From 3c17001b21b9f168c957ced9384abe969019b609 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:24 +0200 Subject: pidfs: validate extensible ioctls Validate extensible ioctls stricter than we do now. Reviewed-by: Aleksa Sarai Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/fs.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index d7ab4f96d705..2f2edc53bf3c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -4023,4 +4023,18 @@ static inline bool vfs_empty_path(int dfd, const char __user *path) int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter); +static inline bool extensible_ioctl_valid(unsigned int cmd_a, + unsigned int cmd_b, size_t min_size) +{ + if (_IOC_DIR(cmd_a) != _IOC_DIR(cmd_b)) + return false; + if (_IOC_TYPE(cmd_a) != _IOC_TYPE(cmd_b)) + return false; + if (_IOC_NR(cmd_a) != _IOC_NR(cmd_b)) + return false; + if (_IOC_SIZE(cmd_a) < min_size) + return false; + return true; +} + #endif /* _LINUX_FS_H */ -- cgit v1.2.3 From e3e1812f8e25ac277f5cc9249802365300c582e3 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:28 +0200 Subject: ns: move to_ns_common() to ns_common.h Move the helper to ns_common.h where it belongs. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 20 ++++++++++++++++++++ include/linux/nsproxy.h | 11 ----------- 2 files changed, 20 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 7d22ea50b098..bc2e0758e1c9 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -6,6 +6,15 @@ struct proc_ns_operations; +struct cgroup_namespace; +struct ipc_namespace; +struct mnt_namespace; +struct net; +struct pid_namespace; +struct time_namespace; +struct user_namespace; +struct uts_namespace; + struct ns_common { struct dentry *stashed; const struct proc_ns_operations *ops; @@ -13,4 +22,15 @@ struct ns_common { refcount_t count; }; +#define to_ns_common(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: &(__ns)->ns, \ + struct ipc_namespace *: &(__ns)->ns, \ + struct mnt_namespace *: &(__ns)->ns, \ + struct net *: &(__ns)->ns, \ + struct pid_namespace *: &(__ns)->ns, \ + struct time_namespace *: &(__ns)->ns, \ + struct user_namespace *: &(__ns)->ns, \ + struct uts_namespace *: &(__ns)->ns) + #endif diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index dab6a1734a22..e6bec522b139 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h @@ -42,17 +42,6 @@ struct nsproxy { }; extern struct nsproxy init_nsproxy; -#define to_ns_common(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: &(__ns->ns), \ - struct ipc_namespace *: &(__ns->ns), \ - struct net *: &(__ns->ns), \ - struct pid_namespace *: &(__ns->ns), \ - struct mnt_namespace *: &(__ns->ns), \ - struct time_namespace *: &(__ns->ns), \ - struct user_namespace *: &(__ns->ns), \ - struct uts_namespace *: &(__ns->ns)) - /* * A structure to encompass all bits needed to install * a partial or complete new set of namespaces. -- cgit v1.2.3 From 9296f46a9645cf753d2522093485cebe77635aa6 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:29 +0200 Subject: nsfs: add nsfs.h header And move the stuff out from proc_ns.h where it really doesn't belong. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/nsfs.h | 26 ++++++++++++++++++++++++++ include/linux/proc_ns.h | 13 +------------ 2 files changed, 27 insertions(+), 12 deletions(-) create mode 100644 include/linux/nsfs.h (limited to 'include/linux') diff --git a/include/linux/nsfs.h b/include/linux/nsfs.h new file mode 100644 index 000000000000..fb84aa538091 --- /dev/null +++ b/include/linux/nsfs.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2025 Christian Brauner */ + +#ifndef _LINUX_NSFS_H +#define _LINUX_NSFS_H + +#include + +struct path; +struct task_struct; +struct proc_ns_operations; + +int ns_get_path(struct path *path, struct task_struct *task, + const struct proc_ns_operations *ns_ops); +typedef struct ns_common *ns_get_path_helper_t(void *); +int ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb, + void *private_data); + +bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino); + +int ns_get_name(char *buf, size_t size, struct task_struct *task, + const struct proc_ns_operations *ns_ops); +void nsfs_init(void); + +#endif /* _LINUX_NSFS_H */ + diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 4b20375f3783..5e1a4b378b79 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -5,7 +5,7 @@ #ifndef _LINUX_PROC_NS_H #define _LINUX_PROC_NS_H -#include +#include #include struct pid_namespace; @@ -75,16 +75,5 @@ static inline int ns_alloc_inum(struct ns_common *ns) #define ns_free_inum(ns) proc_free_inum((ns)->inum) #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private) -extern int ns_get_path(struct path *path, struct task_struct *task, - const struct proc_ns_operations *ns_ops); -typedef struct ns_common *ns_get_path_helper_t(void *); -extern int ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb, - void *private_data); - -extern bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino); - -extern int ns_get_name(char *buf, size_t size, struct task_struct *task, - const struct proc_ns_operations *ns_ops); -extern void nsfs_init(void); #endif /* _LINUX_PROC_NS_H */ -- cgit v1.2.3 From 660def10b01b248fd97255afacb7b0e305ac833a Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:30 +0200 Subject: ns: uniformly initialize ns_common No point in cargo-culting the same code across all the different types. Use one common initializer. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/proc_ns.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux') diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 5e1a4b378b79..dbb119bda097 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -72,6 +72,22 @@ static inline int ns_alloc_inum(struct ns_common *ns) return proc_alloc_inum(&ns->inum); } +static inline int ns_common_init(struct ns_common *ns, + const struct proc_ns_operations *ops, + bool alloc_inum) +{ + if (alloc_inum) { + int ret; + ret = proc_alloc_inum(&ns->inum); + if (ret) + return ret; + } + refcount_set(&ns->count, 1); + ns->stashed = NULL; + ns->ops = ops; + return 0; +} + #define ns_free_inum(ns) proc_free_inum((ns)->inum) #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private) -- cgit v1.2.3 From 86c5aba210b145d7de011a5abaf9b785aa70a183 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:39 +0200 Subject: ns: remove ns_alloc_inum() It's now unused. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/proc_ns.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index dbb119bda097..e50d312f9fee 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -66,12 +66,6 @@ static inline void proc_free_inum(unsigned int inum) {} #endif /* CONFIG_PROC_FS */ -static inline int ns_alloc_inum(struct ns_common *ns) -{ - WRITE_ONCE(ns->stashed, NULL); - return proc_alloc_inum(&ns->inum); -} - static inline int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, bool alloc_inum) -- cgit v1.2.3 From 885fc8ac0a4dc70f5d87b80b0977292870e35c60 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:40 +0200 Subject: nstree: make iterator generic Move the namespace iteration infrastructure originally introduced for mount namespaces into a generic library usable by all namespace types. Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 9 +++++ include/linux/nstree.h | 91 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/proc_ns.h | 3 ++ 3 files changed, 103 insertions(+) create mode 100644 include/linux/nstree.h (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index bc2e0758e1c9..7224072cccc5 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -3,6 +3,7 @@ #define _LINUX_NS_COMMON_H #include +#include struct proc_ns_operations; @@ -20,6 +21,14 @@ struct ns_common { const struct proc_ns_operations *ops; unsigned int inum; refcount_t count; + union { + struct { + u64 ns_id; + struct rb_node ns_tree_node; + struct list_head ns_list_node; + }; + struct rcu_head ns_rcu; + }; }; #define to_ns_common(__ns) \ diff --git a/include/linux/nstree.h b/include/linux/nstree.h new file mode 100644 index 000000000000..29ad6402260c --- /dev/null +++ b/include/linux/nstree.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_NSTREE_H +#define _LINUX_NSTREE_H + +#include +#include +#include +#include +#include +#include + +/** + * struct ns_tree - Namespace tree + * @ns_tree: Rbtree of namespaces of a particular type + * @ns_list: Sequentially walkable list of all namespaces of this type + * @ns_tree_lock: Seqlock to protect the tree and list + */ +struct ns_tree { + struct rb_root ns_tree; + struct list_head ns_list; + seqlock_t ns_tree_lock; + int type; +}; + +extern struct ns_tree cgroup_ns_tree; +extern struct ns_tree ipc_ns_tree; +extern struct ns_tree mnt_ns_tree; +extern struct ns_tree net_ns_tree; +extern struct ns_tree pid_ns_tree; +extern struct ns_tree time_ns_tree; +extern struct ns_tree user_ns_tree; +extern struct ns_tree uts_ns_tree; + +#define to_ns_tree(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: &(cgroup_ns_tree), \ + struct ipc_namespace *: &(ipc_ns_tree), \ + struct net *: &(net_ns_tree), \ + struct pid_namespace *: &(pid_ns_tree), \ + struct mnt_namespace *: &(mnt_ns_tree), \ + struct time_namespace *: &(time_ns_tree), \ + struct user_namespace *: &(user_ns_tree), \ + struct uts_namespace *: &(uts_ns_tree)) + +u64 ns_tree_gen_id(struct ns_common *ns); +void __ns_tree_add_raw(struct ns_common *ns, struct ns_tree *ns_tree); +void __ns_tree_remove(struct ns_common *ns, struct ns_tree *ns_tree); +struct ns_common *ns_tree_lookup_rcu(u64 ns_id, int ns_type); +struct ns_common *__ns_tree_adjoined_rcu(struct ns_common *ns, + struct ns_tree *ns_tree, + bool previous); + +static inline void __ns_tree_add(struct ns_common *ns, struct ns_tree *ns_tree) +{ + ns_tree_gen_id(ns); + __ns_tree_add_raw(ns, ns_tree); +} + +/** + * ns_tree_add_raw - Add a namespace to a namespace + * @ns: Namespace to add + * + * This function adds a namespace to the appropriate namespace tree + * without assigning a id. + */ +#define ns_tree_add_raw(__ns) __ns_tree_add_raw(to_ns_common(__ns), to_ns_tree(__ns)) + +/** + * ns_tree_add - Add a namespace to a namespace tree + * @ns: Namespace to add + * + * This function assigns a new id to the namespace and adds it to the + * appropriate namespace tree and list. + */ +#define ns_tree_add(__ns) __ns_tree_add(to_ns_common(__ns), to_ns_tree(__ns)) + +/** + * ns_tree_remove - Remove a namespace from a namespace tree + * @ns: Namespace to remove + * + * This function removes a namespace from the appropriate namespace + * tree and list. + */ +#define ns_tree_remove(__ns) __ns_tree_remove(to_ns_common(__ns), to_ns_tree(__ns)) + +#define ns_tree_adjoined_rcu(__ns, __previous) \ + __ns_tree_adjoined_rcu(to_ns_common(__ns), to_ns_tree(__ns), __previous) + +#define ns_tree_active(__ns) (!RB_EMPTY_NODE(&to_ns_common(__ns)->ns_tree_node)) + +#endif /* _LINUX_NSTREE_H */ diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index e50d312f9fee..7f89f0829e60 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -79,6 +79,9 @@ static inline int ns_common_init(struct ns_common *ns, refcount_set(&ns->count, 1); ns->stashed = NULL; ns->ops = ops; + ns->ns_id = 0; + RB_CLEAR_NODE(&ns->ns_tree_node); + INIT_LIST_HEAD(&ns->ns_list_node); return 0; } -- cgit v1.2.3 From b36c823b9a4be5b0c8e38c3fd60cade7d41c216c Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:46 +0200 Subject: time: support ns lookup Support the generic ns lookup infrastructure to support file handles for namespaces. Reviewed-by: Thomas Gleixner Signed-off-by: Christian Brauner --- include/linux/time_namespace.