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
...

MAINTAINERS

···
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/vdso
 F:	include/asm-generic/vdso/vsyscall.h
 F:	include/vdso/
+F:	kernel/time/namespace_vdso.c
 F:	kernel/time/vsyscall.c
 F:	lib/vdso/
 F:	tools/testing/selftests/vDSO/
···
 F:	kernel/time/itimer.c
 F:	kernel/time/posix-*
 F:	kernel/time/namespace.c
+F:	kernel/time/namespace_vdso.c
 
 POWER MANAGEMENT CORE
 M:	"Rafael J. Wysocki" <[e-mail]>

arch/arm/include/asm/vdso/gettimeofday.h

···
 #include <asm/errno.h>
 #include <asm/unistd.h>
 #include <asm/vdso/cp15.h>
+#include <vdso/clocksource.h>
+#include <vdso/time32.h>
 #include <uapi/linux/time.h>
 
 #define VDSO_HAS_CLOCK_GETRES		1

arch/arm64/include/asm/vdso/compat_gettimeofday.h

···
 
 #ifndef __ASSEMBLER__
 
+#include <vdso/clocksource.h>
+#include <vdso/time32.h>
+
 #include <asm/barrier.h>
 #include <asm/unistd_compat_32.h>
 #include <asm/errno.h>

arch/arm64/include/asm/vdso/gettimeofday.h

···
 
 #ifndef __ASSEMBLER__
 
+#include <vdso/clocksource.h>
+
 #include <asm/alternative.h>
 #include <asm/arch_timer.h>
 #include <asm/barrier.h>

arch/loongarch/kernel/process.c

···
 #include <asm/switch_to.h>
 #include <asm/unwind.h>
 #include <asm/vdso.h>
+#include <asm/vdso/vdso.h>
 
 #ifdef CONFIG_STACKPROTECTOR
 #include <linux/stackprotector.h>

arch/loongarch/kernel/vdso.c

···
 
 #include <asm/page.h>
 #include <asm/vdso.h>
+#include <asm/vdso/vdso.h>
 #include <vdso/helpers.h>
 #include <vdso/vsyscall.h>
 #include <vdso/datapage.h>

arch/mips/include/asm/vdso/vdso.h

···
  * Author: Alex Smith <[e-mail]>
  */
 
+#ifndef __ASM_VDSO_VDSO_H
+#define __ASM_VDSO_VDSO_H
+
 #include <asm/sgidefs.h>
 #include <vdso/page.h>
 
···
 #endif /* CONFIG_CLKSRC_MIPS_GIC */
 
 #endif /* __ASSEMBLER__ */
+
+#endif /* __ASM_VDSO_VDSO_H */

arch/mips/kernel/vdso.c

···
 #include <asm/mips-cps.h>
 #include <asm/page.h>
 #include <asm/vdso.h>
+#include <asm/vdso/vdso.h>
 #include <vdso/helpers.h>
 #include <vdso/vsyscall.h>
 

arch/powerpc/include/asm/vdso/gettimeofday.h

···
 #include <asm/barrier.h>
 #include <asm/unistd.h>
 #include <uapi/linux/time.h>
+#include <vdso/time32.h>
 
 #define VDSO_HAS_CLOCK_GETRES		1
 

arch/powerpc/include/asm/vdso/processor.h

···
 
 #ifndef __ASSEMBLER__
 
+#include <asm/cputable.h>
+#include <asm/feature-fixups.h>
+
 /* Macros for adjusting thread priority (hardware multi-threading) */
 #ifdef CONFIG_PPC64
 #define HMT_very_low()		asm volatile("or 31, 31, 31	# very low priority")

arch/powerpc/kernel/compat_audit.c

···
 // SPDX-License-Identifier: GPL-2.0
-#undef __powerpc64__
 #include <linux/audit_arch.h>
-#include <asm/unistd.h>
+#include <asm/unistd_32.h>
 
 #include "audit_32.h"
 

arch/s390/Makefile

···
 KBUILD_LDFLAGS	:= -m elf64_s390
 KBUILD_AFLAGS_MODULE += -fPIC
 KBUILD_CFLAGS_MODULE += -fPIC
-KBUILD_AFLAGS	+= -m64
-KBUILD_CFLAGS	+= -m64
+KBUILD_CPPFLAGS	+= -m64
 KBUILD_CFLAGS	+= -fPIC
 LDFLAGS_vmlinux	:= $(call ld-option,-no-pie)
 extra_tools	:= relocs

arch/sparc/Kconfig

···
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select GENERIC_TIME_VSYSCALL
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_PTE_SPECIAL
 	select PCI_DOMAINS if PCI
 	select ARCH_HAS_GIGANTIC_PAGE
···
 	select ARCH_SUPPORTS_SCHED_SMT if SMP
 	select ARCH_SUPPORTS_SCHED_MC  if SMP
 	select ARCH_HAS_LAZY_MMU_MODE
+	select HAVE_GENERIC_VDSO
+	select GENERIC_GETTIMEOFDAY
 
 config ARCH_PROC_KCORE_TEXT
 	def_bool y

arch/sparc/include/asm/clocksource.h

···
 #ifndef _ASM_SPARC_CLOCKSOURCE_H
 #define _ASM_SPARC_CLOCKSOURCE_H
 
-/* VDSO clocksources */
-#define VCLOCK_NONE   0  /* Nothing userspace can do. */
-#define VCLOCK_TICK   1  /* Use %tick.  */
-#define VCLOCK_STICK  2  /* Use %stick. */
-
-struct arch_clocksource_data {
-	int vclock_mode;
-};
-
 #endif /* _ASM_SPARC_CLOCKSOURCE_H */

arch/sparc/include/asm/processor.h

···
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef ___ASM_SPARC_PROCESSOR_H
 #define ___ASM_SPARC_PROCESSOR_H
+
+#include <asm/vdso/processor.h>
+
 #if defined(__sparc__) && defined(__arch64__)
 #include <asm/processor_64.h>
 #else

arch/sparc/include/asm/processor_32.h

···
 extern struct task_struct *last_task_used_math;
 int do_mathemu(struct pt_regs *regs, struct task_struct *fpt);
 
-#define cpu_relax()	barrier()
-
 extern void (*sparc_idle)(void);
 
 #endif

arch/sparc/include/asm/processor_64.h

···
 #define KSTK_EIP(tsk)  (task_pt_regs(tsk)->tpc)
 #define KSTK_ESP(tsk)  (task_pt_regs(tsk)->u_regs[UREG_FP])
 
-/* Please see the commentary in asm/backoff.h for a description of
- * what these instructions are doing and how they have been chosen.
- * To make a long story short, we are trying to yield the current cpu
- * strand during busy loops.
- */
-#ifdef	BUILD_VDSO
-#define	cpu_relax()	asm volatile("\n99:\n\t"			\
-				     "rd	%%ccr, %%g0\n\t"	\
-				     "rd	%%ccr, %%g0\n\t"	\
-				     "rd	%%ccr, %%g0\n\t"	\
-				     ::: "memory")
-#else /* ! BUILD_VDSO */
-#define cpu_relax()	asm volatile("\n99:\n\t"			\
-				     "rd	%%ccr, %%g0\n\t"	\
-				     "rd	%%ccr, %%g0\n\t"	\
-				     "rd	%%ccr, %%g0\n\t"	\
-				     ".section	.pause_3insn_patch,\"ax\"\n\t"\
-				     ".word	99b\n\t"		\
-				     "wr	%%g0, 128, %%asr27\n\t"	\
-				     "nop\n\t"				\
-				     "nop\n\t"				\
-				     ".previous"			\
-				     ::: "memory")
-#endif
-
 /* Prefetch support.  This is tuned for UltraSPARC-III and later.
  * UltraSPARC-I will treat these as nops, and UltraSPARC-II has
  * a shallower prefetch queue than later chips.

arch/sparc/include/asm/vdso.h

···
 struct vdso_image {
 	void *data;
 	unsigned long size;   /* Always a multiple of PAGE_SIZE */
-
-	long sym_vvar_start;  /* Negative offset to the vvar area */
 };
 
 #ifdef CONFIG_SPARC64

arch/sparc/include/asm/vdso/clocksource.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSO_CLOCKSOURCE_H
+#define __ASM_VDSO_CLOCKSOURCE_H
+
+/* VDSO clocksources */
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_TICK,	\
+	VDSO_CLOCKMODE_STICK
+
+#endif /* __ASM_VDSO_CLOCKSOURCE_H */

