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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/cache.h>#include <linux/errno.h>#include <linux/time.h>#include <linux/proc_fs.h>#include <linux/stat.h>#include <linux/mm.h>#include <linux/module.h>#include <linux/namei.h>#include <linux/slab.h>#include <linux/printk.h>#include <linux/mount.h>#include <linux/init.h>#include <linux/idr.h>#include <linux/bitops.h>#include <linux/spinlock.h>#include <linux/completion.h>#include <linux/uaccess.h>#include <linux/seq_file.h>
#include "internal.h"
static DEFINE_RWLOCK(proc_subdir_lock);
struct kmem_cache *proc_dir_entry_cache __ro_after_init;
void pde_free(struct proc_dir_entry *pde){ if (S_ISLNK(pde->mode)) kfree(pde->data); if (pde->name != pde->inline_name) kfree(pde->name); kmem_cache_free(proc_dir_entry_cache, pde);}
static int proc_match(const char *name, struct proc_dir_entry *de, unsigned int len){ if (len < de->namelen) return -1; if (len > de->namelen) return 1;
return memcmp(name, de->name, len);}
static struct proc_dir_entry *pde_subdir_first(struct proc_dir_entry *dir){ return rb_entry_safe(rb_first(&dir->subdir), struct proc_dir_entry, subdir_node);}
static struct proc_dir_entry *pde_subdir_next(struct proc_dir_entry *dir){ return rb_entry_safe(rb_next(&dir->subdir_node), struct proc_dir_entry, subdir_node);}
static struct proc_dir_entry *pde_subdir_find(struct proc_dir_entry *dir, const char *name, unsigned int len){ struct rb_node *node = dir->subdir.rb_node;
while (node) { struct proc_dir_entry *de = rb_entry(node, struct proc_dir_entry, subdir_node); int result = proc_match(name, de, len);
if (result < 0) node = node->rb_left; else if (result > 0) node = node->rb_right; else return de; } return NULL;}
static bool pde_subdir_insert(struct proc_dir_entry *dir, struct proc_dir_entry *de){ struct rb_root *root = &dir->subdir; struct rb_node **new = &root->rb_node, *parent = NULL;
/* Figure out where to put new node */ while (*new) { struct proc_dir_entry *this = rb_entry(*new, struct proc_dir_entry, subdir_node); int result = proc_match(de->name, this, de->namelen);
parent = *new; if (result < 0) new = &(*new)->rb_left; else if (result > 0) new = &(*new)->rb_right; else return false; }
/* Add new node and rebalance tree. */ rb_link_node(&de->subdir_node, parent, new); rb_insert_color(&de->subdir_node, root); if (S_ISDIR(de->mode)) dir->nlink++; return true;}
static int proc_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *iattr){ struct inode *inode = d_inode(dentry); struct proc_dir_entry *de = PDE(inode); int error;
error = setattr_prepare(&nop_mnt_idmap, dentry, iattr); if (error) return error;
setattr_copy(&nop_mnt_idmap, inode, iattr);
proc_set_user(de, inode->i_uid, inode->i_gid); de->mode = inode->i_mode; return 0;}
static int proc_getattr(struct mnt_idmap *idmap, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int query_flags){ struct inode *inode = d_inode(path->dentry); struct proc_dir_entry *de = PDE(inode); if (de) { nlink_t nlink = READ_ONCE(de->nlink); if (nlink > 0) { set_nlink(inode, nlink); } }
generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); return 0;}
static const struct inode_operations proc_file_inode_operations = { .setattr = proc_setattr,};
/* * This function parses a name such as "tty/driver/serial", and * returns the struct proc_dir_entry for "/proc/tty/driver", and * returns "serial" in residual. */static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret, const char **residual){ const char *cp = name, *next; struct proc_dir_entry *de;
