[tip: timers/vdso] x86/vdso: Respect COMPAT_32BIT_TIME

[tip-bot2 for Thomas Weißschuh]

The following commit has been merged into the timers/vdso branch of tip:

Commit-ID:     1a4660da3130f7b1e88d8afa3c4a9982c14bcea6
Gitweb:        https://git.kernel.org/tip/1a4660da3130f7b1e88d8afa3c4a9982c14bcea6
Author:        Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
AuthorDate:    Thu, 02 Jul 2026 10:21:27 +02:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxx>
CommitterDate: Tue, 07 Jul 2026 23:52:53 +02:00

x86/vdso: Respect COMPAT_32BIT_TIME

If CONFIG_COMPAT_32BIT_TIME is disabled then the vDSO should not
provide any 32-bit time related functionality. This is the intended
effect of the kconfig option and also the fallback system calls would
also not be implemented.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Link: https://patch.msgid.link/20260702-vdso-compat_32bit_time-v3-3-db9f36d8d432@xxxxxxxxxxxxx
---
 arch/x86/entry/vdso/common/vclock_gettime.c | 20 ++++++++++++--------
 arch/x86/entry/vdso/vdso32/vdso32.lds.S     |  2 ++-
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/arch/x86/entry/vdso/common/vclock_gettime.c b/arch/x86/entry/vdso/common/vclock_gettime.c
index 57066f3..304dbd1 100644
--- a/arch/x86/entry/vdso/common/vclock_gettime.c
+++ b/arch/x86/entry/vdso/common/vclock_gettime.c
@@ -15,6 +15,7 @@
 
 #include "lib/vdso/gettimeofday.c"
 
+#if defined(__x86_64__) || defined(CONFIG_COMPAT_32BIT_TIME)
 int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
 {
 	return __cvdso_gettimeofday(tv, tz);
@@ -29,6 +30,7 @@ __kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
 }
 
 __kernel_old_time_t time(__kernel_old_time_t *t)	__attribute__((weak, alias("__vdso_time")));
+#endif /* CONFIG_COMPAT_32BIT_TIME */
 
 
 #if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64)
@@ -51,6 +53,7 @@ int clock_getres(clockid_t, struct __kernel_timespec *)
 
 #else
 /* i386 only */
+#ifdef CONFIG_COMPAT_32BIT_TIME
 int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts)
 {
 	return __cvdso_clock_gettime32(clock, ts);
@@ -59,14 +62,6 @@ int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts)
 int clock_gettime(clockid_t, struct old_timespec32 *)
 	__attribute__((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 *)
-	__attribute__((weak, alias("__vdso_clock_gettime64")));
-
 int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res)
 {
 	return __cvdso_clock_getres_time32(clock, res);
@@ -74,6 +69,15 @@ 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")));
+#endif /* CONFIG_COMPAT_32BIT_TIME */
+
+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 *)
+	__attribute__((weak, alias("__vdso_clock_gettime64")));
 
 int __vdso_clock_getres_time64(clockid_t clock, struct __kernel_timespec *ts)
 {
diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
index cee8f7f..0062919 100644
--- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
@@ -23,10 +23,12 @@ VERSION
 {
 	LINUX_2.6 {
 	global:
+#ifdef CONFIG_COMPAT_32BIT_TIME
 		__vdso_clock_gettime;
 		__vdso_gettimeofday;
 		__vdso_time;
 		__vdso_clock_getres;
+#endif /* CONFIG_COMPAT_32BIT_TIME */
 		__vdso_clock_gettime64;
 		__vdso_clock_getres_time64;
 		__vdso_getcpu;