Merge tag 'namespaces-7.1-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull namespace update from Christian Brauner: "Add two simple helper macros for the namespace infrastructure" * tag 'namespaces-7.1-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: nsproxy: Add FOR_EACH_NS_TYPE() X-macro and CLONE_NS_ALL

Linus Torvalds committed 7 months ago

Commit dc0dfa72 parents fc825e5 935a0493 files · +41 −23Browse files

Unified · Split

3 files

include/linux/ns/ns_common_types.h +34 −10
kernel/fork.c +3 −4
kernel/nsproxy.c +4 −9

include/linux/ns/ns_common_types.h+34−10

@@ -7,6 +7,7 @@ · 6 unmodified lines
7	7	#include <linux/rbtree.h>
8	8	#include <linux/refcount.h>
9	9	#include <linux/types.h>
	10	+#include <uapi/linux/sched.h>
10	11
11	12	struct cgroup_namespace;
12	13	struct dentry;
@@ -184,15 +185,38 @@ struct ns_common { · 171 unmodified lines
184	185	struct user_namespace *: (IS_ENABLED(CONFIG_USER_NS) ? &userns_operations : NULL), \
185	186	struct uts_namespace *: (IS_ENABLED(CONFIG_UTS_NS) ? &utsns_operations : NULL))
186	187
187		−#define ns_common_type(__ns) \
188		− _Generic((__ns), \
189		− struct cgroup_namespace *: CLONE_NEWCGROUP, \
190		− struct ipc_namespace *: CLONE_NEWIPC, \
191		− struct mnt_namespace *: CLONE_NEWNS, \
192		− struct net *: CLONE_NEWNET, \
193		− struct pid_namespace *: CLONE_NEWPID, \
194		− struct time_namespace *: CLONE_NEWTIME, \
195		− struct user_namespace *: CLONE_NEWUSER, \
196		− struct uts_namespace *: CLONE_NEWUTS)
	188	+/*
	189	+ * FOR_EACH_NS_TYPE - Canonical list of namespace types
	190	+ *
	191	+ * Enumerates all (struct type, CLONE_NEW* flag) pairs. This is the
	192	+ * single source of truth used to derive ns_common_type() and
	193	+ * CLONE_NS_ALL. When adding a new namespace type, add a single entry
	194	+ * here; all consumers update automatically.
	195	+ *
	196	+ * @X: Callback macro taking (struct_name, clone_flag) as arguments.
	197	+ */
	198	+#define FOR_EACH_NS_TYPE(X) \
	199	+ X(cgroup_namespace, CLONE_NEWCGROUP) \
	200	+ X(ipc_namespace, CLONE_NEWIPC) \
	201	+ X(mnt_namespace, CLONE_NEWNS) \
	202	+ X(net, CLONE_NEWNET) \
	203	+ X(pid_namespace, CLONE_NEWPID) \
	204	+ X(time_namespace, CLONE_NEWTIME) \
	205	+ X(user_namespace, CLONE_NEWUSER) \
	206	+ X(uts_namespace, CLONE_NEWUTS)
	207	+
	208	+/* Bitmask of all known CLONE_NEW* flags. */
	209	+#define _NS_TYPE_FLAG_OR(struct_name, flag) \| (flag)
	210	+#define CLONE_NS_ALL (0 FOR_EACH_NS_TYPE(_NS_TYPE_FLAG_OR))
	211	+
	212	+/*
	213	+ * ns_common_type - Map a namespace struct pointer to its CLONE_NEW* flag
	214	+ *
	215	+ * Uses a leading-comma pattern so the FOR_EACH_NS_TYPE expansion
	216	+ * produces ", struct foo *: FLAG" entries without a trailing comma.
	217	+ */
	218	+#define _NS_TYPE_ASSOC(struct_name, flag) , struct struct_name *: (flag)
	219	+
	220	+#define ns_common_type(__ns) _Generic((__ns)FOR_EACH_NS_TYPE(_NS_TYPE_ASSOC))
197	221
198	222	#endif /* _LINUX_NS_COMMON_TYPES_H */