de = *ret ?: &proc_root; while ((next = strchr(cp, '/')) != NULL) { de = pde_subdir_find(de, cp, next - cp); if (!de) { WARN(1, "name '%s'\n", name); return -ENOENT; } cp = next + 1; } *residual = cp; *ret = de; return 0;}
static int xlate_proc_name(const char *name, struct proc_dir_entry **ret, const char **residual){ int rv;
read_lock(&proc_subdir_lock); rv = __xlate_proc_name(name, ret, residual); read_unlock(&proc_subdir_lock); return rv;}
static DEFINE_IDA(proc_inum_ida);
#define PROC_DYNAMIC_FIRST 0xF0000000U
/* * Return an inode number between PROC_DYNAMIC_FIRST and * 0xffffffff, or zero on failure. */int proc_alloc_inum(unsigned int *inum){ int i;
i = ida_alloc_max(&proc_inum_ida, UINT_MAX - PROC_DYNAMIC_FIRST, GFP_KERNEL); if (i < 0) return i;
*inum = PROC_DYNAMIC_FIRST + (unsigned int)i; return 0;}
void proc_free_inum(unsigned int inum){ ida_free(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);}
static int proc_misc_d_revalidate(struct inode *dir, const struct qstr *name, struct dentry *dentry, unsigned int flags){ if (flags & LOOKUP_RCU) return -ECHILD;
if (atomic_read(&PDE(d_inode(dentry))->in_use) < 0) return 0; /* revalidate */ return 1;}
static int proc_misc_d_delete(const struct dentry *dentry){ return atomic_read(&PDE(d_inode(dentry))->in_use) < 0;}
static const struct dentry_operations proc_misc_dentry_ops = { .d_revalidate = proc_misc_d_revalidate, .d_delete = proc_misc_d_delete,};
/* * Don't create negative dentries here, return -ENOENT by hand * instead. */struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry, struct proc_dir_entry *de){ struct inode *inode;
read_lock(&proc_subdir_lock); de = pde_subdir_find(de, dentry->d_name.name, dentry->d_name.len); if (de) { pde_get(de); read_unlock(&proc_subdir_lock); inode = proc_get_inode(dir->i_sb, de); if (!inode) return ERR_PTR(-ENOMEM); if (de->flags & PROC_ENTRY_FORCE_LOOKUP) return d_splice_alias_ops(inode, dentry, &proc_net_dentry_ops); return d_splice_alias_ops(inode, dentry, &proc_misc_dentry_ops); } read_unlock(&proc_subdir_lock); return ERR_PTR(-ENOENT);}
struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags){ struct proc_fs_info *fs_info = proc_sb_info(dir->i_sb);
if (fs_info->pidonly == PROC_PIDONLY_ON) return ERR_PTR(-ENOENT);
return proc_lookup_de(dir, dentry, PDE(dir));}
/* * This returns non-zero if at EOF, so that the /proc * root directory can use this and check if it should * continue with the <pid> entries.. * * Note that the VFS-layer doesn't care about the return * value of the readdir() call, as long as it's non-negative * for success.. */int proc_readdir_de(struct file *file, struct dir_context *ctx, struct proc_dir_entry *de){ int i;
if (!dir_emit_dots(file, ctx)) return 0;
i = ctx->pos - 2; read_lock(&proc_subdir_lock); de = pde_subdir_first(de); for (;;) { if (!de) { read_unlock(&proc_subdir_lock); return 0; } if (!i) break; de = pde_subdir_next(de); i--; }
do { struct proc_dir_entry *next; pde_get(de); read_unlock(&proc_subdir_lock); if (!dir_emit(ctx, de->name, de->namelen, de->low_ino, de->mode >> 12)) { pde_put(de); return 0; } ctx->pos++; read_lock(&proc_subdir_lock); next = pde_subdir_next(de); pde_put(de); de = next; } while (de); read_unlock(&proc_subdir_lock); return 1;}
int proc_readdir(struct file *file, struct dir_context *ctx){ struct inode *inode = file_inode(file); struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
if (fs_info->pidonly == PROC_PIDONLY_ON) return 1;
return proc_readdir_de(file, ctx, PDE(inode));}
