proc: Add fs_context support to procfs
Add fs_context support to procfs. Signed-off-by: David Howells <dhowells@redhat.com> cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
David Howells
Al Viro
Родитель
60a3c3a58e
Коммит
66f592e2ec
|
|
@ -127,7 +127,6 @@ const struct super_operations proc_sops = {
|
|||
.drop_inode = generic_delete_inode,
|
||||
.evict_inode = proc_evict_inode,
|
||||
.statfs = simple_statfs,
|
||||
.remount_fs = proc_remount,
|
||||
.show_options = proc_show_options,
|
||||
};
|
||||
|
||||
|
|
|
|||
|
|
@ -270,7 +270,6 @@ 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 *);
|
||||
|
||||
/*
|
||||
* task_[no]mmu.c
|
||||
|
|
|
|||
189
fs/proc/root.c
189
fs/proc/root.c
|
|
@ -19,74 +19,89 @@
|
|||
#include <linux/module.h>
|
||||
#include <linux/bitops.h>
|
||||
#include <linux/user_namespace.h>
|
||||
#include <linux/fs_context.h>
|
||||
#include <linux/mount.h>
|
||||
#include <linux/pid_namespace.h>
|
||||
#include <linux/parser.h>
|
||||
#include <linux/fs_parser.h>
|
||||
#include <linux/cred.h>
|
||||
#include <linux/magic.h>
|
||||
#include <linux/slab.h>
|
||||
|
||||
#include "internal.h"
|
||||
|
||||
enum {
|
||||
Opt_gid, Opt_hidepid, Opt_err,
|
||||
struct proc_fs_context {
|
||||
struct pid_namespace *pid_ns;
|
||||
unsigned int mask;
|
||||
int hidepid;
|
||||
int gid;
|
||||
};
|
||||
|
||||
static const match_table_t tokens = {
|
||||
{Opt_hidepid, "hidepid=%u"},
|
||||
{Opt_gid, "gid=%u"},
|
||||
{Opt_err, NULL},
|
||||
enum proc_param {
|
||||
Opt_gid,
|
||||
Opt_hidepid,
|
||||
};
|
||||
|
||||
static int proc_parse_options(char *options, struct pid_namespace *pid)
|
||||
static const struct fs_parameter_spec proc_param_specs[] = {
|
||||
fsparam_u32("gid", Opt_gid),
|
||||
fsparam_u32("hidepid", Opt_hidepid),
|
||||
{}
|
||||
};
|
||||
|
||||
static const struct fs_parameter_description proc_fs_parameters = {
|
||||
.name = "proc",
|
||||
.specs = proc_param_specs,
|
||||
};
|
||||
|
||||
static int proc_parse_param(struct fs_context *fc, struct fs_parameter *param)
|
||||
{
|
||||
char *p;
|
||||
substring_t args[MAX_OPT_ARGS];
|
||||
int option;
|
||||
struct proc_fs_context *ctx = fc->fs_private;
|
||||
struct fs_parse_result result;
|
||||
int opt;
|
||||
|
||||
if (!options)
|
||||
return 1;
|
||||
opt = fs_parse(fc, &proc_fs_parameters, param, &result);
|
||||
if (opt < 0)
|
||||
return opt;
|
||||
|
||||
while ((p = strsep(&options, ",")) != NULL) {
|
||||
int token;
|
||||
if (!*p)
|
||||
continue;
|
||||
switch (opt) {
|
||||
case Opt_gid:
|
||||
ctx->gid = result.uint_32;
|
||||
break;
|
||||
|
||||
args[0].to = args[0].from = NULL;
|
||||
token = match_token(p, tokens, args);
|
||||
switch (token) {
|
||||
case Opt_gid:
|
||||
if (match_int(&args[0], &option))
|
||||
return 0;
|
||||
pid->pid_gid = make_kgid(current_user_ns(), option);
|
||||
break;
|
||||
case Opt_hidepid:
|
||||
if (match_int(&args[0], &option))
|
||||
return 0;
|
||||
if (option < HIDEPID_OFF ||
|
||||
option > HIDEPID_INVISIBLE) {
|
||||
pr_err("proc: hidepid value must be between 0 and 2.\n");
|
||||
return 0;
|
||||
}
|
||||
pid->hide_pid = option;
|
||||
break;
|
||||
default:
|
||||
pr_err("proc: unrecognized mount option \"%s\" "
|
||||
"or missing value\n", p);
|
||||
return 0;
|
||||
}
|
||||
case Opt_hidepid:
|
||||
ctx->hidepid = result.uint_32;
|
||||
if (ctx->hidepid < HIDEPID_OFF ||
|
||||
ctx->hidepid > HIDEPID_INVISIBLE)
|
||||
return invalf(fc, "proc: hidepid value must be between 0 and 2.\n");
|
||||
break;
|
||||
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
return 1;
|
||||
ctx->mask |= 1 << opt;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int proc_fill_super(struct super_block *s, void *data, int silent)
|
||||
static void proc_apply_options(struct super_block *s,
|
||||
struct fs_context *fc,
|
||||
struct pid_namespace *pid_ns,
|
||||
struct user_namespace *user_ns)
|
||||
{
|
||||
struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
|
||||
struct proc_fs_context *ctx = fc->fs_private;
|
||||
|
||||
if (ctx->mask & (1 << Opt_gid))
|
||||
pid_ns->pid_gid = make_kgid(user_ns, ctx->gid);
|
||||
if (ctx->mask & (1 << Opt_hidepid))
|
||||
pid_ns->hide_pid = ctx->hidepid;
|
||||
}
|
||||
|
||||