kernel/fork.c+3−4

@@ -46,6 +46,7 @@ · 45 unmodified lines
46	46	#include <linux/mm_inline.h>
47	47	#include <linux/memblock.h>
48	48	#include <linux/nsproxy.h>
	49	+#include <linux/ns/ns_common_types.h>
49	50	#include <linux/capability.h>
50	51	#include <linux/cpu.h>
51	52	#include <linux/cgroup.h>
@@ -3045,11 +3046,9 @@ void __init proc_caches_init(void) · 2993 unmodified lines
3045	3046	*/
3046	3047	static int check_unshare_flags(unsigned long unshare_flags)
3047	3048	{
3048		− if (unshare_flags & ~(CLONE_THREAD\|CLONE_FS\|CLONE_NEWNS\|CLONE_SIGHAND\|
	3049	+ if (unshare_flags & ~(CLONE_THREAD\|CLONE_FS\|CLONE_SIGHAND\|
3049	3050	CLONE_VM\|CLONE_FILES\|CLONE_SYSVSEM\|
3050		− CLONE_NEWUTS\|CLONE_NEWIPC\|CLONE_NEWNET\|
3051		− CLONE_NEWUSER\|CLONE_NEWPID\|CLONE_NEWCGROUP\|
3052		− CLONE_NEWTIME))
	3051	+ CLONE_NS_ALL))
3053	3052	return -EINVAL;
3054	3053	/*
3055	3054	* Not implemented, but pretend it works if there is nothing

kernel/nsproxy.c+4−9

@@ -12,6 +12,7 @@ · 11 unmodified lines
12	12	#include <linux/slab.h>
13	13	#include <linux/export.h>
14	14	#include <linux/nsproxy.h>
	15	+#include <linux/ns/ns_common_types.h>
15	16	#include <linux/init_task.h>
16	17	#include <linux/mnt_namespace.h>
17	18	#include <linux/utsname.h>
@@ -170,9 +171,7 @@ int copy_namespaces(u64 flags, struct task_struct *tsk) · 152 unmodified lines
170	171	struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
171	172	struct nsproxy *new_ns;
172	173
173		− if (likely(!(flags & (CLONE_NEWNS \| CLONE_NEWUTS \| CLONE_NEWIPC \|
174		− CLONE_NEWPID \| CLONE_NEWNET \|
175		− CLONE_NEWCGROUP \| CLONE_NEWTIME)))) {
	174	+ if (likely(!(flags & (CLONE_NS_ALL & ~CLONE_NEWUSER)))) {
176	175	if ((flags & CLONE_VM) \|\|
177	176	likely(old_ns->time_ns_for_children == old_ns->time_ns)) {
178	177	get_nsproxy(old_ns);
@@ -214,9 +213,7 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, · 35 unmodified lines
214	213	struct user_namespace *user_ns;
215	214	int err = 0;
216	215
217		− if (!(unshare_flags & (CLONE_NEWNS \| CLONE_NEWUTS \| CLONE_NEWIPC \|
218		− CLONE_NEWNET \| CLONE_NEWPID \| CLONE_NEWCGROUP \|
219		− CLONE_NEWTIME)))
	216	+ if (!(unshare_flags & (CLONE_NS_ALL & ~CLONE_NEWUSER)))
220	217	return 0;
221	218
222	219	user_ns = new_cred ? new_cred->user_ns : current_user_ns();
@@ -292,9 +289,7 @@ int exec_task_namespaces(void) · 69 unmodified lines
292	289
293	290	static int check_setns_flags(unsigned long flags)
294	291	{
295		− if (!flags \|\| (flags & ~(CLONE_NEWNS \| CLONE_NEWUTS \| CLONE_NEWIPC \|
296		− CLONE_NEWNET \| CLONE_NEWTIME \| CLONE_NEWUSER \|
297		− CLONE_NEWPID \| CLONE_NEWCGROUP)))
	292	+ if (!flags \|\| (flags & ~CLONE_NS_ALL))
298	293	return -EINVAL;
299	294
300	295	#ifndef CONFIG_USER_NS