1 files changed, 245 insertions, 109 deletions

diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 651d09a11dde..c1e8eb984da8 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -1,19 +1,19 @@
+/* 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)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
 #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;
@@ -24,50 +24,107 @@ struct mempolicy;
  * tree) of these proc_dir_entries, so that we can dynamically
  * add new files to /proc.
  *
- * The "next" pointer creates a linked list of one /proc directory,
- * while parent/subdir create the directory structure (every
- * /proc file has a parent, but "subdir" is NULL for all
- * non-directory entries).
+ * 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;
-	umode_t mode;
 	nlink_t nlink;
 	kuid_t uid;
 	kgid_t gid;
 	loff_t size;
-	const struct inode_operations *proc_iops;
-	const struct file_operations *proc_fops;
-	struct proc_dir_entry *next, *parent, *subdir;
-	void *data;
-	atomic_t count;		/* use count */
-	atomic_t in_use;	/* number of callers into module in progress; */
-			/* negative -> it's going away RSN */
-	struct completion *pde_unload_completion;
-	struct list_head pde_openers;	/* who did ->open, but not ->release */
-	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
+	struct proc_dir_entry *parent;
+	struct rb_root subdir;
+	struct rb_node subdir_node;
+	char *name;
+	umode_t mode;
+	u8 flags;
 	u8 namelen;
-	char name[];
-};
+	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;
+}
+
+static inline void pde_make_permanent(struct proc_dir_entry *pde)
+{
+	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 *);
-	int (*proc_read)(struct task_struct *task, char *page);
 	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;
-	int fd;
+	unsigned int fd;
 	union proc_op op;
 	struct proc_dir_entry *pde;
 	struct ctl_table_header *sysctl;
-	struct ctl_table *sysctl_entry;
-	struct proc_ns ns;
+	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
@@ -82,58 +139,20 @@ static inline struct proc_dir_entry *PDE(const struct inode *inode)
 	return PROC_I(inode)->pde;
 }
 
-static inline void *__PDE_DATA(const struct inode *inode)
-{
-	return PDE(inode)->data;
-}
-
-static inline struct pid *proc_pid(struct inode *inode)
+static inline struct pid *proc_pid(const struct inode *inode)
 {
 	return PROC_I(inode)->pid;
 }
 
-static inline struct task_struct *get_proc_task(struct inode *inode)
+static inline struct task_struct *get_proc_task(const struct inode *inode)
 {
 	return get_pid_task(proc_pid(inode), PIDTYPE_PID);
 }
 
-static inline int task_dumpable(struct task_struct *task)
-{
-	int dumpable = 0;
-	struct mm_struct *mm;
-
-	task_lock(task);
-	mm = task->mm;
-	if (mm)
-		dumpable = get_dumpable(mm);
-	task_unlock(task);
-	if (dumpable == SUID_DUMP_USER)
-		return 1;
-	return 0;
-}
-
-static inline unsigned name_to_int(struct dentry *dentry)
-{
-	const char *name = dentry->d_name.name;
-	int len = dentry->d_name.len;
-	unsigned n = 0;
-
-	if (len > 1 && *name == '0')
-		goto out;
-	while (len-- > 0) {
-		unsigned c = *name++ - '0';
-		if (c > 9)
-			goto out;
-		if (n >= (~0U-9)/10)
-			goto out;
-		n *= 10;
-		n += c;
-	}
-	return n;
-out:
-	return ~0U;
-}
+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..
  */
@@ -142,11 +161,87 @@ out:
 /* 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 *,
@@ -160,64 +255,68 @@ extern int proc_pid_statm(struct seq_file *, struct pid_namespace *,
  * base.c
  */
 extern const struct dentry_operations pid_dentry_operations;
-extern int pid_getattr(struct vfsmount *, struct dentry *, struct kstat *);
-extern int proc_setattr(struct dentry *, struct iattr *);
-extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *);
-extern int pid_revalidate(struct dentry *, unsigned int);
+extern int pid_getattr(struct mnt_idmap *, const struct path *,
+		       struct kstat *, u32, unsigned int);
+extern int proc_setattr(struct mnt_idmap *, struct dentry *,
+			struct iattr *);
+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 *);
-extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
+struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
 extern loff_t mem_lseek(struct file *, loff_t, int);
 
 /* Lookups */
-typedef int instantiate_t(struct inode *, struct dentry *,
+typedef struct dentry *instantiate_t(struct dentry *,
 				     struct task_struct *, const void *);
-extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, int,
+bool proc_fill_cache(struct file *, struct dir_context *, const char *, unsigned int,
 			   instantiate_t, struct task_struct *, const void *);
 
 /*
  * generic.c
  */
-extern spinlock_t proc_subdir_lock;
-
+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);
-extern struct dentry *proc_lookup_de(struct proc_dir_entry *, struct inode *,
-				     struct dentry *);
+struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
 extern int proc_readdir(struct file *, struct dir_context *);
-extern int proc_readdir_de(struct proc_dir_entry *, struct file *, struct dir_context *);
+int proc_readdir_de(struct file *, struct dir_context *, struct proc_dir_entry *);
 
-static inline struct proc_dir_entry *pde_get(struct proc_dir_entry *pde)
+static inline void pde_get(struct proc_dir_entry *pde)
 {
-	atomic_inc(&pde->count);
-	return 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 file *file;
 	struct list_head lh;
-	int closing;
+	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;
 
-extern void proc_init_inodecache(void);
+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 int proc_fill_super(struct super_block *);
 extern void proc_entry_rundown(struct proc_dir_entry *);
 
 /*
- * proc_devtree.c
- */
-#ifdef CONFIG_PROC_DEVICETREE
-extern void proc_device_tree_init(void);
-#endif
-
-/*
  * proc_namespaces.c
  */
 extern const struct inode_operations proc_ns_dir_inode_operations;
@@ -241,14 +340,22 @@ static inline int proc_net_init(void) { return 0; }
 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_PROC_SYSCTL
 extern int proc_sys_init(void);
-extern void sysctl_head_put(struct ctl_table_header *);
+extern void proc_sys_evict_inode(struct inode *inode,
+				 struct ctl_table_header *head);
 #else
 static inline void proc_sys_init(void) { }
-static inline void sysctl_head_put(struct ctl_table_header *head) { }
+static inline void proc_sys_evict_inode(struct  inode *inode,
+					struct ctl_table_header *head) { }
 #endif
 
 /*
@@ -266,28 +373,38 @@ static inline void proc_tty_init(void) {}
 extern struct proc_dir_entry proc_root;
 
 extern void proc_self_init(void);
-extern int proc_remount(struct super_block *, int *, char *);
+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 pid *pid;
+	struct inode *inode;
 	struct task_struct *task;
-#ifdef CONFIG_MMU
-	struct vm_area_struct *tail_vma;
-#endif
+	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_tid_maps_operations;
 extern const struct file_operations proc_pid_numa_maps_operations;
-extern const struct file_operations proc_tid_numa_maps_operations;
 extern const struct file_operations proc_pid_smaps_operations;
-extern const struct file_operations proc_tid_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;
 
@@ -296,3 +413,22 @@ 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);
+}