alistair23-linux/include/linux/proc_fs.h
Linus Torvalds 9ff7258575 Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull proc updates from Eric Biederman:
 "This has four sets of changes:

   - modernize proc to support multiple private instances

   - ensure we see the exit of each process tid exactly

   - remove has_group_leader_pid

   - use pids not tasks in posix-cpu-timers lookup

  Alexey updated proc so each mount of proc uses a new superblock. This
  allows people to actually use mount options with proc with no fear of
  messing up another mount of proc. Given the kernel's internal mounts
  of proc for things like uml this was a real problem, and resulted in
  Android's hidepid mount options being ignored and introducing security
  issues.

  The rest of the changes are small cleanups and fixes that came out of
  my work to allow this change to proc. In essence it is swapping the
  pids in de_thread during exec which removes a special case the code
  had to handle. Then updating the code to stop handling that special
  case"

* 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  proc: proc_pid_ns takes super_block as an argument
  remove the no longer needed pid_alive() check in __task_pid_nr_ns()
  posix-cpu-timers: Replace __get_task_for_clock with pid_for_clock
  posix-cpu-timers: Replace cpu_timer_pid_type with clock_pid_type
  posix-cpu-timers: Extend rcu_read_lock removing task_struct references
  signal: Remove has_group_leader_pid
  exec: Remove BUG_ON(has_group_leader_pid)
  posix-cpu-timer:  Unify the now redundant code in lookup_task
  posix-cpu-timer: Tidy up group_leader logic in lookup_task
  proc: Ensure we see the exit of each process tid exactly once
  rculist: Add hlists_swap_heads_rcu
  proc: Use PIDTYPE_TGID in next_tgid
  Use proc_pid_ns() to get pid_namespace from the proc superblock
  proc: use named enums for better readability
  proc: use human-readable values for hidepid
  docs: proc: add documentation for "hidepid=4" and "subset=pid" options and new mount behavior
  proc: add option to mount only a pids subset
  proc: instantiate only pids that we can ptrace on 'hidepid=4' mount option
  proc: allow to mount many instances of proc in one pid namespace
  proc: rename struct proc_fs_info to proc_fs_opts
2020-06-04 13:54:34 -07:00