arch/sparc/include/asm/vdso/gettimeofday.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ */
+
+#ifndef _ASM_SPARC_VDSO_GETTIMEOFDAY_H
+#define _ASM_SPARC_VDSO_GETTIMEOFDAY_H
+
+#include <uapi/linux/time.h>
+#include <uapi/linux/unistd.h>
+
+#include <vdso/align.h>
+#include <vdso/clocksource.h>
+#include <vdso/datapage.h>
+#include <vdso/page.h>
+
+#include <linux/types.h>
+
+#ifdef	CONFIG_SPARC64
+static __always_inline u64 vread_tick(void)
+{
+	u64	ret;
+
+	__asm__ __volatile__("rd %%tick, %0" : "=r" (ret));
+	return ret;
+}
+
+static __always_inline u64 vread_tick_stick(void)
+{
+	u64	ret;
+
+	__asm__ __volatile__("rd %%asr24, %0" : "=r" (ret));
+	return ret;
+}
+#else
+static __always_inline u64 vdso_shift_ns(u64 val, u32 amt)
+{
+	u64 ret;
+
+	__asm__ __volatile__("sllx %H1, 32, %%g1\n\t"
+			     "srl %L1, 0, %L1\n\t"
+			     "or %%g1, %L1, %%g1\n\t"
+			     "srlx %%g1, %2, %L0\n\t"
+			     "srlx %L0, 32, %H0"
+			     : "=r" (ret)
+			     : "r" (val), "r" (amt)
+			     : "g1");
+	return ret;
+}
+#define vdso_shift_ns vdso_shift_ns
+
+static __always_inline u64 vread_tick(void)
+{
+	register unsigned long long ret asm("o4");
+
+	__asm__ __volatile__("rd %%tick, %L0\n\t"
+			     "srlx %L0, 32, %H0"
+			     : "=r" (ret));
+	return ret;
+}
+
+static __always_inline u64 vread_tick_stick(void)
+{
+	register unsigned long long ret asm("o4");
+
+	__asm__ __volatile__("rd %%asr24, %L0\n\t"
+			     "srlx %L0, 32, %H0"
+			     : "=r" (ret));
+	return ret;
+}
+#endif
+
+static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, const struct vdso_time_data *vd)
+{
+	if (likely(clock_mode == VDSO_CLOCKMODE_STICK))
+		return vread_tick_stick();
+	else
+		return vread_tick();
+}
+
+#ifdef	CONFIG_SPARC64
+#define SYSCALL_STRING							\
+	"ta	0x6d;"							\
+	"bcs,a	1f;"							\
+	" sub	%%g0, %%o0, %%o0;"					\
+	"1:"
+#else
+#define SYSCALL_STRING							\
+	"ta	0x10;"							\
+	"bcs,a	1f;"							\
+	" sub	%%g0, %%o0, %%o0;"					\
+	"1:"
+#endif
+
+#define SYSCALL_CLOBBERS						\
+	"f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",			\
+	"f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",		\
+	"f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",		\
+	"f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",		\
+	"f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46",		\
+	"f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62",		\
+	"cc", "memory"
+
+#ifdef CONFIG_SPARC64
+
+static __always_inline
+long clock_gettime_fallback(clockid_t clock, struct __kernel_timespec *ts)
+{
+	register long num __asm__("g1") = __NR_clock_gettime;
+	register long o0 __asm__("o0") = clock;
+	register long o1 __asm__("o1") = (long) ts;
+
+	__asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
+			     "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
+	return o0;
+}
+
+#else /* !CONFIG_SPARC64 */
+
+static __always_inline
+long clock_gettime_fallback(clockid_t clock, struct __kernel_timespec *ts)
+{
+	register long num __asm__("g1") = __NR_clock_gettime64;
+	register long o0 __asm__("o0") = clock;
+	register long o1 __asm__("o1") = (long) ts;
+
+	__asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
+			     "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
+	return o0;
+}
+
+static __always_inline
+long clock_gettime32_fallback(clockid_t clock, struct old_timespec32 *ts)
+{
+	register long num __asm__("g1") = __NR_clock_gettime;
+	register long o0 __asm__("o0") = clock;
+	register long o1 __asm__("o1") = (long) ts;
+
+	__asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
+			     "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
+	return o0;
+}
+
+#endif /* CONFIG_SPARC64 */
+
+static __always_inline
+long gettimeofday_fallback(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+	register long num __asm__("g1") = __NR_gettimeofday;
+	register long o0 __asm__("o0") = (long) tv;
+	register long o1 __asm__("o1") = (long) tz;
+
+	__asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
+			     "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
+	return o0;
+}
+
+static __always_inline const struct vdso_time_data *__arch_get_vdso_u_time_data(void)
+{
+	unsigned long ret;
+
+	/*
+	 * SPARC does not support native PC-relative code relocations.
+	 * Calculate the address manually, works for 32 and 64 bit code.
+	 */
+	__asm__ __volatile__(
+		"1:\n"
+		"call 3f\n"                     // Jump over the embedded data and set up %o7
+		"nop\n"                         // Delay slot
+		"2:\n"
+		".word vdso_u_time_data - .\n"  // Embedded offset to external symbol
+		"3:\n"
+		"add %%o7, 2b - 1b, %%o7\n"     // Point %o7 to the embedded offset
+		"ldsw [%%o7], %0\n"             // Load the offset
+		"add %0, %%o7, %0\n"            // Calculate the absolute address
+		: "=r" (ret)
+		:
+		: "o7");
+
+	return (const struct vdso_time_data *)ret;
+}
+#define __arch_get_vdso_u_time_data __arch_get_vdso_u_time_data
+
+#endif /* _ASM_SPARC_VDSO_GETTIMEOFDAY_H */

arch/sparc/include/asm/vdso/processor.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_SPARC_VDSO_PROCESSOR_H
+#define _ASM_SPARC_VDSO_PROCESSOR_H
+
+#include <linux/compiler.h>
+
+#if defined(__arch64__)
+
+/* Please see the commentary in asm/backoff.h for a description of
+ * what these instructions are doing and how they have been chosen.
+ * To make a long story short, we are trying to yield the current cpu
+ * strand during busy loops.
+ */
+#ifdef	BUILD_VDSO
+#define	cpu_relax()	asm volatile("\n99:\n\t"			\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     ::: "memory")
+#else /* ! BUILD_VDSO */
+#define cpu_relax()	asm volatile("\n99:\n\t"			\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     "rd	%%ccr, %%g0\n\t"	\
+				     ".section	.pause_3insn_patch,\"ax\"\n\t"\
+				     ".word	99b\n\t"		\
+				     "wr	%%g0, 128, %%asr27\n\t"	\
+				     "nop\n\t"				\
+				     "nop\n\t"				\
+				     ".previous"			\
+				     ::: "memory")
+#endif /* BUILD_VDSO */
+
+#else /* ! __arch64__ */
+
+#define cpu_relax()	barrier()
+
+#endif /* __arch64__ */
+
+#endif /* _ASM_SPARC_VDSO_PROCESSOR_H */

arch/sparc/include/asm/vdso/vsyscall.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_SPARC_VDSO_VSYSCALL_H
+#define _ASM_SPARC_VDSO_VSYSCALL_H
+
+#define __VDSO_PAGES 4
+
+#include <asm-generic/vdso/vsyscall.h>
+
+#endif /* _ASM_SPARC_VDSO_VSYSCALL_H */

arch/sparc/include/asm/vvar.h

···
-/*
- * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
- */
-
-#ifndef _ASM_SPARC_VVAR_DATA_H
-#define _ASM_SPARC_VVAR_DATA_H
-
-#include <asm/clocksource.h>
-#include <asm/processor.h>
-#include <asm/barrier.h>
-#include <linux/time.h>
-#include <linux/types.h>
-
-struct vvar_data {
-	unsigned int seq;
-
-	int vclock_mode;
-	struct { /* extract of a clocksource struct */
-		u64	cycle_last;
-		u64	mask;
-		int	mult;
-		int	shift;
-	} clock;
-	/* open coded 'struct timespec' */
-	u64		wall_time_sec;
-	u64		wall_time_snsec;
-	u64		monotonic_time_snsec;
-	u64		monotonic_time_sec;
-	u64		monotonic_time_coarse_sec;
-	u64		monotonic_time_coarse_nsec;
-	u64		wall_time_coarse_sec;
-	u64		wall_time_coarse_nsec;
-
-	int		tz_minuteswest;
-	int		tz_dsttime;
-};
-
-extern struct vvar_data *vvar_data;
-extern int vdso_fix_stick;
-
-static inline unsigned int vvar_read_begin(const struct vvar_data *s)
-{
-	unsigned int ret;
-
-repeat:
-	ret = READ_ONCE(s->seq);
-	if (unlikely(ret & 1)) {
-		cpu_relax();
-		goto repeat;
-	}
-	smp_rmb(); /* Finish all reads before we return seq */
-	return ret;
-}
-
-static inline int vvar_read_retry(const struct vvar_data *s,
-					unsigned int start)
-{
-	smp_rmb(); /* Finish all reads before checking the value of seq */
-	return unlikely(s->seq != start);
-}
-
-static inline void vvar_write_begin(struct vvar_data *s)
-{
-	++s->seq;
-	smp_wmb(); /* Makes sure that increment of seq is reflected */
-}
-
-static inline void vvar_write_end(struct vvar_data *s)
-{
-	smp_wmb(); /* Makes the value of seq current before we increment */
-	++s->seq;
-}
-
-
-#endif /* _ASM_SPARC_VVAR_DATA_H */

arch/sparc/kernel/Makefile

···
 obj-y                   += time_$(BITS).o
 obj-$(CONFIG_SPARC32)   += windows.o
 obj-y                   += cpu.o
-obj-$(CONFIG_SPARC64)	+= vdso.o
 obj-$(CONFIG_SPARC32)   += devices.o
 obj-y                   += ptrace_$(BITS).o
 obj-y                   += unaligned_$(BITS).o

arch/sparc/kernel/time_64.c

···
 	if (tlb_type == spitfire) {
 		if (is_hummingbird()) {
 			init_tick_ops(&hbtick_operations);
-			clocksource_tick.archdata.vclock_mode = VCLOCK_NONE;
+			clocksource_tick.vdso_clock_mode = VDSO_CLOCKMODE_NONE;
 		} else {
 			init_tick_ops(&tick_operations);
-			clocksource_tick.archdata.vclock_mode = VCLOCK_TICK;
+			clocksource_tick.vdso_clock_mode = VDSO_CLOCKMODE_TICK;
 		}
 	} else {
 		init_tick_ops(&stick_operations);
-		clocksource_tick.archdata.vclock_mode = VCLOCK_STICK;
+		clocksource_tick.vdso_clock_mode = VDSO_CLOCKMODE_STICK;
 	}
 }
 

arch/sparc/kernel/vdso.c

···
-/*
- *  Copyright (C) 2001 Andrea Arcangeli <[e-mail]> SuSE
- *  Copyright 2003 Andi Kleen, SuSE Labs.
- *
- *  Thanks to [e-mail] for some useful hint.
- *  Special thanks to Ingo Molnar for his early experience with
- *  a different vsyscall implementation for Linux/IA32 and for the name.
- */
-
-#include <linux/time.h>
-#include <linux/timekeeper_internal.h>
-
-#include <asm/vvar.h>
-
-void update_vsyscall_tz(void)
-{
-	if (unlikely(vvar_data == NULL))
-		return;
-
-	vvar_data->tz_minuteswest = sys_tz.tz_minuteswest;
-	vvar_data->tz_dsttime = sys_tz.tz_dsttime;
-}
-
-void update_vsyscall(struct timekeeper *tk)
-{
-	struct vvar_data *vdata = vvar_data;
-
-	if (unlikely(vdata == NULL))
-		return;
-
-	vvar_write_begin(vdata);
-	vdata->vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
-	vdata->clock.cycle_last = tk->tkr_mono.cycle_last;
-	vdata->clock.mask = tk->tkr_mono.mask;
-	vdata->clock.mult = tk->tkr_mono.mult;
-	vdata->clock.shift = tk->tkr_mono.shift;
-
-	vdata->wall_time_sec = tk->xtime_sec;
-	vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec;
-
-	vdata->monotonic_time_sec = tk->xtime_sec +
-				    tk->wall_to_monotonic.tv_sec;
-	vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec +
-				      (tk->wall_to_monotonic.tv_nsec <<
-				       tk->tkr_mono.shift);
-
-	while (vdata->monotonic_time_snsec >=
-	       (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
-		vdata->monotonic_time_snsec -=
-				((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
-		vdata->monotonic_time_sec++;
-	}
-
-	vdata->wall_time_coarse_sec = tk->xtime_sec;
-	vdata->wall_time_coarse_nsec =
-			(long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
-
-	vdata->monotonic_time_coarse_sec =
-		vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec;
-	vdata->monotonic_time_coarse_nsec =
-		vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
-
-	while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) {
-		vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC;
-		vdata->monotonic_time_coarse_sec++;
-	}
-
-	vvar_write_end(vdata);
-}

arch/sparc/vdso/Makefile

···
 # Building vDSO images for sparc.
 #
 
+# Include the generic Makefile to check the built vDSO:
+include $(srctree)/lib/vdso/Makefile.include
+
 # files to link into the vdso
 vobjs-y := vdso-note.o vclock_gettime.o
 
···
 KBUILD_CFLAGS_32 += -mv8plus
 $(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
 
+CHECKFLAGS_32 := $(filter-out -m64 -D__sparc_v9__ -D__arch64__, $(CHECKFLAGS)) -m32
+$(obj)/vdso32.so.dbg: CHECKFLAGS = $(CHECKFLAGS_32)
+
 $(obj)/vdso32.so.dbg: FORCE \
 			$(obj)/vdso32/vdso32.lds \
 			$(obj)/vdso32/vclock_gettime.o \
···
 quiet_cmd_vdso = VDSO    $@
       cmd_vdso = $(LD) -nostdlib -o $@ \
 		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
-		       -T $(filter %.lds,$^) $(filter %.o,$^)
+		       -T $(filter %.lds,$^) $(filter %.o,$^); \
+		       $(cmd_vdso_check)
 
-VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 -Bsymbolic --no-undefined
+VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 -Bsymbolic --no-undefined -z noexecstack

arch/sparc/vdso/vclock_gettime.c

···
  * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
  */
 
-#include <linux/kernel.h>
-#include <linux/time.h>
-#include <linux/string.h>
-#include <asm/io.h>
-#include <asm/unistd.h>
-#include <asm/timex.h>
-#include <asm/clocksource.h>
-#include <asm/vvar.h>
+#include <linux/compiler.h>
+#include <linux/types.h>
 
-#ifdef	CONFIG_SPARC64
-#define SYSCALL_STRING							\
-	"ta	0x6d;"							\
-	"bcs,a	1f;"							\
-	" sub	%%g0, %%o0, %%o0;"					\
-	"1:"
+#include <vdso/gettime.h>
+
+#include <asm/vdso/gettimeofday.h>
+
+#include "../../../../lib/vdso/gettimeofday.c"
+
+int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+	return __cvdso_gettimeofday(tv, tz);
+}
+
+int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
+	__weak __alias(__vdso_gettimeofday);
+
+#if defined(CONFIG_SPARC64)
+int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime(clock, ts);
+}
+
+int clock_gettime(clockid_t, struct __kernel_timespec *)
+	__weak __alias(__vdso_clock_gettime);
+
 #else
-#define SYSCALL_STRING							\
-	"ta	0x10;"							\
-	"bcs,a	1f;"							\
-	" sub	%%g0, %%o0, %%o0;"					\
-	"1:"
+
+int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts)
+{
+	return __cvdso_clock_gettime32(clock, ts);
+}
+
+int clock_gettime(clockid_t, struct old_timespec32 *)
+	__weak __alias(__vdso_clock_gettime);
+
+int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime(clock, ts);
+}
+
+int clock_gettime64(clockid_t, struct __kernel_timespec *)
+	__weak __alias(__vdso_clock_gettime64);
+
 #endif
-
-#define SYSCALL_CLOBBERS						\
-	"f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",			\
-	"f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",		\
-	"f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",		\
-	"f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",		\
-	"f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46",		\
-	"f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62",		\
-	"cc", "memory"
-
-/*
- * Compute the vvar page's address in the process address space, and return it
- * as a pointer to the vvar_data.
- */
-notrace static __always_inline struct vvar_data *get_vvar_data(void)
-{
-	unsigned long ret;
-
-	/*
-	 * vdso data page is the first vDSO page so grab the PC
-	 * and move up a page to get to the data page.
-	 */
-	__asm__("rd %%pc, %0" : "=r" (ret));
-	ret &= ~(8192 - 1);
-	ret -= 8192;
-
-	return (struct vvar_data *) ret;
-}
-
-notrace static long vdso_fallback_gettime(long clock, struct __kernel_old_timespec *ts)
-{
-	register long num __asm__("g1") = __NR_clock_gettime;
-	register long o0 __asm__("o0") = clock;
-	register long o1 __asm__("o1") = (long) ts;
-
-	__asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
-			     "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
-	return o0;
-}
-
-notrace static long vdso_fallback_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
-{
-	register long num __asm__("g1") = __NR_gettimeofday;
-	register long o0 __asm__("o0") = (long) tv;
-	register long o1 __asm__("o1") = (long) tz;
-
-	__asm__ __volatile__(SYSCALL_STRING : "=r" (o0) : "r" (num),
-			     "0" (o0), "r" (o1) : SYSCALL_CLOBBERS);
-	return o0;
-}
-
-#ifdef	CONFIG_SPARC64
-notrace static __always_inline u64 __shr64(u64 val, int amt)
-{
-	return val >> amt;
-}
-
-notrace static __always_inline u64 vread_tick(void)
-{
-	u64	ret;
-
-	__asm__ __volatile__("rd %%tick, %0" : "=r" (ret));
-	return ret;
-}
-
-notrace static __always_inline u64 vread_tick_stick(void)
-{
-	u64	ret;
-
-	__asm__ __volatile__("rd %%asr24, %0" : "=r" (ret));
-	return ret;
-}
-#else
-notrace static __always_inline u64 __shr64(u64 val, int amt)
-{
-	u64 ret;
-
-	__asm__ __volatile__("sllx %H1, 32, %%g1\n\t"
-			     "srl %L1, 0, %L1\n\t"
-			     "or %%g1, %L1, %%g1\n\t"
-			     "srlx %%g1, %2, %L0\n\t"
-			     "srlx %L0, 32, %H0"
-			     : "=r" (ret)
-			     : "r" (val), "r" (amt)
-			     : "g1");
-	return ret;
-}
-
-notrace static __always_inline u64 vread_tick(void)
-{
-	register unsigned long long ret asm("o4");
-
-	__asm__ __volatile__("rd %%tick, %L0\n\t"
-			     "srlx %L0, 32, %H0"
-			     : "=r" (ret));
-	return ret;
-}
-
-notrace static __always_inline u64 vread_tick_stick(void)
-{
-	register unsigned long long ret asm("o4");
-
-	__asm__ __volatile__("rd %%asr24, %L0\n\t"
-			     "srlx %L0, 32, %H0"
-			     : "=r" (ret));
-	return ret;
-}
-#endif
-
-notrace static __always_inline u64 vgetsns(struct vvar_data *vvar)
-{
-	u64 v;
-	u64 cycles;
-
-	cycles = vread_tick();
-	v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
-	return v * vvar->clock.mult;
-}
-
-notrace static __always_inline u64 vgetsns_stick(struct vvar_data *vvar)
-{
-	u64 v;
-	u64 cycles;
-
-	cycles = vread_tick_stick();
-	v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
-	return v * vvar->clock.mult;
-}
-
-notrace static __always_inline int do_realtime(struct vvar_data *vvar,
-					       struct __kernel_old_timespec *ts)
-{
-	unsigned long seq;
-	u64 ns;
-
-	do {
-		seq = vvar_read_begin(vvar);
-		ts->tv_sec = vvar->wall_time_sec;
-		ns = vvar->wall_time_snsec;
-		ns += vgetsns(vvar);
-		ns = __shr64(ns, vvar->clock.shift);
-	} while (unlikely(vvar_read_retry(vvar, seq)));
-
-	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
-	ts->tv_nsec = ns;
-
-	return 0;
-}
-
-notrace static __always_inline int do_realtime_stick(struct vvar_data *vvar,
-						     struct __kernel_old_timespec *ts)
-{
-	unsigned long seq;
-	u64 ns;
-
-	do {
-		seq = vvar_read_begin(vvar);
-		ts->tv_sec = vvar->wall_time_sec;
-		ns = vvar->wall_time_snsec;
-		ns += vgetsns_stick(vvar);
-		ns = __shr64(ns, vvar->clock.shift);
-	} while (unlikely(vvar_read_retry(vvar, seq)));
-
-	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
-	ts->tv_nsec = ns;
-
-	return 0;
-}
-
-notrace static __always_inline int do_monotonic(struct vvar_data *vvar,
-						struct __kernel_old_timespec *ts)
-{
-	unsigned long seq;
-	u64 ns;
-
-	do {
-		seq = vvar_read_begin(vvar);
-		ts->tv_sec = vvar->monotonic_time_sec;
-		ns = vvar->monotonic_time_snsec;
-		ns += vgetsns(vvar);
-		ns = __shr64(ns, vvar->clock.shift);
-	} while (unlikely(vvar_read_retry(vvar, seq)));
-
-	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
-	ts->tv_nsec = ns;
-
-	return 0;
-}
-
-notrace static __always_inline int do_monotonic_stick(struct vvar_data *vvar,
-						      struct __kernel_old_timespec *ts)
-{
-	unsigned long seq;
-	u64 ns;
-
-	do {
-		seq = vvar_read_begin(vvar);
-		ts->tv_sec = vvar->monotonic_time_sec;
-		ns = vvar->monotonic_time_snsec;
-		ns += vgetsns_stick(vvar);
-		ns = __shr64(ns, vvar->clock.shift);
-	} while (unlikely(vvar_read_retry(vvar, seq)));
-
-	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
-	ts->tv_nsec = ns;
-
-	return 0;
-}
-
-notrace static int do_realtime_coarse(struct vvar_data *vvar,
-				      struct __kernel_old_timespec *ts)
-{
-	unsigned long seq;
-
-	do {
-		seq = vvar_read_begin(vvar);
-		ts->tv_sec = vvar->wall_time_coarse_sec;
-		ts->tv_nsec = vvar->wall_time_coarse_nsec;
-	} while (unlikely(vvar_read_retry(vvar, seq)));
-	return 0;
-}
-
-notrace static int do_monotonic_coarse(struct vvar_data *vvar,
-				       struct __kernel_old_timespec *ts)
-{
-	unsigned long seq;
-
-	do {
-		seq = vvar_read_begin(vvar);
-		ts->tv_sec = vvar->monotonic_time_coarse_sec;
-		ts->tv_nsec = vvar->monotonic_time_coarse_nsec;
-	} while (unlikely(vvar_read_retry(vvar, seq)));
-
-	return 0;
-}
-
-notrace int
-__vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
-{
-	struct vvar_data *vvd = get_vvar_data();
-
-	switch (clock) {
-	case CLOCK_REALTIME:
-		if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
-			break;
-		return do_realtime(vvd, ts);
-	case CLOCK_MONOTONIC:
-		if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
-			break;
-		return do_monotonic(vvd, ts);
-	case CLOCK_REALTIME_COARSE:
-		return do_realtime_coarse(vvd, ts);
-	case CLOCK_MONOTONIC_COARSE:
-		return do_monotonic_coarse(vvd, ts);
-	}
-	/*
-	 * Unknown clock ID ? Fall back to the syscall.
-	 */
-	return vdso_fallback_gettime(clock, ts);
-}
-int
-clock_gettime(clockid_t, struct __kernel_old_timespec *)
-	__attribute__((weak, alias("__vdso_clock_gettime")));
-
-notrace int
-__vdso_clock_gettime_stick(clockid_t clock, struct __kernel_old_timespec *ts)
-{
-	struct vvar_data *vvd = get_vvar_data();
-
-	switch (clock) {
-	case CLOCK_REALTIME:
-		if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
-			break;
-		return do_realtime_stick(vvd, ts);
-	case CLOCK_MONOTONIC:
-		if (unlikely(vvd->vclock_mode == VCLOCK_NONE))
-			break;
-		return do_monotonic_stick(vvd, ts);
-	case CLOCK_REALTIME_COARSE:
-		return do_realtime_coarse(vvd, ts);
-	case CLOCK_MONOTONIC_COARSE:
-		return do_monotonic_coarse(vvd, ts);
-	}
-	/*
-	 * Unknown clock ID ? Fall back to the syscall.
-	 */
-	return vdso_fallback_gettime(clock, ts);
-}
-
-notrace int
-__vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
-{
-	struct vvar_data *vvd = get_vvar_data();
-
-	if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
-		if (likely(tv != NULL)) {
-			union tstv_t {
-				struct __kernel_old_timespec ts;
-				struct __kernel_old_timeval tv;
-			} *tstv = (union tstv_t *) tv;
-			do_realtime(vvd, &tstv->ts);
-			/*
-			 * Assign before dividing to ensure that the division is
-			 * done in the type of tv_usec, not tv_nsec.
-			 *
-			 * There cannot be > 1 billion usec in a second:
-			 * do_realtime() has already distributed such overflow
-			 * into tv_sec.  So we can assign it to an int safely.
-			 */
-			tstv->tv.tv_usec = tstv->ts.tv_nsec;
-			tstv->tv.tv_usec /= 1000;
-		}
-		if (unlikely(tz != NULL)) {
-			/* Avoid memcpy. Some old compilers fail to inline it */
-			tz->tz_minuteswest = vvd->tz_minuteswest;
-			tz->tz_dsttime = vvd->tz_dsttime;
-		}
-		return 0;
-	}
-	return vdso_fallback_gettimeofday(tv, tz);
-}
-int
-gettimeofday(struct __kernel_old_timeval *, struct timezone *)
-	__attribute__((weak, alias("__vdso_gettimeofday")));
-
-notrace int
-__vdso_gettimeofday_stick(struct __kernel_old_timeval *tv, struct timezone *tz)
-{
-	struct vvar_data *vvd = get_vvar_data();
-
-	if (likely(vvd->vclock_mode != VCLOCK_NONE)) {
-		if (likely(tv != NULL)) {
-			union tstv_t {
-				struct __kernel_old_timespec ts;
-				struct __kernel_old_timeval tv;
-			} *tstv = (union tstv_t *) tv;
-			do_realtime_stick(vvd, &tstv->ts);
-			/*
-			 * Assign before dividing to ensure that the division is
-			 * done in the type of tv_usec, not tv_nsec.
-			 *
-			 * There cannot be > 1 billion usec in a second:
-			 * do_realtime() has already distributed such overflow
-			 * into tv_sec.  So we can assign it to an int safely.
-			 */
-			tstv->tv.tv_usec = tstv->ts.tv_nsec;
-			tstv->tv.tv_usec /= 1000;
-		}
-		if (unlikely(tz != NULL)) {
-			/* Avoid memcpy. Some old compilers fail to inline it */
-			tz->tz_minuteswest = vvd->tz_minuteswest;
-			tz->tz_dsttime = vvd->tz_dsttime;
-		}
-		return 0;
-	}
-	return vdso_fallback_gettimeofday(tv, tz);
-}

