Merge tag 'timers-vdso-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull vdso updates from Thomas Gleixner:

 - Make the handling of compat functions consistent and more robust

 - Rework the underlying data store so that it is dynamically allocated,
   which allows the conversion of the last holdout SPARC64 to the
   generic VDSO implementation

 - Rework the SPARC64 VDSO to utilize the generic implementation

 - Mop up the left overs of the non-generic VDSO support in the core
   code

 - Expand the VDSO selftest and make them more robust

 - Allow time namespaces to be enabled independently of the generic VDSO
   support, which was not possible before due to SPARC64 not using it

 - Various cleanups and improvements in the related code

* tag 'timers-vdso-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
  timens: Use task_lock guard in timens_get*()
  timens: Use mutex guard in proc_timens_set_offset()
  timens: Simplify some calls to put_time_ns()
  timens: Add a __free() wrapper for put_time_ns()
  timens: Remove dependency on the vDSO
  vdso/timens: Move functions to new file
  selftests: vDSO: vdso_test_correctness: Add a test for time()
  selftests: vDSO: vdso_test_correctness: Use facilities from parse_vdso.c
  selftests: vDSO: vdso_test_correctness: Handle different tv_usec types
  selftests: vDSO: vdso_test_correctness: Drop SYS_getcpu fallbacks
  selftests: vDSO: vdso_test_gettimeofday: Remove nolibc checks
  Revert "selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers"
  random: vDSO: Remove ifdeffery
  random: vDSO: Trim vDSO includes
  vdso/datapage: Trim down unnecessary includes
  vdso/datapage: Remove inclusion of gettimeofday.h
  vdso/helpers: Explicitly include vdso/processor.h
  vdso/gettimeofday: Add explicit includes
  random: vDSO: Add explicit includes
  MIPS: vdso: Explicitly include asm/vdso/vdso.h
  ...

5 files changed, 225 insertions, 171 deletions

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 6a11964377e6..02aac7c5aa76 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -9,10 +9,6 @@
 config CLOCKSOURCE_WATCHDOG
 	bool
 
-# Architecture has extra clocksource data
-config ARCH_CLOCKSOURCE_DATA
-	bool
-
 # Architecture has extra clocksource init called from registration
 config ARCH_CLOCKSOURCE_INIT
 	bool
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index f7d52d9543cc..eaf290c972f9 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -30,5 +30,6 @@ obj-$(CONFIG_GENERIC_GETTIMEOFDAY)		+= vsyscall.o
 obj-$(CONFIG_DEBUG_FS)				+= timekeeping_debug.o
 obj-$(CONFIG_TEST_UDELAY)			+= test_udelay.o
 obj-$(CONFIG_TIME_NS)				+= namespace.o
+obj-$(CONFIG_TIME_NS_VDSO)			+= namespace_vdso.o
 obj-$(CONFIG_TEST_CLOCKSOURCE_WATCHDOG)		+= clocksource-wdtest.o
 obj-$(CONFIG_TIME_KUNIT_TEST)			+= time_test.o
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
index 652744e00eb4..4bca3f78c8ea 100644
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -18,8 +18,9 @@
 #include <linux/cred.h>
 #include <linux/err.h>
 #include <linux/mm.h>
+#include <linux/cleanup.h>
 
-#include <vdso/datapage.h>
+#include "namespace_internal.h"
 
 ktime_t do_timens_ktime_to_host(clockid_t clockid, ktime_t tim,
 				struct timens_offsets *ns_offsets)
@@ -93,8 +94,8 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns,
 	if (!ns)
 		goto fail_dec;
 
-	ns->vvar_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
-	if (!ns->vvar_page)
+	err = timens_vdso_alloc_vvar_page(ns);
+	if (err)
 		goto fail_free;
 
 	err = ns_common_init(ns);
@@ -109,7 +110,7 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns,
 	return ns;
 
 fail_free_page:
-	__free_page(ns->vvar_page);
+	timens_vdso_free_vvar_page(ns);
 fail_free:
 	kfree(ns);
 fail_dec:
@@ -138,117 +139,7 @@ struct time_namespace *copy_time_ns(u64 flags,
 	return clone_time_ns(user_ns, old_ns);
 }
 