static int proc_fill_super(struct super_block *s, struct fs_context *fc)
|
||||
{
|
||||
struct pid_namespace *pid_ns = get_pid_ns(s->s_fs_info);
|
||||
struct inode *root_inode;
|
||||
int ret;
|
||||
|
||||
if (!proc_parse_options(data, ns))
|
||||
return -EINVAL;
|
||||
proc_apply_options(s, fc, pid_ns, current_user_ns());
|
||||
|
||||
/* User space would break if executables or devices appear on proc */
|
||||
s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
|
||||
|
|
@ -127,27 +142,55 @@ static int proc_fill_super(struct super_block *s, void *data, int silent)
|
|||
return proc_setup_thread_self(s);
|
||||
}
|
||||
|
||||
int proc_remount(struct super_block *sb, int *flags, char *data)
|
||||
static int proc_reconfigure(struct fs_context *fc)
|
||||
{
|
||||
struct super_block *sb = fc->root->d_sb;
|
||||
struct pid_namespace *pid = sb->s_fs_info;
|
||||
|
||||
sync_filesystem(sb);
|
||||
return !proc_parse_options(data, pid);
|
||||
|
||||
proc_apply_options(sb, fc, pid, current_user_ns());
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct dentry *proc_mount(struct file_system_type *fs_type,
|
||||
int flags, const char *dev_name, void *data)
|
||||
static int proc_get_tree(struct fs_context *fc)
|
||||
{
|
||||
struct pid_namespace *ns;
|
||||
struct proc_fs_context *ctx = fc->fs_private;
|
||||
|
||||
if (flags & SB_KERNMOUNT) {
|
||||
ns = data;
|
||||
data = NULL;
|
||||
} else {
|
||||
ns = task_active_pid_ns(current);
|
||||
}
|
||||
put_user_ns(fc->user_ns);
|
||||
fc->user_ns = get_user_ns(ctx->pid_ns->user_ns);
|
||||
fc->s_fs_info = ctx->pid_ns;
|
||||
return vfs_get_super(fc, vfs_get_keyed_super, proc_fill_super);
|
||||
}
|
||||
|
||||
return mount_ns(fs_type, flags, data, ns, ns->user_ns, proc_fill_super);
|
||||
static void proc_fs_context_free(struct fs_context *fc)
|
||||
{
|
||||
struct proc_fs_context *ctx = fc->fs_private;
|
||||
|
||||
if (ctx->pid_ns)
|
||||
put_pid_ns(ctx->pid_ns);
|
||||
kfree(ctx);
|
||||
}
|
||||
|
||||
static const struct fs_context_operations proc_fs_context_ops = {
|
||||
.free = proc_fs_context_free,
|
||||
.parse_param = proc_parse_param,
|
||||
.get_tree = proc_get_tree,
|
||||
.reconfigure = proc_reconfigure,
|
||||
};
|
||||
|
||||
static int proc_init_fs_context(struct fs_context *fc)
|
||||
{
|
||||
struct proc_fs_context *ctx;
|
||||
|
||||
ctx = kzalloc(sizeof(struct proc_fs_context), GFP_KERNEL);
|
||||
if (!ctx)
|
||||
return -ENOMEM;
|
||||
|
||||
ctx->pid_ns = get_pid_ns(task_active_pid_ns(current));
|
||||
fc->fs_private = ctx;
|
||||
fc->ops = &proc_fs_context_ops;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void proc_kill_sb(struct super_block *sb)
|
||||
|
|
@ -164,10 +207,11 @@ static void proc_kill_sb(struct super_block *sb)
|
|||
}
|
||||
|
||||
static struct file_system_type proc_fs_type = {
|
||||
.name = "proc",
|
||||
.mount = proc_mount,
|
||||
.kill_sb = proc_kill_sb,
|
||||
.fs_flags = FS_USERNS_MOUNT,
|
||||
.name = "proc",
|
||||
.init_fs_context = proc_init_fs_context,
|
||||
.parameters = &proc_fs_parameters,
|
||||
.kill_sb = proc_kill_sb,
|
||||
.fs_flags = FS_USERNS_MOUNT,
|
||||
};
|
||||
|
||||
void __init proc_root_init(void)
|
||||
|
|
@ -205,7 +249,7 @@ static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentr
|
|||
{
|
||||
if (!proc_pid_lookup(dir, dentry, flags))
|
||||
return NULL;
|
||||
|
||||
|
||||
return proc_lookup(dir, dentry, flags);
|
||||
}
|
||||
|
||||
|
|
@ -258,9 +302,28 @@ struct proc_dir_entry proc_root = {
|
|||
|
||||
int pid_ns_prepare_proc(struct pid_namespace *ns)
|
||||
{
|
||||
struct proc_fs_context *ctx;
|
||||
struct fs_context *fc;
|
||||
struct vfsmount *mnt;
|
||||
|
||||
mnt = kern_mount_data(&proc_fs_type, ns);
|
||||
fc = fs_context_for_mount(&proc_fs_type, SB_KERNMOUNT);
|
||||
if (IS_ERR(fc))
|
||||
return PTR_ERR(fc);
|
||||
|
||||
if (fc->user_ns != ns->user_ns) {
|
||||
put_user_ns(fc->user_ns);
|
||||
fc->user_ns = get_user_ns(ns->user_ns);
|
||||
}
|
||||
|
||||
ctx = fc->fs_private;
|
||||
if (ctx->pid_ns != ns) {
|
||||
put_pid_ns(ctx->pid_ns);
|
||||
get_pid_ns(ns);
|
||||
ctx->pid_ns = ns;
|
||||
}
|
||||
|
||||
mnt = fc_mount(fc);
|
||||
put_fs_context(fc);
|
||||
if (IS_ERR(mnt))
|
||||
return PTR_ERR(mnt);
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче