/* SPDX-License-Identifier: GPL-2.0-or-later *//* Internal procfs definitions * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/proc_fs.h>#include <linux/proc_ns.h>#include <linux/refcount.h>#include <linux/spinlock.h>#include <linux/atomic.h>#include <linux/binfmts.h>#include <linux/sched/coredump.h>#include <linux/sched/task.h>#include <linux/mm.h> struct ctl_table_header;struct mempolicy; /* * This is not completely implemented yet. The idea is to * create an in-memory tree (like the actual /proc filesystem * tree) of these proc_dir_entries, so that we can dynamically * add new files to /proc. * * parent/subdir are used for the directory structure (every /proc file has a * parent, but "subdir" is empty for all non-directory entries). * subdir_node is used to build the rb tree "subdir" of the parent. */struct proc_dir_entry {	/*	 * number of callers into module in progress;	 * negative -> it's going away RSN	 */	atomic_t in_use;	refcount_t refcnt;	struct list_head pde_openers;	/* who did ->open, but not ->release */	/* protects ->pde_openers and all struct pde_opener instances */	spinlock_t pde_unload_lock;	struct completion *pde_unload_completion;	const struct inode_operations *proc_iops;	union {		const struct proc_ops *proc_ops;		const struct file_operations *proc_dir_ops;	};	union {		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;	nlink_t nlink;	kuid_t uid;	kgid_t gid;	loff_t size;	struct proc_dir_entry *parent;	struct rb_root subdir;	struct rb_node subdir_node;	char *name;	umode_t mode;	u8 flags;	u8 namelen;	char inline_name[];} __randomize_layout; #define SIZEOF_PDE	(				\	sizeof(struct proc_dir_entry) < 128 ? 128 :	\	sizeof(struct proc_dir_entry) < 192 ? 192 :	\	sizeof(struct proc_dir_entry) < 256 ? 256 :	\	sizeof(struct proc_dir_entry) < 512 ? 512 :	\	0)#define SIZEOF_PDE_INLINE_NAME (SIZEOF_PDE - sizeof(struct proc_dir_entry)) static inline bool pde_is_permanent(const struct proc_dir_entry *pde){	return pde->flags & PROC_ENTRY_PERMANENT;} /* This is for builtin code, not even for modules which are compiled in. */static inline void pde_make_permanent(struct proc_dir_entry *pde){	/* Ensure magic flag does something. */	static_assert(PROC_ENTRY_PERMANENT != 0);	pde->flags |= PROC_ENTRY_PERMANENT;} static inline bool pde_has_proc_read_iter(const struct proc_dir_entry *pde){	return pde->flags & PROC_ENTRY_proc_read_iter;} static inline bool pde_has_proc_compat_ioctl(const struct proc_dir_entry *pde){#ifdef CONFIG_COMPAT	return pde->flags & PROC_ENTRY_proc_compat_ioctl;#else	return false;#endif} static inline bool pde_has_proc_lseek(const struct proc_dir_entry *pde){	return pde->flags & PROC_ENTRY_proc_lseek;} extern struct kmem_cache *proc_dir_entry_cache;void pde_free(struct proc_dir_entry *pde); union proc_op {	int (*proc_get_link)(struct dentry *, struct path *, struct task_struct *);	int (*proc_show)(struct seq_file *m,		struct pid_namespace *ns, struct pid *pid,		struct task_struct *task);	int lsmid;}; struct proc_inode {	struct pid *pid;	unsigned int fd;	union proc_op op;	struct proc_dir_entry *pde;	struct ctl_table_header *sysctl;	const struct ctl_table *sysctl_entry;	struct hlist_node sibling_inodes;	const struct proc_ns_operations *ns_ops;	struct inode vfs_inode;} __randomize_layout; /* * General functions */static inline struct proc_inode *PROC_I(const struct inode *inode){	return container_of(inode, struct proc_inode, vfs_inode);} static inline struct proc_dir_entry *PDE(const struct inode *inode){	return PROC_I(inode)->pde;} static inline struct pid *proc_pid(const struct inode *inode){	return PROC_I(inode)->pid;} static inline struct task_struct *get_proc_task(const struct inode *inode){	return get_pid_task(proc_pid(inode), PIDTYPE_PID);} void task_dump_owner(struct task_struct *task, umode_t mode,		     kuid_t *ruid, kgid_t *rgid); unsigned name_to_int(const struct qstr *qstr);/* * Offset of the first process in the /proc root directory.. */#define