arch/sparc/vdso/vdso-layout.lds.S

···
  * This script controls its layout.
  */
 
-#if defined(BUILD_VDSO64)
-# define SHDR_SIZE 64
-#elif defined(BUILD_VDSO32)
-# define SHDR_SIZE 40
-#else
-# error unknown VDSO target
-#endif
-
-#define NUM_FAKE_SHDRS 7
+#include <vdso/datapage.h>
+#include <vdso/page.h>
+#include <asm/vdso/vsyscall.h>
 
 SECTIONS
 {
···
 	 * segment. Page size is 8192 for both 64-bit and 32-bit vdso binaries
 	 */
 
-	vvar_start = . -8192;
-	vvar_data = vvar_start;
+	VDSO_VVAR_SYMS
 
 	. = SIZEOF_HEADERS;
 
···
 		*(.bss*)
 		*(.dynbss*)
 		*(.gnu.linkonce.b.*)
-
-		/*
-		 * Ideally this would live in a C file: kept in here for
-		 * compatibility with x86-64.
-		 */
-		VDSO_FAKE_SECTION_TABLE_START = .;
-		. = . + NUM_FAKE_SHDRS * SHDR_SIZE;
-		VDSO_FAKE_SECTION_TABLE_END = .;
 	}						:text
-
-	.fake_shstrtab	: { *(.fake_shstrtab) }		:text
-
 
 	.note		: { *(.note.*) }		:text	:note
 

arch/sparc/vdso/vdso.lds.S

···
 	global:
 		clock_gettime;
 		__vdso_clock_gettime;
-		__vdso_clock_gettime_stick;
 		gettimeofday;
 		__vdso_gettimeofday;
-		__vdso_gettimeofday_stick;
 	local: *;
 	};
 }

arch/sparc/vdso/vdso2c.c

···
 
 const char *outfilename;
 
-/* Symbols that we need in vdso2c. */
-enum {
-	sym_vvar_start,
-	sym_VDSO_FAKE_SECTION_TABLE_START,
-	sym_VDSO_FAKE_SECTION_TABLE_END,
-};
-
-struct vdso_sym {
-	const char *name;
-	int export;
-};
-
-struct vdso_sym required_syms[] = {
-	[sym_vvar_start] = {"vvar_start", 1},
-	[sym_VDSO_FAKE_SECTION_TABLE_START] = {
-		"VDSO_FAKE_SECTION_TABLE_START", 0
-	},
-	[sym_VDSO_FAKE_SECTION_TABLE_END] = {
-		"VDSO_FAKE_SECTION_TABLE_END", 0
-	},
-};
-
 __attribute__((format(printf, 1, 2))) __attribute__((noreturn))
 static void fail(const char *format, ...)
 {
···
 
 #define PUT_BE(x, val)					\
 	PBE(x, val, 64, PBE(x, val, 32, PBE(x, val, 16, LAST_PBE(x, val))))
-
-#define NSYMS ARRAY_SIZE(required_syms)
 
 #define BITSFUNC3(name, bits, suffix) name##bits##suffix
 #define BITSFUNC2(name, bits, suffix) BITSFUNC3(name, bits, suffix)

arch/sparc/vdso/vdso2c.h

···
 	unsigned long mapping_size;
 	int i;
 	unsigned long j;
-	ELF(Shdr) *symtab_hdr = NULL, *strtab_hdr;
+	ELF(Shdr) *symtab_hdr = NULL;
 	ELF(Ehdr) *hdr = (ELF(Ehdr) *)raw_addr;
 	ELF(Dyn) *dyn = 0, *dyn_end = 0;
-	INT_BITS syms[NSYMS] = {};
-
 	ELF(Phdr) *pt = (ELF(Phdr) *)(raw_addr + GET_BE(&hdr->e_phoff));
 
 	/* Walk the segment table. */
···
 	if (!symtab_hdr)
 		fail("no symbol table\n");
 
-	strtab_hdr = raw_addr + GET_BE(&hdr->e_shoff) +
-		GET_BE(&hdr->e_shentsize) * GET_BE(&symtab_hdr->sh_link);
-
-	/* Walk the symbol table */
-	for (i = 0;
-	     i < GET_BE(&symtab_hdr->sh_size) / GET_BE(&symtab_hdr->sh_entsize);
-	     i++) {
-		int k;
-
-		ELF(Sym) *sym = raw_addr + GET_BE(&symtab_hdr->sh_offset) +
-			GET_BE(&symtab_hdr->sh_entsize) * i;
-		const char *name = raw_addr + GET_BE(&strtab_hdr->sh_offset) +
-			GET_BE(&sym->st_name);
-
-		for (k = 0; k < NSYMS; k++) {
-			if (!strcmp(name, required_syms[k].name)) {
-				if (syms[k]) {
-					fail("duplicate symbol %s\n",
-					     required_syms[k].name);
-				}
-
-				/*
-				 * Careful: we use negative addresses, but
-				 * st_value is unsigned, so we rely
-				 * on syms[k] being a signed type of the
-				 * correct width.
-				 */
-				syms[k] = GET_BE(&sym->st_value);
-			}
-		}
-	}
-
-	/* Validate mapping addresses. */
-	if (syms[sym_vvar_start] % 8192)
-		fail("vvar_begin must be a multiple of 8192\n");
-
 	if (!name) {
 		fwrite(stripped_addr, stripped_len, 1, outfile);
 		return;
···
 	fprintf(outfile, "const struct vdso_image %s_builtin = {\n", name);
 	fprintf(outfile, "\t.data = raw_data,\n");
 	fprintf(outfile, "\t.size = %lu,\n", mapping_size);
-	for (i = 0; i < NSYMS; i++) {
-		if (required_syms[i].export && syms[i])
-			fprintf(outfile, "\t.sym_%s = %" PRIi64 ",\n",
-				required_syms[i].name, (int64_t)syms[i]);
-	}
 	fprintf(outfile, "};\n");
 }

arch/sparc/vdso/vdso32/vdso32.lds.S

···
 	global:
 		clock_gettime;
 		__vdso_clock_gettime;
-		__vdso_clock_gettime_stick;
+		clock_gettime64;
+		__vdso_clock_gettime64;
 		gettimeofday;
 		__vdso_gettimeofday;
-		__vdso_gettimeofday_stick;
 	local: *;
 	};
 }

arch/sparc/vdso/vma.c

···
 #include <linux/linkage.h>
 #include <linux/random.h>
 #include <linux/elf.h>
+#include <linux/vdso_datastore.h>
 #include <asm/cacheflush.h>
 #include <asm/spitfire.h>
 #include <asm/vdso.h>
-#include <asm/vvar.h>
 #include <asm/page.h>
 
-unsigned int __read_mostly vdso_enabled = 1;
+#include <vdso/datapage.h>
+#include <asm/vdso/vsyscall.h>
 
-static struct vm_special_mapping vvar_mapping = {
-	.name = "[vvar]"
-};
+unsigned int __read_mostly vdso_enabled = 1;
 
 #ifdef	CONFIG_SPARC64
 static struct vm_special_mapping vdso_mapping64 = {
···
 };
 #endif
 