/* * These are the generic /proc directory operations. They * use the in-memory "struct proc_dir_entry" tree to parse * the /proc directory. */static const struct file_operations proc_dir_operations = { .llseek = generic_file_llseek, .read = generic_read_dir, .iterate_shared = proc_readdir,};
static int proc_net_d_revalidate(struct inode *dir, const struct qstr *name, struct dentry *dentry, unsigned int flags){ return 0;}
const struct dentry_operations proc_net_dentry_ops = { .d_revalidate = proc_net_d_revalidate, .d_delete = always_delete_dentry,};
/* * proc directories can do almost nothing.. */static const struct inode_operations proc_dir_inode_operations = { .lookup = proc_lookup, .getattr = proc_getattr, .setattr = proc_setattr,};
static void pde_set_flags(struct proc_dir_entry *pde){ const struct proc_ops *proc_ops = pde->proc_ops;
if (!proc_ops) return;
if (proc_ops->proc_flags & PROC_ENTRY_PERMANENT) pde->flags |= PROC_ENTRY_PERMANENT; if (proc_ops->proc_read_iter) pde->flags |= PROC_ENTRY_proc_read_iter;#ifdef CONFIG_COMPAT if (proc_ops->proc_compat_ioctl) pde->flags |= PROC_ENTRY_proc_compat_ioctl;#endif if (proc_ops->proc_lseek) pde->flags |= PROC_ENTRY_proc_lseek;}
/* returns the registered entry, or frees dp and returns NULL on failure */struct proc_dir_entry *proc_register(struct proc_dir_entry *dir, struct proc_dir_entry *dp){ if (proc_alloc_inum(&dp->low_ino)) goto out_free_entry;
if (!S_ISDIR(dp->mode)) pde_set_flags(dp);
write_lock(&proc_subdir_lock); dp->parent = dir; if (pde_subdir_insert(dir, dp) == false) { WARN(1, "proc_dir_entry '%s/%s' already registered\n", dir->name, dp->name); write_unlock(&proc_subdir_lock); goto out_free_inum; } write_unlock(&proc_subdir_lock);
return dp;out_free_inum: proc_free_inum(dp->low_ino);out_free_entry: pde_free(dp); return NULL;}
static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, const char *name, umode_t mode, nlink_t nlink){ struct proc_dir_entry *ent = NULL; const char *fn; struct qstr qstr;
if (xlate_proc_name(name, parent, &fn) != 0) goto out; qstr.name = fn; qstr.len = strnlen(fn, NAME_MAX + 1); if (qstr.len == 0) { WARN(1, "empty name\n"); return NULL; } if (qstr.len > NAME_MAX) { WARN(1, "name too long\n"); return NULL; } if (qstr.len == 1 && fn[0] == '.') { WARN(1, "name '.'\n"); return NULL; } if (qstr.len == 2 && fn[0] == '.' && fn[1] == '.') { WARN(1, "name '..'\n"); return NULL; } if (*parent == &proc_root && name_to_int(&qstr) != ~0U) { WARN(1, "create '/proc/%s' by hand\n", qstr.name); return NULL; } if (is_empty_pde(*parent)) { WARN(1, "attempt to add to permanently empty directory"); return NULL; }
ent = kmem_cache_zalloc(proc_dir_entry_cache, GFP_KERNEL); if (!ent) goto out;
if (qstr.len + 1 <= SIZEOF_PDE_INLINE_NAME) { ent->name = ent->inline_name; } else { ent->name = kmalloc(qstr.len + 1, GFP_KERNEL); if (!ent->name) { pde_free(ent); return NULL; } }
memcpy(ent->name, fn, qstr.len + 1); ent->namelen = qstr.len; ent->mode = mode; ent->nlink = nlink; ent->subdir = RB_ROOT; refcount_set(&ent->refcnt, 1); spin_lock_init(&ent->pde_unload_lock); INIT_LIST_HEAD(&ent->pde_openers); proc_set_user(ent, (*parent)->uid, (*parent)->gid);
/* Revalidate everything under /proc/${pid}/net */ if ((*parent)->flags & PROC_ENTRY_FORCE_LOOKUP) pde_force_lookup(ent);
out: return ent;}
struct proc_dir_entry *proc_symlink(const char *name, struct proc_dir_entry *parent, const char *dest){ struct proc_dir_entry *ent;
ent = __proc_create(&parent, name, (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