216 lines
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C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* The proc filesystem constants/structures
*/
#ifndef _LINUX_PROC_FS_H
#define _LINUX_PROC_FS_H
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/fs.h>
struct proc_dir_entry;
struct seq_file;
struct seq_operations;
enum {
/*
* All /proc entries using this ->proc_ops instance are never removed.
*
* If in doubt, ignore this flag.
*/
#ifdef MODULE
PROC_ENTRY_PERMANENT = 0U,
#else
PROC_ENTRY_PERMANENT = 1U << 0,
#endif
};
struct proc_ops {
unsigned int proc_flags;
int (*proc_open)(struct inode *, struct file *);
ssize_t (*proc_read)(struct file *, char __user *, size_t, loff_t *);
ssize_t (*proc_write)(struct file *, const char __user *, size_t, loff_t *);
loff_t (*proc_lseek)(struct file *, loff_t, int);
int (*proc_release)(struct inode *, struct file *);
__poll_t (*proc_poll)(struct file *, struct poll_table_struct *);
long (*proc_ioctl)(struct file *, unsigned int, unsigned long);
#ifdef CONFIG_COMPAT
long (*proc_compat_ioctl)(struct file *, unsigned int, unsigned long);
#endif
int (*proc_mmap)(struct file *, struct vm_area_struct *);
unsigned long (*proc_get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
} __randomize_layout;
/* definitions for hide_pid field */
enum proc_hidepid {
HIDEPID_OFF = 0,
HIDEPID_NO_ACCESS = 1,
HIDEPID_INVISIBLE = 2,
HIDEPID_NOT_PTRACEABLE = 4, /* Limit pids to only ptraceable pids */
};
/* definitions for proc mount option pidonly */
enum proc_pidonly {
PROC_PIDONLY_OFF = 0,
PROC_PIDONLY_ON = 1,
};
struct proc_fs_info {
struct pid_namespace *pid_ns;
struct dentry *proc_self; /* For /proc/self */
struct dentry *proc_thread_self; /* For /proc/thread-self */
kgid_t pid_gid;
enum proc_hidepid hide_pid;
enum proc_pidonly pidonly;
};
static inline struct proc_fs_info *proc_sb_info(struct super_block *sb)
{
return sb->s_fs_info;
}
#ifdef CONFIG_PROC_FS
typedef int (*proc_write_t)(struct file *, char *, size_t);
extern void proc_root_init(void);
extern void proc_flush_pid(struct pid *);
extern struct proc_dir_entry *proc_symlink(const char *,
struct proc_dir_entry *, const char *);
extern struct proc_dir_entry *proc_mkdir(const char *, struct proc_dir_entry *);
extern struct proc_dir_entry *proc_mkdir_data(const char *, umode_t,
struct proc_dir_entry *, void *);
extern struct proc_dir_entry *proc_mkdir_mode(const char *, umode_t,
struct proc_dir_entry *);
struct proc_dir_entry *proc_create_mount_point(const char *name);
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);
#define proc_create_seq_data(name, mode, parent, ops, data) \
proc_create_seq_private(name, mode, parent, ops, 0, data)
#define proc_create_seq(name, mode, parent, ops) \
proc_create_seq_private(name, mode, parent, ops, 0, NULL)
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);
#define proc_create_single(name, mode, parent, show) \
proc_create_single_data(name, mode, parent, show, NULL)
extern struct proc_dir_entry *proc_create_data(const char *, umode_t,
struct proc_dir_entry *,
const struct proc_ops *,
void *);
struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops);
extern void proc_set_size(struct proc_dir_entry *, loff_t);
extern void proc_set_user(struct proc_dir_entry *, kuid_t, kgid_t);
extern void *PDE_DATA(const struct inode *);
extern void *proc_get_parent_data(const struct inode *);
extern void proc_remove(struct proc_dir_entry *);
extern void remove_proc_entry(const char *, struct proc_dir_entry *);
extern int remove_proc_subtree(const char *, struct proc_dir_entry *);
struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
struct proc_dir_entry *parent, const struct seq_operations *ops,
unsigned int state_size, void *data);
#define proc_create_net(name, mode, parent, ops, state_size) \
proc_create_net_data(name, mode, parent, ops, state_size, NULL)
struct proc_dir_entry *proc_create_net_single(const char *name, umode_t mode,
struct proc_dir_entry *parent,
int (*show)(struct seq_file *, void *), void *data);
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 *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);
extern struct pid *tgid_pidfd_to_pid(const struct file *file);
extern int bpf_iter_init_seq_net(void *priv_data);
extern void bpf_iter_fini_seq_net(void *priv_data);
#ifdef CONFIG_PROC_PID_ARCH_STATUS
/*
* The architecture which selects CONFIG_PROC_PID_ARCH_STATUS must
* provide proc_pid_arch_status() definition.
*/
int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task);
#endif /* CONFIG_PROC_PID_ARCH_STATUS */
#else /* CONFIG_PROC_FS */
static inline void proc_root_init(void)
{
}
static inline void proc_flush_pid(struct pid *pid)
{
}
static inline struct proc_dir_entry *proc_symlink(const char *name,
struct proc_dir_entry *parent,const char *dest) { return NULL;}
static inline struct proc_dir_entry *proc_mkdir(const char *name,
struct proc_dir_entry *parent) {return NULL;}
static inline struct proc_dir_entry *proc_create_mount_point(const char *name) { return NULL; }
static inline struct proc_dir_entry *proc_mkdir_data(const char *name,
umode_t mode, struct proc_dir_entry *parent, void *data) { return NULL; }
static inline struct proc_dir_entry *proc_mkdir_mode(const char *name,
umode_t mode, struct proc_dir_entry *parent) { return NULL; }
#define proc_create_seq_private(name, mode, parent, ops, size, data) ({NULL;})
#define proc_create_seq_data(name, mode, parent, ops, data) ({NULL;})
#define proc_create_seq(name, mode, parent, ops) ({NULL;})
#define proc_create_single(name, mode, parent, show) ({NULL;})
#define proc_create_single_data(name, mode, parent, show, data) ({NULL;})
#define proc_create(name, mode, parent, proc_ops) ({NULL;})
#define proc_create_data(name, mode, parent, proc_ops, data) ({NULL;})
static inline void proc_set_size(struct proc_dir_entry *de, loff_t size) {}
static inline void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid) {}
static inline void *PDE_DATA(const struct inode *inode) {BUG(); return NULL;}
static inline void *proc_get_parent_data(const struct inode *inode) { BUG(); return NULL; }
static inline void proc_remove(struct proc_dir_entry *de) {}
#define remove_proc_entry(name, parent) do {} while (0)
static inline int remove_proc_subtree(const char *name, struct proc_dir_entry *parent) { return 0; }
#define proc_create_net_data(name, mode, parent, ops, state_size, data) ({NULL;})
#define proc_create_net(name, mode, parent, state_size, ops) ({NULL;})
#define proc_create_net_single(name, mode, parent, show, data) ({NULL;})
static inline struct pid *tgid_pidfd_to_pid(const struct file *file)
{
return ERR_PTR(-EBADF);
}
#endif /* CONFIG_PROC_FS */
struct net;
static inline struct proc_dir_entry *proc_net_mkdir(
struct net *net, const char *name, struct proc_dir_entry *parent)
{
return proc_mkdir_data(name, 0, parent, net);
}
struct ns_common;
int open_related_ns(struct ns_common *ns,
struct ns_common *(*get_ns)(struct ns_common *ns));
/* get the associated pid namespace for a file in procfs */
static inline struct pid_namespace *proc_pid_ns(struct super_block *sb)
{
return proc_sb_info(sb)->pid_ns;
}
bool proc_ns_file(const struct file *file);
#endif /* _LINUX_PROC_FS_H */