-struct vvar_data *vvar_data;
-
-struct vdso_elfinfo32 {
-	Elf32_Ehdr	*hdr;
-	Elf32_Sym	*dynsym;
-	unsigned long	dynsymsize;
-	const char	*dynstr;
-	unsigned long	text;
-};
-
-struct vdso_elfinfo64 {
-	Elf64_Ehdr	*hdr;
-	Elf64_Sym	*dynsym;
-	unsigned long	dynsymsize;
-	const char	*dynstr;
-	unsigned long	text;
-};
-
-struct vdso_elfinfo {
-	union {
-		struct vdso_elfinfo32 elf32;
-		struct vdso_elfinfo64 elf64;
-	} u;
-};
-
-static void *one_section64(struct vdso_elfinfo64 *e, const char *name,
-			   unsigned long *size)
-{
-	const char *snames;
-	Elf64_Shdr *shdrs;
-	unsigned int i;
-
-	shdrs = (void *)e->hdr + e->hdr->e_shoff;
-	snames = (void *)e->hdr + shdrs[e->hdr->e_shstrndx].sh_offset;
-	for (i = 1; i < e->hdr->e_shnum; i++) {
-		if (!strcmp(snames+shdrs[i].sh_name, name)) {
-			if (size)
-				*size = shdrs[i].sh_size;
-			return (void *)e->hdr + shdrs[i].sh_offset;
-		}
-	}
-	return NULL;
-}
-
-static int find_sections64(const struct vdso_image *image, struct vdso_elfinfo *_e)
-{
-	struct vdso_elfinfo64 *e = &_e->u.elf64;
-
-	e->hdr = image->data;
-	e->dynsym = one_section64(e, ".dynsym", &e->dynsymsize);
-	e->dynstr = one_section64(e, ".dynstr", NULL);
-
-	if (!e->dynsym || !e->dynstr) {
-		pr_err("VDSO64: Missing symbol sections.\n");
-		return -ENODEV;
-	}
-	return 0;
-}
-
-static Elf64_Sym *find_sym64(const struct vdso_elfinfo64 *e, const char *name)
-{
-	unsigned int i;
-
-	for (i = 0; i < (e->dynsymsize / sizeof(Elf64_Sym)); i++) {
-		Elf64_Sym *s = &e->dynsym[i];
-		if (s->st_name == 0)
-			continue;
-		if (!strcmp(e->dynstr + s->st_name, name))
-			return s;
-	}
-	return NULL;
-}
-
-static int patchsym64(struct vdso_elfinfo *_e, const char *orig,
-		      const char *new)
-{
-	struct vdso_elfinfo64 *e = &_e->u.elf64;
-	Elf64_Sym *osym = find_sym64(e, orig);
-	Elf64_Sym *nsym = find_sym64(e, new);
-
-	if (!nsym || !osym) {
-		pr_err("VDSO64: Missing symbols.\n");
-		return -ENODEV;
-	}
-	osym->st_value = nsym->st_value;
-	osym->st_size = nsym->st_size;
-	osym->st_info = nsym->st_info;
-	osym->st_other = nsym->st_other;
-	osym->st_shndx = nsym->st_shndx;
-
-	return 0;
-}
-
-static void *one_section32(struct vdso_elfinfo32 *e, const char *name,
-			   unsigned long *size)
-{
-	const char *snames;
-	Elf32_Shdr *shdrs;
-	unsigned int i;
-
-	shdrs = (void *)e->hdr + e->hdr->e_shoff;
-	snames = (void *)e->hdr + shdrs[e->hdr->e_shstrndx].sh_offset;
-	for (i = 1; i < e->hdr->e_shnum; i++) {
-		if (!strcmp(snames+shdrs[i].sh_name, name)) {
-			if (size)
-				*size = shdrs[i].sh_size;
-			return (void *)e->hdr + shdrs[i].sh_offset;
-		}
-	}
-	return NULL;
-}
-
-static int find_sections32(const struct vdso_image *image, struct vdso_elfinfo *_e)
-{
-	struct vdso_elfinfo32 *e = &_e->u.elf32;
-
-	e->hdr = image->data;
-	e->dynsym = one_section32(e, ".dynsym", &e->dynsymsize);
-	e->dynstr = one_section32(e, ".dynstr", NULL);
-
-	if (!e->dynsym || !e->dynstr) {
-		pr_err("VDSO32: Missing symbol sections.\n");
-		return -ENODEV;
-	}
-	return 0;
-}
-
-static Elf32_Sym *find_sym32(const struct vdso_elfinfo32 *e, const char *name)
-{
-	unsigned int i;
-
-	for (i = 0; i < (e->dynsymsize / sizeof(Elf32_Sym)); i++) {
-		Elf32_Sym *s = &e->dynsym[i];
-		if (s->st_name == 0)
-			continue;
-		if (!strcmp(e->dynstr + s->st_name, name))
-			return s;
-	}
-	return NULL;
-}
-
-static int patchsym32(struct vdso_elfinfo *_e, const char *orig,
-		      const char *new)
-{
-	struct vdso_elfinfo32 *e = &_e->u.elf32;
-	Elf32_Sym *osym = find_sym32(e, orig);
-	Elf32_Sym *nsym = find_sym32(e, new);
-
-	if (!nsym || !osym) {
-		pr_err("VDSO32: Missing symbols.\n");
-		return -ENODEV;
-	}
-	osym->st_value = nsym->st_value;
-	osym->st_size = nsym->st_size;
-	osym->st_info = nsym->st_info;
-	osym->st_other = nsym->st_other;
-	osym->st_shndx = nsym->st_shndx;
-
-	return 0;
-}
-
-static int find_sections(const struct vdso_image *image, struct vdso_elfinfo *e,
-			 bool elf64)
-{
-	if (elf64)
-		return find_sections64(image, e);
-	else
-		return find_sections32(image, e);
-}
-
-static int patch_one_symbol(struct vdso_elfinfo *e, const char *orig,
-			    const char *new_target, bool elf64)
-{
-	if (elf64)
-		return patchsym64(e, orig, new_target);
-	else
-		return patchsym32(e, orig, new_target);
-}
-
-static int stick_patch(const struct vdso_image *image, struct vdso_elfinfo *e, bool elf64)
-{
-	int err;
-
-	err = find_sections(image, e, elf64);
-	if (err)
-		return err;
-
-	err = patch_one_symbol(e,
-			       "__vdso_gettimeofday",
-			       "__vdso_gettimeofday_stick", elf64);
-	if (err)
-		return err;
-
-	return patch_one_symbol(e,
-				"__vdso_clock_gettime",
-				"__vdso_clock_gettime_stick", elf64);
-	return 0;
-}
-
 /*
- * Allocate pages for the vdso and vvar, and copy in the vdso text from the
+ * Allocate pages for the vdso and copy in the vdso text from the
  * kernel image.
  */
 static int __init init_vdso_image(const struct vdso_image *image,
···
 				  bool elf64)
 {
 	int cnpages = (image->size) / PAGE_SIZE;
-	struct page *dp, **dpp = NULL;
 	struct page *cp, **cpp = NULL;
-	struct vdso_elfinfo ei;
-	int i, dnpages = 0;
-
-	if (tlb_type != spitfire) {
-		int err = stick_patch(image, &ei, elf64);
-		if (err)
-			return err;
-	}
+	int i;
 
 	/*
 	 * First, the vdso text.  This is initialied data, an integral number of
···
 		copy_page(page_address(cp), image->data + i * PAGE_SIZE);
 	}
 
-	/*
-	 * Now the vvar page.  This is uninitialized data.
-	 */
-
-	if (vvar_data == NULL) {
-		dnpages = (sizeof(struct vvar_data) / PAGE_SIZE) + 1;
-		if (WARN_ON(dnpages != 1))
-			goto oom;
-		dpp = kzalloc_objs(struct page *, dnpages);
-		vvar_mapping.pages = dpp;
-
-		if (!dpp)
-			goto oom;
-
-		dp = alloc_page(GFP_KERNEL);
-		if (!dp)
-			goto oom;
-
-		dpp[0] = dp;
-		vvar_data = page_address(dp);
-		memset(vvar_data, 0, PAGE_SIZE);
-
-		vvar_data->seq = 0;
-	}
-
 	return 0;
  oom:
 	if (cpp != NULL) {
···
 		}
 		kfree(cpp);
 		vdso_mapping->pages = NULL;
-	}
-
-	if (dpp != NULL) {
-		for (i = 0; i < dnpages; i++) {
-			if (dpp[i] != NULL)
-				__free_page(dpp[i]);
-		}
-		kfree(dpp);
-		vvar_mapping.pages = NULL;
 	}
 
 	pr_warn("Cannot allocate vdso\n");
···
 	return start + (offset << PAGE_SHIFT);
 }
 
+static_assert(VDSO_NR_PAGES == __VDSO_PAGES);
+
 static int map_vdso(const struct vdso_image *image,
 		struct vm_special_mapping *vdso_mapping)
 {
+	const size_t area_size = image->size + VDSO_NR_PAGES * PAGE_SIZE;
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	unsigned long text_start, addr = 0;
···
 	 * region is free.
 	 */
 	if (current->flags & PF_RANDOMIZE) {
-		addr = get_unmapped_area(NULL, 0,
-					 image->size - image->sym_vvar_start,
-					 0, 0);
+		addr = get_unmapped_area(NULL, 0, area_size, 0, 0);
 		if (IS_ERR_VALUE(addr)) {
 			ret = addr;
 			goto up_fail;
 		}
-		addr = vdso_addr(addr, image->size - image->sym_vvar_start);
+		addr = vdso_addr(addr, area_size);
 	}
-	addr = get_unmapped_area(NULL, addr,
-				 image->size - image->sym_vvar_start, 0, 0);
+	addr = get_unmapped_area(NULL, addr, area_size, 0, 0);
 	if (IS_ERR_VALUE(addr)) {
 		ret = addr;
 		goto up_fail;
 	}
 
-	text_start = addr - image->sym_vvar_start;
+	text_start = addr + VDSO_NR_PAGES * PAGE_SIZE;
 	current->mm->context.vdso = (void __user *)text_start;
 
 	/*
···
 		goto up_fail;
 	}
 
-	vma = _install_special_mapping(mm,
-				       addr,
-				       -image->sym_vvar_start,
-				       VM_READ|VM_MAYREAD,
-				       &vvar_mapping);
+	vma = vdso_install_vvar_mapping(mm, addr);
 
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);

arch/x86/entry/vdso/vdso32/Makefile

···
 flags-$(CONFIG_X86_64)	+= -include $(src)/fake_32bit_build.h
 flags-remove-y          := -m64
 
