Merge tag 'timers-vdso-2026-10-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull VDSO updates from Thomas Gleixner:
 "Updates for the VDSO subsystem:

   - Ensure that the CLOCK_AUX base calculations are properly scaled
     against the base timekeeper. The update function failed to take the
     fractional nanosecond part into account, which results in a
     rounding error.

   - Cleanup and consolidate the vsyscall headers to get rid of
     pointless copies all over the architectures.

   - Replace a runtime conditional in the time getter function for
     namespaced clocks by simple pointer arithmetic which speeds up the
     read function"

* tag 'timers-vdso-2026-10-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  vdso/vsyscall: Keep the CLOCK_AUX base scaled
  vdso/math64: Add and use __iter_div64_u64_rem()
  vdso/math64: Use OPTIMIZER_HIDE_VAR() in __iter_div_u64_rem()
  vdso/gettimeofday: Avoid runtime conditional in do_hres_timens()
  vdso: Remove __ASSEMBLER__ guards from vsyscall.h
  vdso: Add asm-generic/vdso/vsyscall.h
  vdso: Remove unnecessary vdso/vsyscall.h includes
  riscv/hwprobe: Include vdso/datapage.h
  arm64/vdso: Delete asm/vdso/vsyscall.h inclusions
  x86/vdso: Delete asm/vdso/vsyscall.h inclusions
  sparc/vdso: Delete asm/vdso/vsyscall.h inclusion
  s390/vdso: Delete asm/vdso/vsyscall.h inclusions
  sparc/vdso: Move __VDSO_PAGES to asm/vdso.h
  x86/vdso: Move vDSO page definitions to asm/vdso.h
  vdso: Delete asm-generic/vdso/vsyscall.h
  vdso/vsyscall: Define fallback time synchronization functions in vsyscall.c
  vdso/getrandom: Define fallback __arch_get_vdso_u_rng_data() in getrandom.c
  vdso/gettimeofday: Define fallback __arch_get_vdso_u_time_data() in gettimeofday.c
  vdso: Move the kernel-side time update helpers to a new header

2 files changed, 20 insertions, 11 deletions

diff --git a/lib/vdso/getrandom.c b/lib/vdso/getrandom.c
index 2851afa9154f..e0fa10bbefc9 100644
--- a/lib/vdso/getrandom.c
+++ b/lib/vdso/getrandom.c
@@ -16,8 +16,12 @@
 #include <uapi/linux/mman.h>
 #include <uapi/linux/random.h>
 
-/* Bring in default accessors */
-#include <vdso/vsyscall.h>
+#ifndef __arch_get_vdso_u_rng_data
+static __always_inline const struct vdso_rng_data *__arch_get_vdso_u_rng_data(void)
+{
+	return &vdso_u_rng_data;
+}
+#endif
 
 #define MEMCPY_AND_ZERO_SRC(type, dst, src, len) do {				\
 	while (len >= sizeof(type)) {						\
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index f7a591aba59f..c0e81996532d 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -27,9 +27,6 @@
 
 #include <linux/build_bug.h>
 
-/* Bring in default accessors */
-#include <vdso/vsyscall.h>
-
 #ifndef vdso_calc_ns
 
 #ifdef VDSO_DELTA_NOMASK
@@ -93,6 +90,13 @@ static inline bool vdso_cycles_ok(u64 cycles)
 }
 #endif
 
+#ifndef __arch_get_vdso_u_time_data
+static __always_inline const struct vdso_time_data *__arch_get_vdso_u_time_data(void)
+{
+	return &vdso_u_time_data;
+}
+#endif
+
 static __always_inline bool vdso_clockid_valid(clockid_t clock)
 {
 	/* Check for negative values or invalid clocks */
@@ -136,21 +140,22 @@ const struct vdso_time_data *vdso_timens_data(const struct vdso_time_data *vd)
 }
 
 static __always_inline
+const struct vdso_clock *vdso_timens_clock(const struct vdso_clock *vc)
+{
+	return (void *)vc + PAGE_SIZE;
+}
+
+static __always_inline
 bool do_hres_timens(const struct vdso_time_data *vdns, const struct vdso_clock *vcns,
 		    clockid_t clk, struct __kernel_timespec *ts)
 {
 	const struct vdso_time_data *vd = vdso_timens_data(vdns);
+	const struct vdso_clock *vc = vdso_timens_clock(vcns);
 	const struct timens_offset *offs = &vcns->offset[clk];
-	const struct vdso_clock *vc = vd->clock_data;
 	u32 seq;
 	s64 sec;
 	u64 ns;
 
-	if (clk != CLOCK_MONOTONIC_RAW)
-		vc = &vc[CS_HRES_COARSE];
-	else
-		vc = &vc[CS_RAW];
-
 	do {
 		seq = vdso_read_begin(vc);