diff options
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/generic.c | 26 | ||||
| -rw-r--r-- | fs/proc/inode.c | 5 | ||||
| -rw-r--r-- | fs/proc/internal.h | 20 | ||||
| -rw-r--r-- | fs/proc/proc_net.c | 92 | ||||
| -rw-r--r-- | fs/proc/root.c | 3 |
5 files changed, 134 insertions, 12 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 7b4d9714f248..6ac1c92997ea 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -409,7 +409,7 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, if (!ent) goto out; - if (qstr.len + 1 <= sizeof(ent->inline_name)) { + if (qstr.len + 1 <= SIZEOF_PDE_INLINE_NAME) { ent->name = ent->inline_name; } else { ent->name = kmalloc(qstr.len + 1, GFP_KERNEL); @@ -740,3 +740,27 @@ void *PDE_DATA(const struct inode *inode) return __PDE_DATA(inode); } EXPORT_SYMBOL(PDE_DATA); + +/* + * Pull a user buffer into memory and pass it to the file's write handler if + * one is supplied. The ->write() method is permitted to modify the + * kernel-side buffer. + */ +ssize_t proc_simple_write(struct file *f, const char __user *ubuf, size_t size, + loff_t *_pos) +{ + struct proc_dir_entry *pde = PDE(file_inode(f)); + char *buf; + int ret; + + if (!pde->write) + return -EACCES; + if (size == 0 || size > PAGE_SIZE - 1) + return -EINVAL; + buf = memdup_user_nul(ubuf, size); + if (IS_ERR(buf)) + return PTR_ERR(buf); + ret = pde->write(f, buf, size); + kfree(buf); + return ret == 0 ? size : ret; +} diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 2cf3b74391ca..85ffbd27f288 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -105,9 +105,8 @@ void __init proc_init_kmemcache(void) kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0, SLAB_ACCOUNT|SLAB_PANIC, NULL); proc_dir_entry_cache = kmem_cache_create_usercopy( - "proc_dir_entry", sizeof(struct proc_dir_entry), 0, SLAB_PANIC, - offsetof(struct proc_dir_entry, inline_name), - sizeof_field(struct proc_dir_entry, inline_name), NULL); + "proc_dir_entry", SIZEOF_PDE_SLOT, 0, SLAB_PANIC, + OFFSETOF_PDE_NAME, SIZEOF_PDE_INLINE_NAME, NULL); } static int proc_show_options(struct seq_file *seq, struct dentry *root) diff --git a/fs/proc/internal.h b/fs/proc/internal.h index 50cb22a08c2f..da3dbfa09e79 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -48,6 +48,7 @@ struct proc_dir_entry { const struct seq_operations *seq_ops; int (*single_show)(struct seq_file *, void *); }; + proc_write_t write; void *data; unsigned int state_size; unsigned int low_ino; @@ -61,14 +62,20 @@ struct proc_dir_entry { char *name; umode_t mode; u8 namelen; -#ifdef CONFIG_64BIT -#define SIZEOF_PDE_INLINE_NAME (192-155) -#else -#define SIZEOF_PDE_INLINE_NAME (128-95) -#endif - char inline_name[SIZEOF_PDE_INLINE_NAME]; + char inline_name[]; } __randomize_layout; +#define OFFSETOF_PDE_NAME offsetof(struct proc_dir_entry, inline_name) +#define SIZEOF_PDE_SLOT \ + (OFFSETOF_PDE_NAME + 34 <= 64 ? 64 : \ + OFFSETOF_PDE_NAME + 34 <= 128 ? 128 : \ + OFFSETOF_PDE_NAME + 34 <= 192 ? 192 : \ + OFFSETOF_PDE_NAME + 34 <= 256 ? 256 : \ + OFFSETOF_PDE_NAME + 34 <= 512 ? 512 : \ + 0) + +#define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE_SLOT - OFFSETOF_PDE_NAME) + extern struct kmem_cache *proc_dir_entry_cache; void pde_free(struct proc_dir_entry *pde); @@ -189,6 +196,7 @@ static inline bool is_empty_pde(const struct proc_dir_entry *pde) { return S_ISDIR(pde->mode) && !pde->proc_iops; } +extern ssize_t proc_simple_write(struct file *, const char __user *, size_t, loff_t *); /* * inode.c diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c index 7d94fa005b0d..d5e0fcb3439e 100644 --- a/fs/proc/proc_net.c +++ b/fs/proc/proc_net.c @@ -46,6 +46,9 @@ static int seq_open_net(struct inode *inode, struct file *file) WARN_ON_ONCE(state_size < sizeof(*p)); + if (file->f_mode & FMODE_WRITE && !PDE(inode)->write) + return -EACCES; + net = get_proc_net(inode); if (!net) return -ENXIO; @@ -73,6 +76,7 @@ static int seq_release_net(struct inode *ino, struct file *f) static const struct file_operations proc_net_seq_fops = { .open = seq_open_net, .read = seq_read, + .write = proc_simple_write, .llseek = seq_lseek, .release = seq_release_net, }; @@ -93,6 +97,50 @@ struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode, } EXPORT_SYMBOL_GPL(proc_create_net_data); +/** + * proc_create_net_data_write - Create a writable net_ns-specific proc