[tip:timers/vdso] x86/vdso: Add clock_gettime64() entry point

[tip-bot for Vincenzo Frascino]

Commit-ID:  22ca962288c0a1c9729e8e440b9bb9ad05df6db6
Gitweb:     https://git.kernel.org/tip/22ca962288c0a1c9729e8e440b9bb9ad05df6db6
Author:     Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
AuthorDate: Fri, 21 Jun 2019 10:52:51 +0100
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Sat, 22 Jun 2019 21:21:10 +0200

x86/vdso: Add clock_gettime64() entry point

Linux 5.1 gained the new clock_gettime64() syscall to address the Y2038
problem on 32bit systems. The x86 VDSO is missing support for this variant
of clock_gettime().

Update the x86 specific vDSO library accordingly so it exposes the new time
getter.

[ tglx: Massaged changelog ]

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Huw Davies <huw@xxxxxxxxxxxxxxx>
Cc: Shijith Thotton <sthotton@xxxxxxxxxxx>
Cc: Andre Przywara <andre.przywara@xxxxxxx>
Link: https://lkml.kernel.org/r/20190621095252.32307-25-vincenzo.frascino@xxxxxxx

---
 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 1a648b509d46..d9ff616bb0f6 100644
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -67,6 +67,14 @@ 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);
diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
index 991b26cc855b..c7720995ab1a 100644
--- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
@@ -27,6 +27,7 @@ VERSION
 		__vdso_gettimeofday;
 		__vdso_time;
 		__vdso_clock_getres;
+		__vdso_clock_gettime64;
 	};
 
 	LINUX_2.5 {