/* * fs/sysfs/bin.c - sysfs binary file implementation * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Matthew Wilcox * Copyright (c) 2004 Silicon Graphics, Inc. * Copyright (c) 2007 SUSE Linux Products GmbH * Copyright (c) 2007 Tejun Heo <teheo@suse.de> * * This file is released under the GPLv2. * * Please see Documentation/filesystems/sysfs.txt for more information. */ #undef DEBUG #include <linux/errno.h> #include <linux/fs.h> #include <linux/kernel.h> #include <linux/kobject.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/mutex.h> #include <linux/mm.h> #include <asm/uaccess.h> #include "sysfs.h" /* * There's one bin_buffer for each open file. * * filp->private_data points to bin_buffer and * sysfs_dirent->s_bin_attr.buffers points to a the bin_buffer s * sysfs_dirent->s_bin_attr.buffers is protected by sysfs_bin_lock */ static DEFINE_MUTEX(sysfs_bin_lock); struct bin_buffer { struct mutex mutex; void *buffer; int mmapped; const struct vm_operations_struct *vm_ops; struct file *file; struct hlist_node list; }; static int fill_read(struct file *file, char *buffer, loff_t off, size_t count) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; int rc; /* need attr_sd for attr, its parent for kobj */ if (!sysfs_get_active(attr_sd)) return -ENODEV; rc = -EIO; if (attr->read) rc = attr->read(file, kobj, attr, buffer, off, count); sysfs_put_active(attr_sd); return rc; } static ssize_t read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) { struct bin_buffer *bb = file->private_data; int size = file->f_path.dentry->d_inode->i_size; loff_t offs = *off; int count = min_t(size_t, bytes, PAGE_SIZE); char *temp; if (!bytes) return 0; if (size) { if (offs > size) return 0; if (offs + count > size) count = size - offs; } temp = kmalloc(count, GFP_KERNEL); if (!temp) return -ENOMEM; mutex_lock(&bb->mutex); count = fill_read(file, bb->buffer, offs, count); if (count < 0) { mutex_unlock(&bb->mutex); goto out_free; } memcpy(temp, bb->buffer, count); mutex_unlock(&bb->mutex); if (copy_to_user(userbuf, temp, count)) { count = -EFAULT; goto out_free; } pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); *off = offs + count; out_free: kfree(temp); return count; } static int flush_write(struct file *file, char *buffer, loff_t offset, size_t count) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; int rc; /* need attr_sd for attr, its parent for kobj */ if (!sysfs_get_active(attr_sd)) return -ENODEV; rc = -EIO; if (attr->write) rc = attr->write(file, kobj, attr, buffer, offset, count); sysfs_put_active(attr_sd); return rc; } static ssize_t write(struct file *file, const char __user *userbuf, size_t bytes, loff_t *off) { struct bin_buffer *bb = file->private_data; int size = file->f_path.dentry->d_inode->i_size; loff_t offs = *off; int count = min_t(size_t, bytes, PAGE_SIZE); char *temp; if (!bytes) return 0; if (size) { if (offs > size) return 0; if (offs + count > size) count = size - offs; } temp = memdup_user(userbuf, count); if (IS_ERR(temp)) return PTR_ERR(temp); mutex_lock(&bb->mutex); memcpy(bb->buffer, temp, count); count = flush_write(file, bb->buffer, offs, count); mutex_unlock(&bb->mutex); if (count > 0) *off = offs + count; kfree(temp); return count; } static void bin_vma_open(struct vm_area_struct *vma) { struct file *file = vma->vm_file; struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; if (!bb->vm_ops) return; if (!sysfs_get_active(attr_sd)) return; if (bb->vm_ops->open) bb->vm_ops->open(vma); sysfs_put_active(attr_sd); } static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct file *file = vma->vm_file; struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; if (!bb->vm_ops) return VM_FAULT_SIGBUS; if (!sysfs_get_active(attr_sd)) return VM_FAULT_SIGBUS; ret = VM_FAULT_SIGBUS; if (bb->vm_ops->fault) ret = bb->vm_ops->fault(vma, vmf); sysfs_put_active(attr_sd); return ret; } static int bin_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct file *file = vma->vm_file; struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; if (!bb->vm_ops) return VM_FAULT_SIGBUS; if (!sysfs_get_active(attr_sd)) return VM_FAULT_SIGBUS; ret = 0; if (bb->vm_ops->page_mkwrite) ret = bb->vm_ops->page_mkwrite(vma, vmf); sysfs_put_active(attr_sd); return ret; } static int bin_access(struct vm_area_struct *vma, unsigned long addr, void *buf, int len, int write) { struct file *file = vma->vm_file; struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; if (!bb->vm_ops) return -EINVAL; if (!sysfs_get_active(attr_sd)) return -EINVAL; ret = -EINVAL; if (bb->vm_ops->access) ret = bb->vm_ops->access(vma, addr, buf, len, write); sysfs_put_active(attr_sd); return ret; } #ifdef CONFIG_NUMA static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new) { struct file *file = vma->vm_file; struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; if (!bb->vm_ops) return 0; if (!sysfs_get_active(attr_sd)) return -EINVAL; ret = 0; if (bb->vm_ops->set_policy) ret = bb->vm_ops->set_policy(vma, new); sysfs_put_active(attr_sd); return ret; } static struct mempolicy *bin_get_policy(struct vm_area_struct *vma, unsigned long addr) { struct file *file = vma->vm_file; struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct mempolicy *pol; if (!bb->vm_ops) return vma->vm_policy; if (!sysfs_get_active(attr_sd)) return vma->vm_policy; pol = vma->vm_policy; if (bb->vm_ops->get_policy) pol = bb->vm_ops->get_policy(vma, addr); sysfs_put_active(attr_sd); return pol; } static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, const nodemask_t *to, unsigned long flags) { struct file *file = vma->vm_file; struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; int ret; if (!bb->vm_ops) return 0; if (!sysfs_get_active(attr_sd)) return 0; ret = 0; if (bb->vm_ops->migrate) ret = bb->vm_ops->migrate(vma, from, to, flags); sysfs_put_active(attr_sd); return ret; } #endif static const struct vm_operations_struct bin_vm_ops = { .open = bin_vma_open, .fault = bin_fault, .page_mkwrite = bin_page_mkwrite, .access = bin_access, #ifdef CONFIG_NUMA .set_policy = bin_set_policy, .get_policy = bin_get_policy, .migrate = bin_migrate, #endif }; static int mmap(struct file *file, struct vm_area_struct *vma) { struct bin_buffer *bb = file->private_data; struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; int rc; mutex_lock(&bb->mutex); /* need attr_sd for attr, its parent for kobj */ rc = -ENODEV; if (!sysfs_get_active(attr_sd)) goto out_unlock; rc = -EINVAL; if (!attr->mmap) goto out_put; rc = attr->mmap(file, kobj, attr, vma); if (rc) goto out_put; /* * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() * to satisfy versions of X which crash if the mmap fails: that * substitutes a new vm_file, and we don't then want bin_vm_ops. */ if (vma->vm_file != file) goto out_put; rc = -EINVAL; if (bb->mmapped && bb->vm_ops != vma->vm_ops) goto out_put; /* * It is not possible to successfully wrap close. * So error if someone is trying to use close. */ rc = -EINVAL; if (vma->vm_ops && vma->vm_ops->close) goto out_put; rc = 0; bb->mmapped = 1; bb->vm_ops = vma->vm_ops; vma->vm_ops = &bin_vm_ops; out_put: sysfs_put_active(attr_sd); out_unlock: mutex_unlock(&bb->mutex); return rc; } static int open(struct inode * inode, struct file * file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; struct bin_buffer *bb = NULL; int error; /* binary file operations requires both @sd and its parent */ if (!sysfs_get_active(attr_sd)) return -ENODEV; error = -EACCES; if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap)) goto err_out; if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap)) goto err_out; error = -ENOMEM; bb = kzalloc(sizeof(*bb), GFP_KERNEL); if (!bb) goto err_out; bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!bb->buffer) goto err_out; mutex_init(&bb->mutex); bb->file = file; file->private_data = bb; mutex_lock(&sysfs_bin_lock); hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers); mutex_unlock(&sysfs_bin_lock); /* open succeeded, put active references */ sysfs_put_active(attr_sd); return 0; err_out: sysfs_put_active(attr_sd); kfree(bb); return error; } static int release(struct inode * inode, struct file * file) { struct bin_buffer *bb = file->private_data; mutex_lock(&sysfs_bin_lock); hlist_del(&bb->list); mutex_unlock(&sysfs_bin_lock); kfree(bb->buffer); kfree(bb); return 0; } const struct file_operations bin_fops = { .read = read, .write = write, .mmap = mmap, .llseek = generic_file_llseek, .open = open, .release = release, }; void unmap_bin_file(struct sysfs_dirent *attr_sd) { struct bin_buffer *bb; struct hlist_node *tmp; if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR) return; mutex_lock(&sysfs_bin_lock); hlist_for_each_entry(bb, tmp, &attr_sd->s_bin_attr.buffers, list) { struct inode *inode = bb->file->f_path.dentry->d_inode; unmap_mapping_range(inode->i_mapping, 0, 0, 1); } mutex_unlock(&sysfs_bin_lock); } /** * sysfs_create_bin_file - create binary file for object. * @kobj: object. * @attr: attribute descriptor. */ int sysfs_create_bin_file(struct kobject *kobj, const struct bin_attribute *attr) { BUG_ON(!kobj || !kobj->sd || !attr); return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); } /** * sysfs_remove_bin_file - remove binary file for object. * @kobj: object. * @attr: attribute descriptor. */ void sysfs_remove_bin_file(struct kobject *kobj, const struct bin_attribute *attr) { sysfs_hash_and_remove(kobj->sd, NULL, attr->attr.name); } EXPORT_SYMBOL_GPL(sysfs_create_bin_file); EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);