-static struct timens_offset offset_from_ts(struct timespec64 off)
-{
-	struct timens_offset ret;
-
-	ret.sec = off.tv_sec;
-	ret.nsec = off.tv_nsec;
-
-	return ret;
-}
-
-/*
- * A time namespace VVAR page has the same layout as the VVAR page which
- * contains the system wide VDSO data.
- *
- * For a normal task the VVAR pages are installed in the normal ordering:
- *     VVAR
- *     PVCLOCK
- *     HVCLOCK
- *     TIMENS   <- Not really required
- *
- * Now for a timens task the pages are installed in the following order:
- *     TIMENS
- *     PVCLOCK
- *     HVCLOCK
- *     VVAR
- *
- * The check for vdso_clock->clock_mode is in the unlikely path of
- * the seq begin magic. So for the non-timens case most of the time
- * 'seq' is even, so the branch is not taken.
- *
- * If 'seq' is odd, i.e. a concurrent update is in progress, the extra check
- * for vdso_clock->clock_mode is a non-issue. The task is spin waiting for the
- * update to finish and for 'seq' to become even anyway.
- *
- * Timens page has vdso_clock->clock_mode set to VDSO_CLOCKMODE_TIMENS which
- * enforces the time namespace handling path.
- */
-static void timens_setup_vdso_clock_data(struct vdso_clock *vc,
-					 struct time_namespace *ns)
-{
-	struct timens_offset *offset = vc->offset;
-	struct timens_offset monotonic = offset_from_ts(ns->offsets.monotonic);
-	struct timens_offset boottime = offset_from_ts(ns->offsets.boottime);
-
-	vc->seq				= 1;
-	vc->clock_mode			= VDSO_CLOCKMODE_TIMENS;
-	offset[CLOCK_MONOTONIC]		= monotonic;
-	offset[CLOCK_MONOTONIC_RAW]	= monotonic;
-	offset[CLOCK_MONOTONIC_COARSE]	= monotonic;
-	offset[CLOCK_BOOTTIME]		= boottime;
-	offset[CLOCK_BOOTTIME_ALARM]	= boottime;
-}
-
-struct page *find_timens_vvar_page(struct vm_area_struct *vma)
-{
-	if (likely(vma->vm_mm == current->mm))
-		return current->nsproxy->time_ns->vvar_page;
-
-	/*
-	 * VM_PFNMAP | VM_IO protect .fault() handler from being called
-	 * through interfaces like /proc/$pid/mem or
-	 * process_vm_{readv,writev}() as long as there's no .access()
-	 * in special_mapping_vmops().
-	 * For more details check_vma_flags() and __access_remote_vm()
-	 */
-
-	WARN(1, "vvar_page accessed remotely");
-
-	return NULL;
-}
-
-/*
- * Protects possibly multiple offsets writers racing each other
- * and tasks entering the namespace.
- */
-static DEFINE_MUTEX(offset_lock);
-
-static void timens_set_vvar_page(struct task_struct *task,
-				struct time_namespace *ns)
-{
-	struct vdso_time_data *vdata;
-	struct vdso_clock *vc;
-	unsigned int i;
-
-	if (ns == &init_time_ns)
-		return;
-
-	/* Fast-path, taken by every task in namespace except the first. */
-	if (likely(ns->frozen_offsets))
-		return;
-
-	mutex_lock(&offset_lock);
-	/* Nothing to-do: vvar_page has been already initialized. */
-	if (ns->frozen_offsets)
-		goto out;
-
-	ns->frozen_offsets = true;
-	vdata = page_address(ns->vvar_page);
-	vc = vdata->clock_data;
-
-	for (i = 0; i < CS_BASES; i++)
-		timens_setup_vdso_clock_data(&vc[i], ns);
-
-	if (IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS)) {
-		for (i = 0; i < ARRAY_SIZE(vdata->aux_clock_data); i++)
-			timens_setup_vdso_clock_data(&vdata->aux_clock_data[i], ns);
-	}
-
-out:
-	mutex_unlock(&offset_lock);
-}
+DEFINE_MUTEX(timens_offset_lock);
 
 void free_time_ns(struct time_namespace *ns)
 {
@@ -256,41 +147,39 @@ void free_time_ns(struct time_namespace *ns)
 	dec_time_namespaces(ns->ucounts);
 	put_user_ns(ns->user_ns);
 	ns_common_free(ns);
-	__free_page(ns->vvar_page);
+	timens_vdso_free_vvar_page(ns);
 	/* Concurrent nstree traversal depends on a grace period. */
 	kfree_rcu(ns, ns.ns_rcu);
 }
 
 static struct ns_common *timens_get(struct task_struct *task)
 {
-	struct time_namespace *ns = NULL;
+	struct time_namespace *ns;
 	struct nsproxy *nsproxy;
 
-	task_lock(task);
+	guard(task_lock)(task);
 	nsproxy = task->nsproxy;
-	if (nsproxy) {
-		ns = nsproxy->time_ns;
-		get_time_ns(ns);
-	}
-	task_unlock(task);
+	if (!nsproxy)
+		return NULL;
 
-	return ns ? &ns->ns : NULL;
+	ns = nsproxy->time_ns;
+	get_time_ns(ns);
+	return &ns->ns;
 }
 
 static struct ns_common *timens_for_children_get(struct task_struct *task)
 {
-	struct time_namespace *ns = NULL;
+	struct time_namespace *ns;
 	struct nsproxy *nsproxy;
 
-	task_lock(task);
+	guard(task_lock)(task);
 	nsproxy = task->nsproxy;
-	if (nsproxy) {
-		ns = nsproxy->time_ns_for_children;
-		get_time_ns(ns);
-	}
-	task_unlock(task);
+	if (!nsproxy)
+		return NULL;
 
-	return ns ? &ns->ns : NULL;
+	ns = nsproxy->time_ns_for_children;
+	get_time_ns(ns);
+	return &ns->ns;
 }
 
 static void timens_put(struct ns_common *ns)
@@ -298,12 +187,6 @@ static void timens_put(struct ns_common *ns)
 	put_time_ns(to_time_ns(ns));
 }
 
-void timens_commit(struct task_struct *tsk, struct time_namespace *ns)
-{
-	timens_set_vvar_page(tsk, ns);
-	vdso_join_timens(tsk, ns);
-}
-
 static int timens_install(struct nsset *nsset, struct ns_common *new)
 {
 	struct nsproxy *nsproxy = nsset->nsproxy;
@@ -367,36 +250,33 @@ static void show_offset(struct seq_file *m, int clockid, struct timespec64 *ts)
 
 void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m)
 {
-	struct ns_common *ns;
-	struct time_namespace *time_ns;
+	struct time_namespace *time_ns __free(time_ns) = NULL;
+	struct ns_common *ns = timens_for_children_get(p);
 
-	ns = timens_for_children_get(p);
 	if (!ns)
 		return;
+
 	time_ns = to_time_ns(ns);
 
 	show_offset(m, CLOCK_MONOTONIC, &time_ns->offsets.monotonic);
 	show_offset(m, CLOCK_BOOTTIME, &time_ns->offsets.boottime);
-	put_time_ns(time_ns);
 }
 
 int proc_timens_set_offset(struct file *file, struct task_struct *p,
 			   struct proc_timens_offset *offsets, int noffsets)
 {
-	struct ns_common *ns;
-	struct time_namespace *time_ns;
+	struct time_namespace *time_ns __free(time_ns) = NULL;
+	struct ns_common *ns = timens_for_children_get(p);
 	struct timespec64 tp;
-	int i, err;
+	int i;
 
-	ns = timens_for_children_get(p);
 	if (!ns)
 		return -ESRCH;
+
 	time_ns = to_time_ns(ns);
 
-	if (!file_ns_capable(file, time_ns->user_ns, CAP_SYS_TIME)) {
-		put_time_ns(time_ns);
+	if (!file_ns_capable(file, time_ns->user_ns, CAP_SYS_TIME))
 		return -EPERM;
-	}
 
 	for (i = 0; i < noffsets; i++) {
 		struct proc_timens_offset *off = &offsets[i];
@@ -409,15 +289,12 @@ int proc_timens_set_offset(struct file *file, struct task_struct *p,
 			ktime_get_boottime_ts64(&tp);
 			break;
 		default:
-			err = -EINVAL;
-			goto out;
+			return -EINVAL;
 		}
 
