diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/debugfs/file.c | 54 | ||||
| -rw-r--r-- | fs/kernfs/file.c | 73 | ||||
| -rw-r--r-- | fs/pstore/ram.c | 1 | ||||
| -rw-r--r-- | fs/sysfs/file.c | 59 |
4 files changed, 154 insertions, 33 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 8e0f2f4..517e649 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -22,6 +22,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/atomic.h> +#include <linux/device.h> static ssize_t default_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) @@ -762,3 +763,56 @@ struct dentry *debugfs_create_regset32(const char *name, umode_t mode, EXPORT_SYMBOL_GPL(debugfs_create_regset32); #endif /* CONFIG_HAS_IOMEM */ + +struct debugfs_devm_entry { + int (*read)(struct seq_file *seq, void *data); + struct device *dev; +}; + +static int debugfs_devm_entry_open(struct inode *inode, struct file *f) +{ + struct debugfs_devm_entry *entry = inode->i_private; + + return single_open(f, entry->read, entry->dev); +} + +static const struct file_operations debugfs_devm_entry_ops = { + .owner = THIS_MODULE, + .open = debugfs_devm_entry_open, + .release = single_release, + .read = seq_read, + .llseek = seq_lseek +}; + +/** + * debugfs_create_devm_seqfile - create a debugfs file that is bound to device. + * + * @dev: device related to this debugfs file. + * @name: name of the debugfs file. + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the debugfs filesystem. + * @read_fn: function pointer called to print the seq_file content. + */ +struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, + struct dentry *parent, + int (*read_fn)(struct seq_file *s, + void *data)) +{ + struct debugfs_devm_entry *entry; + + if (IS_ERR(parent)) + return ERR_PTR(-ENOENT); + + entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL); + if (!entry) + return ERR_PTR(-ENOMEM); + + entry->read = read_fn; + entry->dev = dev; + + return debugfs_create_file(name, S_IRUGO, parent, entry, + &debugfs_devm_entry_ops); +} +EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile); + diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 4429d6d..697390e 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -106,7 +106,7 @@ static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) const struct kernfs_ops *ops; /* - * @of->mutex nests outside active ref and is just to ensure that + * @of->mutex nests outside active ref and is primarily to ensure that * the ops aren't called concurrently for the same open file. */ mutex_lock(&of->mutex); @@ -189,13 +189,16 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of, const struct kernfs_ops *ops; char *buf; - buf = kmalloc(len, GFP_KERNEL); + buf = of->prealloc_buf; + if (!buf) + buf = kmalloc(len, GFP_KERNEL); if (!buf) return -ENOMEM; /* - * @of->mutex nests outside active ref and is just to ensure that - * the ops aren't called concurrently for the same open file. + * @of->mutex nests outside active ref and is used both to ensure that + * the ops aren't called concurrently for the same open file, and + * to provide exclusive access to ->prealloc_buf (when that exists). */ mutex_lock(&of->mutex); if (!kernfs_get_active(of->kn)) { @@ -210,21 +213,22 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of, else len = -EINVAL; - kernfs_put_active(of->kn); - mutex_unlock(&of->mutex); - if (len < 0) - goto out_free; + goto out_unlock; if (copy_to_user(user_buf, buf, len)) { len = -EFAULT; - goto out_free; + goto out_unlock; } *ppos += len; + out_unlock: + kernfs_put_active(of->kn); + mutex_unlock(&of->mutex); out_free: - kfree(buf); + if (buf != of->prealloc_buf) + kfree(buf); return len; } @@ -278,19 +282,16 @@ static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf, len = min_t(size_t, count, PAGE_SIZE); } - buf = kmalloc(len + 1, GFP_KERNEL); + buf = of->prealloc_buf; + if (!buf) + buf = kmalloc(len + 1, GFP_KERNEL); if (!buf) return -ENOMEM; - if (copy_from_user(buf, user_buf, len)) { - len = -EFAULT; - goto out_free; - } - buf[len] = '\0'; /* guarantee string termination */ - /* - * @of->mutex nests outside active ref and is just to ensure that - * the ops aren't called concurrently for the same open file. + * @of->mutex nests outside active ref and is used both to ensure that + * the ops aren't called concurrently for the same open file, and + * to provide exclusive access to ->prealloc_buf (when that exists). */ mutex_lock(&of->mutex); if (!kernfs_get_active(of->kn)) { @@ -299,19 +300,27 @@ static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf, goto out_free; } + if (copy_from_user(buf, user_buf, len)) { + len = -EFAULT; + goto out_unlock; + } + buf[len] = '\0'; /* guarantee string termination */ + ops = kernfs_ops(of->kn); if (ops->write) len = ops->write(of, buf, len, *ppos); else len = -EINVAL; - kernfs_put_active(of->kn); - mutex_unlock(&of->mutex); - if (len > 0) *ppos += len; + +out_unlock: + kernfs_put_active(of->kn); + mutex_unlock(&of->mutex); out_free: - kfree(buf); + if (buf != of->prealloc_buf) + kfree(buf); return len; } @@ -685,6 +694,22 @@ static int kernfs_fop_open(struct inode *inode, struct file *file) */ of->atomic_write_len = ops->atomic_write_len; + error = -EINVAL; + /* + * ->seq_show is incompatible with ->prealloc, + * as seq_read does its own allocation. + * ->read must be used instead. + */ + if (ops->prealloc && ops->seq_show) + goto err_free; + if (ops->prealloc) { + int len = of->atomic_write_len ?: PAGE_SIZE; + of->prealloc_buf = kmalloc(len + 1, GFP_KERNEL); + error = -ENOMEM; + if (!of->prealloc_buf) + goto err_free; + } + /* * Always instantiate seq_file even if read access doesn't use * seq_file or is not requested. This unifies private data access @@ -715,6 +740,7 @@ static int kernfs_fop_open(struct inode *inode, struct file *file) err_close: seq_release(inode, file); err_free: + kfree(of->prealloc_buf); kfree(of); err_out: kernfs_put_active(kn); @@ -728,6 +754,7 @@ static int kernfs_fop_release(struct inode *inode, struct file *filp) kernfs_put_open_node(kn, of); seq_release(inode, filp); + kfree(of->prealloc_buf); kfree(of); return 0; diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 2f389ce5..8613e5b 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -561,7 +561,6 @@ static struct platform_driver ramoops_driver = { .remove = __exit_p(ramoops_remove), .driver = { .name = "ramoops", - .owner = THIS_MODULE, }, }; diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index e9ef59b..dfe928a 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -102,6 +102,22 @@ static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf, return battr->read(of->file, kobj, battr, buf, pos, count); } +/* kernfs read callback for regular sysfs files with pre-alloc */ +static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf, + size_t count, loff_t pos) +{ + const struct sysfs_ops *ops = sysfs_file_ops(of->kn); + struct kobject *kobj = of->kn->parent->priv; + + /* + * If buf != of->prealloc_buf, we don't know how + * large it is, so cannot safely pass it to ->show + */ + if (pos || WARN_ON_ONCE(buf != of->prealloc_buf)) + return 0; + return ops->show(kobj, of->kn->priv, buf); +} + /* kernfs write callback for regular sysfs files */ static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) @@ -125,7 +141,7 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf, if (size) { if (size <= pos) - return 0; + return -EFBIG; count = min_t(ssize_t, count, size - pos); } if (!count) @@ -184,6 +200,22 @@ static const struct kernfs_ops sysfs_file_kfops_rw = { .write = sysfs_kf_write, }; +static const struct kernfs_ops sysfs_prealloc_kfops_ro = { + .read = sysfs_kf_read, + .prealloc = true, +}; + +static const struct kernfs_ops sysfs_prealloc_kfops_wo = { + .write = sysfs_kf_write, + .prealloc = true, +}; + +static const struct kernfs_ops sysfs_prealloc_kfops_rw = { + .read = sysfs_kf_read, + .write = sysfs_kf_write, + .prealloc = true, +}; + static const struct kernfs_ops sysfs_bin_kfops_ro = { .read = sysfs_kf_bin_read, }; @@ -222,13 +254,22 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent, kobject_name(kobj))) return -EINVAL; - if (sysfs_ops->show && sysfs_ops->store) - ops = &sysfs_file_kfops_rw; - else if (sysfs_ops->show) - ops = &sysfs_file_kfops_ro; - else if (sysfs_ops->store) - ops = &sysfs_file_kfops_wo; - else + if (sysfs_ops->show && sysfs_ops->store) { + if (mode & SYSFS_PREALLOC) + ops = &sysfs_prealloc_kfops_rw; + else + ops = &sysfs_file_kfops_rw; + } else if (sysfs_ops->show) { + if (mode & SYSFS_PREALLOC) + ops = &sysfs_prealloc_kfops_ro; + else + ops = &sysfs_file_kfops_ro; + } else if (sysfs_ops->store) { + if (mode & SYSFS_PREALLOC) + ops = &sysfs_prealloc_kfops_wo; + else + ops = &sysfs_file_kfops_wo; + } else ops = &sysfs_file_kfops_empty; size = PAGE_SIZE; @@ -253,7 +294,7 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent, if (!attr->ignore_lockdep) key = attr->key ?: (struct lock_class_key *)&attr->skey; #endif - kn = __kernfs_create_file(parent, attr->name, mode, size, ops, + kn = __kernfs_create_file(parent, attr->name, mode & 0777, size, ops, (void *)attr, ns, true, key); if (IS_ERR(kn)) { if (PTR_ERR(kn) == -EEXIST) |