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index bb2c52f4fc94..7f6af7a9771e 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -33,6 +33,7 @@ struct time_namespace { extern struct time_namespace init_time_ns; #ifdef CONFIG_TIME_NS +void __init time_ns_init(void); extern int vdso_join_timens(struct task_struct *task, struct time_namespace *ns); extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns); @@ -108,6 +109,10 @@ static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) } #else +static inline void __init time_ns_init(void) +{ +} + static inline int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) { -- cgit v1.2.3 From d7afdf889561058068ab46fd8f306c70ef29216a Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:49 +0200 Subject: ns: add to__ns() to respective headers Every namespace type has a container_of(ns, , ns) static inline function that is currently not exposed in the header. So we have a bunch of places that open-code it via container_of(). Move it to the headers so we can use it directly. Reviewed-by: Aleksa Sarai Signed-off-by: Christian Brauner --- include/linux/cgroup.h | 5 +++++ include/linux/ipc_namespace.h | 5 +++++ include/linux/pid_namespace.h | 5 +++++ include/linux/time_namespace.h | 4 ++++ include/linux/user_namespace.h | 5 +++++ include/linux/utsname.h | 5 +++++ 6 files changed, 29 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b18fb5fcb38e..9ca25346f7cb 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -794,6 +794,11 @@ extern struct cgroup_namespace init_cgroup_ns; #ifdef CONFIG_CGROUPS +static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) +{ + return container_of(ns, struct cgroup_namespace, ns); +} + void free_cgroup_ns(struct cgroup_namespace *ns); struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h index e8240cf2611a..924e4754374f 100644 --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -129,6 +129,11 @@ static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } #endif #if defined(CONFIG_IPC_NS) +static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns) +{ + return container_of(ns, struct ipc_namespace, ns); +} + extern struct ipc_namespace *copy_ipcs(unsigned long flags, struct user_namespace *user_ns, struct ipc_namespace *ns); diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 7c67a5811199..ba0efc8c8596 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -54,6 +54,11 @@ extern struct pid_namespace init_pid_ns; #define PIDNS_ADDING (1U << 31) #ifdef CONFIG_PID_NS +static inline struct pid_namespace *to_pid_ns(struct ns_common *ns) +{ + return container_of(ns, struct pid_namespace, ns); +} + static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns) { if (ns != &init_pid_ns) diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 7f6af7a9771e..a47a4ce4183e 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -33,6 +33,10 @@ struct time_namespace { extern struct time_namespace init_time_ns; #ifdef CONFIG_TIME_NS +static inline struct time_namespace *to_time_ns(struct ns_common *ns) +{ + return container_of(ns, struct time_namespace, ns); +} void __init time_ns_init(void); extern int vdso_join_timens(struct task_struct *task, struct time_namespace *ns); diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index a0bb6d012137..a09056ad090e 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -168,6 +168,11 @@ static inline void set_userns_rlimit_max(struct user_namespace *ns, #ifdef CONFIG_USER_NS +static inline struct user_namespace *to_user_ns(struct ns_common *ns) +{ + return container_of(ns, struct user_namespace, ns); +} + static inline struct user_namespace *get_user_ns(struct user_namespace *ns) { if (ns) diff --git a/include/linux/utsname.h b/include/linux/utsname.h index bf7613ba412b..5d34c4f0f945 100644 --- a/include/linux/utsname.h +++ b/include/linux/utsname.h @@ -30,6 +30,11 @@ struct uts_namespace { extern struct uts_namespace init_uts_ns; #ifdef CONFIG_UTS_NS +static inline struct uts_namespace *to_uts_ns(struct ns_common *ns) +{ + return container_of(ns, struct uts_namespace, ns); +} + static inline void get_uts_ns(struct uts_namespace *ns) { refcount_inc(&ns->ns.count); -- cgit v1.2.3 From d2afdb73f8ad77b49eca9d110d0c54bf30d1df0f Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:50 +0200 Subject: nsfs: add current_in_namespace() Add a helper to easily check whether a given namespace is the caller's current namespace. This is currently open-coded in a lot of places. Simply switch on the type and compare the results. Reviewed-by: Aleksa Sarai Signed-off-by: Christian Brauner --- include/linux/nsfs.h | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/nsfs.h b/include/linux/nsfs.h index fb84aa538091..e5a5fa83d36b 100644 --- a/include/linux/nsfs.h +++ b/include/linux/nsfs.h @@ -5,6 +5,8 @@ #define _LINUX_NSFS_H #include +#include +#include struct path; struct task_struct; @@ -22,5 +24,17 @@ int ns_get_name(char *buf, size_t size, struct task_struct *task, const struct proc_ns_operations *ns_ops); void nsfs_init(void); -#endif /* _LINUX_NSFS_H */ +#define __current_namespace_from_type(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: current->nsproxy->cgroup_ns, \ + struct ipc_namespace *: current->nsproxy->ipc_ns, \ + struct net *: current->nsproxy->net_ns, \ + struct pid_namespace *: task_active_pid_ns(current), \ + struct mnt_namespace *: current->nsproxy->mnt_ns, \ + struct time_namespace *: current->nsproxy->time_ns, \ + struct user_namespace *: current_user_ns(), \ + struct uts_namespace *: current->nsproxy->uts_ns) + +#define current_in_namespace(__ns) (__current_namespace_from_type(__ns) == __ns) +#endif /* _LINUX_NSFS_H */ -- cgit v1.2.3 From 5222470b2fbb3740f931f189db33dd1367b1ae75 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:51 +0200 Subject: nsfs: support file handles A while ago we added support for file handles to pidfs so pidfds can be encoded and decoded as file handles. Userspace has adopted this quickly and it's proven very useful. Implement file handles for namespaces as well. A process is not always able to open /proc/self/ns/. That requires procfs to be mounted and for /proc/self/ or /proc/self/ns/ to not be overmounted. However, userspace can always derive a namespace fd from a pidfd. And that always works for a task's own namespace. There's no need to introduce unnecessary behavioral differences between /proc/self/ns/ fds, pidfd-derived namespace fds, and file-handle-derived namespace fds. So namespace file handles are always decodable if the caller is located in the namespace the file handle refers to. This also allows a task to e.g., store a set of file handles to its namespaces in a file on-disk so it can verify when it gets rexeced that they're still valid and so on. This is akin to the pidfd use-case. Or just plainly for namespace comparison reasons where a file handle to the task's own namespace can be easily compared against others. Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner --- include/linux/exportfs.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index cfb0dd1ea49c..3aac58a520c7 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -122,6 +122,12 @@ enum fid_type { FILEID_BCACHEFS_WITHOUT_PARENT = 0xb1, FILEID_BCACHEFS_WITH_PARENT = 0xb2, + /* + * + * 64 bit namespace identifier, 32 bit namespace type, 32 bit inode number. + */ + FILEID_NSFS = 0xf1, + /* * 64 bit unique kernfs id */ -- cgit v1.2.3 From 93f67a7ddadf6ed8997c000df9790e5d64617196 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 17 Sep 2025 12:28:00 +0200 Subject: uts: split namespace into separate header We have dedicated headers for all namespace types. Add one for the uts namespace as well. Now it's consistent for all namespace types. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/uts_namespace.h | 65 +++++++++++++++++++++++++++++++++++++++++++ include/linux/utsname.h | 58 +------------------------------------- 2 files changed, 66 insertions(+), 57 deletions(-) create mode 100644 include/linux/uts_namespace.h (limited to 'include/linux') diff --git a/include/linux/uts_namespace.h b/include/linux/uts_namespace.h new file mode 100644 index 000000000000..c2b619bb4e57 --- /dev/null +++ b/include/linux/uts_namespace.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_UTS_NAMESPACE_H +#define _LINUX_UTS_NAMESPACE_H + +#include +#include + +struct user_namespace; +extern struct user_namespace init_user_ns; + +struct uts_namespace { + struct new_utsname name; + struct user_namespace *user_ns; + struct ucounts *ucounts; + struct ns_common ns; +} __randomize_layout; + +extern struct uts_namespace init_uts_ns; + +#ifdef CONFIG_UTS_NS +static inline struct uts_namespace *to_uts_ns(struct ns_common *ns) +{ + return container_of(ns, struct uts_namespace, ns); +} + +static inline void get_uts_ns(struct uts_namespace *ns) +{ + refcount_inc(&ns->ns.count); +} + +extern struct uts_namespace *copy_utsname(unsigned long flags, + struct user_namespace *user_ns, struct uts_namespace *old_ns); +extern void free_uts_ns(struct uts_namespace *ns); + +static inline void put_uts_ns(struct uts_namespace *ns) +{ + if (refcount_dec_and_test(&ns->ns.count)) + free_uts_ns(ns); +} + +void uts_ns_init(void); +#else +static inline void get_uts_ns(struct uts_namespace *ns) +{ +} + +static inline void put_uts_ns(struct uts_namespace *ns) +{ +} + +static inline struct uts_namespace *copy_utsname(unsigned long flags, + struct user_namespace *user_ns, struct uts_namespace *old_ns) +{ + if (flags & CLONE_NEWUTS) + return ERR_PTR(-EINVAL); + + return old_ns; +} + +static inline void uts_ns_init(void) +{ +} +#endif + +#endif /* _LINUX_UTS_NAMESPACE_H */ diff --git a/include/linux/utsname.h b/include/linux/utsname.h index 5d34c4f0f945..547bd4439706 100644 --- a/include/linux/utsname.h +++ b/include/linux/utsname.h @@ -7,7 +7,7 @@ #include #include #include -#include +#include enum uts_proc { UTS_PROC_ARCH, @@ -18,62 +18,6 @@ enum uts_proc { UTS_PROC_DOMAINNAME, }; -struct user_namespace; -extern struct user_namespace init_user_ns; - -struct uts_namespace { - struct new_utsname name; - struct user_namespace *user_ns; - struct ucounts *ucounts; - struct ns_common ns; -} __randomize_layout; -extern struct uts_namespace init_uts_ns; - -#ifdef CONFIG_UTS_NS -static inline struct uts_namespace *to_uts_ns(struct ns_common *ns) -{ - return container_of(ns, struct uts_namespace, ns); -} - -static inline void get_uts_ns(struct uts_namespace *ns) -{ - refcount_inc(&ns->ns.count); -} - -extern struct uts_namespace *copy_utsname(unsigned long flags, - struct user_namespace *user_ns, struct uts_namespace *old_ns); -extern void free_uts_ns(struct uts_namespace *ns); - -static inline void put_uts_ns(struct uts_namespace *ns) -{ - if (refcount_dec_and_test(&ns->ns.count)) - free_uts_ns(ns); -} - -void uts_ns_init(void); -#else -static inline void get_uts_ns(struct uts_namespace *ns) -{ -} - -static inline void put_uts_ns(struct uts_namespace *ns) -{ -} - -static inline struct uts_namespace *copy_utsname(unsigned long flags, - struct user_namespace *user_ns, struct uts_namespace *old_ns) -{ - if (flags & CLONE_NEWUTS) - return ERR_PTR(-EINVAL); - - return old_ns; -} - -static inline void uts_ns_init(void) -{ -} -#endif - #ifdef CONFIG_PROC_SYSCTL extern void uts_proc_notify(enum uts_proc proc); #else -- cgit v1.2.3 From b2a0b192084acd0a86d66cbbc61e17ba1f5bd583 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 17 Sep 2025 12:28:01 +0200 Subject: mnt: expose pointer to init_mnt_ns There's various scenarios where we need to know whether we are in the initial set of namespaces or not to e.g., shortcut permission checking. All namespaces expose that information. Let's do that too. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/mnt_namespace.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h index 70b366b64816..6d1c4c218c14 100644 --- a/include/linux/mnt_namespace.h +++ b/include/linux/mnt_namespace.h @@ -11,6 +11,8 @@ struct fs_struct; struct user_namespace; struct ns_common; +extern struct mnt_namespace init_mnt_ns; + extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *, struct user_namespace *, struct fs_struct *); extern void put_mnt_ns(struct mnt_namespace *ns); -- cgit v1.2.3 From f74ca6da113d5d4b21c00bb4da3f3c137162b4fe Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 17 Sep 2025 12:28:02 +0200 Subject: nscommon: move to separate file It's really awkward spilling the ns common infrastructure into multiple headers. Move it to a separate file. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 3 +++ include/linux/proc_ns.h | 19 ------------------- 2 files changed, 3 insertions(+), 19 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 7224072cccc5..78b17fe80b62 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -31,6 +31,9 @@ struct ns_common { }; }; +int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, + bool alloc_inum); + #define to_ns_common(__ns) \ _Generic((__ns), \ struct cgroup_namespace *: &(__ns)->ns, \ diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 7f89f0829e60..9f21670b5824 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -66,25 +66,6 @@ static inline void proc_free_inum(unsigned int inum) {} #endif /* CONFIG_PROC_FS */ -static inline int ns_common_init(struct ns_common *ns, - const struct proc_ns_operations *ops, - bool alloc_inum) -{ - if (alloc_inum) { - int ret; - ret = proc_alloc_inum(&ns->inum); - if (ret) - return ret; - } - refcount_set(&ns->count, 1); - ns->stashed = NULL; - ns->ops = ops; - ns->ns_id = 0; - RB_CLEAR_NODE(&ns->ns_tree_node); - INIT_LIST_HEAD(&ns->ns_list_node); - return 0; -} - #define ns_free_inum(ns) proc_free_inum((ns)->inum) #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private) -- cgit v1.2.3 From 5fc6bef178f1b644f1439e520c8f83bfc83a1252 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 17 Sep 2025 12:28:03 +0200 Subject: cgroup: split namespace into separate header We have dedicated headers for all namespace types. Add one for the cgroup namespace as well. Now it's consistent for all namespace types and easy to figure out what to include. Acked-by: Tejun Heo Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/cgroup.h | 51 +----------------------------------- include/linux/cgroup_namespace.h | 56 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 57 insertions(+), 50 deletions(-) create mode 100644 include/linux/cgroup_namespace.h (limited to 'include/linux') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 9ca25346f7cb..5156fed8cbc3 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -27,6 +27,7 @@ #include #include +#include struct kernel_clone_args; @@ -783,56 +784,6 @@ static inline void cgroup_sk_free(struct sock_cgroup_data *skcd) {} #endif /* CONFIG_CGROUP_DATA */ -struct cgroup_namespace { - struct ns_common ns; - struct user_namespace *user_ns; - struct ucounts *ucounts; - struct css_set *root_cset; -}; - -extern struct cgroup_namespace init_cgroup_ns; - -#ifdef CONFIG_CGROUPS - -static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) -{ - return container_of(ns, struct cgroup_namespace, ns); -} - -void free_cgroup_ns(struct cgroup_namespace *ns); - -struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, - struct user_namespace *user_ns, - struct cgroup_namespace *old_ns); - -int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, - struct cgroup_namespace *ns); - -static inline void get_cgroup_ns(struct cgroup_namespace *ns) -{ - refcount_inc(&ns->ns.count); -} - -static inline void put_cgroup_ns(struct cgroup_namespace *ns) -{ - if (refcount_dec_and_test(&ns->ns.count)) - free_cgroup_ns(ns); -} - -#else /* !CONFIG_CGROUPS */ - -static inline void free_cgroup_ns(struct cgroup_namespace *ns) { } -static inline struct cgroup_namespace * -copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, - struct cgroup_namespace *old_ns) -{ - return old_ns; -} - -static inline void get_cgroup_ns(struct cgroup_namespace *ns) { } -static inline void put_cgroup_ns(struct cgroup_namespace *ns) { } - -#endif /* !CONFIG_CGROUPS */ #ifdef CONFIG_CGROUPS diff --git a/include/linux/cgroup_namespace.h b/include/linux/cgroup_namespace.h new file mode 100644 index 000000000000..c02bb76c5e32 --- /dev/null +++ b/include/linux/cgroup_namespace.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_CGROUP_NAMESPACE_H +#define _LINUX_CGROUP_NAMESPACE_H + +struct cgroup_namespace { + struct ns_common ns; + struct user_namespace *user_ns; + struct ucounts *ucounts; + struct css_set *root_cset; +}; + +extern struct cgroup_namespace init_cgroup_ns; + +#ifdef CONFIG_CGROUPS + +static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) +{ + return container_of(ns, struct cgroup_namespace, ns); +} + +void free_cgroup_ns(struct cgroup_namespace *ns); + +struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, + struct user_namespace *user_ns, + struct cgroup_namespace *old_ns); + +int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, + struct cgroup_namespace *ns); + +static inline void get_cgroup_ns(struct cgroup_namespace *ns) +{ + refcount_inc(&ns->ns.count); +} + +static inline void put_cgroup_ns(struct cgroup_namespace *ns) +{ + if (refcount_dec_and_test(&ns->ns.count)) + free_cgroup_ns(ns); +} + +#else /* !CONFIG_CGROUPS */ + +static inline void free_cgroup_ns(struct cgroup_namespace *ns) { } +static inline struct cgroup_namespace * +copy_cgroup_ns(unsigned long flags, struct user_namespace *user_ns, + struct cgroup_namespace *old_ns) +{ + return old_ns; +} + +static inline void get_cgroup_ns(struct cgroup_namespace *ns) { } +static inline void put_cgroup_ns(struct cgroup_namespace *ns) { } + +#endif /* !CONFIG_CGROUPS */ + +#endif /* _LINUX_CGROUP_NAMESPACE_H */ -- cgit v1.2.3 From 5612ff3ec588be09f11a9424db6d1186bcdeb3fa Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 17 Sep 2025 12:28:07 +0200 Subject: nscommon: simplify initialization There's a lot of information that namespace implementers don't need to know about at all. Encapsulate this all in the initialization helper. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 78b17fe80b62..05c7a7dd211b 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -16,6 +16,15 @@ struct time_namespace; struct user_namespace; struct uts_namespace; +extern struct cgroup_namespace init_cgroup_ns; +extern struct ipc_namespace init_ipc_ns; +extern struct mnt_namespace init_mnt_ns; +extern struct net init_net; +extern struct pid_namespace init_pid_ns; +extern struct time_namespace init_time_ns; +extern struct user_namespace init_user_ns; +extern struct uts_namespace init_uts_ns; + struct ns_common { struct dentry *stashed; const struct proc_ns_operations *ops; @@ -31,8 +40,7 @@ struct ns_common { }; }; -int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, - bool alloc_inum); +int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum); #define to_ns_common(__ns) \ _Generic((__ns), \ @@ -45,4 +53,31 @@ int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, struct user_namespace *: &(__ns)->ns, \ struct uts_namespace *: &(__ns)->ns) +#define ns_init_inum(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: CGROUP_NS_INIT_INO, \ + struct ipc_namespace *: IPC_NS_INIT_INO, \ + struct mnt_namespace *: MNT_NS_INIT_INO, \ + struct net *: NET_NS_INIT_INO, \ + struct pid_namespace *: PID_NS_INIT_INO, \ + struct time_namespace *: TIME_NS_INIT_INO, \ + struct user_namespace *: USER_NS_INIT_INO, \ + struct uts_namespace *: UTS_NS_INIT_INO) + +#define ns_init_ns(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: &init_cgroup_ns, \ + struct ipc_namespace *: &init_ipc_ns, \ + struct mnt_namespace *: &init_mnt_ns, \ + struct net *: &init_net, \ + struct pid_namespace *: &init_pid_ns, \ + struct time_namespace *: &init_time_ns, \ + struct user_namespace *: &init_user_ns, \ + struct uts_namespace *: &init_uts_ns) + +#define ns_common_init(__ns, __ops) \ + __ns_common_init(to_ns_common(__ns), __ops, (((__ns) == ns_init_ns(__ns)) ? ns_init_inum(__ns) : 0)) + +#define ns_common_init_inum(__ns, __ops, __inum) __ns_common_init(to_ns_common(__ns), __ops, __inum) + #endif -- cgit v1.2.3 From be5f21d3985f00827e09b798f7a07ebd6dd7f54a Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 17 Sep 2025 12:28:08 +0200 Subject: ns: add ns_common_free() And drop ns_free_inum(). Anything common that can be wasted centrally should be wasted in the new common helper. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 3 +++ include/linux/proc_ns.h | 2 -- 2 files changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 05c7a7dd211b..19833ac547f9 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -41,6 +41,7 @@ struct ns_common { }; int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum); +void __ns_common_free(struct ns_common *ns); #define to_ns_common(__ns) \ _Generic((__ns), \ @@ -80,4 +81,6 @@ int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, #define ns_common_init_inum(__ns, __ops, __inum) __ns_common_init(to_ns_common(__ns), __ops, __inum) +#define ns_common_free(__ns) __ns_common_free(to_ns_common((__ns))) + #endif diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 9f21670b5824..08016f6e0e6f 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -66,8 +66,6 @@ static inline void proc_free_inum(unsigned int inum) {} #endif /* CONFIG_PROC_FS */ -#define ns_free_inum(ns) proc_free_inum((ns)->inum) - #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private) #endif /* _LINUX_PROC_NS_H */ -- cgit v1.2.3 From 224ef741ce87aa6474b82e0eb76e0e8e1bafe544 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:46 +0200 Subject: ns: add reference count helpers Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 45 +++++++++++++++++++++++++++++++++++---------- 1 file changed, 35 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 19833ac547f9..65e258e1fdc6 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -43,16 +43,24 @@ struct ns_common { int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum); void __ns_common_free(struct ns_common *ns); -#define to_ns_common(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: &(__ns)->ns, \ - struct ipc_namespace *: &(__ns)->ns, \ - struct mnt_namespace *: &(__ns)->ns, \ - struct net *: &(__ns)->ns, \ - struct pid_namespace *: &(__ns)->ns, \ - struct time_namespace *: &(__ns)->ns, \ - struct user_namespace *: &(__ns)->ns, \ - struct uts_namespace *: &(__ns)->ns) +#define to_ns_common(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: &(__ns)->ns, \ + const struct cgroup_namespace *: &(__ns)->ns, \ + struct ipc_namespace *: &(__ns)->ns, \ + const struct ipc_namespace *: &(__ns)->ns, \ + struct mnt_namespace *: &(__ns)->ns, \ + const struct mnt_namespace *: &(__ns)->ns, \ + struct net *: &(__ns)->ns, \ + const struct net *: &(__ns)->ns, \ + struct pid_namespace *: &(__ns)->ns, \ + const struct pid_namespace *: &(__ns)->ns, \ + struct time_namespace *: &(__ns)->ns, \ + const struct time_namespace *: &(__ns)->ns, \ + struct user_namespace *: &(__ns)->ns, \ + const struct user_namespace *: &(__ns)->ns, \ + struct uts_namespace *: &(__ns)->ns, \ + const struct uts_namespace *: &(__ns)->ns) #define ns_init_inum(__ns) \ _Generic((__ns), \ @@ -83,4 +91,21 @@ void __ns_common_free(struct ns_common *ns); #define ns_common_free(__ns) __ns_common_free(to_ns_common((__ns))) +static __always_inline __must_check bool __ns_ref_put(struct ns_common *ns) +{ + return refcount_dec_and_test(&ns->count); +} + +static __always_inline __must_check bool __ns_ref_get(struct ns_common *ns) +{ + return refcount_inc_not_zero(&ns->count); +} + +#define ns_ref_read(__ns) refcount_read(&to_ns_common((__ns))->count) +#define ns_ref_inc(__ns) refcount_inc(&to_ns_common((__ns))->count) +#define ns_ref_get(__ns) __ns_ref_get(to_ns_common((__ns))) +#define ns_ref_put(__ns) __ns_ref_put(to_ns_common((__ns))) +#define ns_ref_put_and_lock(__ns, __lock) \ + refcount_dec_and_lock(&to_ns_common((__ns))->count, (__lock)) + #endif -- cgit v1.2.3 From 06099e374f3ab818f0501671b21493ba2e1b94b9 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:48 +0200 Subject: cgroup: port to ns_ref_*() helpers Stop accessing ns.count directly. Acked-by: Tejun Heo Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/cgroup_namespace.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/cgroup_namespace.h b/include/linux/cgroup_namespace.h index c02bb76c5e32..b7dbf4d623d2 100644 --- a/include/linux/cgroup_namespace.h +++ b/include/linux/cgroup_namespace.h @@ -29,12 +29,12 @@ int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, static inline void get_cgroup_ns(struct cgroup_namespace *ns) { - refcount_inc(&ns->ns.count); + ns_ref_inc(ns); } static inline void put_cgroup_ns(struct cgroup_namespace *ns) { - if (refcount_dec_and_test(&ns->ns.count)) + if (ns_ref_put(ns)) free_cgroup_ns(ns); } -- cgit v1.2.3 From d4825c99d6a738c565d5142ce37369368a4352da Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:49 +0200 Subject: ipc: port to ns_ref_*() helpers Stop accessing ns.count directly. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ipc_namespace.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h index 924e4754374f..21eff63f47da 100644 --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -140,14 +140,14 @@ extern struct ipc_namespace *copy_ipcs(unsigned long flags, static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) { if (ns) - refcount_inc(&ns->ns.count); + ns_ref_inc(ns); return ns; } static inline struct ipc_namespace *get_ipc_ns_not_zero(struct ipc_namespace *ns) { if (ns) { - if (refcount_inc_not_zero(&ns->ns.count)) + if (ns_ref_get(ns)) return ns; } -- cgit v1.2.3 From 07897b38eadf5a370a6001790239f23036d5b970 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:50 +0200 Subject: pid: port to ns_ref_*() helpers Stop accessing ns.count directly. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/pid_namespace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index ba0efc8c8596..5b2f29d369c4 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -62,7 +62,7 @@ static inline struct pid_namespace *to_pid_ns(struct ns_common *ns) static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns) { if (ns != &init_pid_ns) - refcount_inc(&ns->ns.count); + ns_ref_inc(ns); return ns; } -- cgit v1.2.3 From e0c173f1fa02c0b08720aa8aa0cc91c3063146ae Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:51 +0200 Subject: time: port to ns_ref_*() helpers Stop accessing ns.count directly. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/time_namespace.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index a47a4ce4183e..f3b9567cf1f4 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -44,7 +44,7 @@ extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns); static inline struct time_namespace *get_time_ns(struct time_namespace *ns) { - refcount_inc(&ns->ns.count); + ns_ref_inc(ns); return ns; } @@ -57,7 +57,7 @@ struct page *find_timens_vvar_page(struct vm_area_struct *vma); static inline void put_time_ns(struct time_namespace *ns) { - if (refcount_dec_and_test(&ns->ns.count)) + if (ns_ref_put(ns)) free_time_ns(ns); } -- cgit v1.2.3 From 96d997ea5ad1911cc393ffdb5c928b532f2f921a Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:52 +0200 Subject: user: port to ns_ref_*() helpers Stop accessing ns.count directly. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/user_namespace.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index a09056ad090e..9a9aebbf96b9 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -176,7 +176,7 @@ static inline struct user_namespace *to_user_ns(struct ns_common *ns) static inline struct user_namespace *get_user_ns(struct user_namespace *ns) { if (ns) - refcount_inc(&ns->ns.count); + ns_ref_inc(ns); return ns; } @@ -186,7 +186,7 @@ extern void __put_user_ns(struct user_namespace *ns); static inline void put_user_ns(struct user_namespace *ns) { - if (ns && refcount_dec_and_test(&ns->ns.count)) + if (ns && ns_ref_put(ns)) __put_user_ns(ns); } -- cgit v1.2.3 From 2438b7d63ad866d6b2bb7b8d3455a6365d9b0fbe Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:56 +0200 Subject: uts: port to ns_ref_*() helpers Stop accessing ns.count directly. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/uts_namespace.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uts_namespace.h b/include/linux/uts_namespace.h index c2b619bb4e57..23b4f0e1b338 100644 --- a/include/linux/uts_namespace.h +++ b/include/linux/uts_namespace.h @@ -25,7 +25,7 @@ static inline struct uts_namespace *to_uts_ns(struct ns_common *ns) static inline void get_uts_ns(struct uts_namespace *ns) { - refcount_inc(&ns->ns.count); + ns_ref_inc(ns); } extern struct uts_namespace *copy_utsname(unsigned long flags, @@ -34,7 +34,7 @@ extern void free_uts_ns(struct uts_namespace *ns); static inline void put_uts_ns(struct uts_namespace *ns) { - if (refcount_dec_and_test(&ns->ns.count)) + if (ns_ref_put(ns)) free_uts_ns(ns); } -- cgit v1.2.3 From 024596a4e2802e457a9f92af79f246fa9631f8de Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 18 Sep 2025 12:11:59 +0200 Subject: ns: rename to __ns_ref Make it easier to grep and rename to ns_count. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 65e258e1fdc6..aea8528d799a 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -29,7 +29,7 @@ struct ns_common { struct dentry *stashed; const struct proc_ns_operations *ops; unsigned int inum; - refcount_t count; + refcount_t __ns_ref; /* do not use directly */ union { struct { u64 ns_id; @@ -93,19 +93,19 @@ void __ns_common_free(struct ns_common *ns); static __always_inline __must_check bool __ns_ref_put(struct ns_common *ns) { - return refcount_dec_and_test(&ns->count); + return refcount_dec_and_test(&ns->__ns_ref); } static __always_inline __must_check bool __ns_ref_get(struct ns_common *ns) { - return refcount_inc_not_zero(&ns->count); + return refcount_inc_not_zero(&ns->__ns_ref); } -#define ns_ref_read(__ns) refcount_read(&to_ns_common((__ns))->count) -#define ns_ref_inc(__ns) refcount_inc(&to_ns_common((__ns))->count) +#define ns_ref_read(__ns) refcount_read(&to_ns_common((__ns))->__ns_ref) +#define ns_ref_inc(__ns) refcount_inc(&to_ns_common((__ns))->__ns_ref) #define ns_ref_get(__ns) __ns_ref_get(to_ns_common((__ns))) #define ns_ref_put(__ns) __ns_ref_put(to_ns_common((__ns))) #define ns_ref_put_and_lock(__ns, __lock) \ - refcount_dec_and_lock(&to_ns_common((__ns))->count, (__lock)) + refcount_dec_and_lock(&to_ns_common((__ns))->__ns_ref, (__lock)) #endif -- cgit v1.2.3 From 8535bd38b4d58a3d19bf8e7dfa66e1d8180b316a Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 22 Sep 2025 14:42:35 +0200 Subject: cgroup: add missing ns_common include Add the missing include of the ns_common header. Acked-by: Tejun Heo Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/cgroup_namespace.