+# Checker flags
+CHECKFLAGS := $(subst -m64,-m32,$(CHECKFLAGS))
+CHECKFLAGS := $(subst -D__x86_64__,-D__i386__,$(CHECKFLAGS))
+
 # The location of this include matters!
 include $(src)/../common/Makefile.include
 

drivers/char/random.c

···
 #include <linux/sched/isolation.h>
 #include <crypto/chacha.h>
 #include <crypto/blake2s.h>
-#ifdef CONFIG_VDSO_GETRANDOM
-#include <vdso/getrandom.h>
 #include <vdso/datapage.h>
-#include <vdso/vsyscall.h>
-#endif
 #include <asm/archrandom.h>
 #include <asm/processor.h>
 #include <asm/irq.h>
···
 	if (next_gen == ULONG_MAX)
 		++next_gen;
 	WRITE_ONCE(base_crng.generation, next_gen);
-#ifdef CONFIG_VDSO_GETRANDOM
+
 	/* base_crng.generation's invalid value is ULONG_MAX, while
 	 * vdso_k_rng_data->generation's invalid value is 0, so add one to the
 	 * former to arrive at the latter. Use smp_store_release so that this
···
 	 * because the vDSO side only checks whether the value changed, without
 	 * actually using or interpreting the value.
 	 */
-	smp_store_release((unsigned long *)&vdso_k_rng_data->generation, next_gen + 1);
-#endif
+	if (IS_ENABLED(CONFIG_VDSO_GETRANDOM))
+		smp_store_release((unsigned long *)&vdso_k_rng_data->generation, next_gen + 1);
+
 	if (!static_branch_likely(&crng_is_ready))
 		crng_init = CRNG_READY;
 	spin_unlock_irqrestore(&base_crng.lock, flags);
···
 		if (system_dfl_wq)
 			queue_work(system_dfl_wq, &set_ready);
 		atomic_notifier_call_chain(&random_ready_notifier, 0, NULL);
-#ifdef CONFIG_VDSO_GETRANDOM
-		WRITE_ONCE(vdso_k_rng_data->is_ready, true);
-#endif
+		if (IS_ENABLED(CONFIG_VDSO_GETRANDOM))
+			WRITE_ONCE(vdso_k_rng_data->is_ready, true);
 		wake_up_interruptible(&crng_init_wait);
 		kill_fasync(&fasync, SIGIO, POLL_IN);
 		pr_notice("crng init done\n");

include/asm-generic/bitsperlong.h

···
 #error Inconsistent word size. Check asm/bitsperlong.h
 #endif
 
+#if __CHAR_BIT__ * __SIZEOF_LONG__ != __BITS_PER_LONG
+#error Inconsistent word size. Check asm/bitsperlong.h
+#endif
+
+#ifndef __ASSEMBLER__
+_Static_assert(sizeof(long) * 8 == __BITS_PER_LONG,
+	       "Inconsistent word size. Check asm/bitsperlong.h");
+#endif
+
 #ifndef BITS_PER_LONG_LONG
 #define BITS_PER_LONG_LONG 64
 #endif

include/linux/clocksource.h

···
 struct clocksource;
 struct module;
 
-#if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \
-    defined(CONFIG_GENERIC_GETTIMEOFDAY)
+#if defined(CONFIG_GENERIC_GETTIMEOFDAY)
 #include <asm/clocksource.h>
 #endif
 
···
 	u32			shift;
 	u64			max_idle_ns;
 	u32			maxadj;
-#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
-	struct arch_clocksource_data archdata;
-#endif
 	u64			max_cycles;
 	u64			max_raw_delta;
 	const char		*name;

include/linux/time_namespace.h

···
 #include <linux/ns_common.h>
 #include <linux/err.h>
 #include <linux/time64.h>
+#include <linux/cleanup.h>
 
 struct user_namespace;
 extern struct user_namespace init_user_ns;
···
 	struct ucounts		*ucounts;
 	struct ns_common	ns;
 	struct timens_offsets	offsets;
+#ifdef CONFIG_TIME_NS_VDSO
 	struct page		*vvar_page;
+#endif
 	/* If set prevents changing offsets after any task joined namespace. */
 	bool			frozen_offsets;
 } __randomize_layout;
···
 	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);
-extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns);
 
 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
 {
···
 				    struct time_namespace *old_ns);
 void free_time_ns(struct time_namespace *ns);
 void timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
-struct page *find_timens_vvar_page(struct vm_area_struct *vma);
 
 static inline void put_time_ns(struct time_namespace *ns)
 {
···
 {
 }
 
-static inline int vdso_join_timens(struct task_struct *task,
-				   struct time_namespace *ns)
-{
-	return 0;
-}
-
-static inline void timens_commit(struct task_struct *tsk,
-				 struct time_namespace *ns)
-{
-}
-
 static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
 {
 	return NULL;
···
 	return;
 }
 
-static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
-{
-	return NULL;
-}
-
 static inline void timens_add_monotonic(struct timespec64 *ts) { }
 static inline void timens_add_boottime(struct timespec64 *ts) { }
 
···
 	return tim;
 }
 #endif
+
+#ifdef CONFIG_TIME_NS_VDSO
+extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns);
+struct page *find_timens_vvar_page(struct vm_area_struct *vma);
+#else /* !CONFIG_TIME_NS_VDSO */
+static inline void timens_commit(struct task_struct *tsk, struct time_namespace *ns)
+{
+}
+
+static inline struct page *find_timens_vvar_page(struct vm_area_struct *vma)
+{
+	return NULL;
+}
+#endif /* CONFIG_TIME_NS_VDSO */
+
+DEFINE_FREE(time_ns, struct time_namespace *, if (_T) put_time_ns(_T))
 
 #endif /* _LINUX_TIMENS_H */

include/linux/vdso_datastore.h

···
 #ifndef _LINUX_VDSO_DATASTORE_H
 #define _LINUX_VDSO_DATASTORE_H
 
+#ifdef CONFIG_HAVE_GENERIC_VDSO
 #include <linux/mm_types.h>
 
 extern const struct vm_special_mapping vdso_vvar_mapping;
 struct vm_area_struct *vdso_install_vvar_mapping(struct mm_struct *mm, unsigned long addr);
+
+void __init vdso_setup_data_pages(void);
+#else /* !CONFIG_HAVE_GENERIC_VDSO */
+static inline void vdso_setup_data_pages(void) { }
+#endif /* CONFIG_HAVE_GENERIC_VDSO */
 
 #endif /* _LINUX_VDSO_DATASTORE_H */

include/vdso/datapage.h

···
 
 #ifndef __ASSEMBLY__
 
-#include <linux/compiler.h>
+#include <linux/types.h>
+
 #include <uapi/linux/bits.h>
 #include <uapi/linux/time.h>
-#include <uapi/linux/types.h>
-#include <uapi/asm-generic/errno-base.h>
 
 #include <vdso/align.h>
 #include <vdso/bits.h>
 #include <vdso/cache.h>
-#include <vdso/clocksource.h>
-#include <vdso/ktime.h>
-#include <vdso/limits.h>
-#include <vdso/math64.h>
 #include <vdso/page.h>
-#include <vdso/processor.h>
 #include <vdso/time.h>
-#include <vdso/time32.h>
-#include <vdso/time64.h>
 
 #ifdef CONFIG_ARCH_HAS_VDSO_TIME_DATA
 #include <asm/vdso/time_data.h>
···
  * @mask:		clocksource mask
  * @mult:		clocksource multiplier
  * @shift:		clocksource shift
- * @basetime[clock_id]:	basetime per clock_id
- * @offset[clock_id]:	time namespace offset per clock_id
+ * @basetime:		basetime per clock_id
+ * @offset:		time namespace offset per clock_id
  *
  * See also struct vdso_time_data for basic access and ordering information as
  * struct vdso_clock is used there.
···
 	VDSO_ARCH_PAGES_END = VDSO_ARCH_PAGES_START + VDSO_ARCH_DATA_PAGES - 1,
 	VDSO_NR_PAGES
 };
-
-/*
- * The generic vDSO implementation requires that gettimeofday.h
- * provides:
- * - __arch_get_hw_counter(): to get the hw counter based on the
- *   clock_mode.
- * - gettimeofday_fallback(): fallback for gettimeofday.
- * - clock_gettime_fallback(): fallback for clock_gettime.
- * - clock_getres_fallback(): fallback for clock_getres.
- */
-#include <asm/vdso/gettimeofday.h>
 
 #else /* !__ASSEMBLY__ */
 

include/vdso/helpers.h

···
 
 #include <asm/barrier.h>
 #include <vdso/datapage.h>
+#include <vdso/processor.h>
+#include <vdso/clocksource.h>
+
+static __always_inline bool vdso_is_timens_clock(const struct vdso_clock *vc)
+{
+	return IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS;
+}
 
 static __always_inline u32 vdso_read_begin(const struct vdso_clock *vc)
 {
···
 	return seq;
 }
 
+/*
+ * Variant of vdso_read_begin() to handle VDSO_CLOCKMODE_TIMENS.
+ *
+ * Time namespace enabled tasks have a special VVAR page installed which has
+ * vc->seq set to 1 and vc->clock_mode set to VDSO_CLOCKMODE_TIMENS. For non
+ * time namespace affected tasks this does not affect performance because if
+ * vc->seq is odd, i.e. a concurrent update is in progress the extra check for
+ * vc->clock_mode is just a few extra instructions while spin waiting for
+ * vc->seq to become even again.
+ */
+static __always_inline bool vdso_read_begin_timens(const struct vdso_clock *vc, u32 *seq)
+{
+	while (unlikely((*seq = READ_ONCE(vc->seq)) & 1)) {
+		if (vdso_is_timens_clock(vc))
+			return true;
+		cpu_relax();
+	}
+	smp_rmb();
+
+	return false;
+}
+
 static __always_inline u32 vdso_read_retry(const struct vdso_clock *vc,
 					   u32 start)
 {
···
 
 	smp_rmb();
 	seq = READ_ONCE(vc->seq);
-	return seq != start;
+	return unlikely(seq != start);
 }
 
 static __always_inline void vdso_write_seq_begin(struct vdso_clock *vc)

init/Kconfig

···
 
 config TIME_NS
 	bool "TIME namespace"
-	depends on GENERIC_GETTIMEOFDAY
 	default y
 	help
 	  In this namespace boottime and monotonic clocks can be set.
 	  The time will keep going with the same pace.
+
+config TIME_NS_VDSO
+	def_bool TIME_NS && GENERIC_GETTIMEOFDAY
 
 config IPC_NS
 	bool "IPC namespace"

init/main.c

···
 #include <linux/ptdump.h>
 #include <linux/time_namespace.h>
 #include <linux/unaligned.h>
+#include <linux/vdso_datastore.h>
 #include <net/net_namespace.h>
 
 #include <asm/io.h>
···
 	srcu_init();
 	hrtimers_init();
 	softirq_init();
+	vdso_setup_data_pages();
 	timekeeping_init();
 	time_init();
 

kernel/time/Kconfig

···
 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

kernel/time/Makefile

···
 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

kernel/time/namespace.c

···
 #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)
···
 	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);
···
 	return ns;
 
 fail_free_page:
-	__free_page(ns->vvar_page);
+	timens_vdso_free_vvar_page(ns);
 fail_free:
 	kfree(ns);
 fail_dec:
···
 	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)
 {
···
 	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)
 {
 	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)
···
 
 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];
···
 			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);
 		/*
···
 		 * 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];
···
 		*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 = {

kernel/time/namespace_internal.h

···
+/* 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 */

kernel/time/namespace_vdso.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Author: Andrei Vagin <[e-mail]>
+ * Author: Dmitry Safonov <[e-mail]>
+ */
+
+#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);
+}

lib/vdso/datastore.c

···
 // SPDX-License-Identifier: GPL-2.0-only
 
-#include <linux/linkage.h>
-#include <linux/mmap_lock.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/time_namespace.h>
 #include <linux/types.h>
 #include <linux/vdso_datastore.h>
 #include <vdso/datapage.h>
 
-/*
- * The vDSO data page.
- */
+static u8 vdso_initdata[VDSO_NR_PAGES * PAGE_SIZE] __aligned(PAGE_SIZE) __initdata = {};
+
 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
-static union {
-	struct vdso_time_data	data;
-	u8			page[PAGE_SIZE];
-} vdso_time_data_store __page_aligned_data;
-struct vdso_time_data *vdso_k_time_data = &vdso_time_data_store.data;
-static_assert(sizeof(vdso_time_data_store) == PAGE_SIZE);
+struct vdso_time_data *vdso_k_time_data __refdata =
+	(void *)&vdso_initdata[VDSO_TIME_PAGE_OFFSET * PAGE_SIZE];
+
+static_assert(sizeof(struct vdso_time_data) <= PAGE_SIZE);
 #endif /* CONFIG_GENERIC_GETTIMEOFDAY */
 