file + * @name: The name of the file. + * @mode: The file's access mode. + * @parent: The parent directory in which to create. + * @ops: The seq_file ops with which to read the file. + * @write: The write method which which to 'modify' the file. + * @data: Data for retrieval by PDE_DATA(). + * + * Create a network namespaced proc file in the @parent directory with the + * specified @name and @mode that allows reading of a file that displays a + * series of elements and also provides for the file accepting writes that have + * some arbitrary effect. + * + * The functions in the @ops table are used to iterate over items to be + * presented and extract the readable content using the seq_file interface. + * + * The @write function is called with the data copied into a kernel space + * scratch buffer and has a NUL appended for convenience. The buffer may be + * modified by the @write function. @write should return 0 on success. + * + * The @data value is accessible from the @show and @write functions by calling + * PDE_DATA() on the file inode. The network namespace must be accessed by + * calling seq_file_net() on the seq_file struct. + */ +struct proc_dir_entry *proc_create_net_data_write(const char *name, umode_t mode, + struct proc_dir_entry *parent, + const struct seq_operations *ops, + proc_write_t write, + unsigned int state_size, void *data) +{ + struct proc_dir_entry *p; + + p = proc_create_reg(name, mode, &parent, data); + if (!p) + return NULL; + p->proc_fops = &proc_net_seq_fops; + p->seq_ops = ops; + p->state_size = state_size; + p->write = write; + return proc_register(parent, p); +} +EXPORT_SYMBOL_GPL(proc_create_net_data_write); + static int single_open_net(struct inode *inode, struct file *file) { struct proc_dir_entry *de = PDE(inode); @@ -119,6 +167,7 @@ static int single_release_net(struct inode *ino, struct file *f) static const struct file_operations proc_net_single_fops = { .open = single_open_net, .read = seq_read, + .write = proc_simple_write, .llseek = seq_lseek, .release = single_release_net, }; @@ -138,6 +187,49 @@ struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode, } EXPORT_SYMBOL_GPL(proc_create_net_single); +/** + * proc_create_net_single_write - Create a writable net_ns-specific proc file + * @name: The name of the file. + * @mode: The file's access mode. + * @parent: The parent directory in which to create. + * @show: The seqfile show method with which to read the file. + * @write: The write method which which to 'modify' the file. + * @data: Data for retrieval by PDE_DATA(). + * + * Create a network-namespaced proc file in the @parent directory with the + * specified @name and @mode that allows reading of a file that displays a + * single element rather than a series and also provides for the file accepting + * writes that have some arbitrary effect. + * + * The @show function is called to extract the readable content via the + * seq_file interface. + * + * The @write function is called with the data copied into a kernel space + * scratch buffer and has a NUL appended for convenience. The buffer may be + * modified by the @write function. @write should return 0 on success. + * + * The @data value is accessible from the @show and @write functions by calling + * PDE_DATA() on the file inode. The network namespace must be accessed by + * calling seq_file_single_net() on the seq_file struct. + */ +struct proc_dir_entry *proc_create_net_single_write(const char *name, umode_t mode, + struct proc_dir_entry *parent, + int (*show)(struct seq_file *, void *), + proc_write_t write, + void *data) +{ + struct proc_dir_entry *p; + + p = proc_create_reg(name, mode, &parent, data); + if (!p) + return NULL; + p->proc_fops = &proc_net_single_fops; + p->single_show = show; + p->write = write; + return proc_register(parent, p); +} +EXPORT_SYMBOL_GPL(proc_create_net_single_write); + static struct net *get_proc_task_net(struct inode *dir) { struct task_struct *task; diff --git a/fs/proc/root.c b/fs/proc/root.c index 61b7340b357a..f4b1a9d2eca6 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -204,8 +204,7 @@ struct proc_dir_entry proc_root = { .proc_fops = &proc_root_operations, .parent = &proc_root, .subdir = RB_ROOT, - .name = proc_root.inline_name, - .inline_name = "/proc", + .name = "/proc", }; int pid_ns_prepare_proc(struct pid_namespace *ns) |