-		err = -ERANGE;
-
 		if (off->val.tv_sec > KTIME_SEC_MAX ||
 		    off->val.tv_sec < -KTIME_SEC_MAX)
-			goto out;
+			return -ERANGE;
 
 		tp = timespec64_add(tp, off->val);
 		/*
@@ -425,16 +302,13 @@ int proc_timens_set_offset(struct file *file, struct task_struct *p,
 		 * still unreachable.
 		 */
 		if (tp.tv_sec < 0 || tp.tv_sec > KTIME_SEC_MAX / 2)
-			goto out;
+			return -ERANGE;
 	}
 
-	mutex_lock(&offset_lock);
-	if (time_ns->frozen_offsets) {
-		err = -EACCES;
-		goto out_unlock;
-	}
+	guard(mutex)(&timens_offset_lock);
+	if (time_ns->frozen_offsets)
+		return -EACCES;
 
-	err = 0;
 	/* Don't report errors after this line */
 	for (i = 0; i < noffsets; i++) {
 		struct proc_timens_offset *off = &offsets[i];
@@ -452,12 +326,7 @@ int proc_timens_set_offset(struct file *file, struct task_struct *p,
 		*offset = off->val;
 	}
 
-out_unlock:
-	mutex_unlock(&offset_lock);
-out:
-	put_time_ns(time_ns);
-
-	return err;
+	return 0;
 }
 