 #ifdef CONFIG_VDSO_GETRANDOM
-static union {
-	struct vdso_rng_data	data;
-	u8			page[PAGE_SIZE];
-} vdso_rng_data_store __page_aligned_data;
-struct vdso_rng_data *vdso_k_rng_data = &vdso_rng_data_store.data;
-static_assert(sizeof(vdso_rng_data_store) == PAGE_SIZE);
+struct vdso_rng_data *vdso_k_rng_data __refdata =
+	(void *)&vdso_initdata[VDSO_RNG_PAGE_OFFSET * PAGE_SIZE];
+
+static_assert(sizeof(struct vdso_rng_data) <= PAGE_SIZE);
 #endif /* CONFIG_VDSO_GETRANDOM */
 
 #ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA
-static union {
-	struct vdso_arch_data	data;
-	u8			page[VDSO_ARCH_DATA_SIZE];
-} vdso_arch_data_store __page_aligned_data;
-struct vdso_arch_data *vdso_k_arch_data = &vdso_arch_data_store.data;
+struct vdso_arch_data *vdso_k_arch_data __refdata =
+	(void *)&vdso_initdata[VDSO_ARCH_PAGES_START * PAGE_SIZE];
 #endif /* CONFIG_ARCH_HAS_VDSO_ARCH_DATA */
+
+void __init vdso_setup_data_pages(void)
+{
+	unsigned int order = get_order(VDSO_NR_PAGES * PAGE_SIZE);
+	struct page *pages;
+
+	/*
+	 * Allocate the data pages dynamically. SPARC does not support mapping
+	 * static pages to be mapped into userspace.
+	 * It is also a requirement for mlockall() support.
+	 *
+	 * Do not use folios. In time namespaces the pages are mapped in a different order
+	 * to userspace, which is not handled by the folio optimizations in finish_fault().
+	 */
+	pages = alloc_pages(GFP_KERNEL, order);
+	if (!pages)
+		panic("Unable to allocate VDSO storage pages");
+
+	/* The pages are mapped one-by-one into userspace and each one needs to be refcounted. */
+	split_page(pages, order);
+
+	/* Move the data already written by other subsystems to the new pages */
+	memcpy(page_address(pages), vdso_initdata, VDSO_NR_PAGES * PAGE_SIZE);
+
+	if (IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY))
+		vdso_k_time_data = page_address(pages + VDSO_TIME_PAGE_OFFSET);
+
+	if (IS_ENABLED(CONFIG_VDSO_GETRANDOM))
+		vdso_k_rng_data = page_address(pages + VDSO_RNG_PAGE_OFFSET);
+
+	if (IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA))
+		vdso_k_arch_data = page_address(pages + VDSO_ARCH_PAGES_START);
+}
 
 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 addr, pfn;
-	vm_fault_t err;
+	struct page *page, *timens_page;
+
+	timens_page = find_timens_vvar_page(vma);
 
 	switch (vmf->pgoff) {
 	case VDSO_TIME_PAGE_OFFSET:
 		if (!IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY))
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_time_data));
+		page = virt_to_page(vdso_k_time_data);
 		if (timens_page) {
 			/*
 			 * Fault in VVAR page too, since it will be accessed
 			 * to get clock data anyway.
 			 */
+			unsigned long addr;
+			vm_fault_t err;
+
 			addr = vmf->address + VDSO_TIMENS_PAGE_OFFSET * PAGE_SIZE;
-			err = vmf_insert_pfn(vma, addr, pfn);
+			err = vmf_insert_page(vma, addr, page);
 			if (unlikely(err & VM_FAULT_ERROR))
 				return err;
-			pfn = page_to_pfn(timens_page);
+			page = timens_page;
 		}
 		break;
 	case VDSO_TIMENS_PAGE_OFFSET:
···
 		 */
 		if (!IS_ENABLED(CONFIG_TIME_NS) || !timens_page)
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_time_data));
+		page = virt_to_page(vdso_k_time_data);
 		break;
 	case VDSO_RNG_PAGE_OFFSET:
 		if (!IS_ENABLED(CONFIG_VDSO_GETRANDOM))
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_rng_data));
+		page = virt_to_page(vdso_k_rng_data);
 		break;
 	case VDSO_ARCH_PAGES_START ... VDSO_ARCH_PAGES_END:
 		if (!IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA))
 			return VM_FAULT_SIGBUS;
-		pfn = __phys_to_pfn(__pa_symbol(vdso_k_arch_data)) +
-			vmf->pgoff - VDSO_ARCH_PAGES_START;
+		page = virt_to_page(vdso_k_arch_data) + vmf->pgoff - VDSO_ARCH_PAGES_START;
 		break;
 	default:
 		return VM_FAULT_SIGBUS;
 	}
 
-	return vmf_insert_pfn(vma, vmf->address, pfn);
+	get_page(page);
+	vmf->page = page;
+	return 0;
 }
 
 const struct vm_special_mapping vdso_vvar_mapping = {
···
 {
 	return _install_special_mapping(mm, addr, VDSO_NR_PAGES * PAGE_SIZE,
 					VM_READ | VM_MAYREAD | VM_IO | VM_DONTDUMP |
-					VM_PFNMAP | VM_SEALED_SYSMAP,
+					VM_MIXEDMAP | VM_SEALED_SYSMAP,
 					&vdso_vvar_mapping);
 }
-
-#ifdef CONFIG_TIME_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.
- */
-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, &vdso_vvar_mapping))
-			zap_vma_pages(vma);
-	}
-	mmap_read_unlock(mm);
-
-	return 0;
-}
-#endif

lib/vdso/getrandom.c

···
 #include <linux/minmax.h>
 #include <vdso/datapage.h>
 #include <vdso/getrandom.h>
+#include <vdso/limits.h>
 #include <vdso/unaligned.h>
+#include <asm/barrier.h>
 #include <asm/vdso/getrandom.h>
+#include <uapi/linux/errno.h>
 #include <uapi/linux/mman.h>
 #include <uapi/linux/random.h>
 

lib/vdso/gettimeofday.c

···
  * Generic userspace implementations of gettimeofday() and similar.
  */
 #include <vdso/auxclock.h>
+#include <vdso/clocksource.h>
 #include <vdso/datapage.h>
 #include <vdso/helpers.h>
+#include <vdso/ktime.h>
+#include <vdso/limits.h>
+#include <vdso/math64.h>
+#include <vdso/time32.h>
+#include <vdso/time64.h>
+
+/*
+ * The generic vDSO implementation requires that gettimeofday.h
+ * provides:
+ * - __arch_get_hw_counter(): to get the hw counter based on the
+ *   clock_mode.
+ * - gettimeofday_fallback(): fallback for gettimeofday.
+ * - clock_gettime_fallback(): fallback for clock_gettime.
+ * - clock_getres_fallback(): fallback for clock_getres.
+ */
+#include <asm/vdso/gettimeofday.h>
 
 /* Bring in default accessors */
 #include <vdso/vsyscall.h>
···
 
 		if (!vdso_get_timestamp(vd, vc, clk, &sec, &ns))
 			return false;
-	} while (unlikely(vdso_read_retry(vc, seq)));
+	} while (vdso_read_retry(vc, seq));
 
 	/* Add the namespace offset */
 	sec += offs->sec;
···
 		return false;
 
 	do {
-		/*
-		 * Open coded function vdso_read_begin() to handle
-		 * VDSO_CLOCKMODE_TIMENS. Time namespace enabled tasks have a
-		 * special VVAR page installed which has vc->seq set to 1 and
-		 * vc->clock_mode set to VDSO_CLOCKMODE_TIMENS. For non time
-		 * namespace affected tasks this does not affect performance
-		 * because if vc->seq is odd, i.e. a concurrent update is in
-		 * progress the extra check for vc->clock_mode is just a few
-		 * extra instructions while spin waiting for vc->seq to become
-		 * even again.
-		 */
-		while (unlikely((seq = READ_ONCE(vc->seq)) & 1)) {
-			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
-				return do_hres_timens(vd, vc, clk, ts);
-			cpu_relax();
-		}
-		smp_rmb();
+		if (vdso_read_begin_timens(vc, &seq))
+			return do_hres_timens(vd, vc, clk, ts);
 
 		if (!vdso_get_timestamp(vd, vc, clk, &sec, &ns))
 			return false;
-	} while (unlikely(vdso_read_retry(vc, seq)));
+	} while (vdso_read_retry(vc, seq));
 
 	vdso_set_timespec(ts, sec, ns);
 
···
 		seq = vdso_read_begin(vc);
 		sec = vdso_ts->sec;
 		nsec = vdso_ts->nsec;
-	} while (unlikely(vdso_read_retry(vc, seq)));
+	} while (vdso_read_retry(vc, seq));
 
 	/* Add the namespace offset */
 	sec += offs->sec;
···
 	u32 seq;
 
 	do {
-		/*
-		 * Open coded function vdso_read_begin() to handle
-		 * VDSO_CLOCK_TIMENS. See comment in do_hres().
-		 */
-		while ((seq = READ_ONCE(vc->seq)) & 1) {
-			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
-				return do_coarse_timens(vd, vc, clk, ts);
-			cpu_relax();
-		}
-		smp_rmb();
+		if (vdso_read_begin_timens(vc, &seq))
+			return do_coarse_timens(vd, vc, clk, ts);
 
 		ts->tv_sec = vdso_ts->sec;
 		ts->tv_nsec = vdso_ts->nsec;
-	} while (unlikely(vdso_read_retry(vc, seq)));
+	} while (vdso_read_retry(vc, seq));
 
 	return true;
 }
···
 	vc = &vd->aux_clock_data[idx];
 
 	do {
-		/*
-		 * Open coded function vdso_read_begin() to handle
-		 * VDSO_CLOCK_TIMENS. See comment in do_hres().
-		 */
-		while ((seq = READ_ONCE(vc->seq)) & 1) {
-			if (IS_ENABLED(CONFIG_TIME_NS) && vc->clock_mode == VDSO_CLOCKMODE_TIMENS) {
-				vd = __arch_get_vdso_u_timens_data(vd);
-				vc = &vd->aux_clock_data[idx];
-				/* Re-read from the real time data page */
-				continue;
-			}
-			cpu_relax();
+		if (vdso_read_begin_timens(vc, &seq)) {
+			vd = __arch_get_vdso_u_timens_data(vd);
+			vc = &vd->aux_clock_data[idx];
+			/* Re-read from the real time data page */
+			continue;
 		}
-		smp_rmb();
 
