Merge tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull VDSO infrastructure updates from Thomas Gleixner:

 - Consolidate the VDSO storage

   The VDSO data storage and data layout has been largely architecture
   specific for historical reasons. That increases the maintenance
   effort and causes inconsistencies over and over.

   There is no real technical reason for architecture specific layouts
   and implementations. The architecture specific details can easily be
   integrated into a generic layout, which also reduces the amount of
   duplicated code for managing the mappings.

   Convert all architectures over to a unified layout and common mapping
   infrastructure. This splits the VDSO data layout into subsystem
   specific blocks, timekeeping, random and architecture parts, which
   provides a better structure and allows to improve and update the
   functionalities without conflict and interaction.

 - Rework the timekeeping data storage

   The current implementation is designed for exposing system
   timekeeping accessors, which was good enough at the time when it was
   designed.

   PTP and Time Sensitive Networking (TSN) change that as there are
   requirements to expose independent PTP clocks, which are not related
   to system timekeeping.

   Replace the monolithic data storage by a structured layout, which
   allows to add support for independent PTP clocks on top while reusing
   both the data structures and the time accessor implementations.

* tag 'timers-vdso-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits)
  sparc/vdso: Always reject undefined references during linking
  x86/vdso: Always reject undefined references during linking
  vdso: Rework struct vdso_time_data and introduce struct vdso_clock
  vdso: Move architecture related data before basetime data
  powerpc/vdso: Prepare introduction of struct vdso_clock
  arm64/vdso: Prepare introduction of struct vdso_clock
  x86/vdso: Prepare introduction of struct vdso_clock
  time/namespace: Prepare introduction of struct vdso_clock
  vdso/namespace: Rename timens_setup_vdso_data() to reflect new vdso_clock struct
  vdso/vsyscall: Prepare introduction of struct vdso_clock
  vdso/gettimeofday: Prepare helper functions for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_coarse_timens() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_coarse() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_hres_timens() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare do_hres() for introduction of struct vdso_clock
  vdso/gettimeofday: Prepare introduction of struct vdso_clock
  vdso/helpers: Prepare introduction of struct vdso_clock
  vdso/datapage: Define vdso_clock to prepare for multiple PTP clocks
  vdso: Make vdso_time_data cacheline aligned
  arm64: Make asm/cache.h compatible with vDSO
  ...

5 files changed, 11 insertions, 97 deletions

diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index bcd3b816306c..04a4e5495512 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -450,8 +450,7 @@ static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs,
 
 static int __init init_hwprobe_vdso_data(void)
 {
-	struct vdso_data *vd = __arch_get_k_vdso_data();
-	struct arch_vdso_time_data *avd = &vd->arch_data;
+	struct vdso_arch_data *avd = vdso_k_arch_data;
 	u64 id_bitsmash = 0;
 	struct riscv_hwprobe pair;
 	int key;
diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index 3ca3ae4277e1..cc2895d1fbc2 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -13,20 +13,11 @@
 #include <linux/err.h>
 #include <asm/page.h>
 #include <asm/vdso.h>
-#include <linux/time_namespace.h>
+#include <linux/vdso_datastore.h>
 #include <vdso/datapage.h>
 #include <vdso/vsyscall.h>
 
-enum vvar_pages {
-	VVAR_DATA_PAGE_OFFSET,
-	VVAR_TIMENS_PAGE_OFFSET,
-	VVAR_NR_PAGES,
-};
-
-#define VVAR_SIZE  (VVAR_NR_PAGES << PAGE_SHIFT)
-
-static union vdso_data_store vdso_data_store __page_aligned_data;
-struct vdso_data *vdso_data = vdso_data_store.data;
+#define VVAR_SIZE  (VDSO_NR_PAGES << PAGE_SHIFT)
 
 struct __vdso_info {
 	const char *name;
@@ -79,78 +70,6 @@ static void __init __vdso_init(struct __vdso_info *vdso_info)
 	vdso_info->cm->pages = vdso_pagelist;
 }
 