 const struct proc_ns_operations timens_operations = {
diff --git a/kernel/time/namespace_internal.h b/kernel/time/namespace_internal.h
new file mode 100644
index 000000000000..b37ba179f43b
--- /dev/null
+++ b/kernel/time/namespace_internal.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TIME_NAMESPACE_INTERNAL_H
+#define _TIME_NAMESPACE_INTERNAL_H
+
+#include <linux/mutex.h>
+
+struct time_namespace;
+
+/*
+ * Protects possibly multiple offsets writers racing each other
+ * and tasks entering the namespace.
+ */
+extern struct mutex timens_offset_lock;
+
+#ifdef CONFIG_TIME_NS_VDSO
+int timens_vdso_alloc_vvar_page(struct time_namespace *ns);
+void timens_vdso_free_vvar_page(struct time_namespace *ns);
+#else /* !CONFIG_TIME_NS_VDSO */
+static inline int timens_vdso_alloc_vvar_page(struct time_namespace *ns)
+{
+	return 0;
+}
+static inline void timens_vdso_free_vvar_page(struct time_namespace *ns)
+{
+}
+#endif /* CONFIG_TIME_NS_VDSO */
+
+#endif /* _TIME_NAMESPACE_INTERNAL_H */
diff --git a/kernel/time/namespace_vdso.c b/kernel/time/namespace_vdso.c
new file mode 100644
index 000000000000..88c075cd16a3
--- /dev/null
+++ b/kernel/time/namespace_vdso.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Andrei Vagin <avagin@openvz.org>
+ * Author: Dmitry Safonov <dima@arista.com>
+ */
+
+#include <linux/cleanup.h>
+#include <linux/mm.h>
+#include <linux/time_namespace.h>
+#include <linux/time.h>
+#include <linux/vdso_datastore.h>
+
+#include <vdso/clocksource.h>
+#include <vdso/datapage.h>
+
+#include "namespace_internal.h"
+
+static struct timens_offset offset_from_ts(struct timespec64 off)
+{
+	struct timens_offset ret;
+
+	ret.sec = off.tv_sec;
+	ret.nsec = off.tv_nsec;
+
+	return ret;
+}
+
+/*
+ * A time namespace VVAR page has the same layout as the VVAR page which
+ * contains the system wide VDSO data.
+ *
+ * For a normal task the VVAR pages are installed in the normal ordering:
+ *     VVAR
+ *     PVCLOCK
+ *     HVCLOCK
+ *     TIMENS   <- Not really required
+ *
+ * Now for a timens task the pages are installed in the following order:
+ *     TIMENS
+ *     PVCLOCK
+ *     HVCLOCK
+ *     VVAR
+ *
+ * The check for vdso_clock->clock_mode is in the unlikely path of
+ * the seq begin magic. So for the non-timens case most of the time
+ * 'seq' is even, so the branch is not taken.
+ *
+ * If 'seq' is odd, i.e. a concurrent update is in progress, the extra check
+ * for vdso_clock->clock_mode is a non-issue. The task is spin waiting for the
+ * update to finish and for 'seq' to become even anyway.
+ *
+ * Timens page has vdso_clock->clock_mode set to VDSO_CLOCKMODE_TIMENS which
+ * enforces the time namespace handling path.
+ */
+static void timens_setup_vdso_clock_data(struct vdso_clock *vc,
+					 struct time_namespace *ns)
+{
+	struct timens_offset *offset = vc->offset;
+	struct timens_offset monotonic = offset_from_ts(ns->offsets.monotonic);
+	struct timens_offset boottime = offset_from_ts(ns->offsets.boottime);
+
+	vc->seq				= 1;
+	vc->clock_mode			= VDSO_CLOCKMODE_TIMENS;
+	offset[CLOCK_MONOTONIC]		= monotonic;
+	offset[CLOCK_MONOTONIC_RAW]	= monotonic;
+	offset[CLOCK_MONOTONIC_COARSE]	= monotonic;
+	offset[CLOCK_BOOTTIME]		= boottime;
+	offset[CLOCK_BOOTTIME_ALARM]	= boottime;
+}
+
+struct page *find_timens_vvar_page(struct vm_area_struct *vma)
+{
+	if (likely(vma->vm_mm == current->mm))
+		return current->nsproxy->time_ns->vvar_page;
+
+	/*
+	 * VM_PFNMAP | VM_IO protect .fault() handler from being called
+	 * through interfaces like /proc/$pid/mem or
+	 * process_vm_{readv,writev}() as long as there's no .access()
+	 * in special_mapping_vmops().
+	 * For more details check_vma_flags() and __access_remote_vm()
+	 */
+
+	WARN(1, "vvar_page accessed remotely");
+
+	return NULL;
+}
+
+static void timens_set_vvar_page(struct task_struct *task,
+				struct time_namespace *ns)
+{
+	struct vdso_time_data *vdata;
+	struct vdso_clock *vc;
+	unsigned int i;
+
+	if (ns == &init_time_ns)
+		return;
+
+	/* Fast-path, taken by every task in namespace except the first. */
+	if (likely(ns->frozen_offsets))
+		return;
+
+	guard(mutex)(&timens_offset_lock);
+	/* Nothing to-do: vvar_page has been already initialized. */
+	if (ns->frozen_offsets)
+		return;
+
+	ns->frozen_offsets = true;
+	vdata = page_address(ns->vvar_page);
+	vc = vdata->clock_data;
+
+	for (i = 0; i < CS_BASES; i++)
+		timens_setup_vdso_clock_data(&vc[i], ns);
+
+	if (IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS)) {
+		for (i = 0; i < ARRAY_SIZE(vdata->aux_clock_data); i++)
+			timens_setup_vdso_clock_data(&vdata->aux_clock_data[i], ns);
+	}
+}
+
+/*
+ * The vvar page layout depends on whether a task belongs to the root or
+ * non-root time namespace. Whenever a task changes its namespace, the VVAR
+ * page tables are cleared and then they will be re-faulted with a
+ * corresponding layout.
+ * See also the comment near timens_setup_vdso_clock_data() for details.
+ */
+static int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
+{
+	struct mm_struct *mm = task->mm;
+	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, 0);
+
+	guard(mmap_read_lock)(mm);
+	for_each_vma(vmi, vma) {
+		if (vma_is_special_mapping(vma, &vdso_vvar_mapping))
+			zap_vma_pages(vma);
+	}
+	return 0;
+}
+
+void timens_commit(struct task_struct *tsk, struct time_namespace *ns)
+{
+	timens_set_vvar_page(tsk, ns);
+	vdso_join_timens(tsk, ns);
+}
+
+int timens_vdso_alloc_vvar_page(struct time_namespace *ns)
+{
+	ns->vvar_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+	if (!ns->vvar_page)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void timens_vdso_free_vvar_page(struct time_namespace *ns)
+{
+	__free_page(ns->vvar_page);
+}