode); if (!S_ISCHR(inode->i_mode) || !device) return; mutex_lock(&binderfs_minors_mutex); --info->device_count; ida_free(&binderfs_minors, device->miscdev.minor); mutex_unlock(&binderfs_minors_mutex); if (refcount_dec_and_test(&device->ref)) { binder_remove_device(device); kfree(device->context.name); kfree(device); } } static int binderfs_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param) { int opt; struct binderfs_mount_opts *ctx = fc->fs_private; struct fs_parse_result result; opt = fs_parse(fc, binderfs_fs_parameters, param, &result); if (opt < 0) return opt; switch (opt) { case Opt_max: if (result.uint_32 > BINDERFS_MAX_MINOR) return invalfc(fc, "Bad value for '%s'", param->key); ctx->max = result.uint_32; break; case Opt_stats_mode: if (!capable(CAP_SYS_ADMIN)) return -EPERM; ctx->stats_mode = result.uint_32; break; default: return invalfc(fc, "Unsupported parameter '%s'", param->key); } return 0; } static int binderfs_fs_context_reconfigure(struct fs_context *fc) { struct binderfs_mount_opts *ctx = fc->fs_private; struct binderfs_info *info = BINDERFS_SB(fc->root->d_sb); if (info->mount_opts.stats_mode != ctx->stats_mode) return invalfc(fc, "Binderfs stats mode cannot be changed during a remount"); info->mount_opts.stats_mode = ctx->stats_mode; info->mount_opts.max = ctx->max; return 0; } static int binderfs_show_options(struct seq_file *seq, struct dentry *root) { struct binderfs_info *info = BINDERFS_SB(root->d_sb); if (info->mount_opts.max <= BINDERFS_MAX_MINOR) seq_printf(seq, ",max=%d", info->mount_opts.max); switch (info->mount_opts.stats_mode) { case binderfs_stats_mode_unset: break; case binderfs_stats_mode_global: seq_printf(seq, ",stats=global"); break; } return 0; } static const struct super_operations binderfs_super_ops = { .evict_inode = binderfs_evict_inode, .show_options = binderfs_show_options, .statfs = simple_statfs, }; static inline bool is_binderfs_control_device(const struct dentry *dentry) { struct binderfs_info *info = dentry->d_sb->s_fs_info; return info->control_dentry == dentry; } static int binderfs_rename(struct mnt_idmap *idmap, struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { if (is_binderfs_control_device(old_dentry) || is_binderfs_control_device(new_dentry)) return -EPERM; return simple_rename(idmap, old_dir, old_dentry, new_dir, new_dentry, flags); } static int binderfs_unlink(struct inode *dir, struct dentry *dentry) { if (is_binderfs_control_device(dentry)) return -EPERM; return simple_unlink(dir, dentry); } static const struct file_operations binder_ctl_fops = { .owner = THIS_MODULE, .open = nonseekable_open, .unlocked_ioctl = binder_ctl_ioctl, .compat_ioctl = binder_ctl_ioctl, .llseek = noop_llseek, }; /** * binderfs_binder_ctl_create - create a new binder-control device * @sb: super block of the binderfs mount * * This function creates a new binder-control device node in the binderfs mount * referred to by @sb. * * Return: 0 on success, negative errno on failure */ static int binderfs_binder_ctl_create(struct super_block *sb) { int minor, ret; struct dentry *dentry; struct binder_device *device; struct inode *inode = NULL; struct dentry *root = sb->s_root; struct binderfs_info *info = sb->s_fs_info; #if defined(CONFIG_IPC_NS) bool use_reserve = (info->ipc_ns == &init_ipc_ns); #else bool use_reserve = true; #endif device = kzalloc_obj(*device); if (!device) return -ENOMEM; ret = -ENOMEM; inode = new_inode(sb); if (!inode) goto out; /* Reserve a new minor number for the new device. */ mutex_lock(&binderfs_minors_mutex); minor = ida_alloc_max(&binderfs_minors, use_reserve ? BINDERFS_MAX_MINOR - 1 : BINDERFS_MAX_MINOR_CAPPED - 1, GFP_KERNEL); mutex_unlock(&binderfs_minors_mutex); if (minor < 0) { ret = minor; goto out; } inode->i_ino = SECOND_INODE; simple_inode_init_ts(inode); init_special_inode(inode, S_IFCHR | 0600, MKDEV(MAJOR(binderfs_dev), minor)); inode->i_fop = &binder_ctl_fops; inode->i_uid = info->root_uid; inode->i_gid = info->root_gid; refcount_set(&device->ref, 1); device->binderfs_inode = inode; device->miscdev.minor = minor; dentry = d_alloc_name(root, "binder-control"); if (!dentry) goto out; inode->i_private = device; info->control_dentry = dentry; d_make_persistent(dentry, inode); dput(dentry); return 0; out: kfree(device); iput(inode); return ret; } static const struct inode_operations binderfs_dir_inode_operations = { .lookup = simple_lookup, .rename = binderfs_rename, .unlink = binderfs_unlink, }; static struct inode *binderfs_make_inode(struct super_block *sb, int mode) { struct inode *ret; ret = new_inode(sb); if (ret) { ret->i_ino = iunique(sb, BINDERFS_MAX_MINOR + INODE_OFFSET); ret->i_mode = mode; simple_inode_init_ts(ret); } return ret; } struct dentry *binderfs_create_file(struct dentry *parent, const char *name, const struct file_operations *fops, void *data) { struct dentry *dentry; struct inode *new_inode, *parent_inode; struct super_block *sb; parent_inode = d_inode(parent); dentry = simple_start_creating(parent, name); if (IS_ERR(dentry)) return dentry; sb = parent_inode->i_sb; new_inode = binderfs_make_inode(sb, S_IFREG | 0444); if (!new_inode) { simple_done_creating(dentry); return ERR_PTR(-ENOMEM); } new_inode->i_fop = fops; new_inode->i_private = data; d_make_persistent(dentry, new_inode); fsnotify_create(parent_inode, dentry); simple_done_creating(dentry); return dentry; // borrowed } static struct dentry *binderfs_create_dir(struct dentry *parent, const char *name) {