-#ifdef CONFIG_TIME_NS
-struct vdso_data *arch_get_vdso_data(void *vvar_page)
-{
-	return (struct vdso_data *)(vvar_page);
-}
-
-static const struct vm_special_mapping rv_vvar_map;
-
-/*
- * The vvar mapping contains data for a specific time namespace, so when a task
- * changes namespace we must unmap its vvar data for the old namespace.
- * Subsequent faults will map in data for the new namespace.
- *
- * For more details see timens_setup_vdso_data().
- */
-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);
-
-	mmap_read_lock(mm);
-
-	for_each_vma(vmi, vma) {
-		if (vma_is_special_mapping(vma, &rv_vvar_map))
-			zap_vma_pages(vma);
-	}
-
-	mmap_read_unlock(mm);
-	return 0;
-}
-#endif
-
-static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
-			     struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-	struct page *timens_page = find_timens_vvar_page(vma);
-	unsigned long pfn;
-
-	switch (vmf->pgoff) {
-	case VVAR_DATA_PAGE_OFFSET:
-		if (timens_page)
-			pfn = page_to_pfn(timens_page);
-		else
-			pfn = sym_to_pfn(vdso_data);
-		break;
-#ifdef CONFIG_TIME_NS
-	case VVAR_TIMENS_PAGE_OFFSET:
-		/*
-		 * If a task belongs to a time namespace then a namespace
-		 * specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
-		 * the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
-		 * offset.
-		 * See also the comment near timens_setup_vdso_data().
-		 */
-		if (!timens_page)
-			return VM_FAULT_SIGBUS;
-		pfn = sym_to_pfn(vdso_data);
-		break;
-#endif /* CONFIG_TIME_NS */
-	default:
-		return VM_FAULT_SIGBUS;
-	}
-
-	return vmf_insert_pfn(vma, vmf->address, pfn);
-}
-
-static const struct vm_special_mapping rv_vvar_map = {
-	.name   = "[vvar]",
-	.fault = vvar_fault,
-};
-
 static struct vm_special_mapping rv_vdso_map __ro_after_init = {
 	.name   = "[vdso]",
 	.mremap = vdso_mremap,
@@ -196,7 +115,7 @@ static int __setup_additional_pages(struct mm_struct *mm,
 	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
 	void *ret;
 
-	BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
+	BUILD_BUG_ON(VDSO_NR_PAGES != __VDSO_PAGES);
 
 	vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT;
 	/* Be sure to map the data page */
@@ -208,8 +127,7 @@ static int __setup_additional_pages(struct mm_struct *mm,
 		goto up_fail;
 	}
 
-	ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
-		(VM_READ | VM_MAYREAD | VM_PFNMAP), &rv_vvar_map);
+	ret = vdso_install_vvar_mapping(mm, vdso_base);
 	if (IS_ERR(ret))
 		goto up_fail;
 
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 9a1b555e8733..ad73607abc28 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -2,7 +2,7 @@
 # Copied from arch/tile/kernel/vdso/Makefile
 
 # Include the generic Makefile to check the built vdso.
-include $(srctree)/lib/vdso/Makefile
+include $(srctree)/lib/vdso/Makefile.include
 # Symbols present in the vdso
 vdso-syms  = rt_sigreturn
 ifdef CONFIG_64BIT
diff --git a/arch/riscv/kernel/vdso/hwprobe.c b/arch/riscv/kernel/vdso/hwprobe.c
index a158c029344f..2ddeba6c68dd 100644
--- a/arch/riscv/kernel/vdso/hwprobe.c
+++ b/arch/riscv/kernel/vdso/hwprobe.c
@@ -16,8 +16,7 @@ static int riscv_vdso_get_values(struct riscv_hwprobe *pairs, size_t pair_count,
 				 size_t cpusetsize, unsigned long *cpus,
 				 unsigned int flags)
 {
-	const struct vdso_data *vd = __arch_get_vdso_data();
-	const struct arch_vdso_time_data *avd = &vd->arch_data;
+	const struct vdso_arch_data *avd = &vdso_u_arch_data;
 	bool all_cpus = !cpusetsize && !cpus;
 	struct riscv_hwprobe *p = pairs;
 	struct riscv_hwprobe *end = pairs + pair_count;
@@ -51,8 +50,7 @@ static int riscv_vdso_get_cpus(struct riscv_hwprobe *pairs, size_t pair_count,
 			       size_t cpusetsize, unsigned long *cpus,
 			       unsigned int flags)
 {
-	const struct vdso_data *vd = __arch_get_vdso_data();
-	const struct arch_vdso_time_data *avd = &vd->arch_data;
+	const struct vdso_arch_data *avd = &vdso_u_arch_data;
 	struct riscv_hwprobe *p = pairs;
 	struct riscv_hwprobe *end = pairs + pair_count;
 	unsigned char *c = (unsigned char *)cpus;
diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S
index cbe2a179331d..8e86965a8aae 100644
--- a/arch/riscv/kernel/vdso/vdso.lds.S
+++ b/arch/riscv/kernel/vdso/vdso.lds.S
@@ -4,15 +4,14 @@
  */
 #include <asm/page.h>
 #include <asm/vdso.h>
+#include <vdso/datapage.h>
 
 OUTPUT_ARCH(riscv)
 
 SECTIONS
 {
-	PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
-#ifdef CONFIG_TIME_NS
-	PROVIDE(_timens_data = _vdso_data + PAGE_SIZE);
-#endif
+	VDSO_VVAR_SYMS
+
 	. = SIZEOF_HEADERS;
 
 	.hash		: { *(.hash) }			:text