 		/* Auxclock disabled? */
 		if (vc->clock_mode == VDSO_CLOCKMODE_NONE)
···
 
 		if (!vdso_get_timestamp(vd, vc, VDSO_BASE_AUX, &sec, &ns))
 			return false;
-	} while (unlikely(vdso_read_retry(vc, seq)));
+	} while (vdso_read_retry(vc, seq));
 
 	vdso_set_timespec(ts, sec, ns);
 
···
 	return do_hres(vd, vc, clock, ts);
 }
 
-static __maybe_unused int
+static int
 __cvdso_clock_gettime_data(const struct vdso_time_data *vd, clockid_t clock,
 			   struct __kernel_timespec *ts)
 {
···
 }
 
 #ifdef BUILD_VDSO32
-static __maybe_unused int
+static int
 __cvdso_clock_gettime32_data(const struct vdso_time_data *vd, clockid_t clock,
 			     struct old_timespec32 *res)
 {
···
 }
 #endif /* BUILD_VDSO32 */
 
-static __maybe_unused int
+static int
 __cvdso_gettimeofday_data(const struct vdso_time_data *vd,
 			  struct __kernel_old_timeval *tv, struct timezone *tz)
 {
···
 	}
 
 	if (unlikely(tz != NULL)) {
-		if (IS_ENABLED(CONFIG_TIME_NS) &&
-		    vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+		if (vdso_is_timens_clock(vc))
 			vd = __arch_get_vdso_u_timens_data(vd);
 
 		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
···
 }
 
 #ifdef VDSO_HAS_TIME
-static __maybe_unused __kernel_old_time_t
+static __kernel_old_time_t
 __cvdso_time_data(const struct vdso_time_data *vd, __kernel_old_time_t *time)
 {
 	const struct vdso_clock *vc = vd->clock_data;
 	__kernel_old_time_t t;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) &&
-	    vc->clock_mode == VDSO_CLOCKMODE_TIMENS) {
+	if (vdso_is_timens_clock(vc)) {
 		vd = __arch_get_vdso_u_timens_data(vd);
 		vc = vd->clock_data;
 	}
···
 	if (!vdso_clockid_valid(clock))
 		return false;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) &&
-	    vc->clock_mode == VDSO_CLOCKMODE_TIMENS)
+	if (vdso_is_timens_clock(vc))
 		vd = __arch_get_vdso_u_timens_data(vd);
 
 	/*
···
 	return true;
 }
 
-static __maybe_unused
+static
 int __cvdso_clock_getres_data(const struct vdso_time_data *vd, clockid_t clock,
 			      struct __kernel_timespec *res)
 {
···
 }
 
 #ifdef BUILD_VDSO32
-static __maybe_unused int
+static int
 __cvdso_clock_getres_time32_data(const struct vdso_time_data *vd, clockid_t clock,
 				 struct old_timespec32 *res)
 {

tools/testing/selftests/vDSO/Makefile

···
 
 include ../lib.mk
 
-CFLAGS += $(TOOLS_INCLUDES)
-
 CFLAGS_NOLIBC := -nostdlib -nostdinc -ffreestanding -fno-asynchronous-unwind-tables \
 		 -fno-stack-protector -include $(top_srcdir)/tools/include/nolibc/nolibc.h \
 		 -I$(top_srcdir)/tools/include/nolibc/ $(KHDR_INCLUDES)
···
 $(OUTPUT)/vdso_test_gettimeofday: parse_vdso.c vdso_test_gettimeofday.c
 $(OUTPUT)/vdso_test_getcpu: parse_vdso.c vdso_test_getcpu.c
 $(OUTPUT)/vdso_test_abi: parse_vdso.c vdso_test_abi.c
+$(OUTPUT)/vdso_test_correctness: parse_vdso.c vdso_test_correctness.c
 
 $(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c | headers
 $(OUTPUT)/vdso_standalone_test_x86: CFLAGS:=$(CFLAGS_NOLIBC) $(CFLAGS)
-
-$(OUTPUT)/vdso_test_correctness: vdso_test_correctness.c
-$(OUTPUT)/vdso_test_correctness: LDFLAGS += -ldl
 
 $(OUTPUT)/vdso_test_getrandom: parse_vdso.c
 $(OUTPUT)/vdso_test_getrandom: CFLAGS += -isystem $(top_srcdir)/tools/include \

tools/testing/selftests/vDSO/parse_vdso.c

···
 #include <stdint.h>
 #include <string.h>
 #include <limits.h>
-#include <linux/auxvec.h>
-#include <linux/elf.h>
+#include <elf.h>
 
 #include "parse_vdso.h"
 

tools/testing/selftests/vDSO/vdso_test_correctness.c

···
 #include <time.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <sys/auxv.h>
 #include <sys/syscall.h>
-#include <dlfcn.h>
 #include <string.h>
 #include <errno.h>
 #include <sched.h>
 #include <stdbool.h>
 #include <limits.h>
 
+#include "parse_vdso.h"
 #include "vdso_config.h"
 #include "vdso_call.h"
 #include "kselftest.h"
 
+static const char *version;
 static const char **name;
-
-#ifndef SYS_getcpu
-# ifdef __x86_64__
-#  define SYS_getcpu 309
-# else
-#  define SYS_getcpu 318
-# endif
-#endif
 
 #ifndef __NR_clock_gettime64
 #define __NR_clock_gettime64	403
···
 typedef long (*vgtod_t)(struct timeval *tv, struct timezone *tz);
 
 vgtod_t vdso_gettimeofday;
+
+typedef time_t (*vtime_t)(__kernel_time_t *tloc);
+
+vtime_t vdso_time;
 
 typedef long (*getcpu_t)(unsigned *, unsigned *, void *);
 
···
 
 static void fill_function_pointers(void)
 {
-	void *vdso = dlopen("linux-vdso.so.1",
-			    RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-	if (!vdso)
-		vdso = dlopen("linux-gate.so.1",
-			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-	if (!vdso)
-		vdso = dlopen("linux-vdso32.so.1",
-			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-	if (!vdso)
-		vdso = dlopen("linux-vdso64.so.1",
-			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
-	if (!vdso) {
+	unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
+
+	if (!sysinfo_ehdr) {
 		printf("[WARN]\tfailed to find vDSO\n");
 		return;
 	}
 
-	vdso_getcpu = (getcpu_t)dlsym(vdso, name[4]);
+	vdso_init_from_sysinfo_ehdr(sysinfo_ehdr);
+
+	vdso_getcpu = (getcpu_t)vdso_sym(version, name[4]);
 	if (!vdso_getcpu)
 		printf("Warning: failed to find getcpu in vDSO\n");
 
 	vgetcpu = (getcpu_t) vsyscall_getcpu();
 
-	vdso_clock_gettime = (vgettime_t)dlsym(vdso, name[1]);
+	vdso_clock_gettime = (vgettime_t)vdso_sym(version, name[1]);
 	if (!vdso_clock_gettime)
 		printf("Warning: failed to find clock_gettime in vDSO\n");
 
 #if defined(VDSO_32BIT)
-	vdso_clock_gettime64 = (vgettime64_t)dlsym(vdso, name[5]);
+	vdso_clock_gettime64 = (vgettime64_t)vdso_sym(version, name[5]);
 	if (!vdso_clock_gettime64)
 		printf("Warning: failed to find clock_gettime64 in vDSO\n");
 #endif
 
-	vdso_gettimeofday = (vgtod_t)dlsym(vdso, name[0]);
+	vdso_gettimeofday = (vgtod_t)vdso_sym(version, name[0]);
 	if (!vdso_gettimeofday)
 		printf("Warning: failed to find gettimeofday in vDSO\n");
+
+	vdso_time = (vtime_t)vdso_sym(version, name[2]);
+	if (!vdso_time)
+		printf("Warning: failed to find time in vDSO\n");
 
 }
 
···
 static inline int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
 {
 	return syscall(__NR_gettimeofday, tv, tz);
+}
+
+static inline __kernel_old_time_t sys_time(__kernel_old_time_t *tloc)
+{
+#ifdef __NR_time
+	return syscall(__NR_time, tloc);
+#else
+	errno = ENOSYS;
+	return -1;
+#endif
 }
 
 static void test_getcpu(void)
···
 		return;
 	}
 
-	printf("\t%llu.%06ld %llu.%06ld %llu.%06ld\n",
-	       (unsigned long long)start.tv_sec, start.tv_usec,
-	       (unsigned long long)vdso.tv_sec, vdso.tv_usec,
-	       (unsigned long long)end.tv_sec, end.tv_usec);
+	printf("\t%llu.%06lld %llu.%06lld %llu.%06lld\n",
+	       (unsigned long long)start.tv_sec, (long long)start.tv_usec,
+	       (unsigned long long)vdso.tv_sec, (long long)vdso.tv_usec,
+	       (unsigned long long)end.tv_sec, (long long)end.tv_usec);
 
 	if (!tv_leq(&start, &vdso) || !tv_leq(&vdso, &end)) {
 		printf("[FAIL]\tTimes are out of sequence\n");
···
 	VDSO_CALL(vdso_gettimeofday, 2, &vdso, NULL);
 }
 
+static void test_time(void)
+{
+	__kernel_old_time_t start, end, vdso_ret, vdso_param;
+
+	if (!vdso_time)
+		return;
+
+	printf("[RUN]\tTesting time...\n");
+
+	if (sys_time(&start) < 0) {
+		if (errno == -ENOSYS) {
+			printf("[SKIP]\tNo time() support\n");
+		} else {
+			printf("[FAIL]\tsys_time failed (%d)\n", errno);
+			nerrs++;
+		}
+		return;
+	}
+
+	vdso_ret = VDSO_CALL(vdso_time, 1, &vdso_param);
+	end = sys_time(NULL);
+
+	if (vdso_ret < 0 || end < 0) {
+		printf("[FAIL]\tvDSO returned %d, syscall errno=%d\n",
+		       (int)vdso_ret, errno);
+		nerrs++;
+		return;
+	}
+
+	printf("\t%lld %lld %lld\n",
+	       (long long)start,
+	       (long long)vdso_ret,
+	       (long long)end);
+
+	if (vdso_ret != vdso_param) {
+		printf("[FAIL]\tinconsistent return values: %lld %lld\n",
+		       (long long)vdso_ret, (long long)vdso_param);
+		nerrs++;
+		return;
+	}
+
+	if (!(start <= vdso_ret) || !(vdso_ret <= end)) {
+		printf("[FAIL]\tTimes are out of sequence\n");
+		nerrs++;
+	}
+}
+
 int main(int argc, char **argv)
 {
+	version = versions[VDSO_VERSION];
 	name = (const char **)&names[VDSO_NAMES];
 
 	fill_function_pointers();
···
 	test_clock_gettime();
 	test_clock_gettime64();
 	test_gettimeofday();
+	test_time();
 
 	/*
 	 * Test getcpu() last so that, if something goes wrong setting affinity,

tools/testing/selftests/vDSO/vdso_test_gettimeofday.c

···
  */
 
 #include <stdio.h>
-#ifndef NOLIBC
 #include <sys/auxv.h>
 #include <sys/time.h>
-#endif
 
 #include "kselftest.h"
 #include "parse_vdso.h"