if (ent) { ent->size = strlen(dest); ent->data = kmemdup(dest, ent->size + 1, GFP_KERNEL); if (ent->data) { ent->proc_iops = &proc_link_inode_operations; ent = proc_register(parent, ent); } else { pde_free(ent); ent = NULL; } } return ent;}EXPORT_SYMBOL(proc_symlink);
struct proc_dir_entry *_proc_mkdir(const char *name, umode_t mode, struct proc_dir_entry *parent, void *data, bool force_lookup){ struct proc_dir_entry *ent;
if (mode == 0) mode = S_IRUGO | S_IXUGO;
ent = __proc_create(&parent, name, S_IFDIR | mode, 2); if (ent) { ent->data = data; ent->proc_dir_ops = &proc_dir_operations; ent->proc_iops = &proc_dir_inode_operations; if (force_lookup) { pde_force_lookup(ent); } ent = proc_register(parent, ent); } return ent;}EXPORT_SYMBOL_GPL(_proc_mkdir);
struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode, struct proc_dir_entry *parent, void *data){ return _proc_mkdir(name, mode, parent, data, false);}EXPORT_SYMBOL_GPL(proc_mkdir_data);
struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode, struct proc_dir_entry *parent){ return proc_mkdir_data(name, mode, parent, NULL);}EXPORT_SYMBOL(proc_mkdir_mode);
struct proc_dir_entry *proc_mkdir(const char *name, struct proc_dir_entry *parent){ return proc_mkdir_data(name, 0, parent, NULL);}EXPORT_SYMBOL(proc_mkdir);
struct proc_dir_entry *proc_create_mount_point(const char *name){ umode_t mode = S_IFDIR | S_IRUGO | S_IXUGO; struct proc_dir_entry *ent, *parent = NULL;
ent = __proc_create(&parent, name, mode, 2); if (ent) { ent->data = NULL; ent->proc_dir_ops = NULL; ent->proc_iops = NULL; ent = proc_register(parent, ent); } return ent;}EXPORT_SYMBOL(proc_create_mount_point);
struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode, struct proc_dir_entry **parent, void *data){ struct proc_dir_entry *p;
if ((mode & S_IFMT) == 0) mode |= S_IFREG; if ((mode & S_IALLUGO) == 0) mode |= S_IRUGO; if (WARN_ON_ONCE(!S_ISREG(mode))) return NULL;
p = __proc_create(parent, name, mode, 1); if (p) { p->proc_iops = &proc_file_inode_operations; p->data = data; } return p;}
struct proc_dir_entry *proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops, void *data){ struct proc_dir_entry *p;
p = proc_create_reg(name, mode, &parent, data); if (!p) return NULL; p->proc_ops = proc_ops; return proc_register(parent, p);}EXPORT_SYMBOL(proc_create_data); struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops){ return proc_create_data(name, mode, parent, proc_ops, NULL);}EXPORT_SYMBOL(proc_create);
static int proc_seq_open(struct inode *inode, struct file *file){ struct proc_dir_entry *de = PDE(inode);
if (de->state_size) return seq_open_private(file, de->seq_ops, de->state_size); return seq_open(file, de->seq_ops);}
static int proc_seq_release(struct inode *inode, struct file *file){ struct proc_dir_entry *de = PDE(inode);
if (de->state_size) return seq_release_private(inode, file); return seq_release(inode, file);}
static const struct proc_ops proc_seq_ops = { /* not permanent -- can call into arbitrary seq_operations */ .proc_open = proc_seq_open, .proc_read_iter = seq_read_iter, .proc_lseek = seq_lseek, .proc_release = proc_seq_release,};
struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct seq_operations *ops, 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_ops = &proc_seq_ops; p->seq_ops = ops; p->state_size = state_size; return proc_register(parent, p);}EXPORT_SYMBOL(proc_create_seq_private);
static int proc_single_open(struct inode *inode, struct file *file){ struct proc_dir_entry *de = PDE(inode);
return single_open(file, de->single_show, de->data);}
static const struct proc_ops proc_single_ops = { /* not permanent -- can call into arbitrary ->single_show */ .proc_open = proc_single_open, .proc_read_iter = seq_read_iter, .proc_lseek = seq_lseek, .proc_release = single_release,};
struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode, struct proc_dir_entry *parent, int (*show)(struct seq_file *, void *), void *data){ struct proc_dir_entry *p;
p = proc_create_reg(name, mode, &parent, data); if (!p) return NULL; p->proc_ops = &proc_single_ops; p->single_show = show; return proc_register(parent, p);}EXPORT_SYMBOL(proc_create_single_data);
void proc_set_size(struct proc_dir_entry *de, loff_t size){ de->size = size;}EXPORT_SYMBOL(proc_set_size);
void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid){ de->uid = uid; de->gid = gid;}EXPORT_SYMBOL(proc_set_user);
void pde_put(struct proc_dir_entry *pde){ if (refcount_dec_and_test(&pde->refcnt)) { proc_free_inum(pde->low_ino); pde_free(pde); }}
static void pde_erase(struct proc_dir_entry *pde, struct proc_dir_entry *parent){ rb_erase(&pde->subdir_node, &parent->subdir); RB_CLEAR_NODE(&pde->subdir_node); if (S_ISDIR(pde->mode)) parent->nlink--;}
/* * Remove a /proc entry and free it if it's not currently in use. */void remove_proc_entry(const char *name, struct proc_dir_entry *parent){ struct proc_dir_entry *de = NULL; const char *fn = name; unsigned int len;
write_lock(&proc_subdir_lock); if (__xlate_proc_name(name, &parent, &fn) != 0) { write_unlock(&proc_subdir_lock); return; } len = strlen(fn);
de = pde_subdir_find(parent, fn, len); if (de) { if (unlikely(pde_is_permanent(de))) { WARN(1, "removing permanent /proc entry '%s'", de->name); de = NULL; } else { pde_erase(de, parent); } } write_unlock(&proc_subdir_lock); if (!de) { WARN(1, "name '%s'\n", name); return; }
proc_entry_rundown(de);
WARN(pde_subdir_first(de), "%s: removing non-empty directory '%s/%s', leaking at least '%s'\n", __func__, de->parent->name, de->name, pde_subdir_first(de)->name); pde_put(de);}EXPORT_SYMBOL(remove_proc_entry);
int remove_proc_subtree(const char *name, struct proc_dir_entry *parent){ struct proc_dir_entry *root = NULL, *de, *next; const char *fn = name; unsigned int len;
write_lock(&proc_subdir_lock); if (__xlate_proc_name(name, &parent, &fn) != 0) { write_unlock(&proc_subdir_lock); return -ENOENT; } len = strlen(fn);
root = pde_subdir_find(parent, fn, len); if (!root) { write_unlock(&proc_subdir_lock); return -ENOENT; } if (unlikely(pde_is_permanent(root))) { write_unlock(&proc_subdir_lock); WARN(1, "removing permanent /proc entry '%s/%s'", root->parent->name, root->name); return -EINVAL; } pde_erase(root, parent);
de = root; while (1) { next = pde_subdir_first(de); if (next) { if (unlikely(pde_is_permanent(next))) { write_unlock(&proc_subdir_lock); WARN(1, "removing permanent /proc entry '%s/%s'", next->parent->name, next->name); return -EINVAL; } pde_erase(next, de); de = next; continue; } next = de->parent; write_unlock(&proc_subdir_lock);
proc_entry_rundown(de); if (de == root) break; pde_put(de);
write_lock(&proc_subdir_lock); de = next; } pde_put(root); return 0;}EXPORT_SYMBOL(remove_proc_subtree);
void *proc_get_parent_data(const struct inode *inode){ struct proc_dir_entry *de = PDE(inode); return de->parent->data;}EXPORT_SYMBOL_GPL(proc_get_parent_data);
void proc_remove(struct proc_dir_entry *de){ if (de) remove_proc_subtree(de->name, de->parent);}EXPORT_SYMBOL(proc_remove);
/* * 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;}
/* * Not exported to modules: * modules' /proc files aren't permanent because modules aren't permanent. */void impl_proc_make_permanent(struct proc_dir_entry *pde){ if (pde) pde_make_permanent(pde);}