Extend the vDSO for fast-path access to auxiliary clocks (CLOCK_AUX).
The implementation is based on the generic vDSO infrastructure and works for
all its supported architectures.
Namely x86, arm, arm64, riscv, powerpc, loongarch and s390.
No changes to userspace are necessary.
Based on timers/ptp of tip.git.
This also depends on v6.16-rc2 *exactly*.
The specific dependency is commit 11fcf368506d ("uapi: bitops: use UAPI-safe variant of BITS_PER_LONG again"),
which is available in v6.16-rc2.
Unfortunately that got broken again in v6.16-rc3 by
commit fc92099902fb ("tools headers: Synchronize linux/bits.h with the kernel sources").
Another fix for this is pending [0] and should make it into v6.16.
[0] https://lore.kernel.org/lkml/20250630-uapi-genmask-v1-1-eb0ad956a83e@linutr…
Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
---
Thomas Weißschuh (14):
selftests/timers: Add testcase for auxiliary clocks
vdso/vsyscall: Introduce a helper to fill clock configurations
vdso/vsyscall: Split up __arch_update_vsyscall() into __arch_update_vdso_clock()
vdso/helpers: Add helpers for seqlocks of single vdso_clock
vdso/gettimeofday: Return bool from clock_getres() helpers
vdso/gettimeofday: Return bool from clock_gettime() helpers
vdso/gettimeofday: Introduce vdso_clockid_valid()
vdso/gettimeofday: Introduce vdso_set_timespec()
vdso/gettimeofday: Introduce vdso_get_timestamp()
vdso: Introduce aux_clock_resolution_ns()
vdso/vsyscall: Update auxiliary clock data in the datapage
vdso/gettimeofday: Add support for auxiliary clocks
Revert "selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers"
selftests/timers/auxclock: Test vDSO functionality
arch/arm64/include/asm/vdso/vsyscall.h | 7 +-
include/asm-generic/vdso/vsyscall.h | 6 +-
include/linux/timekeeper_internal.h | 13 +
include/vdso/auxclock.h | 13 +
include/vdso/datapage.h | 5 +
include/vdso/helpers.h | 40 ++-
kernel/time/namespace.c | 5 +
kernel/time/timekeeping.c | 18 +-
kernel/time/vsyscall.c | 70 ++++--
lib/vdso/gettimeofday.c | 212 ++++++++++------
tools/testing/selftests/timers/.gitignore | 1 +
tools/testing/selftests/timers/Makefile | 2 +-
tools/testing/selftests/timers/auxclock.c | 406 ++++++++++++++++++++++++++++++
tools/testing/selftests/vDSO/Makefile | 2 -
tools/testing/selftests/vDSO/parse_vdso.c | 3 +-
15 files changed, 683 insertions(+), 120 deletions(-)
---
base-commit: 4e83b31e48cf2e62aeaed5cd9875c851e36a90d9
change-id: 20250630-vdso-auxclock-97abdf8e042a
Best regards,
--
Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
corrected a minor grammer mistake
Signed-off-by: Pavan Bobba <opensource206(a)gmail.com>
---
tools/testing/selftests/acct/acct_syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/acct/acct_syscall.c b/tools/testing/selftests/acct/acct_syscall.c
index 87c044fb9293..ee2894e4f7bc 100644
--- a/tools/testing/selftests/acct/acct_syscall.c
+++ b/tools/testing/selftests/acct/acct_syscall.c
@@ -22,7 +22,7 @@ int main(void)
ksft_print_header();
ksft_set_plan(1);
- // Check if test is run a root
+ // Check if test is run as root
if (geteuid()) {
ksft_exit_skip("This test needs root to run!\n");
return 1;
--
2.43.0
corrected a minor grammer mistake
Signed-off-by: Pavan Bobba <opensource206(a)gmail.com>
---
tools/testing/selftests/acct/acct_syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/acct/acct_syscall.c b/tools/testing/selftests/acct/acct_syscall.c
index 87c044fb9293..ee2894e4f7bc 100644
--- a/tools/testing/selftests/acct/acct_syscall.c
+++ b/tools/testing/selftests/acct/acct_syscall.c
@@ -22,7 +22,7 @@ int main(void)
ksft_print_header();
ksft_set_plan(1);
- // Check if test is run a root
+ // Check if test is run as root
if (geteuid()) {
ksft_exit_skip("This test needs root to run!\n");
return 1;
--
2.43.0
corrected a minor grammer mistake
Signed-off-by: Pavan Bobba <opensource206(a)gmail.com>
---
tools/testing/selftests/acct/acct_syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/acct/acct_syscall.c b/tools/testing/selftests/acct/acct_syscall.c
index 87c044fb9293..ee2894e4f7bc 100644
--- a/tools/testing/selftests/acct/acct_syscall.c
+++ b/tools/testing/selftests/acct/acct_syscall.c
@@ -22,7 +22,7 @@ int main(void)
ksft_print_header();
ksft_set_plan(1);
- // Check if test is run a root
+ // Check if test is run as root
if (geteuid()) {
ksft_exit_skip("This test needs root to run!\n");
return 1;
--
2.43.0
corrected a minor grammer mistake
Signed-off-by: Pavan Bobba <opensource206(a)gmail.com>
---
tools/testing/selftests/acct/acct_syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/acct/acct_syscall.c b/tools/testing/selftests/acct/acct_syscall.c
index 87c044fb9293..ee2894e4f7bc 100644
--- a/tools/testing/selftests/acct/acct_syscall.c
+++ b/tools/testing/selftests/acct/acct_syscall.c
@@ -22,7 +22,7 @@ int main(void)
ksft_print_header();
ksft_set_plan(1);
- // Check if test is run a root
+ // Check if test is run as root
if (geteuid()) {
ksft_exit_skip("This test needs root to run!\n");
return 1;
--
2.43.0
corrected a minor grammer mistake
Signed-off-by: Pavan Bobba <opensource206(a)gmail.com>
---
tools/testing/selftests/acct/acct_syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/acct/acct_syscall.c b/tools/testing/selftests/acct/acct_syscall.c
index 87c044fb9293..ee2894e4f7bc 100644
--- a/tools/testing/selftests/acct/acct_syscall.c
+++ b/tools/testing/selftests/acct/acct_syscall.c
@@ -22,7 +22,7 @@ int main(void)
ksft_print_header();
ksft_set_plan(1);
- // Check if test is run a root
+ // Check if test is run as root
if (geteuid()) {
ksft_exit_skip("This test needs root to run!\n");
return 1;
--
2.43.0
- Break up the ksft_print_msg statements to follow the 80 char rule.
- Capitalize "POSIX" and rephrase messages for better readability.
- Clarify that false negatives may occur in tests relying on timers
if other threads run on the CPU.
Signed-off-by: I Viswanath <viswanathiyyappan(a)gmail.com>
---
tools/testing/selftests/timers/posix_timers.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c
index f0eceb0faf34..017a9e19ad0f 100644
--- a/tools/testing/selftests/timers/posix_timers.c
+++ b/tools/testing/selftests/timers/posix_timers.c
@@ -673,8 +673,9 @@ int main(int argc, char **argv)
ksft_print_header();
ksft_set_plan(19);
- ksft_print_msg("Testing posix timers. False negative may happen on CPU execution \n");
- ksft_print_msg("based timers if other threads run on the CPU...\n");
+ ksft_print_msg("Testing POSIX timers.\n");
+ ksft_print_msg("False negatives may occur in tests\n");
+ ksft_print_msg("relying on timers if other threads run on the CPU\n");
check_timer_create_exact();
--
2.50.1