FIRST_PROCESS_ENTRY 256 /* Worst case buffer size needed for holding an integer. */#define PROC_NUMBUF 13 #ifdef CONFIG_PAGE_MAPCOUNT/** * folio_precise_page_mapcount() - Number of mappings of this folio page. * @folio: The folio. * @page: The page. * * The number of present user page table entries that reference this page * as tracked via the RMAP: either referenced directly (PTE) or as part of * a larger area that covers this page (e.g., PMD). * * Use this function only for the calculation of existing statistics * (USS, PSS, mapcount_max) and for debugging purposes (/proc/kpagecount). * * Do not add new users. * * Returns: The number of mappings of this folio page. 0 for * folios that are not mapped to user space or are not tracked via the RMAP * (e.g., shared zeropage). */static inline int folio_precise_page_mapcount(struct folio *folio,		struct page *page){	int mapcount = atomic_read(&page->_mapcount) + 1; 	if (page_mapcount_is_type(mapcount))		mapcount = 0;	if (folio_test_large(folio))		mapcount += folio_entire_mapcount(folio); 	return mapcount;}#else /* !CONFIG_PAGE_MAPCOUNT */static inline int folio_precise_page_mapcount(struct folio *folio,		struct page *page){	BUILD_BUG();}#endif /* CONFIG_PAGE_MAPCOUNT */ /** * folio_average_page_mapcount() - Average number of mappings per page in this *				   folio * @folio: The folio. * * The average number of user page table entries that reference each page in * this folio as tracked via the RMAP: either referenced directly (PTE) or * as part of a larger area that covers this page (e.g., PMD). * * The average is calculated by rounding to the nearest integer; however, * to avoid duplicated code in current callers, the average is at least * 1 if any page of the folio is mapped. * * Returns: The average number of mappings per page in this folio. */static inline int folio_average_page_mapcount(struct folio *folio){	int mapcount, entire_mapcount, avg; 	if (!folio_test_large(folio))		return atomic_read(&folio->_mapcount) + 1; 	mapcount = folio_large_mapcount(folio);	if (unlikely(mapcount <= 0))		return 0;	entire_mapcount = folio_entire_mapcount(folio);	if (mapcount <= entire_mapcount)		return entire_mapcount;	mapcount -= entire_mapcount; 	/* Round to closest integer ... */	avg = ((unsigned int)mapcount + folio_large_nr_pages(folio) / 2) >> folio_large_order(folio);	/* ... but return at least 1. */	return max_t(int, avg + entire_mapcount, 1);}/* * array.c */extern const struct file_operations proc_tid_children_operations; extern void proc_task_name(struct seq_file *m, struct task_struct *p,			   bool escape);extern int proc_tid_stat(struct seq_file *, struct pid_namespace *,			 struct pid *, struct task_struct *);extern int proc_tgid_stat(struct seq_file *, struct pid_namespace *,			  struct pid *, struct task_struct *);extern int proc_pid_status(struct seq_file *, struct pid_namespace *,			   struct pid *, struct task_struct *);extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,			  struct pid *, struct task_struct *); /* * base.c */extern const struct dentry_operations pid_dentry_operations;extern int pid_getattr(struct mnt_idmap *, const struct path *,		       struct kstat *, u32, unsigned int);int proc_nochmod_setattr(struct mnt_idmap *idmap, struct dentry *dentry,			struct iattr *attr);extern void proc_pid_evict_inode(struct proc_inode *);extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);extern void pid_update_inode(struct task_struct *, struct inode *);extern int pid_delete_dentry(const struct dentry *);extern int proc_pid_readdir(struct file *, struct dir_context *);struct dentry *proc_pid_lookup(struct dentry *, unsigned int);extern loff_t mem_lseek(struct file *, loff_t, int); /* Lookups */typedef struct dentry *instantiate_t(struct dentry *,				     struct task_struct *, const void *);bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,			   instantiate_t, struct task_struct *, const void *); /* * generic.c */struct