Add ns_debug() that asserts that the correct operations are used for the
namespace type.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 kernel/nscommon.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/kernel/nscommon.c b/kernel/nscommon.c
index 7aa2be6a0c32..3cef89ddef41 100644
--- a/kernel/nscommon.c
+++ b/kernel/nscommon.c
@@ -2,6 +2,55 @@
 
 #include <linux/ns_common.h>
 #include <linux/proc_ns.h>
+#include <linux/vfsdebug.h>
+
+#ifdef CONFIG_DEBUG_VFS
+static void ns_debug(struct ns_common *ns, const struct proc_ns_operations *ops)
+{
+	switch (ns->ops->type) {
+#ifdef CONFIG_CGROUPS
+	case CLONE_NEWCGROUP:
+		VFS_WARN_ON_ONCE(ops != &cgroupns_operations);
+		break;
+#endif
+#ifdef CONFIG_IPC_NS
+	case CLONE_NEWIPC:
+		VFS_WARN_ON_ONCE(ops != &ipcns_operations);
+		break;
+#endif
+	case CLONE_NEWNS:
+		VFS_WARN_ON_ONCE(ops != &mntns_operations);
+		break;
+#ifdef CONFIG_NET_NS
+	case CLONE_NEWNET:
+		VFS_WARN_ON_ONCE(ops != &netns_operations);
+		break;
+#endif
+#ifdef CONFIG_PID_NS
+	case CLONE_NEWPID:
+		VFS_WARN_ON_ONCE(ops != &pidns_operations);
+		break;
+#endif
+#ifdef CONFIG_TIME_NS
+	case CLONE_NEWTIME:
+		VFS_WARN_ON_ONCE(ops != &timens_operations);
+		break;
+#endif
+#ifdef CONFIG_USER_NS
+	case CLONE_NEWUSER:
+		VFS_WARN_ON_ONCE(ops != &userns_operations);
+		break;
+#endif
+#ifdef CONFIG_UTS_NS
+	case CLONE_NEWUTS:
+		VFS_WARN_ON_ONCE(ops != &utsns_operations);
+		break;
+#endif
+	default:
+		VFS_WARN_ON_ONCE(true);
+	}
+}
+#endif
 
 int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum)
 {
@@ -12,6 +61,10 @@ int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,
 	RB_CLEAR_NODE(&ns->ns_tree_node);
 	INIT_LIST_HEAD(&ns->ns_list_node);
 
+#ifdef CONFIG_DEBUG_VFS
+	ns_debug(ns, ops);
+#endif
+
 	if (inum) {
 		ns->inum = inum;
 		return 0;

-- 
2.47.3

On Mon 22-09-25 14:42:37, Christian Brauner wrote:
> Add ns_debug() that asserts that the correct operations are used for the
> namespace type.
> 
> Signed-off-by: Christian Brauner <brauner@kernel.org>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  kernel/nscommon.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/kernel/nscommon.c b/kernel/nscommon.c
> index 7aa2be6a0c32..3cef89ddef41 100644
> --- a/kernel/nscommon.c
> +++ b/kernel/nscommon.c
> @@ -2,6 +2,55 @@
>  
>  #include <linux/ns_common.h>
>  #include <linux/proc_ns.h>
> +#include <linux/vfsdebug.h>
> +
> +#ifdef CONFIG_DEBUG_VFS
> +static void ns_debug(struct ns_common *ns, const struct proc_ns_operations *ops)
> +{
> +	switch (ns->ops->type) {
> +#ifdef CONFIG_CGROUPS
> +	case CLONE_NEWCGROUP:
> +		VFS_WARN_ON_ONCE(ops != &cgroupns_operations);
> +		break;
> +#endif
> +#ifdef CONFIG_IPC_NS
> +	case CLONE_NEWIPC:
> +		VFS_WARN_ON_ONCE(ops != &ipcns_operations);
> +		break;
> +#endif
> +	case CLONE_NEWNS:
> +		VFS_WARN_ON_ONCE(ops != &mntns_operations);
> +		break;
> +#ifdef CONFIG_NET_NS
> +	case CLONE_NEWNET:
> +		VFS_WARN_ON_ONCE(ops != &netns_operations);
> +		break;
> +#endif
> +#ifdef CONFIG_PID_NS
> +	case CLONE_NEWPID:
> +		VFS_WARN_ON_ONCE(ops != &pidns_operations);
> +		break;
> +#endif
> +#ifdef CONFIG_TIME_NS
> +	case CLONE_NEWTIME:
> +		VFS_WARN_ON_ONCE(ops != &timens_operations);
> +		break;
> +#endif
> +#ifdef CONFIG_USER_NS
> +	case CLONE_NEWUSER:
> +		VFS_WARN_ON_ONCE(ops != &userns_operations);
> +		break;
> +#endif
> +#ifdef CONFIG_UTS_NS
> +	case CLONE_NEWUTS:
> +		VFS_WARN_ON_ONCE(ops != &utsns_operations);
> +		break;
> +#endif
> +	default:
> +		VFS_WARN_ON_ONCE(true);
> +	}
> +}
> +#endif
>  
>  int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum)
>  {
> @@ -12,6 +61,10 @@ int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,
>  	RB_CLEAR_NODE(&ns->ns_tree_node);
>  	INIT_LIST_HEAD(&ns->ns_list_node);
>  
> +#ifdef CONFIG_DEBUG_VFS
> +	ns_debug(ns, ops);
> +#endif
> +
>  	if (inum) {
>  		ns->inum = inum;
>  		return 0;
> 
> -- 
> 2.47.3
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR