[PATCH 0/9] vDSO: Provide clock_getres_time64() where applicable

[PATCH 0/9] vDSO: Provide clock_getres_time64() where applicable

[Thomas Weißschuh]

For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI.
    

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
Thomas Weißschuh (9):
      vdso: Add prototype for __vdso_clock_getres_time64()
      selftests: vDSO: vdso_config: Add configurations for clock_getres_time64()
      selftests: vDSO: vdso_test_abi: Use UAPI system call numbers
      selftests: vDSO: vdso_test_abi: Add test for clock_getres_time64()
      x86/vdso: Provide clock_getres_time64() for x86-32
      ARM: VDSO: also patch out __vdso_clock_getres() if unavailable
      ARM: VDSO: provide clock_getres_time64()
      arm64: vdso32: Provide clock_getres_time64()
      MIPS: vdso: Provide getres_time64() for 32-bit ABIs

 arch/arm/kernel/vdso.c                       |  2 +
 arch/arm/vdso/vdso.lds.S                     |  1 +
 arch/arm/vdso/vgettimeofday.c                |  6 +++
 arch/arm64/kernel/vdso32/vdso.lds.S          |  1 +
 arch/arm64/kernel/vdso32/vgettimeofday.c     |  6 +++
 arch/mips/vdso/vdso.lds.S                    |  1 +
 arch/mips/vdso/vgettimeofday.c               |  6 +++
 arch/x86/entry/vdso/vclock_gettime.c         |  8 ++++
 arch/x86/entry/vdso/vdso32/vdso32.lds.S      |  1 +
 include/vdso/gettime.h                       |  1 +
 tools/testing/selftests/vDSO/vdso_config.h   |  4 +-
 tools/testing/selftests/vDSO/vdso_test_abi.c | 55 +++++++++++++++++++++++++++-
 12 files changed, 89 insertions(+), 3 deletions(-)
---
base-commit: 15a11f3ffb629cbbf6efd272239c04a9eb3180e2
change-id: 20251120-vdso-compat-time32-f4684ff250ba

Best regards,
-- 
Thomas Weißschuh <thomas.weissschuh@linutronix.de>

[PATCH 1/9] vdso: Add prototype for __vdso_clock_getres_time64()

[Thomas Weißschuh]

For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI. The generic vDSO library already
provides nearly all necessary building blocks for architectures to
provide this function. Only a prototype is missing.

Add the prototype to the generic header so architectures can start
providing this function.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 include/vdso/gettime.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/vdso/gettime.h b/include/vdso/gettime.h
index 9ac161866653..16a0a0556b86 100644
--- a/include/vdso/gettime.h
+++ b/include/vdso/gettime.h
@@ -20,5 +20,6 @@ int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts);
 __kernel_old_time_t __vdso_time(__kernel_old_time_t *t);
 int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
 int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts);
+int __vdso_clock_getres_time64(clockid_t clock, struct __kernel_timespec *ts);
 
 #endif

-- 
2.52.0

[PATCH 2/9] selftests: vDSO: vdso_config: Add configurations for clock_getres_time64()

[Thomas Weißschuh]

Some architectures will start to implement this function.
Make sure that tests can be written for it.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/vdso_config.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vDSO/vdso_config.h b/tools/testing/selftests/vDSO/vdso_config.h
index 50c261005111..5da223731b81 100644
--- a/tools/testing/selftests/vDSO/vdso_config.h
+++ b/tools/testing/selftests/vDSO/vdso_config.h
@@ -66,7 +66,7 @@ static const char *versions[7] = {
 };
 
 __attribute__((unused))
-static const char *names[2][7] = {
+static const char *names[2][8] = {
 	{
 		"__kernel_gettimeofday",
 		"__kernel_clock_gettime",
@@ -75,6 +75,7 @@ static const char *names[2][7] = {
 		"__kernel_getcpu",
 		"__kernel_clock_gettime64",
 		"__kernel_getrandom",
+		"__kernel_clock_getres_time64",
 	},
 	{
 		"__vdso_gettimeofday",
@@ -84,6 +85,7 @@ static const char *names[2][7] = {
 		"__vdso_getcpu",
 		"__vdso_clock_gettime64",
 		"__vdso_getrandom",
+		"__vdso_clock_getres_time64",
 	},
 };
 

-- 
2.52.0

[PATCH 3/9] selftests: vDSO: vdso_test_abi: Use UAPI system call numbers

[Thomas Weißschuh]

SYS_clock_getres might have been redirected by libc to some other system
call than the actual clock_getres. In the test we want to make sure to
use exactly this system call.

Use the system call number exported by the UAPI headers which is always
correct.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/vdso_test_abi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vDSO/vdso_test_abi.c b/tools/testing/selftests/vDSO/vdso_test_abi.c
index c620317eaeea..a75c12dcb0f1 100644
--- a/tools/testing/selftests/vDSO/vdso_test_abi.c
+++ b/tools/testing/selftests/vDSO/vdso_test_abi.c
@@ -179,7 +179,7 @@ static void vdso_test_clock_getres(clockid_t clk_id)
 		clock_getres_fail++;
 	}
 
-	ret = syscall(SYS_clock_getres, clk_id, &sys_ts);
+	ret = syscall(__NR_clock_getres, clk_id, &sys_ts);
 
 	ksft_print_msg("The syscall resolution is %lld %lld\n",
 			(long long)sys_ts.tv_sec, (long long)sys_ts.tv_nsec);

-- 
2.52.0

[PATCH 4/9] selftests: vDSO: vdso_test_abi: Add test for clock_getres_time64()

[Thomas Weißschuh]

Some architectures will start to implement this function.
Make sure it works correctly.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 tools/testing/selftests/vDSO/vdso_test_abi.c | 53 +++++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/vDSO/vdso_test_abi.c b/tools/testing/selftests/vDSO/vdso_test_abi.c
index a75c12dcb0f1..b162a4ba9c4f 100644
--- a/tools/testing/selftests/vDSO/vdso_test_abi.c
+++ b/tools/testing/selftests/vDSO/vdso_test_abi.c
@@ -36,6 +36,7 @@ typedef long (*vdso_gettimeofday_t)(struct timeval *tv, struct timezone *tz);
 typedef long (*vdso_clock_gettime_t)(clockid_t clk_id, struct timespec *ts);
 typedef long (*vdso_clock_gettime64_t)(clockid_t clk_id, struct vdso_timespec64 *ts);
 typedef long (*vdso_clock_getres_t)(clockid_t clk_id, struct timespec *ts);
+typedef long (*vdso_clock_getres_time64_t)(clockid_t clk_id, struct vdso_timespec64 *ts);
 typedef time_t (*vdso_time_t)(time_t *t);
 
 static const char * const vdso_clock_name[] = {
@@ -196,6 +197,55 @@ static void vdso_test_clock_getres(clockid_t clk_id)
 	}
 }
 
+#ifdef __NR_clock_getres_time64
+static void vdso_test_clock_getres_time64(clockid_t clk_id)
+{
+	int clock_getres_fail = 0;
+
+	/* Find clock_getres. */
+	vdso_clock_getres_time64_t vdso_clock_getres_time64 =
+		(vdso_clock_getres_time64_t)vdso_sym(version, name[7]);
+
+	if (!vdso_clock_getres_time64) {
+		ksft_print_msg("Couldn't find %s\n", name[7]);
+		ksft_test_result_skip("%s %s\n", name[7],
+				      vdso_clock_name[clk_id]);
+		return;
+	}
+
+	struct vdso_timespec64 ts, sys_ts;
+	long ret = VDSO_CALL(vdso_clock_getres_time64, 2, clk_id, &ts);
+
+	if (ret == 0) {
+		ksft_print_msg("The vdso resolution is %lld %lld\n",
+			       (long long)ts.tv_sec, (long long)ts.tv_nsec);
+	} else {
+		clock_getres_fail++;
+	}
+
+	ret = syscall(__NR_clock_getres_time64, clk_id, &sys_ts);
+
+	ksft_print_msg("The syscall resolution is %lld %lld\n",
+			(long long)sys_ts.tv_sec, (long long)sys_ts.tv_nsec);
+
+	if ((sys_ts.tv_sec != ts.tv_sec) || (sys_ts.tv_nsec != ts.tv_nsec))
+		clock_getres_fail++;
+
+	if (clock_getres_fail > 0) {
+		ksft_test_result_fail("%s %s\n", name[7],
+				      vdso_clock_name[clk_id]);
+	} else {
+		ksft_test_result_pass("%s %s\n", name[7],
+				      vdso_clock_name[clk_id]);
+	}
+}
+#else /* !__NR_clock_getres_time64 */
+static void vdso_test_clock_getres_time64(clockid_t clk_id)
+{
+	ksft_test_result_skip("%s %s\n", name[7], vdso_clock_name[clk_id]);
+}
+#endif /* __NR_clock_getres_time64 */
+
 /*
  * This function calls vdso_test_clock_gettime and vdso_test_clock_getres
  * with different values for clock_id.
@@ -208,9 +258,10 @@ static inline void vdso_test_clock(clockid_t clock_id)
 	vdso_test_clock_gettime64(clock_id);
 
 	vdso_test_clock_getres(clock_id);
+	vdso_test_clock_getres_time64(clock_id);
 }
 
-#define VDSO_TEST_PLAN	29
+#define VDSO_TEST_PLAN	38
 
 int main(int argc, char **argv)
 {

-- 
2.52.0

[PATCH 5/9] x86/vdso: Provide clock_getres_time64() for x86-32

[Thomas Weißschuh]

For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/x86/entry/vdso/vclock_gettime.c    | 8 ++++++++
 arch/x86/entry/vdso/vdso32/vdso32.lds.S | 1 +
 2 files changed, 9 insertions(+)

diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c
index 0debc194bd78..027b7e88d753 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -74,4 +74,12 @@ int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res)
 
 int clock_getres(clockid_t, struct old_timespec32 *)
 	__attribute__((weak, alias("__vdso_clock_getres")));
+
+int __vdso_clock_getres_time64(clockid_t clock, struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_getres(clock, ts);
+}
+
+int clock_getres_time64(clockid_t, struct __kernel_timespec *)
+	__attribute__((weak, alias("__vdso_clock_getres_time64")));
 #endif
diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
index 8a3be07006bb..6f977c103584 100644
--- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
@@ -28,6 +28,7 @@ VERSION
 		__vdso_time;
 		__vdso_clock_getres;
 		__vdso_clock_gettime64;
+		__vdso_clock_getres_time64;
 		__vdso_getcpu;
 	};
 

-- 
2.52.0

[PATCH 6/9] ARM: VDSO: also patch out __vdso_clock_getres() if unavailable

[Thomas Weißschuh]

The vDSO code hides symbols which are non-functional.
__vdso_clock_getres() was not added to this list when it got introduced.

Fixes: 052e76a31b4a ("ARM: 8931/1: Add clock_getres entry point")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/arm/kernel/vdso.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index e38a30477f3d..566c40f0f7c7 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -161,6 +161,7 @@ static void __init patch_vdso(void *ehdr)
 		vdso_nullpatch_one(&einfo, "__vdso_gettimeofday");
 		vdso_nullpatch_one(&einfo, "__vdso_clock_gettime");
 		vdso_nullpatch_one(&einfo, "__vdso_clock_gettime64");
+		vdso_nullpatch_one(&einfo, "__vdso_clock_getres");
 	}
 }
 

-- 
2.52.0

[PATCH 7/9] ARM: VDSO: provide clock_getres_time64()

[Thomas Weißschuh]

For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/arm/kernel/vdso.c        | 1 +
 arch/arm/vdso/vdso.lds.S      | 1 +
 arch/arm/vdso/vgettimeofday.c | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 566c40f0f7c7..0108f33d6bed 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -162,6 +162,7 @@ static void __init patch_vdso(void *ehdr)
 		vdso_nullpatch_one(&einfo, "__vdso_clock_gettime");
 		vdso_nullpatch_one(&einfo, "__vdso_clock_gettime64");
 		vdso_nullpatch_one(&einfo, "__vdso_clock_getres");
+		vdso_nullpatch_one(&einfo, "__vdso_clock_getres_time64");
 	}
 }
 
diff --git a/arch/arm/vdso/vdso.lds.S b/arch/arm/vdso/vdso.lds.S
index 7c08371f4400..74d8d8bc8a40 100644
--- a/arch/arm/vdso/vdso.lds.S
+++ b/arch/arm/vdso/vdso.lds.S
@@ -74,6 +74,7 @@ VERSION
 		__vdso_gettimeofday;
 		__vdso_clock_getres;
 		__vdso_clock_gettime64;
+		__vdso_clock_getres_time64;
 	local: *;
 	};
 }
diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
index 3554aa35f1ba..2874dde7e6cf 100644
--- a/arch/arm/vdso/vgettimeofday.c
+++ b/arch/arm/vdso/vgettimeofday.c
@@ -34,6 +34,12 @@ int __vdso_clock_getres(clockid_t clock_id,
 	return __cvdso_clock_getres_time32(clock_id, res);
 }
 
+int __vdso_clock_getres_time64(clockid_t clock_id,
+			       struct __kernel_timespec *res)
+{
+	return __cvdso_clock_getres(clock_id, res);
+}
+
 /* Avoid unresolved references emitted by GCC */
 
 void __aeabi_unwind_cpp_pr0(void)

-- 
2.52.0

[PATCH 8/9] arm64: vdso32: Provide clock_getres_time64()

[Thomas Weißschuh]

For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/arm64/kernel/vdso32/vdso.lds.S      | 1 +
 arch/arm64/kernel/vdso32/vgettimeofday.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/arch/arm64/kernel/vdso32/vdso.lds.S b/arch/arm64/kernel/vdso32/vdso.lds.S
index e02b27487ce8..c374fb0146f3 100644
--- a/arch/arm64/kernel/vdso32/vdso.lds.S
+++ b/arch/arm64/kernel/vdso32/vdso.lds.S
@@ -86,6 +86,7 @@ VERSION
 		__vdso_gettimeofday;
 		__vdso_clock_getres;
 		__vdso_clock_gettime64;
+		__vdso_clock_getres_time64;
 	local: *;
 	};
 }
diff --git a/arch/arm64/kernel/vdso32/vgettimeofday.c b/arch/arm64/kernel/vdso32/vgettimeofday.c
index 29b4d8f61e39..d7b39b0a9668 100644
--- a/arch/arm64/kernel/vdso32/vgettimeofday.c
+++ b/arch/arm64/kernel/vdso32/vgettimeofday.c
@@ -32,6 +32,12 @@ int __vdso_clock_getres(clockid_t clock_id,
 	return __cvdso_clock_getres_time32(clock_id, res);
 }
 
+int __vdso_clock_getres_time64(clockid_t clock_id,
+			       struct __kernel_timespec *res)
+{
+	return __cvdso_clock_getres(clock_id, res);
+}
+
 /* Avoid unresolved references emitted by GCC */
 
 void __aeabi_unwind_cpp_pr0(void)

-- 
2.52.0

Re: [PATCH 8/9] arm64: vdso32: Provide clock_getres_time64()

[Will Deacon]

On Tue, Dec 23, 2025 at 07:59:19AM +0100, Thomas Weißschuh wrote:
> For consistency with __vdso_clock_gettime64() there should also be a
> 64-bit variant of clock_getres(). This will allow the extension of
> CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
> time types from the kernel and UAPI.
> 
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> ---
>  arch/arm64/kernel/vdso32/vdso.lds.S      | 1 +
>  arch/arm64/kernel/vdso32/vgettimeofday.c | 6 ++++++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/arch/arm64/kernel/vdso32/vdso.lds.S b/arch/arm64/kernel/vdso32/vdso.lds.S
> index e02b27487ce8..c374fb0146f3 100644
> --- a/arch/arm64/kernel/vdso32/vdso.lds.S
> +++ b/arch/arm64/kernel/vdso32/vdso.lds.S
> @@ -86,6 +86,7 @@ VERSION
>  		__vdso_gettimeofday;
>  		__vdso_clock_getres;
>  		__vdso_clock_gettime64;
> +		__vdso_clock_getres_time64;
>  	local: *;
>  	};
>  }
> diff --git a/arch/arm64/kernel/vdso32/vgettimeofday.c b/arch/arm64/kernel/vdso32/vgettimeofday.c
> index 29b4d8f61e39..d7b39b0a9668 100644
> --- a/arch/arm64/kernel/vdso32/vgettimeofday.c
> +++ b/arch/arm64/kernel/vdso32/vgettimeofday.c
> @@ -32,6 +32,12 @@ int __vdso_clock_getres(clockid_t clock_id,
>  	return __cvdso_clock_getres_time32(clock_id, res);
>  }
>  
> +int __vdso_clock_getres_time64(clockid_t clock_id,
> +			       struct __kernel_timespec *res)
> +{
> +	return __cvdso_clock_getres(clock_id, res);
> +}
> +
>  /* Avoid unresolved references emitted by GCC */
>  
>  void __aeabi_unwind_cpp_pr0(void)

Acked-by: Will Deacon <will@kernel.org>

Please merge this along with the 32-bit Arm change, as it doesn't make
sense otherwise.

Will

[PATCH 9/9] MIPS: vdso: Provide getres_time64() for 32-bit ABIs

[Thomas Weißschuh]

For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
 arch/mips/vdso/vdso.lds.S      | 1 +
 arch/mips/vdso/vgettimeofday.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/arch/mips/vdso/vdso.lds.S b/arch/mips/vdso/vdso.lds.S
index c8bbe56d89cb..5d08be3a6b85 100644
--- a/arch/mips/vdso/vdso.lds.S
+++ b/arch/mips/vdso/vdso.lds.S
@@ -103,6 +103,7 @@ VERSION
 		__vdso_clock_getres;
 #if _MIPS_SIM != _MIPS_SIM_ABI64
 		__vdso_clock_gettime64;
+		__vdso_clock_getres_time64;
 #endif
 #endif
 	local: *;
diff --git a/arch/mips/vdso/vgettimeofday.c b/arch/mips/vdso/vgettimeofday.c
index 604afea3f336..59627f2f51b7 100644
--- a/arch/mips/vdso/vgettimeofday.c
+++ b/arch/mips/vdso/vgettimeofday.c
@@ -46,6 +46,12 @@ int __vdso_clock_gettime64(clockid_t clock,
 	return __cvdso_clock_gettime(clock, ts);
 }
 
+int __vdso_clock_getres_time64(clockid_t clock,
+			       struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_getres(clock, ts);
+}
+
 #else
 
 int __vdso_clock_gettime(clockid_t clock,

-- 
2.52.0