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authorEric W. Biederman <ebiederm@xmission.com>2016-06-09 23:32:10 +0300
committerEric W. Biederman <ebiederm@xmission.com>2016-06-23 23:41:54 +0300
commite94591d0d90c13166cb6eb54ce5f96ed13d81b55 (patch)
treea52df89fe96d5ed24657c3fed1552ffc1d474b3a
parentd91ee87d8d85a0808c01787e8b4a6b48f2ba487b (diff)
downloadlinux-e94591d0d90c13166cb6eb54ce5f96ed13d81b55.tar.xz
proc: Convert proc_mount to use mount_ns.
Move the call of get_pid_ns, the call of proc_parse_options, and the setting of s_iflags into proc_fill_super so that mount_ns can be used. Convert proc_mount to call mount_ns and remove the now unnecessary code. Acked-by: Seth Forshee <seth.forshee@canonical.com> Reviewed-by: Djalal Harouni <tixxdz@gmail.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
-rw-r--r--fs/proc/inode.c9
-rw-r--r--fs/proc/internal.h3
-rw-r--r--fs/proc/root.c52
3 files changed, 13 insertions, 51 deletions
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 78fa452d65ed..f4817efb25a6 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -457,12 +457,17 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
return inode;
}
-int proc_fill_super(struct super_block *s)
+int proc_fill_super(struct super_block *s, void *data, int silent)
{
+ struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
struct inode *root_inode;
int ret;
- s->s_iflags |= SB_I_USERNS_VISIBLE;
+ if (!proc_parse_options(data, ns))
+ return -EINVAL;
+
+ /* User space would break if executables appear on proc */
+ s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC;
s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index aa2781095bd1..7931c558c192 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -212,7 +212,7 @@ extern const struct inode_operations proc_pid_link_inode_operations;
extern void proc_init_inodecache(void);
extern struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
-extern int proc_fill_super(struct super_block *);
+extern int proc_fill_super(struct super_block *, void *data, int flags);
extern void proc_entry_rundown(struct proc_dir_entry *);
/*
@@ -268,6 +268,7 @@ static inline void proc_tty_init(void) {}
* root.c
*/
extern struct proc_dir_entry proc_root;
+extern int proc_parse_options(char *options, struct pid_namespace *pid);
extern void proc_self_init(void);
extern int proc_remount(struct super_block *, int *, char *);
diff --git a/fs/proc/root.c b/fs/proc/root.c
index a1b2860fec62..8d3e484055a6 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -23,21 +23,6 @@
#include "internal.h"
-static int proc_test_super(struct super_block *sb, void *data)
-{
- return sb->s_fs_info == data;
-}
-
-static int proc_set_super(struct super_block *sb, void *data)
-{
- int err = set_anon_super(sb, NULL);
- if (!err) {
- struct pid_namespace *ns = (struct pid_namespace *)data;
- sb->s_fs_info = get_pid_ns(ns);
- }
- return err;
-}
-
enum {
Opt_gid, Opt_hidepid, Opt_err,
};
@@ -48,7 +33,7 @@ static const match_table_t tokens = {
{Opt_err, NULL},
};
-static int proc_parse_options(char *options, struct pid_namespace *pid)
+int proc_parse_options(char *options, struct pid_namespace *pid)
{
char *p;
substring_t args[MAX_OPT_ARGS];
@@ -100,45 +85,16 @@ int proc_remount(struct super_block *sb, int *flags, char *data)
static struct dentry *proc_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- int err;
- struct super_block *sb;
struct pid_namespace *ns;
- char *options;
if (flags & MS_KERNMOUNT) {
- ns = (struct pid_namespace *)data;
- options = NULL;
+ ns = data;
+ data = NULL;
} else {
ns = task_active_pid_ns(current);
- options = data;
-
- /* Does the mounter have privilege over the pid namespace? */
- if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN))
- return ERR_PTR(-EPERM);
- }
-
- sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns);
- if (IS_ERR(sb))
- return ERR_CAST(sb);
-
- if (!proc_parse_options(options, ns)) {
- deactivate_locked_super(sb);
- return ERR_PTR(-EINVAL);
- }
-
- if (!sb->s_root) {
- err = proc_fill_super(sb);
- if (err) {
- deactivate_locked_super(sb);
- return ERR_PTR(err);
- }
-
- sb->s_flags |= MS_ACTIVE;
- /* User space would break if executables appear on proc */
- sb->s_iflags |= SB_I_NOEXEC;
}
- return dget(sb->s_root);
+ return mount_ns(fs_type, flags, data, ns, ns->user_ns, proc_fill_super);
}
static void proc_kill_sb(struct super_block *sb)