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cgroup_namespace.h b/include/linux/cgroup_namespace.h index b7dbf4d623d2..81ccbdee425b 100644 --- a/include/linux/cgroup_namespace.h +++ b/include/linux/cgroup_namespace.h @@ -2,6 +2,8 @@ #ifndef _LINUX_CGROUP_NAMESPACE_H #define _LINUX_CGROUP_NAMESPACE_H +#include + struct cgroup_namespace { struct ns_common ns; struct user_namespace *user_ns; -- cgit v1.2.3 From d7610cb7454bbd8bf6d58f71b0ed57155d3c545f Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 22 Sep 2025 14:42:36 +0200 Subject: ns: simplify ns_common_init() further Simply derive the ns operations from the namespace type. Acked-by: Thomas Gleixner Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index aea8528d799a..56492cd9ff8d 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -25,6 +25,17 @@ extern struct time_namespace init_time_ns; extern struct user_namespace init_user_ns; extern struct uts_namespace init_uts_ns; +extern const struct proc_ns_operations netns_operations; +extern const struct proc_ns_operations utsns_operations; +extern const struct proc_ns_operations ipcns_operations; +extern const struct proc_ns_operations pidns_operations; +extern const struct proc_ns_operations pidns_for_children_operations; +extern const struct proc_ns_operations userns_operations; +extern const struct proc_ns_operations mntns_operations; +extern const struct proc_ns_operations cgroupns_operations; +extern const struct proc_ns_operations timens_operations; +extern const struct proc_ns_operations timens_for_children_operations; + struct ns_common { struct dentry *stashed; const struct proc_ns_operations *ops; @@ -84,10 +95,21 @@ void __ns_common_free(struct ns_common *ns); struct user_namespace *: &init_user_ns, \ struct uts_namespace *: &init_uts_ns) -#define ns_common_init(__ns, __ops) \ - __ns_common_init(to_ns_common(__ns), __ops, (((__ns) == ns_init_ns(__ns)) ? ns_init_inum(__ns) : 0)) - -#define ns_common_init_inum(__ns, __ops, __inum) __ns_common_init(to_ns_common(__ns), __ops, __inum) +#define to_ns_operations(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: (IS_ENABLED(CONFIG_CGROUPS) ? &cgroupns_operations : NULL), \ + struct ipc_namespace *: (IS_ENABLED(CONFIG_IPC_NS) ? &ipcns_operations : NULL), \ + struct mnt_namespace *: &mntns_operations, \ + struct net *: (IS_ENABLED(CONFIG_NET_NS) ? &netns_operations : NULL), \ + struct pid_namespace *: (IS_ENABLED(CONFIG_PID_NS) ? &pidns_operations : NULL), \ + struct time_namespace *: (IS_ENABLED(CONFIG_TIME_NS) ? &timens_operations : NULL), \ + struct user_namespace *: (IS_ENABLED(CONFIG_USER_NS) ? &userns_operations : NULL), \ + struct uts_namespace *: (IS_ENABLED(CONFIG_UTS_NS) ? &utsns_operations : NULL)) + +#define ns_common_init(__ns) \ + __ns_common_init(to_ns_common(__ns), to_ns_operations(__ns), (((__ns) == ns_init_ns(__ns)) ? ns_init_inum(__ns) : 0)) + +#define ns_common_init_inum(__ns, __inum) __ns_common_init(to_ns_common(__ns), to_ns_operations(__ns), __inum) #define ns_common_free(__ns) __ns_common_free(to_ns_common((__ns))) -- cgit v1.2.3 From 10cdfcd37ade7ce736bc4a1927680f390a6b1f7b Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 24 Sep 2025 13:33:58 +0200 Subject: nstree: make struct ns_tree private Don't expose it directly. There's no need to do that. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/nstree.h | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'include/linux') diff --git a/include/linux/nstree.h b/include/linux/nstree.h index 29ad6402260c..8b8636690473 100644 --- a/include/linux/nstree.h +++ b/include/linux/nstree.h @@ -9,19 +9,6 @@ #include #include -/** - * struct ns_tree - Namespace tree - * @ns_tree: Rbtree of namespaces of a particular type - * @ns_list: Sequentially walkable list of all namespaces of this type - * @ns_tree_lock: Seqlock to protect the tree and list - */ -struct ns_tree { - struct rb_root ns_tree; - struct list_head ns_list; - seqlock_t ns_tree_lock; - int type; -}; - extern struct ns_tree cgroup_ns_tree; extern struct ns_tree ipc_ns_tree; extern struct ns_tree mnt_ns_tree; -- cgit v1.2.3 From 4055526d35746ce8b04bfa5e14e14f28bb163186 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 24 Sep 2025 13:33:59 +0200 Subject: ns: move ns type into struct ns_common It's misplaced in struct proc_ns_operations and ns->ops might be NULL if the namespace is compiled out but we still want to know the type of the namespace for the initial namespace struct. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 30 +++++++++++++++++++++++++----- include/linux/proc_ns.h | 1 - 2 files changed, 25 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 56492cd9ff8d..f5b68b8abb54 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -4,6 +4,7 @@ #include #include +#include struct proc_ns_operations; @@ -37,6 +38,7 @@ extern const struct proc_ns_operations timens_operations; extern const struct proc_ns_operations timens_for_children_operations; struct ns_common { + u32 ns_type; struct dentry *stashed; const struct proc_ns_operations *ops; unsigned int inum; @@ -51,7 +53,7 @@ struct ns_common { }; }; -int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum); +int __ns_common_init(struct ns_common *ns, u32 ns_type, const struct proc_ns_operations *ops, int inum); void __ns_common_free(struct ns_common *ns); #define to_ns_common(__ns) \ @@ -106,10 +108,28 @@ void __ns_common_free(struct ns_common *ns); struct user_namespace *: (IS_ENABLED(CONFIG_USER_NS) ? &userns_operations : NULL), \ struct uts_namespace *: (IS_ENABLED(CONFIG_UTS_NS) ? &utsns_operations : NULL)) -#define ns_common_init(__ns) \ - __ns_common_init(to_ns_common(__ns), to_ns_operations(__ns), (((__ns) == ns_init_ns(__ns)) ? ns_init_inum(__ns) : 0)) - -#define ns_common_init_inum(__ns, __inum) __ns_common_init(to_ns_common(__ns), to_ns_operations(__ns), __inum) +#define ns_common_type(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: CLONE_NEWCGROUP, \ + struct ipc_namespace *: CLONE_NEWIPC, \ + struct mnt_namespace *: CLONE_NEWNS, \ + struct net *: CLONE_NEWNET, \ + struct pid_namespace *: CLONE_NEWPID, \ + struct time_namespace *: CLONE_NEWTIME, \ + struct user_namespace *: CLONE_NEWUSER, \ + struct uts_namespace *: CLONE_NEWUTS) + +#define ns_common_init(__ns) \ + __ns_common_init(to_ns_common(__ns), \ + ns_common_type(__ns), \ + to_ns_operations(__ns), \ + (((__ns) == ns_init_ns(__ns)) ? ns_init_inum(__ns) : 0)) + +#define ns_common_init_inum(__ns, __inum) \ + __ns_common_init(to_ns_common(__ns), \ + ns_common_type(__ns), \ + to_ns_operations(__ns), \ + __inum) #define ns_common_free(__ns) __ns_common_free(to_ns_common((__ns))) diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 08016f6e0e6f..e81b8e596e4f 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -17,7 +17,6 @@ struct inode; struct proc_ns_operations { const char *name; const char *real_ns_name; - int type; struct ns_common *(*get)(struct task_struct *task); void (*put)(struct ns_common *ns); int (*install)(struct nsset *nsset, struct ns_common *ns); -- cgit v1.2.3