proc_dir_entry *proc_create_reg(const char *name, umode_t mode,		struct proc_dir_entry **parent, void *data);struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,		struct proc_dir_entry *dp);extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);extern int proc_readdir(struct file *, struct dir_context *);int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *); static inline void pde_get(struct proc_dir_entry *pde){	refcount_inc(&pde->refcnt);}extern void pde_put(struct proc_dir_entry *); 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 */struct pde_opener {	struct list_head lh;	struct file *file;	bool closing;	struct completion *c;} __randomize_layout;extern const struct inode_operations proc_link_inode_operations;extern const struct inode_operations proc_pid_link_inode_operations;extern const struct super_operations proc_sops; void proc_init_kmemcache(void);void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock);void set_proc_pid_nlink(void);extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);extern void proc_entry_rundown(struct proc_dir_entry *); /* * proc_namespaces.c */extern const struct inode_operations proc_ns_dir_inode_operations;extern const struct file_operations proc_ns_dir_operations; /* * proc_net.c */extern const struct file_operations proc_net_operations;extern const struct inode_operations proc_net_inode_operations; #ifdef CONFIG_NETextern int proc_net_init(void);#elsestatic inline int proc_net_init(void) { return 0; }#endif /* * proc_self.c */extern int proc_setup_self(struct super_block *); /* * proc_thread_self.c */extern int proc_setup_thread_self(struct super_block *);extern void proc_thread_self_init(void); /* * proc_sysctl.c */#ifdef CONFIG_SYSCTLextern int proc_sys_init(void);extern void proc_sys_evict_inode(struct inode *inode,				 struct ctl_table_header *head);#elsestatic inline void proc_sys_init(void) { }static inline void proc_sys_evict_inode(struct  inode *inode,					struct ctl_table_header *head) { }#endif /* * proc_tty.c */#ifdef CONFIG_TTYextern void proc_tty_init(void);#elsestatic inline void proc_tty_init(void) {}#endif /* * root.c */extern struct proc_dir_entry proc_root; extern void proc_self_init(void);extern unsigned self_inum, thread_self_inum; /* * task_[no]mmu.c */struct mem_size_stats; struct proc_maps_locking_ctx {	struct mm_struct *mm;#ifdef CONFIG_PER_VMA_LOCK	bool mmap_locked;	struct vm_area_struct *locked_vma;#endif}; struct proc_maps_private {	struct inode *inode;	struct task_struct *task;	struct vma_iterator iter;	loff_t last_pos;	struct proc_maps_locking_ctx lock_ctx;#ifdef CONFIG_NUMA	struct mempolicy *task_mempolicy;#endif} __randomize_layout; struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode); extern const struct file_operations proc_pid_maps_operations;extern const struct file_operations proc_pid_numa_maps_operations;extern const struct file_operations proc_pid_smaps_operations;extern const struct file_operations proc_pid_smaps_rollup_operations;extern const struct file_operations proc_clear_refs_operations;extern const struct file_operations proc_pagemap_operations; extern unsigned long task_vsize(struct mm_struct *);extern unsigned long task_statm(struct mm_struct *,				unsigned long *, unsigned long *,				unsigned long *, unsigned long *);extern void task_mem(struct seq_file *, struct mm_struct *); extern const struct dentry_operations proc_net_dentry_ops;static inline void pde_force_lookup(struct proc_dir_entry *pde){	/* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */	pde->flags |= PROC_ENTRY_FORCE_LOOKUP;} /* * Add a new procfs dentry that can't serve as a mountpoint. That should * encompass anything that is ephemeral and can just disappear while the * process is still around. */static inline struct dentry *proc_splice_unmountable(struct inode *inode,		struct dentry *dentry, const struct dentry_operations *d_ops){	dont_mount(dentry);	return d_splice_alias_ops(inode, dentry, d_ops);}