From f9bd6733d3f11e24f3949becf277507d422ee1eb Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 9 May 2015 22:09:14 -0500 Subject: sysctl: Allow creating permanently empty directories that serve as mountpoints. Add a magic sysctl table sysctl_mount_point that when used to create a directory forces that directory to be permanently empty. Update the code to use make_empty_dir_inode when accessing permanently empty directories. Update the code to not allow adding to permanently empty directories. Update /proc/sys/fs/binfmt_misc to be a permanently empty directory. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" --- kernel/sysctl.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 2082b1a..c3eee4c 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1531,12 +1531,6 @@ static struct ctl_table vm_table[] = { { } }; -#if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE) -static struct ctl_table binfmt_misc_table[] = { - { } -}; -#endif - static struct ctl_table fs_table[] = { { .procname = "inode-nr", @@ -1690,7 +1684,7 @@ static struct ctl_table fs_table[] = { { .procname = "binfmt_misc", .mode = 0555, - .child = binfmt_misc_table, + .child = sysctl_mount_point, }, #endif { -- cgit v1.1 From f9bb48825a6b5d02f4cabcc78967c75db903dcdc Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 13 May 2015 17:35:41 -0500 Subject: sysfs: Create mountpoints with sysfs_create_mount_point This allows for better documentation in the code and it allows for a simpler and fully correct version of fs_fully_visible to be written. The mount points converted and their filesystems are: /sys/hypervisor/s390/ s390_hypfs /sys/kernel/config/ configfs /sys/kernel/debug/ debugfs /sys/firmware/efi/efivars/ efivarfs /sys/fs/fuse/connections/ fusectl /sys/fs/pstore/ pstore /sys/kernel/tracing/ tracefs /sys/fs/cgroup/ cgroup /sys/kernel/security/ securityfs /sys/fs/selinux/ selinuxfs /sys/fs/smackfs/ smackfs Cc: stable@vger.kernel.org Acked-by: Greg Kroah-Hartman Signed-off-by: "Eric W. Biederman" --- kernel/cgroup.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 469dd54..e8a5491 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1924,8 +1924,6 @@ static struct file_system_type cgroup_fs_type = { .kill_sb = cgroup_kill_sb, }; -static struct kobject *cgroup_kobj; - /** * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy * @task: target task @@ -5044,13 +5042,13 @@ int __init cgroup_init(void) ss->bind(init_css_set.subsys[ssid]); } - cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj); - if (!cgroup_kobj) - return -ENOMEM; + err = sysfs_create_mount_point(fs_kobj, "cgroup"); + if (err) + return err; err = register_filesystem(&cgroup_fs_type); if (err < 0) { - kobject_put(cgroup_kobj); + sysfs_remove_mount_point(fs_kobj, "cgroup"); return err; } -- cgit v1.1